1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/avutil.h"
33 #include "libavutil/buffer.h"
34 #include "libavutil/cpu.h"
35 #include "libavutil/channel_layout.h"
36 #include "libavutil/dict.h"
37 #include "libavutil/frame.h"
38 #include "libavutil/log.h"
39 #include "libavutil/pixfmt.h"
40 #include "libavutil/rational.h"
41 
42 #include "libavcodec/version.h"
43 /**
44  * @defgroup libavc Encoding/Decoding Library
45  * @{
46  *
47  * @defgroup lavc_decoding Decoding
48  * @{
49  * @}
50  *
51  * @defgroup lavc_encoding Encoding
52  * @{
53  * @}
54  *
55  * @defgroup lavc_codec Codecs
56  * @{
57  * @defgroup lavc_codec_native Native Codecs
58  * @{
59  * @}
60  * @defgroup lavc_codec_wrappers External library wrappers
61  * @{
62  * @}
63  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
64  * @{
65  * @}
66  * @}
67  * @defgroup lavc_internal Internal
68  * @{
69  * @}
70  * @}
71  *
72  */
73 
74 /**
75  * @defgroup lavc_core Core functions/structures.
76  * @ingroup libavc
77  *
78  * Basic definitions, functions for querying libavcodec capabilities,
79  * allocating core structures, etc.
80  * @{
81  */
82 
83 
84 /**
85  * Identify the syntax and semantics of the bitstream.
86  * The principle is roughly:
87  * Two decoders with the same ID can decode the same streams.
88  * Two encoders with the same ID can encode compatible streams.
89  * There may be slight deviations from the principle due to implementation
90  * details.
91  *
92  * If you add a codec ID to this list, add it so that
93  * 1. no value of a existing codec ID changes (that would break ABI),
94  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
95  *    This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
96  *
97  * After adding new codec IDs, do not forget to add an entry to the codec
98  * descriptor list and bump libavcodec minor version.
99  */
100 enum AVCodecID {
101     AV_CODEC_ID_NONE,
102 
103     /* video codecs */
104     AV_CODEC_ID_MPEG1VIDEO,
105     AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
106     AV_CODEC_ID_MPEG2VIDEO_XVMC,
107     AV_CODEC_ID_H261,
108     AV_CODEC_ID_H263,
109     AV_CODEC_ID_RV10,
110     AV_CODEC_ID_RV20,
111     AV_CODEC_ID_MJPEG,
112     AV_CODEC_ID_MJPEGB,
113     AV_CODEC_ID_LJPEG,
114     AV_CODEC_ID_SP5X,
115     AV_CODEC_ID_JPEGLS,
116     AV_CODEC_ID_MPEG4,
117     AV_CODEC_ID_RAWVIDEO,
118     AV_CODEC_ID_MSMPEG4V1,
119     AV_CODEC_ID_MSMPEG4V2,
120     AV_CODEC_ID_MSMPEG4V3,
121     AV_CODEC_ID_WMV1,
122     AV_CODEC_ID_WMV2,
123     AV_CODEC_ID_H263P,
124     AV_CODEC_ID_H263I,
125     AV_CODEC_ID_FLV1,
126     AV_CODEC_ID_SVQ1,
127     AV_CODEC_ID_SVQ3,
128     AV_CODEC_ID_DVVIDEO,
129     AV_CODEC_ID_HUFFYUV,
130     AV_CODEC_ID_CYUV,
131     AV_CODEC_ID_H264,
132     AV_CODEC_ID_INDEO3,
133     AV_CODEC_ID_VP3,
134     AV_CODEC_ID_THEORA,
135     AV_CODEC_ID_ASV1,
136     AV_CODEC_ID_ASV2,
137     AV_CODEC_ID_FFV1,
138     AV_CODEC_ID_4XM,
139     AV_CODEC_ID_VCR1,
140     AV_CODEC_ID_CLJR,
141     AV_CODEC_ID_MDEC,
142     AV_CODEC_ID_ROQ,
143     AV_CODEC_ID_INTERPLAY_VIDEO,
144     AV_CODEC_ID_XAN_WC3,
145     AV_CODEC_ID_XAN_WC4,
146     AV_CODEC_ID_RPZA,
147     AV_CODEC_ID_CINEPAK,
148     AV_CODEC_ID_WS_VQA,
149     AV_CODEC_ID_MSRLE,
150     AV_CODEC_ID_MSVIDEO1,
151     AV_CODEC_ID_IDCIN,
152     AV_CODEC_ID_8BPS,
153     AV_CODEC_ID_SMC,
154     AV_CODEC_ID_FLIC,
155     AV_CODEC_ID_TRUEMOTION1,
156     AV_CODEC_ID_VMDVIDEO,
157     AV_CODEC_ID_MSZH,
158     AV_CODEC_ID_ZLIB,
159     AV_CODEC_ID_QTRLE,
160     AV_CODEC_ID_TSCC,
161     AV_CODEC_ID_ULTI,
162     AV_CODEC_ID_QDRAW,
163     AV_CODEC_ID_VIXL,
164     AV_CODEC_ID_QPEG,
165     AV_CODEC_ID_PNG,
166     AV_CODEC_ID_PPM,
167     AV_CODEC_ID_PBM,
168     AV_CODEC_ID_PGM,
169     AV_CODEC_ID_PGMYUV,
170     AV_CODEC_ID_PAM,
171     AV_CODEC_ID_FFVHUFF,
172     AV_CODEC_ID_RV30,
173     AV_CODEC_ID_RV40,
174     AV_CODEC_ID_VC1,
175     AV_CODEC_ID_WMV3,
176     AV_CODEC_ID_LOCO,
177     AV_CODEC_ID_WNV1,
178     AV_CODEC_ID_AASC,
179     AV_CODEC_ID_INDEO2,
180     AV_CODEC_ID_FRAPS,
181     AV_CODEC_ID_TRUEMOTION2,
182     AV_CODEC_ID_BMP,
183     AV_CODEC_ID_CSCD,
184     AV_CODEC_ID_MMVIDEO,
185     AV_CODEC_ID_ZMBV,
186     AV_CODEC_ID_AVS,
187     AV_CODEC_ID_SMACKVIDEO,
188     AV_CODEC_ID_NUV,
189     AV_CODEC_ID_KMVC,
190     AV_CODEC_ID_FLASHSV,
191     AV_CODEC_ID_CAVS,
192     AV_CODEC_ID_JPEG2000,
193     AV_CODEC_ID_VMNC,
194     AV_CODEC_ID_VP5,
195     AV_CODEC_ID_VP6,
196     AV_CODEC_ID_VP6F,
197     AV_CODEC_ID_TARGA,
198     AV_CODEC_ID_DSICINVIDEO,
199     AV_CODEC_ID_TIERTEXSEQVIDEO,
200     AV_CODEC_ID_TIFF,
201     AV_CODEC_ID_GIF,
202     AV_CODEC_ID_DXA,
203     AV_CODEC_ID_DNXHD,
204     AV_CODEC_ID_THP,
205     AV_CODEC_ID_SGI,
206     AV_CODEC_ID_C93,
207     AV_CODEC_ID_BETHSOFTVID,
208     AV_CODEC_ID_PTX,
209     AV_CODEC_ID_TXD,
210     AV_CODEC_ID_VP6A,
211     AV_CODEC_ID_AMV,
212     AV_CODEC_ID_VB,
213     AV_CODEC_ID_PCX,
214     AV_CODEC_ID_SUNRAST,
215     AV_CODEC_ID_INDEO4,
216     AV_CODEC_ID_INDEO5,
217     AV_CODEC_ID_MIMIC,
218     AV_CODEC_ID_RL2,
219     AV_CODEC_ID_ESCAPE124,
220     AV_CODEC_ID_DIRAC,
221     AV_CODEC_ID_BFI,
222     AV_CODEC_ID_CMV,
223     AV_CODEC_ID_MOTIONPIXELS,
224     AV_CODEC_ID_TGV,
225     AV_CODEC_ID_TGQ,
226     AV_CODEC_ID_TQI,
227     AV_CODEC_ID_AURA,
228     AV_CODEC_ID_AURA2,
229     AV_CODEC_ID_V210X,
230     AV_CODEC_ID_TMV,
231     AV_CODEC_ID_V210,
232     AV_CODEC_ID_DPX,
233     AV_CODEC_ID_MAD,
234     AV_CODEC_ID_FRWU,
235     AV_CODEC_ID_FLASHSV2,
236     AV_CODEC_ID_CDGRAPHICS,
237     AV_CODEC_ID_R210,
238     AV_CODEC_ID_ANM,
239     AV_CODEC_ID_BINKVIDEO,
240     AV_CODEC_ID_IFF_ILBM,
241     AV_CODEC_ID_IFF_BYTERUN1,
242     AV_CODEC_ID_KGV1,
243     AV_CODEC_ID_YOP,
244     AV_CODEC_ID_VP8,
245     AV_CODEC_ID_PICTOR,
246     AV_CODEC_ID_ANSI,
247     AV_CODEC_ID_A64_MULTI,
248     AV_CODEC_ID_A64_MULTI5,
249     AV_CODEC_ID_R10K,
250     AV_CODEC_ID_MXPEG,
251     AV_CODEC_ID_LAGARITH,
252     AV_CODEC_ID_PRORES,
253     AV_CODEC_ID_JV,
254     AV_CODEC_ID_DFA,
255     AV_CODEC_ID_WMV3IMAGE,
256     AV_CODEC_ID_VC1IMAGE,
257     AV_CODEC_ID_UTVIDEO,
258     AV_CODEC_ID_BMV_VIDEO,
259     AV_CODEC_ID_VBLE,
260     AV_CODEC_ID_DXTORY,
261     AV_CODEC_ID_V410,
262     AV_CODEC_ID_XWD,
263     AV_CODEC_ID_CDXL,
264     AV_CODEC_ID_XBM,
265     AV_CODEC_ID_ZEROCODEC,
266     AV_CODEC_ID_MSS1,
267     AV_CODEC_ID_MSA1,
268     AV_CODEC_ID_TSCC2,
269     AV_CODEC_ID_MTS2,
270     AV_CODEC_ID_CLLC,
271     AV_CODEC_ID_MSS2,
272     AV_CODEC_ID_VP9,
273     AV_CODEC_ID_AIC,
274     AV_CODEC_ID_ESCAPE130_DEPRECATED,
275     AV_CODEC_ID_G2M_DEPRECATED,
276 
277     AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
278     AV_CODEC_ID_Y41P       = MKBETAG('Y','4','1','P'),
279     AV_CODEC_ID_ESCAPE130  = MKBETAG('E','1','3','0'),
280     AV_CODEC_ID_EXR        = MKBETAG('0','E','X','R'),
281     AV_CODEC_ID_AVRP       = MKBETAG('A','V','R','P'),
282 
283     AV_CODEC_ID_012V       = MKBETAG('0','1','2','V'),
284     AV_CODEC_ID_G2M        = MKBETAG( 0 ,'G','2','M'),
285     AV_CODEC_ID_AVUI       = MKBETAG('A','V','U','I'),
286     AV_CODEC_ID_AYUV       = MKBETAG('A','Y','U','V'),
287     AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
288     AV_CODEC_ID_V308       = MKBETAG('V','3','0','8'),
289     AV_CODEC_ID_V408       = MKBETAG('V','4','0','8'),
290     AV_CODEC_ID_YUV4       = MKBETAG('Y','U','V','4'),
291     AV_CODEC_ID_SANM       = MKBETAG('S','A','N','M'),
292     AV_CODEC_ID_PAF_VIDEO  = MKBETAG('P','A','F','V'),
293     AV_CODEC_ID_AVRN       = MKBETAG('A','V','R','n'),
294     AV_CODEC_ID_CPIA       = MKBETAG('C','P','I','A'),
295     AV_CODEC_ID_XFACE      = MKBETAG('X','F','A','C'),
296     AV_CODEC_ID_SGIRLE     = MKBETAG('S','G','I','R'),
297     AV_CODEC_ID_MVC1       = MKBETAG('M','V','C','1'),
298     AV_CODEC_ID_MVC2       = MKBETAG('M','V','C','2'),
299     AV_CODEC_ID_SNOW       = MKBETAG('S','N','O','W'),
300     AV_CODEC_ID_WEBP       = MKBETAG('W','E','B','P'),
301     AV_CODEC_ID_SMVJPEG    = MKBETAG('S','M','V','J'),
302 
303     /* various PCM "codecs" */
304     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
305     AV_CODEC_ID_PCM_S16LE = 0x10000,
306     AV_CODEC_ID_PCM_S16BE,
307     AV_CODEC_ID_PCM_U16LE,
308     AV_CODEC_ID_PCM_U16BE,
309     AV_CODEC_ID_PCM_S8,
310     AV_CODEC_ID_PCM_U8,
311     AV_CODEC_ID_PCM_MULAW,
312     AV_CODEC_ID_PCM_ALAW,
313     AV_CODEC_ID_PCM_S32LE,
314     AV_CODEC_ID_PCM_S32BE,
315     AV_CODEC_ID_PCM_U32LE,
316     AV_CODEC_ID_PCM_U32BE,
317     AV_CODEC_ID_PCM_S24LE,
318     AV_CODEC_ID_PCM_S24BE,
319     AV_CODEC_ID_PCM_U24LE,
320     AV_CODEC_ID_PCM_U24BE,
321     AV_CODEC_ID_PCM_S24DAUD,
322     AV_CODEC_ID_PCM_ZORK,
323     AV_CODEC_ID_PCM_S16LE_PLANAR,
324     AV_CODEC_ID_PCM_DVD,
325     AV_CODEC_ID_PCM_F32BE,
326     AV_CODEC_ID_PCM_F32LE,
327     AV_CODEC_ID_PCM_F64BE,
328     AV_CODEC_ID_PCM_F64LE,
329     AV_CODEC_ID_PCM_BLURAY,
330     AV_CODEC_ID_PCM_LXF,
331     AV_CODEC_ID_S302M,
332     AV_CODEC_ID_PCM_S8_PLANAR,
333     AV_CODEC_ID_PCM_S24LE_PLANAR = MKBETAG(24,'P','S','P'),
334     AV_CODEC_ID_PCM_S32LE_PLANAR = MKBETAG(32,'P','S','P'),
335     AV_CODEC_ID_PCM_S16BE_PLANAR = MKBETAG('P','S','P',16),
336 
337     /* various ADPCM codecs */
338     AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
339     AV_CODEC_ID_ADPCM_IMA_WAV,
340     AV_CODEC_ID_ADPCM_IMA_DK3,
341     AV_CODEC_ID_ADPCM_IMA_DK4,
342     AV_CODEC_ID_ADPCM_IMA_WS,
343     AV_CODEC_ID_ADPCM_IMA_SMJPEG,
344     AV_CODEC_ID_ADPCM_MS,
345     AV_CODEC_ID_ADPCM_4XM,
346     AV_CODEC_ID_ADPCM_XA,
347     AV_CODEC_ID_ADPCM_ADX,
348     AV_CODEC_ID_ADPCM_EA,
349     AV_CODEC_ID_ADPCM_G726,
350     AV_CODEC_ID_ADPCM_CT,
351     AV_CODEC_ID_ADPCM_SWF,
352     AV_CODEC_ID_ADPCM_YAMAHA,
353     AV_CODEC_ID_ADPCM_SBPRO_4,
354     AV_CODEC_ID_ADPCM_SBPRO_3,
355     AV_CODEC_ID_ADPCM_SBPRO_2,
356     AV_CODEC_ID_ADPCM_THP,
357     AV_CODEC_ID_ADPCM_IMA_AMV,
358     AV_CODEC_ID_ADPCM_EA_R1,
359     AV_CODEC_ID_ADPCM_EA_R3,
360     AV_CODEC_ID_ADPCM_EA_R2,
361     AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
362     AV_CODEC_ID_ADPCM_IMA_EA_EACS,
363     AV_CODEC_ID_ADPCM_EA_XAS,
364     AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
365     AV_CODEC_ID_ADPCM_IMA_ISS,
366     AV_CODEC_ID_ADPCM_G722,
367     AV_CODEC_ID_ADPCM_IMA_APC,
368     AV_CODEC_ID_VIMA       = MKBETAG('V','I','M','A'),
369     AV_CODEC_ID_ADPCM_AFC  = MKBETAG('A','F','C',' '),
370     AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
371     AV_CODEC_ID_ADPCM_DTK  = MKBETAG('D','T','K',' '),
372     AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
373 
374     /* AMR */
375     AV_CODEC_ID_AMR_NB = 0x12000,
376     AV_CODEC_ID_AMR_WB,
377 
378     /* RealAudio codecs*/
379     AV_CODEC_ID_RA_144 = 0x13000,
380     AV_CODEC_ID_RA_288,
381 
382     /* various DPCM codecs */
383     AV_CODEC_ID_ROQ_DPCM = 0x14000,
384     AV_CODEC_ID_INTERPLAY_DPCM,
385     AV_CODEC_ID_XAN_DPCM,
386     AV_CODEC_ID_SOL_DPCM,
387 
388     /* audio codecs */
389     AV_CODEC_ID_MP2 = 0x15000,
390     AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
391     AV_CODEC_ID_AAC,
392     AV_CODEC_ID_AC3,
393     AV_CODEC_ID_DTS,
394     AV_CODEC_ID_VORBIS,
395     AV_CODEC_ID_DVAUDIO,
396     AV_CODEC_ID_WMAV1,
397     AV_CODEC_ID_WMAV2,
398     AV_CODEC_ID_MACE3,
399     AV_CODEC_ID_MACE6,
400     AV_CODEC_ID_VMDAUDIO,
401     AV_CODEC_ID_FLAC,
402     AV_CODEC_ID_MP3ADU,
403     AV_CODEC_ID_MP3ON4,
404     AV_CODEC_ID_SHORTEN,
405     AV_CODEC_ID_ALAC,
406     AV_CODEC_ID_WESTWOOD_SND1,
407     AV_CODEC_ID_GSM, ///< as in Berlin toast format
408     AV_CODEC_ID_QDM2,
409     AV_CODEC_ID_COOK,
410     AV_CODEC_ID_TRUESPEECH,
411     AV_CODEC_ID_TTA,
412     AV_CODEC_ID_SMACKAUDIO,
413     AV_CODEC_ID_QCELP,
414     AV_CODEC_ID_WAVPACK,
415     AV_CODEC_ID_DSICINAUDIO,
416     AV_CODEC_ID_IMC,
417     AV_CODEC_ID_MUSEPACK7,
418     AV_CODEC_ID_MLP,
419     AV_CODEC_ID_GSM_MS, /* as found in WAV */
420     AV_CODEC_ID_ATRAC3,
421     AV_CODEC_ID_VOXWARE,
422     AV_CODEC_ID_APE,
423     AV_CODEC_ID_NELLYMOSER,
424     AV_CODEC_ID_MUSEPACK8,
425     AV_CODEC_ID_SPEEX,
426     AV_CODEC_ID_WMAVOICE,
427     AV_CODEC_ID_WMAPRO,
428     AV_CODEC_ID_WMALOSSLESS,
429     AV_CODEC_ID_ATRAC3P,
430     AV_CODEC_ID_EAC3,
431     AV_CODEC_ID_SIPR,
432     AV_CODEC_ID_MP1,
433     AV_CODEC_ID_TWINVQ,
434     AV_CODEC_ID_TRUEHD,
435     AV_CODEC_ID_MP4ALS,
436     AV_CODEC_ID_ATRAC1,
437     AV_CODEC_ID_BINKAUDIO_RDFT,
438     AV_CODEC_ID_BINKAUDIO_DCT,
439     AV_CODEC_ID_AAC_LATM,
440     AV_CODEC_ID_QDMC,
441     AV_CODEC_ID_CELT,
442     AV_CODEC_ID_G723_1,
443     AV_CODEC_ID_G729,
444     AV_CODEC_ID_8SVX_EXP,
445     AV_CODEC_ID_8SVX_FIB,
446     AV_CODEC_ID_BMV_AUDIO,
447     AV_CODEC_ID_RALF,
448     AV_CODEC_ID_IAC,
449     AV_CODEC_ID_ILBC,
450     AV_CODEC_ID_OPUS_DEPRECATED,
451     AV_CODEC_ID_COMFORT_NOISE,
452     AV_CODEC_ID_TAK_DEPRECATED,
453     AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
454     AV_CODEC_ID_SONIC       = MKBETAG('S','O','N','C'),
455     AV_CODEC_ID_SONIC_LS    = MKBETAG('S','O','N','L'),
456     AV_CODEC_ID_PAF_AUDIO   = MKBETAG('P','A','F','A'),
457     AV_CODEC_ID_OPUS        = MKBETAG('O','P','U','S'),
458     AV_CODEC_ID_TAK         = MKBETAG('t','B','a','K'),
459     AV_CODEC_ID_EVRC        = MKBETAG('s','e','v','c'),
460     AV_CODEC_ID_SMV         = MKBETAG('s','s','m','v'),
461 
462     /* subtitle codecs */
463     AV_CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.
464     AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
465     AV_CODEC_ID_DVB_SUBTITLE,
466     AV_CODEC_ID_TEXT,  ///< raw UTF-8 text
467     AV_CODEC_ID_XSUB,
468     AV_CODEC_ID_SSA,
469     AV_CODEC_ID_MOV_TEXT,
470     AV_CODEC_ID_HDMV_PGS_SUBTITLE,
471     AV_CODEC_ID_DVB_TELETEXT,
472     AV_CODEC_ID_SRT,
473     AV_CODEC_ID_MICRODVD   = MKBETAG('m','D','V','D'),
474     AV_CODEC_ID_EIA_608    = MKBETAG('c','6','0','8'),
475     AV_CODEC_ID_JACOSUB    = MKBETAG('J','S','U','B'),
476     AV_CODEC_ID_SAMI       = MKBETAG('S','A','M','I'),
477     AV_CODEC_ID_REALTEXT   = MKBETAG('R','T','X','T'),
478     AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
479     AV_CODEC_ID_SUBVIEWER  = MKBETAG('S','u','b','V'),
480     AV_CODEC_ID_SUBRIP     = MKBETAG('S','R','i','p'),
481     AV_CODEC_ID_WEBVTT     = MKBETAG('W','V','T','T'),
482     AV_CODEC_ID_MPL2       = MKBETAG('M','P','L','2'),
483     AV_CODEC_ID_VPLAYER    = MKBETAG('V','P','l','r'),
484     AV_CODEC_ID_PJS        = MKBETAG('P','h','J','S'),
485     AV_CODEC_ID_ASS        = MKBETAG('A','S','S',' '),  ///< ASS as defined in Matroska
486 
487     /* other specific kind of codecs (generally used for attachments) */
488     AV_CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.
489     AV_CODEC_ID_TTF = 0x18000,
490     AV_CODEC_ID_BINTEXT    = MKBETAG('B','T','X','T'),
491     AV_CODEC_ID_XBIN       = MKBETAG('X','B','I','N'),
492     AV_CODEC_ID_IDF        = MKBETAG( 0 ,'I','D','F'),
493     AV_CODEC_ID_OTF        = MKBETAG( 0 ,'O','T','F'),
494     AV_CODEC_ID_SMPTE_KLV  = MKBETAG('K','L','V','A'),
495     AV_CODEC_ID_DVD_NAV    = MKBETAG('D','N','A','V'),
496 
497 
498     AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
499 
500     AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
501                                 * stream (only used by libavformat) */
502     AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
503                                 * stream (only used by libavformat) */
504     AV_CODEC_ID_FFMETADATA = 0x21000,   ///< Dummy codec for streams containing only metadata information.
505 
506 #if FF_API_CODEC_ID
507 #include "old_codec_ids.h"
508 #endif
509 };
510 
511 /**
512  * This struct describes the properties of a single codec described by an
513  * AVCodecID.
514  * @see avcodec_get_descriptor()
515  */
516 typedef struct AVCodecDescriptor {
517     enum AVCodecID     id;
518     enum AVMediaType type;
519     /**
520      * Name of the codec described by this descriptor. It is non-empty and
521      * unique for each codec descriptor. It should contain alphanumeric
522      * characters and '_' only.
523      */
524     const char      *name;
525     /**
526      * A more descriptive name for this codec. May be NULL.
527      */
528     const char *long_name;
529     /**
530      * Codec properties, a combination of AV_CODEC_PROP_* flags.
531      */
532     int             props;
533 } AVCodecDescriptor;
534 
535 /**
536  * Codec uses only intra compression.
537  * Video codecs only.
538  */
539 #define AV_CODEC_PROP_INTRA_ONLY    (1 << 0)
540 /**
541  * Codec supports lossy compression. Audio and video codecs only.
542  * @note a codec may support both lossy and lossless
543  * compression modes
544  */
545 #define AV_CODEC_PROP_LOSSY         (1 << 1)
546 /**
547  * Codec supports lossless compression. Audio and video codecs only.
548  */
549 #define AV_CODEC_PROP_LOSSLESS      (1 << 2)
550 /**
551  * Subtitle codec is bitmap based
552  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
553  */
554 #define AV_CODEC_PROP_BITMAP_SUB    (1 << 16)
555 /**
556  * Subtitle codec is text based.
557  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
558  */
559 #define AV_CODEC_PROP_TEXT_SUB      (1 << 17)
560 
561 /**
562  * @ingroup lavc_decoding
563  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
564  * This is mainly needed because some optimized bitstream readers read
565  * 32 or 64 bit at once and could read over the end.<br>
566  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
567  * MPEG bitstreams could cause overread and segfault.
568  */
569 #define FF_INPUT_BUFFER_PADDING_SIZE 16
570 
571 /**
572  * @ingroup lavc_encoding
573  * minimum encoding buffer size
574  * Used to avoid some checks during header writing.
575  */
576 #define FF_MIN_BUFFER_SIZE 16384
577 
578 
579 /**
580  * @ingroup lavc_encoding
581  * motion estimation type.
582  */
583 enum Motion_Est_ID {
584     ME_ZERO = 1,    ///< no search, that is use 0,0 vector whenever one is needed
585     ME_FULL,
586     ME_LOG,
587     ME_PHODS,
588     ME_EPZS,        ///< enhanced predictive zonal search
589     ME_X1,          ///< reserved for experiments
590     ME_HEX,         ///< hexagon based search
591     ME_UMH,         ///< uneven multi-hexagon search
592     ME_TESA,        ///< transformed exhaustive search algorithm
593     ME_ITER=50,     ///< iterative search
594 };
595 
596 /**
597  * @ingroup lavc_decoding
598  */
599 enum AVDiscard{
600     /* We leave some space between them for extensions (drop some
601      * keyframes for intra-only or drop just some bidir frames). */
602     AVDISCARD_NONE    =-16, ///< discard nothing
603     AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
604     AVDISCARD_NONREF  =  8, ///< discard all non reference
605     AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
606     AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
607     AVDISCARD_ALL     = 48, ///< discard all
608 };
609 
610 enum AVColorPrimaries{
611     AVCOL_PRI_BT709       = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
612     AVCOL_PRI_UNSPECIFIED = 2,
613     AVCOL_PRI_BT470M      = 4,
614     AVCOL_PRI_BT470BG     = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
615     AVCOL_PRI_SMPTE170M   = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
616     AVCOL_PRI_SMPTE240M   = 7, ///< functionally identical to above
617     AVCOL_PRI_FILM        = 8,
618     AVCOL_PRI_NB             , ///< Not part of ABI
619 };
620 
621 enum AVColorTransferCharacteristic{
622     AVCOL_TRC_BT709       = 1, ///< also ITU-R BT1361
623     AVCOL_TRC_UNSPECIFIED = 2,
624     AVCOL_TRC_GAMMA22     = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
625     AVCOL_TRC_GAMMA28     = 5, ///< also ITU-R BT470BG
626     AVCOL_TRC_SMPTE240M   = 7,
627     AVCOL_TRC_NB             , ///< Not part of ABI
628 };
629 
630 enum AVColorSpace{
631     AVCOL_SPC_RGB         = 0,
632     AVCOL_SPC_BT709       = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
633     AVCOL_SPC_UNSPECIFIED = 2,
634     AVCOL_SPC_FCC         = 4,
635     AVCOL_SPC_BT470BG     = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
636     AVCOL_SPC_SMPTE170M   = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
637     AVCOL_SPC_SMPTE240M   = 7,
638     AVCOL_SPC_YCOCG       = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
639     AVCOL_SPC_NB             , ///< Not part of ABI
640 };
641 #define AVCOL_SPC_YCGCO AVCOL_SPC_YCOCG
642 
643 enum AVColorRange{
644     AVCOL_RANGE_UNSPECIFIED = 0,
645     AVCOL_RANGE_MPEG        = 1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
646     AVCOL_RANGE_JPEG        = 2, ///< the normal     2^n-1   "JPEG" YUV ranges
647     AVCOL_RANGE_NB             , ///< Not part of ABI
648 };
649 
650 /**
651  *  X   X      3 4 X      X are luma samples,
652  *             1 2        1-6 are possible chroma positions
653  *  X   X      5 6 X      0 is undefined/unknown position
654  */
655 enum AVChromaLocation{
656     AVCHROMA_LOC_UNSPECIFIED = 0,
657     AVCHROMA_LOC_LEFT        = 1, ///< mpeg2/4, h264 default
658     AVCHROMA_LOC_CENTER      = 2, ///< mpeg1, jpeg, h263
659     AVCHROMA_LOC_TOPLEFT     = 3, ///< DV
660     AVCHROMA_LOC_TOP         = 4,
661     AVCHROMA_LOC_BOTTOMLEFT  = 5,
662     AVCHROMA_LOC_BOTTOM      = 6,
663     AVCHROMA_LOC_NB             , ///< Not part of ABI
664 };
665 
666 enum AVAudioServiceType {
667     AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
668     AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
669     AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
670     AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
671     AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
672     AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
673     AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
674     AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
675     AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
676     AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
677 };
678 
679 /**
680  * @ingroup lavc_encoding
681  */
682 typedef struct RcOverride{
683     int start_frame;
684     int end_frame;
685     int qscale; // If this is 0 then quality_factor will be used instead.
686     float quality_factor;
687 } RcOverride;
688 
689 #define FF_MAX_B_FRAMES 16
690 
691 /* encoding support
692    These flags can be passed in AVCodecContext.flags before initialization.
693    Note: Not everything is supported yet.
694 */
695 
696 /**
697  * Allow decoders to produce frames with data planes that are not aligned
698  * to CPU requirements (e.g. due to cropping).
699  */
700 #define CODEC_FLAG_UNALIGNED 0x0001
701 #define CODEC_FLAG_QSCALE 0x0002  ///< Use fixed qscale.
702 #define CODEC_FLAG_4MV    0x0004  ///< 4 MV per MB allowed / advanced prediction for H.263.
703 #define CODEC_FLAG_QPEL   0x0010  ///< Use qpel MC.
704 #define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
705 #define CODEC_FLAG_MV0    0x0040  ///< Always try a MB with MV=<0,0>.
706 /**
707  * The parent program guarantees that the input for B-frames containing
708  * streams is not written to for at least s->max_b_frames+1 frames, if
709  * this is not set the input will be copied.
710  */
711 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
712 #define CODEC_FLAG_PASS1           0x0200   ///< Use internal 2pass ratecontrol in first pass mode.
713 #define CODEC_FLAG_PASS2           0x0400   ///< Use internal 2pass ratecontrol in second pass mode.
714 #define CODEC_FLAG_GRAY            0x2000   ///< Only decode/encode grayscale.
715 #define CODEC_FLAG_EMU_EDGE        0x4000   ///< Don't draw edges.
716 #define CODEC_FLAG_PSNR            0x8000   ///< error[?] variables will be set during encoding.
717 #define CODEC_FLAG_TRUNCATED       0x00010000 /** Input bitstream might be truncated at a random
718                                                   location instead of only at frame boundaries. */
719 #define CODEC_FLAG_NORMALIZE_AQP  0x00020000 ///< Normalize adaptive quantization.
720 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
721 #define CODEC_FLAG_LOW_DELAY      0x00080000 ///< Force low delay.
722 #define CODEC_FLAG_GLOBAL_HEADER  0x00400000 ///< Place global headers in extradata instead of every keyframe.
723 #define CODEC_FLAG_BITEXACT       0x00800000 ///< Use only bitexact stuff (except (I)DCT).
724 /* Fx : Flag for h263+ extra options */
725 #define CODEC_FLAG_AC_PRED        0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
726 #define CODEC_FLAG_LOOP_FILTER    0x00000800 ///< loop filter
727 #define CODEC_FLAG_INTERLACED_ME  0x20000000 ///< interlaced motion estimation
728 #define CODEC_FLAG_CLOSED_GOP     0x80000000
729 #define CODEC_FLAG2_FAST          0x00000001 ///< Allow non spec compliant speedup tricks.
730 #define CODEC_FLAG2_NO_OUTPUT     0x00000004 ///< Skip bitstream encoding.
731 #define CODEC_FLAG2_LOCAL_HEADER  0x00000008 ///< Place global headers at every keyframe instead of in extradata.
732 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
733 #define CODEC_FLAG2_IGNORE_CROP   0x00010000 ///< Discard cropping information from SPS.
734 
735 #define CODEC_FLAG2_CHUNKS        0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
736 #define CODEC_FLAG2_SHOW_ALL      0x00400000 ///< Show all frames before the first keyframe
737 
738 /* Unsupported options :
739  *              Syntax Arithmetic coding (SAC)
740  *              Reference Picture Selection
741  *              Independent Segment Decoding */
742 /* /Fx */
743 /* codec capabilities */
744 
745 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
746 /**
747  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
748  * If not set, it might not use get_buffer() at all or use operations that
749  * assume the buffer was allocated by avcodec_default_get_buffer.
750  */
751 #define CODEC_CAP_DR1             0x0002
752 #define CODEC_CAP_TRUNCATED       0x0008
753 /* Codec can export data for HW decoding (XvMC). */
754 #define CODEC_CAP_HWACCEL         0x0010
755 /**
756  * Encoder or decoder requires flushing with NULL input at the end in order to
757  * give the complete and correct output.
758  *
759  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
760  *       with NULL data. The user can still send NULL data to the public encode
761  *       or decode function, but libavcodec will not pass it along to the codec
762  *       unless this flag is set.
763  *
764  * Decoders:
765  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
766  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
767  * returns frames.
768  *
769  * Encoders:
770  * The encoder needs to be fed with NULL data at the end of encoding until the
771  * encoder no longer returns data.
772  *
773  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
774  *       flag also means that the encoder must set the pts and duration for
775  *       each output packet. If this flag is not set, the pts and duration will
776  *       be determined by libavcodec from the input frame.
777  */
778 #define CODEC_CAP_DELAY           0x0020
779 /**
780  * Codec can be fed a final frame with a smaller size.
781  * This can be used to prevent truncation of the last audio samples.
782  */
783 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
784 /**
785  * Codec can export data for HW decoding (VDPAU).
786  */
787 #define CODEC_CAP_HWACCEL_VDPAU    0x0080
788 /**
789  * Codec can output multiple frames per AVPacket
790  * Normally demuxers return one frame at a time, demuxers which do not do
791  * are connected to a parser to split what they return into proper frames.
792  * This flag is reserved to the very rare category of codecs which have a
793  * bitstream that cannot be split into frames without timeconsuming
794  * operations like full decoding. Demuxers carring such bitstreams thus
795  * may return multiple frames in a packet. This has many disadvantages like
796  * prohibiting stream copy in many cases thus it should only be considered
797  * as a last resort.
798  */
799 #define CODEC_CAP_SUBFRAMES        0x0100
800 /**
801  * Codec is experimental and is thus avoided in favor of non experimental
802  * encoders
803  */
804 #define CODEC_CAP_EXPERIMENTAL     0x0200
805 /**
806  * Codec should fill in channel configuration and samplerate instead of container
807  */
808 #define CODEC_CAP_CHANNEL_CONF     0x0400
809 
810 /**
811  * Codec is able to deal with negative linesizes
812  */
813 #define CODEC_CAP_NEG_LINESIZES    0x0800
814 
815 /**
816  * Codec supports frame-level multithreading.
817  */
818 #define CODEC_CAP_FRAME_THREADS    0x1000
819 /**
820  * Codec supports slice-based (or partition-based) multithreading.
821  */
822 #define CODEC_CAP_SLICE_THREADS    0x2000
823 /**
824  * Codec supports changed parameters at any point.
825  */
826 #define CODEC_CAP_PARAM_CHANGE     0x4000
827 /**
828  * Codec supports avctx->thread_count == 0 (auto).
829  */
830 #define CODEC_CAP_AUTO_THREADS     0x8000
831 /**
832  * Audio encoder supports receiving a different number of samples in each call.
833  */
834 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
835 /**
836  * Codec is intra only.
837  */
838 #define CODEC_CAP_INTRA_ONLY       0x40000000
839 /**
840  * Codec is lossless.
841  */
842 #define CODEC_CAP_LOSSLESS         0x80000000
843 
844 //The following defines may change, don't expect compatibility if you use them.
845 #define MB_TYPE_INTRA4x4   0x0001
846 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
847 #define MB_TYPE_INTRA_PCM  0x0004 //FIXME H.264-specific
848 #define MB_TYPE_16x16      0x0008
849 #define MB_TYPE_16x8       0x0010
850 #define MB_TYPE_8x16       0x0020
851 #define MB_TYPE_8x8        0x0040
852 #define MB_TYPE_INTERLACED 0x0080
853 #define MB_TYPE_DIRECT2    0x0100 //FIXME
854 #define MB_TYPE_ACPRED     0x0200
855 #define MB_TYPE_GMC        0x0400
856 #define MB_TYPE_SKIP       0x0800
857 #define MB_TYPE_P0L0       0x1000
858 #define MB_TYPE_P1L0       0x2000
859 #define MB_TYPE_P0L1       0x4000
860 #define MB_TYPE_P1L1       0x8000
861 #define MB_TYPE_L0         (MB_TYPE_P0L0 | MB_TYPE_P1L0)
862 #define MB_TYPE_L1         (MB_TYPE_P0L1 | MB_TYPE_P1L1)
863 #define MB_TYPE_L0L1       (MB_TYPE_L0   | MB_TYPE_L1)
864 #define MB_TYPE_QUANT      0x00010000
865 #define MB_TYPE_CBP        0x00020000
866 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
867 
868 /**
869  * Pan Scan area.
870  * This specifies the area which should be displayed.
871  * Note there may be multiple such areas for one frame.
872  */
873 typedef struct AVPanScan{
874     /**
875      * id
876      * - encoding: Set by user.
877      * - decoding: Set by libavcodec.
878      */
879     int id;
880 
881     /**
882      * width and height in 1/16 pel
883      * - encoding: Set by user.
884      * - decoding: Set by libavcodec.
885      */
886     int width;
887     int height;
888 
889     /**
890      * position of the top left corner in 1/16 pel for up to 3 fields/frames
891      * - encoding: Set by user.
892      * - decoding: Set by libavcodec.
893      */
894     int16_t position[3][2];
895 }AVPanScan;
896 
897 #define FF_QSCALE_TYPE_MPEG1 0
898 #define FF_QSCALE_TYPE_MPEG2 1
899 #define FF_QSCALE_TYPE_H264  2
900 #define FF_QSCALE_TYPE_VP56  3
901 
902 #if FF_API_GET_BUFFER
903 #define FF_BUFFER_TYPE_INTERNAL 1
904 #define FF_BUFFER_TYPE_USER     2 ///< direct rendering buffers (image is (de)allocated by user)
905 #define FF_BUFFER_TYPE_SHARED   4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
906 #define FF_BUFFER_TYPE_COPY     8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
907 
908 #define FF_BUFFER_HINTS_VALID    0x01 // Buffer hints value is meaningful (if 0 ignore).
909 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
910 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
911 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
912 #endif
913 
914 /**
915  * The decoder will keep a reference to the frame and may reuse it later.
916  */
917 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
918 
919 /**
920  * @defgroup lavc_packet AVPacket
921  *
922  * Types and functions for working with AVPacket.
923  * @{
924  */
925 enum AVPacketSideDataType {
926     AV_PKT_DATA_PALETTE,
927     AV_PKT_DATA_NEW_EXTRADATA,
928 
929     /**
930      * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
931      * @code
932      * u32le param_flags
933      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
934      *     s32le channel_count
935      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
936      *     u64le channel_layout
937      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
938      *     s32le sample_rate
939      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
940      *     s32le width
941      *     s32le height
942      * @endcode
943      */
944     AV_PKT_DATA_PARAM_CHANGE,
945 
946     /**
947      * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
948      * structures with info about macroblocks relevant to splitting the
949      * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
950      * That is, it does not necessarily contain info about all macroblocks,
951      * as long as the distance between macroblocks in the info is smaller
952      * than the target payload size.
953      * Each MB info structure is 12 bytes, and is laid out as follows:
954      * @code
955      * u32le bit offset from the start of the packet
956      * u8    current quantizer at the start of the macroblock
957      * u8    GOB number
958      * u16le macroblock address within the GOB
959      * u8    horizontal MV predictor
960      * u8    vertical MV predictor
961      * u8    horizontal MV predictor for block number 3
962      * u8    vertical MV predictor for block number 3
963      * @endcode
964      */
965     AV_PKT_DATA_H263_MB_INFO,
966 
967     /**
968      * Recommmends skipping the specified number of samples
969      * @code
970      * u32le number of samples to skip from start of this packet
971      * u32le number of samples to skip from end of this packet
972      * u8    reason for start skip
973      * u8    reason for end   skip (0=padding silence, 1=convergence)
974      * @endcode
975      */
976     AV_PKT_DATA_SKIP_SAMPLES=70,
977 
978     /**
979      * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
980      * the packet may contain "dual mono" audio specific to Japanese DTV
981      * and if it is true, recommends only the selected channel to be used.
982      * @code
983      * u8    selected channels (0=mail/left, 1=sub/right, 2=both)
984      * @endcode
985      */
986     AV_PKT_DATA_JP_DUALMONO,
987 
988     /**
989      * A list of zero terminated key/value strings. There is no end marker for
990      * the list, so it is required to rely on the side data size to stop.
991      */
992     AV_PKT_DATA_STRINGS_METADATA,
993 
994     /**
995      * Subtitle event position
996      * @code
997      * u32le x1
998      * u32le y1
999      * u32le x2
1000      * u32le y2
1001      * @endcode
1002      */
1003     AV_PKT_DATA_SUBTITLE_POSITION,
1004 
1005     /**
1006      * Data found in BlockAdditional element of matroska container. There is
1007      * no end marker for the data, so it is required to rely on the side data
1008      * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1009      * by data.
1010      */
1011     AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
1012 
1013     /**
1014      * The optional first identifier line of a WebVTT cue.
1015      */
1016     AV_PKT_DATA_WEBVTT_IDENTIFIER,
1017 
1018     /**
1019      * The optional settings (rendering instructions) that immediately
1020      * follow the timestamp specifier of a WebVTT cue.
1021      */
1022     AV_PKT_DATA_WEBVTT_SETTINGS,
1023 };
1024 
1025 /**
1026  * This structure stores compressed data. It is typically exported by demuxers
1027  * and then passed as input to decoders, or received as output from encoders and
1028  * then passed to muxers.
1029  *
1030  * For video, it should typically contain one compressed frame. For audio it may
1031  * contain several compressed frames.
1032  *
1033  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1034  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1035  * without libavcodec and libavformat major bump.
1036  *
1037  * The semantics of data ownership depends on the buf or destruct (deprecated)
1038  * fields. If either is set, the packet data is dynamically allocated and is
1039  * valid indefinitely until av_free_packet() is called (which in turn calls
1040  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1041  * the packet data is typically backed by some static buffer somewhere and is
1042  * only valid for a limited time (e.g. until the next read call when demuxing).
1043  *
1044  * The side data is always allocated with av_malloc() and is freed in
1045  * av_free_packet().
1046  */
1047 typedef struct AVPacket {
1048     /**
1049      * A reference to the reference-counted buffer where the packet data is
1050      * stored.
1051      * May be NULL, then the packet data is not reference-counted.
1052      */
1053     AVBufferRef *buf;
1054     /**
1055      * Presentation timestamp in AVStream->time_base units; the time at which
1056      * the decompressed packet will be presented to the user.
1057      * Can be AV_NOPTS_VALUE if it is not stored in the file.
1058      * pts MUST be larger or equal to dts as presentation cannot happen before
1059      * decompression, unless one wants to view hex dumps. Some formats misuse
1060      * the terms dts and pts/cts to mean something different. Such timestamps
1061      * must be converted to true pts/dts before they are stored in AVPacket.
1062      */
1063     int64_t pts;
1064     /**
1065      * Decompression timestamp in AVStream->time_base units; the time at which
1066      * the packet is decompressed.
1067      * Can be AV_NOPTS_VALUE if it is not stored in the file.
1068      */
1069     int64_t dts;
1070     uint8_t *data;
1071     int   size;
1072     int   stream_index;
1073     /**
1074      * A combination of AV_PKT_FLAG values
1075      */
1076     int   flags;
1077     /**
1078      * Additional packet data that can be provided by the container.
1079      * Packet can contain several types of side information.
1080      */
1081     struct {
1082         uint8_t *data;
1083         int      size;
1084         enum AVPacketSideDataType type;
1085     } *side_data;
1086     int side_data_elems;
1087 
1088     /**
1089      * Duration of this packet in AVStream->time_base units, 0 if unknown.
1090      * Equals next_pts - this_pts in presentation order.
1091      */
1092     int   duration;
1093 #if FF_API_DESTRUCT_PACKET
1094     attribute_deprecated
1095     void  (*destruct)(struct AVPacket *);
1096     attribute_deprecated
1097     void  *priv;
1098 #endif
1099     int64_t pos;                            ///< byte position in stream, -1 if unknown
1100 
1101     /**
1102      * Time difference in AVStream->time_base units from the pts of this
1103      * packet to the point at which the output from the decoder has converged
1104      * independent from the availability of previous frames. That is, the
1105      * frames are virtually identical no matter if decoding started from
1106      * the very first frame or from this keyframe.
1107      * Is AV_NOPTS_VALUE if unknown.
1108      * This field is not the display duration of the current packet.
1109      * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1110      * set.
1111      *
1112      * The purpose of this field is to allow seeking in streams that have no
1113      * keyframes in the conventional sense. It corresponds to the
1114      * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1115      * essential for some types of subtitle streams to ensure that all
1116      * subtitles are correctly displayed after seeking.
1117      */
1118     int64_t convergence_duration;
1119 } AVPacket;
1120 #define AV_PKT_FLAG_KEY     0x0001 ///< The packet contains a keyframe
1121 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1122 
1123 enum AVSideDataParamChangeFlags {
1124     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT  = 0x0001,
1125     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
1126     AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE    = 0x0004,
1127     AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS     = 0x0008,
1128 };
1129 /**
1130  * @}
1131  */
1132 
1133 struct AVCodecInternal;
1134 
1135 enum AVFieldOrder {
1136     AV_FIELD_UNKNOWN,
1137     AV_FIELD_PROGRESSIVE,
1138     AV_FIELD_TT,          //< Top coded_first, top displayed first
1139     AV_FIELD_BB,          //< Bottom coded first, bottom displayed first
1140     AV_FIELD_TB,          //< Top coded first, bottom displayed first
1141     AV_FIELD_BT,          //< Bottom coded first, top displayed first
1142 };
1143 
1144 /**
1145  * main external API structure.
1146  * New fields can be added to the end with minor version bumps.
1147  * Removal, reordering and changes to existing fields require a major
1148  * version bump.
1149  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1150  * applications.
1151  * sizeof(AVCodecContext) must not be used outside libav*.
1152  */
1153 typedef struct AVCodecContext {
1154     /**
1155      * information on struct for av_log
1156      * - set by avcodec_alloc_context3
1157      */
1158     const AVClass *av_class;
1159     int log_level_offset;
1160 
1161     enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1162     const struct AVCodec  *codec;
1163     char             codec_name[32];
1164     enum AVCodecID     codec_id; /* see AV_CODEC_ID_xxx */
1165 
1166     /**
1167      * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1168      * This is used to work around some encoder bugs.
1169      * A demuxer should set this to what is stored in the field used to identify the codec.
1170      * If there are multiple such fields in a container then the demuxer should choose the one
1171      * which maximizes the information about the used codec.
1172      * If the codec tag field in a container is larger than 32 bits then the demuxer should
1173      * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1174      * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1175      * first.
1176      * - encoding: Set by user, if not then the default based on codec_id will be used.
1177      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1178      */
1179     unsigned int codec_tag;
1180 
1181     /**
1182      * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1183      * This is used to work around some encoder bugs.
1184      * - encoding: unused
1185      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1186      */
1187     unsigned int stream_codec_tag;
1188 
1189     void *priv_data;
1190 
1191     /**
1192      * Private context used for internal data.
1193      *
1194      * Unlike priv_data, this is not codec-specific. It is used in general
1195      * libavcodec functions.
1196      */
1197     struct AVCodecInternal *internal;
1198 
1199     /**
1200      * Private data of the user, can be used to carry app specific stuff.
1201      * - encoding: Set by user.
1202      * - decoding: Set by user.
1203      */
1204     void *opaque;
1205 
1206     /**
1207      * the average bitrate
1208      * - encoding: Set by user; unused for constant quantizer encoding.
1209      * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1210      */
1211     int bit_rate;
1212 
1213     /**
1214      * number of bits the bitstream is allowed to diverge from the reference.
1215      *           the reference can be CBR (for CBR pass1) or VBR (for pass2)
1216      * - encoding: Set by user; unused for constant quantizer encoding.
1217      * - decoding: unused
1218      */
1219     int bit_rate_tolerance;
1220 
1221     /**
1222      * Global quality for codecs which cannot change it per frame.
1223      * This should be proportional to MPEG-1/2/4 qscale.
1224      * - encoding: Set by user.
1225      * - decoding: unused
1226      */
1227     int global_quality;
1228 
1229     /**
1230      * - encoding: Set by user.
1231      * - decoding: unused
1232      */
1233     int compression_level;
1234 #define FF_COMPRESSION_DEFAULT -1
1235 
1236     /**
1237      * CODEC_FLAG_*.
1238      * - encoding: Set by user.
1239      * - decoding: Set by user.
1240      */
1241     int flags;
1242 
1243     /**
1244      * CODEC_FLAG2_*
1245      * - encoding: Set by user.
1246      * - decoding: Set by user.
1247      */
1248     int flags2;
1249 
1250     /**
1251      * some codecs need / can use extradata like Huffman tables.
1252      * mjpeg: Huffman tables
1253      * rv10: additional flags
1254      * mpeg4: global headers (they can be in the bitstream or here)
1255      * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1256      * than extradata_size to avoid problems if it is read with the bitstream reader.
1257      * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1258      * - encoding: Set/allocated/freed by libavcodec.
1259      * - decoding: Set/allocated/freed by user.
1260      */
1261     uint8_t *extradata;
1262     int extradata_size;
1263 
1264     /**
1265      * This is the fundamental unit of time (in seconds) in terms
1266      * of which frame timestamps are represented. For fixed-fps content,
1267      * timebase should be 1/framerate and timestamp increments should be
1268      * identically 1.
1269      * - encoding: MUST be set by user.
1270      * - decoding: Set by libavcodec.
1271      */
1272     AVRational time_base;
1273 
1274     /**
1275      * For some codecs, the time base is closer to the field rate than the frame rate.
1276      * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1277      * if no telecine is used ...
1278      *
1279      * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1280      */
1281     int ticks_per_frame;
1282 
1283     /**
1284      * Codec delay.
1285      *
1286      * Encoding: Number of frames delay there will be from the encoder input to
1287      *           the decoder output. (we assume the decoder matches the spec)
1288      * Decoding: Number of frames delay in addition to what a standard decoder
1289      *           as specified in the spec would produce.
1290      *
1291      * Video:
1292      *   Number of frames the decoded output will be delayed relative to the
1293      *   encoded input.
1294      *
1295      * Audio:
1296      *   For encoding, this is the number of "priming" samples added to the
1297      *   beginning of the stream. The decoded output will be delayed by this
1298      *   many samples relative to the input to the encoder. Note that this
1299      *   field is purely informational and does not directly affect the pts
1300      *   output by the encoder, which should always be based on the actual
1301      *   presentation time, including any delay.
1302      *   For decoding, this is the number of samples the decoder needs to
1303      *   output before the decoder's output is valid. When seeking, you should
1304      *   start decoding this many samples prior to your desired seek point.
1305      *
1306      * - encoding: Set by libavcodec.
1307      * - decoding: Set by libavcodec.
1308      */
1309     int delay;
1310 
1311 
1312     /* video only */
1313     /**
1314      * picture width / height.
1315      * - encoding: MUST be set by user.
1316      * - decoding: May be set by the user before opening the decoder if known e.g.
1317      *             from the container. Some decoders will require the dimensions
1318      *             to be set by the caller. During decoding, the decoder may
1319      *             overwrite those values as required.
1320      */
1321     int width, height;
1322 
1323     /**
1324      * Bitstream width / height, may be different from width/height e.g. when
1325      * the decoded frame is cropped before being output or lowres is enabled.
1326      * - encoding: unused
1327      * - decoding: May be set by the user before opening the decoder if known
1328      *             e.g. from the container. During decoding, the decoder may
1329      *             overwrite those values as required.
1330      */
1331     int coded_width, coded_height;
1332 
1333 #define FF_ASPECT_EXTENDED 15
1334 
1335     /**
1336      * the number of pictures in a group of pictures, or 0 for intra_only
1337      * - encoding: Set by user.
1338      * - decoding: unused
1339      */
1340     int gop_size;
1341 
1342     /**
1343      * Pixel format, see AV_PIX_FMT_xxx.
1344      * May be set by the demuxer if known from headers.
1345      * May be overridden by the decoder if it knows better.
1346      * - encoding: Set by user.
1347      * - decoding: Set by user if known, overridden by libavcodec if known
1348      */
1349     enum AVPixelFormat pix_fmt;
1350 
1351     /**
1352      * Motion estimation algorithm used for video coding.
1353      * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1354      * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1355      * - encoding: MUST be set by user.
1356      * - decoding: unused
1357      */
1358     int me_method;
1359 
1360     /**
1361      * If non NULL, 'draw_horiz_band' is called by the libavcodec
1362      * decoder to draw a horizontal band. It improves cache usage. Not
1363      * all codecs can do that. You must check the codec capabilities
1364      * beforehand.
1365      * When multithreading is used, it may be called from multiple threads
1366      * at the same time; threads might draw different parts of the same AVFrame,
1367      * or multiple AVFrames, and there is no guarantee that slices will be drawn
1368      * in order.
1369      * The function is also used by hardware acceleration APIs.
1370      * It is called at least once during frame decoding to pass
1371      * the data needed for hardware render.
1372      * In that mode instead of pixel data, AVFrame points to
1373      * a structure specific to the acceleration API. The application
1374      * reads the structure and can change some fields to indicate progress
1375      * or mark state.
1376      * - encoding: unused
1377      * - decoding: Set by user.
1378      * @param height the height of the slice
1379      * @param y the y position of the slice
1380      * @param type 1->top field, 2->bottom field, 3->frame
1381      * @param offset offset into the AVFrame.data from which the slice should be read
1382      */
1383     void (*draw_horiz_band)(struct AVCodecContext *s,
1384                             const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1385                             int y, int type, int height);
1386 
1387     /**
1388      * callback to negotiate the pixelFormat
1389      * @param fmt is the list of formats which are supported by the codec,
1390      * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1391      * The first is always the native one.
1392      * @return the chosen format
1393      * - encoding: unused
1394      * - decoding: Set by user, if not set the native format will be chosen.
1395      */
1396     enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1397 
1398     /**
1399      * maximum number of B-frames between non-B-frames
1400      * Note: The output will be delayed by max_b_frames+1 relative to the input.
1401      * - encoding: Set by user.
1402      * - decoding: unused
1403      */
1404     int max_b_frames;
1405 
1406     /**
1407      * qscale factor between IP and B-frames
1408      * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1409      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1410      * - encoding: Set by user.
1411      * - decoding: unused
1412      */
1413     float b_quant_factor;
1414 
1415     /** obsolete FIXME remove */
1416     int rc_strategy;
1417 #define FF_RC_STRATEGY_XVID 1
1418 
1419     int b_frame_strategy;
1420 
1421     /**
1422      * qscale offset between IP and B-frames
1423      * - encoding: Set by user.
1424      * - decoding: unused
1425      */
1426     float b_quant_offset;
1427 
1428     /**
1429      * Size of the frame reordering buffer in the decoder.
1430      * For MPEG-2 it is 1 IPB or 0 low delay IP.
1431      * - encoding: Set by libavcodec.
1432      * - decoding: Set by libavcodec.
1433      */
1434     int has_b_frames;
1435 
1436     /**
1437      * 0-> h263 quant 1-> mpeg quant
1438      * - encoding: Set by user.
1439      * - decoding: unused
1440      */
1441     int mpeg_quant;
1442 
1443     /**
1444      * qscale factor between P and I-frames
1445      * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1446      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1447      * - encoding: Set by user.
1448      * - decoding: unused
1449      */
1450     float i_quant_factor;
1451 
1452     /**
1453      * qscale offset between P and I-frames
1454      * - encoding: Set by user.
1455      * - decoding: unused
1456      */
1457     float i_quant_offset;
1458 
1459     /**
1460      * luminance masking (0-> disabled)
1461      * - encoding: Set by user.
1462      * - decoding: unused
1463      */
1464     float lumi_masking;
1465 
1466     /**
1467      * temporary complexity masking (0-> disabled)
1468      * - encoding: Set by user.
1469      * - decoding: unused
1470      */
1471     float temporal_cplx_masking;
1472 
1473     /**
1474      * spatial complexity masking (0-> disabled)
1475      * - encoding: Set by user.
1476      * - decoding: unused
1477      */
1478     float spatial_cplx_masking;
1479 
1480     /**
1481      * p block masking (0-> disabled)
1482      * - encoding: Set by user.
1483      * - decoding: unused
1484      */
1485     float p_masking;
1486 
1487     /**
1488      * darkness masking (0-> disabled)
1489      * - encoding: Set by user.
1490      * - decoding: unused
1491      */
1492     float dark_masking;
1493 
1494     /**
1495      * slice count
1496      * - encoding: Set by libavcodec.
1497      * - decoding: Set by user (or 0).
1498      */
1499     int slice_count;
1500     /**
1501      * prediction method (needed for huffyuv)
1502      * - encoding: Set by user.
1503      * - decoding: unused
1504      */
1505      int prediction_method;
1506 #define FF_PRED_LEFT   0
1507 #define FF_PRED_PLANE  1
1508 #define FF_PRED_MEDIAN 2
1509 
1510     /**
1511      * slice offsets in the frame in bytes
1512      * - encoding: Set/allocated by libavcodec.
1513      * - decoding: Set/allocated by user (or NULL).
1514      */
1515     int *slice_offset;
1516 
1517     /**
1518      * sample aspect ratio (0 if unknown)
1519      * That is the width of a pixel divided by the height of the pixel.
1520      * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1521      * - encoding: Set by user.
1522      * - decoding: Set by libavcodec.
1523      */
1524     AVRational sample_aspect_ratio;
1525 
1526     /**
1527      * motion estimation comparison function
1528      * - encoding: Set by user.
1529      * - decoding: unused
1530      */
1531     int me_cmp;
1532     /**
1533      * subpixel motion estimation comparison function
1534      * - encoding: Set by user.
1535      * - decoding: unused
1536      */
1537     int me_sub_cmp;
1538     /**
1539      * macroblock comparison function (not supported yet)
1540      * - encoding: Set by user.
1541      * - decoding: unused
1542      */
1543     int mb_cmp;
1544     /**
1545      * interlaced DCT comparison function
1546      * - encoding: Set by user.
1547      * - decoding: unused
1548      */
1549     int ildct_cmp;
1550 #define FF_CMP_SAD    0
1551 #define FF_CMP_SSE    1
1552 #define FF_CMP_SATD   2
1553 #define FF_CMP_DCT    3
1554 #define FF_CMP_PSNR   4
1555 #define FF_CMP_BIT    5
1556 #define FF_CMP_RD     6
1557 #define FF_CMP_ZERO   7
1558 #define FF_CMP_VSAD   8
1559 #define FF_CMP_VSSE   9
1560 #define FF_CMP_NSSE   10
1561 #define FF_CMP_W53    11
1562 #define FF_CMP_W97    12
1563 #define FF_CMP_DCTMAX 13
1564 #define FF_CMP_DCT264 14
1565 #define FF_CMP_CHROMA 256
1566 
1567     /**
1568      * ME diamond size & shape
1569      * - encoding: Set by user.
1570      * - decoding: unused
1571      */
1572     int dia_size;
1573 
1574     /**
1575      * amount of previous MV predictors (2a+1 x 2a+1 square)
1576      * - encoding: Set by user.
1577      * - decoding: unused
1578      */
1579     int last_predictor_count;
1580 
1581     /**
1582      * prepass for motion estimation
1583      * - encoding: Set by user.
1584      * - decoding: unused
1585      */
1586     int pre_me;
1587 
1588     /**
1589      * motion estimation prepass comparison function
1590      * - encoding: Set by user.
1591      * - decoding: unused
1592      */
1593     int me_pre_cmp;
1594 
1595     /**
1596      * ME prepass diamond size & shape
1597      * - encoding: Set by user.
1598      * - decoding: unused
1599      */
1600     int pre_dia_size;
1601 
1602     /**
1603      * subpel ME quality
1604      * - encoding: Set by user.
1605      * - decoding: unused
1606      */
1607     int me_subpel_quality;
1608 
1609     /**
1610      * DTG active format information (additional aspect ratio
1611      * information only used in DVB MPEG-2 transport streams)
1612      * 0 if not set.
1613      *
1614      * - encoding: unused
1615      * - decoding: Set by decoder.
1616      */
1617     int dtg_active_format;
1618 #define FF_DTG_AFD_SAME         8
1619 #define FF_DTG_AFD_4_3          9
1620 #define FF_DTG_AFD_16_9         10
1621 #define FF_DTG_AFD_14_9         11
1622 #define FF_DTG_AFD_4_3_SP_14_9  13
1623 #define FF_DTG_AFD_16_9_SP_14_9 14
1624 #define FF_DTG_AFD_SP_4_3       15
1625 
1626     /**
1627      * maximum motion estimation search range in subpel units
1628      * If 0 then no limit.
1629      *
1630      * - encoding: Set by user.
1631      * - decoding: unused
1632      */
1633     int me_range;
1634 
1635     /**
1636      * intra quantizer bias
1637      * - encoding: Set by user.
1638      * - decoding: unused
1639      */
1640     int intra_quant_bias;
1641 #define FF_DEFAULT_QUANT_BIAS 999999
1642 
1643     /**
1644      * inter quantizer bias
1645      * - encoding: Set by user.
1646      * - decoding: unused
1647      */
1648     int inter_quant_bias;
1649 
1650     /**
1651      * slice flags
1652      * - encoding: unused
1653      * - decoding: Set by user.
1654      */
1655     int slice_flags;
1656 #define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
1657 #define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1658 #define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1659 
1660     /**
1661      * XVideo Motion Acceleration
1662      * - encoding: forbidden
1663      * - decoding: set by decoder
1664      */
1665     int xvmc_acceleration;
1666 
1667     /**
1668      * macroblock decision mode
1669      * - encoding: Set by user.
1670      * - decoding: unused
1671      */
1672     int mb_decision;
1673 #define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
1674 #define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits
1675 #define FF_MB_DECISION_RD     2        ///< rate distortion
1676 
1677     /**
1678      * custom intra quantization matrix
1679      * - encoding: Set by user, can be NULL.
1680      * - decoding: Set by libavcodec.
1681      */
1682     uint16_t *intra_matrix;
1683 
1684     /**
1685      * custom inter quantization matrix
1686      * - encoding: Set by user, can be NULL.
1687      * - decoding: Set by libavcodec.
1688      */
1689     uint16_t *inter_matrix;
1690 
1691     /**
1692      * scene change detection threshold
1693      * 0 is default, larger means fewer detected scene changes.
1694      * - encoding: Set by user.
1695      * - decoding: unused
1696      */
1697     int scenechange_threshold;
1698 
1699     /**
1700      * noise reduction strength
1701      * - encoding: Set by user.
1702      * - decoding: unused
1703      */
1704     int noise_reduction;
1705 
1706     /**
1707      * Motion estimation threshold below which no motion estimation is
1708      * performed, but instead the user specified motion vectors are used.
1709      *
1710      * - encoding: Set by user.
1711      * - decoding: unused
1712      */
1713     int me_threshold;
1714 
1715     /**
1716      * Macroblock threshold below which the user specified macroblock types will be used.
1717      * - encoding: Set by user.
1718      * - decoding: unused
1719      */
1720     int mb_threshold;
1721 
1722     /**
1723      * precision of the intra DC coefficient - 8
1724      * - encoding: Set by user.
1725      * - decoding: unused
1726      */
1727     int intra_dc_precision;
1728 
1729     /**
1730      * Number of macroblock rows at the top which are skipped.
1731      * - encoding: unused
1732      * - decoding: Set by user.
1733      */
1734     int skip_top;
1735 
1736     /**
1737      * Number of macroblock rows at the bottom which are skipped.
1738      * - encoding: unused
1739      * - decoding: Set by user.
1740      */
1741     int skip_bottom;
1742 
1743     /**
1744      * Border processing masking, raises the quantizer for mbs on the borders
1745      * of the picture.
1746      * - encoding: Set by user.
1747      * - decoding: unused
1748      */
1749     float border_masking;
1750 
1751     /**
1752      * minimum MB lagrange multipler
1753      * - encoding: Set by user.
1754      * - decoding: unused
1755      */
1756     int mb_lmin;
1757 
1758     /**
1759      * maximum MB lagrange multipler
1760      * - encoding: Set by user.
1761      * - decoding: unused
1762      */
1763     int mb_lmax;
1764 
1765     /**
1766      *
1767      * - encoding: Set by user.
1768      * - decoding: unused
1769      */
1770     int me_penalty_compensation;
1771 
1772     /**
1773      *
1774      * - encoding: Set by user.
1775      * - decoding: unused
1776      */
1777     int bidir_refine;
1778 
1779     /**
1780      *
1781      * - encoding: Set by user.
1782      * - decoding: unused
1783      */
1784     int brd_scale;
1785 
1786     /**
1787      * minimum GOP size
1788      * - encoding: Set by user.
1789      * - decoding: unused
1790      */
1791     int keyint_min;
1792 
1793     /**
1794      * number of reference frames
1795      * - encoding: Set by user.
1796      * - decoding: Set by lavc.
1797      */
1798     int refs;
1799 
1800     /**
1801      * chroma qp offset from luma
1802      * - encoding: Set by user.
1803      * - decoding: unused
1804      */
1805     int chromaoffset;
1806 
1807     /**
1808      * Multiplied by qscale for each frame and added to scene_change_score.
1809      * - encoding: Set by user.
1810      * - decoding: unused
1811      */
1812     int scenechange_factor;
1813 
1814     /**
1815      *
1816      * Note: Value depends upon the compare function used for fullpel ME.
1817      * - encoding: Set by user.
1818      * - decoding: unused
1819      */
1820     int mv0_threshold;
1821 
1822     /**
1823      * Adjust sensitivity of b_frame_strategy 1.
1824      * - encoding: Set by user.
1825      * - decoding: unused
1826      */
1827     int b_sensitivity;
1828 
1829     /**
1830      * Chromaticity coordinates of the source primaries.
1831      * - encoding: Set by user
1832      * - decoding: Set by libavcodec
1833      */
1834     enum AVColorPrimaries color_primaries;
1835 
1836     /**
1837      * Color Transfer Characteristic.
1838      * - encoding: Set by user
1839      * - decoding: Set by libavcodec
1840      */
1841     enum AVColorTransferCharacteristic color_trc;
1842 
1843     /**
1844      * YUV colorspace type.
1845      * - encoding: Set by user
1846      * - decoding: Set by libavcodec
1847      */
1848     enum AVColorSpace colorspace;
1849 
1850     /**
1851      * MPEG vs JPEG YUV range.
1852      * - encoding: Set by user
1853      * - decoding: Set by libavcodec
1854      */
1855     enum AVColorRange color_range;
1856 
1857     /**
1858      * This defines the location of chroma samples.
1859      * - encoding: Set by user
1860      * - decoding: Set by libavcodec
1861      */
1862     enum AVChromaLocation chroma_sample_location;
1863 
1864     /**
1865      * Number of slices.
1866      * Indicates number of picture subdivisions. Used for parallelized
1867      * decoding.
1868      * - encoding: Set by user
1869      * - decoding: unused
1870      */
1871     int slices;
1872 
1873     /** Field order
1874      * - encoding: set by libavcodec
1875      * - decoding: Set by user.
1876      */
1877     enum AVFieldOrder field_order;
1878 
1879     /* audio only */
1880     int sample_rate; ///< samples per second
1881     int channels;    ///< number of audio channels
1882 
1883     /**
1884      * audio sample format
1885      * - encoding: Set by user.
1886      * - decoding: Set by libavcodec.
1887      */
1888     enum AVSampleFormat sample_fmt;  ///< sample format
1889 
1890     /* The following data should not be initialized. */
1891     /**
1892      * Number of samples per channel in an audio frame.
1893      *
1894      * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1895      *   except the last must contain exactly frame_size samples per channel.
1896      *   May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1897      *   frame size is not restricted.
1898      * - decoding: may be set by some decoders to indicate constant frame size
1899      */
1900     int frame_size;
1901 
1902     /**
1903      * Frame counter, set by libavcodec.
1904      *
1905      * - decoding: total number of frames returned from the decoder so far.
1906      * - encoding: total number of frames passed to the encoder so far.
1907      *
1908      *   @note the counter is not incremented if encoding/decoding resulted in
1909      *   an error.
1910      */
1911     int frame_number;
1912 
1913     /**
1914      * number of bytes per packet if constant and known or 0
1915      * Used by some WAV based audio codecs.
1916      */
1917     int block_align;
1918 
1919     /**
1920      * Audio cutoff bandwidth (0 means "automatic")
1921      * - encoding: Set by user.
1922      * - decoding: unused
1923      */
1924     int cutoff;
1925 
1926 #if FF_API_REQUEST_CHANNELS
1927     /**
1928      * Decoder should decode to this many channels if it can (0 for default)
1929      * - encoding: unused
1930      * - decoding: Set by user.
1931      * @deprecated Deprecated in favor of request_channel_layout.
1932      */
1933     int request_channels;
1934 #endif
1935 
1936     /**
1937      * Audio channel layout.
1938      * - encoding: set by user.
1939      * - decoding: set by user, may be overwritten by libavcodec.
1940      */
1941     uint64_t channel_layout;
1942 
1943     /**
1944      * Request decoder to use this channel layout if it can (0 for default)
1945      * - encoding: unused
1946      * - decoding: Set by user.
1947      */
1948     uint64_t request_channel_layout;
1949 
1950     /**
1951      * Type of service that the audio stream conveys.
1952      * - encoding: Set by user.
1953      * - decoding: Set by libavcodec.
1954      */
1955     enum AVAudioServiceType audio_service_type;
1956 
1957     /**
1958      * desired sample format
1959      * - encoding: Not used.
1960      * - decoding: Set by user.
1961      * Decoder will decode to this format if it can.
1962      */
1963     enum AVSampleFormat request_sample_fmt;
1964 
1965 #if FF_API_GET_BUFFER
1966     /**
1967      * Called at the beginning of each frame to get a buffer for it.
1968      *
1969      * The function will set AVFrame.data[], AVFrame.linesize[].
1970      * AVFrame.extended_data[] must also be set, but it should be the same as
1971      * AVFrame.data[] except for planar audio with more channels than can fit
1972      * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
1973      * many data pointers as it can hold.
1974      *
1975      * if CODEC_CAP_DR1 is not set then get_buffer() must call
1976      * avcodec_default_get_buffer() instead of providing buffers allocated by
1977      * some other means.
1978      *
1979      * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
1980      * need it. avcodec_default_get_buffer() aligns the output buffer properly,
1981      * but if get_buffer() is overridden then alignment considerations should
1982      * be taken into account.
1983      *
1984      * @see avcodec_default_get_buffer()
1985      *
1986      * Video:
1987      *
1988      * If pic.reference is set then the frame will be read later by libavcodec.
1989      * avcodec_align_dimensions2() should be used to find the required width and
1990      * height, as they normally need to be rounded up to the next multiple of 16.
1991      *
1992      * If frame multithreading is used and thread_safe_callbacks is set,
1993      * it may be called from a different thread, but not from more than one at
1994      * once. Does not need to be reentrant.
1995      *
1996      * @see release_buffer(), reget_buffer()
1997      * @see avcodec_align_dimensions2()
1998      *
1999      * Audio:
2000      *
2001      * Decoders request a buffer of a particular size by setting
2002      * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2003      * however, utilize only part of the buffer by setting AVFrame.nb_samples
2004      * to a smaller value in the output frame.
2005      *
2006      * Decoders cannot use the buffer after returning from
2007      * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2008      * is assumed to be released immediately upon return. In some rare cases,
2009      * a decoder may need to call get_buffer() more than once in a single
2010      * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2011      * called again after it has already been called once, the previously
2012      * acquired buffer is assumed to be released at that time and may not be
2013      * reused by the decoder.
2014      *
2015      * As a convenience, av_samples_get_buffer_size() and
2016      * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2017      * functions to find the required data size and to fill data pointers and
2018      * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2019      * since all planes must be the same size.
2020      *
2021      * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2022      *
2023      * - encoding: unused
2024      * - decoding: Set by libavcodec, user can override.
2025      *
2026      * @deprecated use get_buffer2()
2027      */
2028     attribute_deprecated
2029     int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2030 
2031     /**
2032      * Called to release buffers which were allocated with get_buffer.
2033      * A released buffer can be reused in get_buffer().
2034      * pic.data[*] must be set to NULL.
2035      * May be called from a different thread if frame multithreading is used,
2036      * but not by more than one thread at once, so does not need to be reentrant.
2037      * - encoding: unused
2038      * - decoding: Set by libavcodec, user can override.
2039      *
2040      * @deprecated custom freeing callbacks should be set from get_buffer2()
2041      */
2042     attribute_deprecated
2043     void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2044 
2045     /**
2046      * Called at the beginning of a frame to get cr buffer for it.
2047      * Buffer type (size, hints) must be the same. libavcodec won't check it.
2048      * libavcodec will pass previous buffer in pic, function should return
2049      * same buffer or new buffer with old frame "painted" into it.
2050      * If pic.data[0] == NULL must behave like get_buffer().
2051      * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2052      * avcodec_default_reget_buffer() instead of providing buffers allocated by
2053      * some other means.
2054      * - encoding: unused
2055      * - decoding: Set by libavcodec, user can override.
2056      */
2057     attribute_deprecated
2058     int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2059 #endif
2060 
2061     /**
2062      * This callback is called at the beginning of each frame to get data
2063      * buffer(s) for it. There may be one contiguous buffer for all the data or
2064      * there may be a buffer per each data plane or anything in between. What
2065      * this means is, you may set however many entries in buf[] you feel necessary.
2066      * Each buffer must be reference-counted using the AVBuffer API (see description
2067      * of buf[] below).
2068      *
2069      * The following fields will be set in the frame before this callback is
2070      * called:
2071      * - format
2072      * - width, height (video only)
2073      * - sample_rate, channel_layout, nb_samples (audio only)
2074      * Their values may differ from the corresponding values in
2075      * AVCodecContext. This callback must use the frame values, not the codec
2076      * context values, to calculate the required buffer size.
2077      *
2078      * This callback must fill the following fields in the frame:
2079      * - data[]
2080      * - linesize[]
2081      * - extended_data:
2082      *   * if the data is planar audio with more than 8 channels, then this
2083      *     callback must allocate and fill extended_data to contain all pointers
2084      *     to all data planes. data[] must hold as many pointers as it can.
2085      *     extended_data must be allocated with av_malloc() and will be freed in
2086      *     av_frame_unref().
2087      *   * otherwise exended_data must point to data
2088      * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2089      *   the frame's data and extended_data pointers must be contained in these. That
2090      *   is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2091      *   AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2092      *   and av_buffer_ref().
2093      * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2094      *   this callback and filled with the extra buffers if there are more
2095      *   buffers than buf[] can hold. extended_buf will be freed in
2096      *   av_frame_unref().
2097      *
2098      * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2099      * avcodec_default_get_buffer2() instead of providing buffers allocated by
2100      * some other means.
2101      *
2102      * Each data plane must be aligned to the maximum required by the target
2103      * CPU.
2104      *
2105      * @see avcodec_default_get_buffer2()
2106      *
2107      * Video:
2108      *
2109      * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2110      * (read and/or written to if it is writable) later by libavcodec.
2111      *
2112      * If CODEC_FLAG_EMU_EDGE is not set in s->flags, the buffer must contain an
2113      * edge of the size returned by avcodec_get_edge_width() on all sides.
2114      *
2115      * avcodec_align_dimensions2() should be used to find the required width and
2116      * height, as they normally need to be rounded up to the next multiple of 16.
2117      *
2118      * If frame multithreading is used and thread_safe_callbacks is set,
2119      * this callback may be called from a different thread, but not from more
2120      * than one at once. Does not need to be reentrant.
2121      *
2122      * @see avcodec_align_dimensions2()
2123      *
2124      * Audio:
2125      *
2126      * Decoders request a buffer of a particular size by setting
2127      * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2128      * however, utilize only part of the buffer by setting AVFrame.nb_samples
2129      * to a smaller value in the output frame.
2130      *
2131      * As a convenience, av_samples_get_buffer_size() and
2132      * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2133      * functions to find the required data size and to fill data pointers and
2134      * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2135      * since all planes must be the same size.
2136      *
2137      * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2138      *
2139      * - encoding: unused
2140      * - decoding: Set by libavcodec, user can override.
2141      */
2142     int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2143 
2144     /**
2145      * If non-zero, the decoded audio and video frames returned from
2146      * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2147      * and are valid indefinitely. The caller must free them with
2148      * av_frame_unref() when they are not needed anymore.
2149      * Otherwise, the decoded frames must not be freed by the caller and are
2150      * only valid until the next decode call.
2151      *
2152      * - encoding: unused
2153      * - decoding: set by the caller before avcodec_open2().
2154      */
2155     int refcounted_frames;
2156 
2157     /* - encoding parameters */
2158     float qcompress;  ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2159     float qblur;      ///< amount of qscale smoothing over time (0.0-1.0)
2160 
2161     /**
2162      * minimum quantizer
2163      * - encoding: Set by user.
2164      * - decoding: unused
2165      */
2166     int qmin;
2167 
2168     /**
2169      * maximum quantizer
2170      * - encoding: Set by user.
2171      * - decoding: unused
2172      */
2173     int qmax;
2174 
2175     /**
2176      * maximum quantizer difference between frames
2177      * - encoding: Set by user.
2178      * - decoding: unused
2179      */
2180     int max_qdiff;
2181 
2182     /**
2183      * ratecontrol qmin qmax limiting method
2184      * 0-> clipping, 1-> use a nice continuous function to limit qscale wthin qmin/qmax.
2185      * - encoding: Set by user.
2186      * - decoding: unused
2187      */
2188     float rc_qsquish;
2189 
2190     float rc_qmod_amp;
2191     int rc_qmod_freq;
2192 
2193     /**
2194      * decoder bitstream buffer size
2195      * - encoding: Set by user.
2196      * - decoding: unused
2197      */
2198     int rc_buffer_size;
2199 
2200     /**
2201      * ratecontrol override, see RcOverride
2202      * - encoding: Allocated/set/freed by user.
2203      * - decoding: unused
2204      */
2205     int rc_override_count;
2206     RcOverride *rc_override;
2207 
2208     /**
2209      * rate control equation
2210      * - encoding: Set by user
2211      * - decoding: unused
2212      */
2213     const char *rc_eq;
2214 
2215     /**
2216      * maximum bitrate
2217      * - encoding: Set by user.
2218      * - decoding: unused
2219      */
2220     int rc_max_rate;
2221 
2222     /**
2223      * minimum bitrate
2224      * - encoding: Set by user.
2225      * - decoding: unused
2226      */
2227     int rc_min_rate;
2228 
2229     float rc_buffer_aggressivity;
2230 
2231     /**
2232      * initial complexity for pass1 ratecontrol
2233      * - encoding: Set by user.
2234      * - decoding: unused
2235      */
2236     float rc_initial_cplx;
2237 
2238     /**
2239      * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2240      * - encoding: Set by user.
2241      * - decoding: unused.
2242      */
2243     float rc_max_available_vbv_use;
2244 
2245     /**
2246      * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2247      * - encoding: Set by user.
2248      * - decoding: unused.
2249      */
2250     float rc_min_vbv_overflow_use;
2251 
2252     /**
2253      * Number of bits which should be loaded into the rc buffer before decoding starts.
2254      * - encoding: Set by user.
2255      * - decoding: unused
2256      */
2257     int rc_initial_buffer_occupancy;
2258 
2259 #define FF_CODER_TYPE_VLC       0
2260 #define FF_CODER_TYPE_AC        1
2261 #define FF_CODER_TYPE_RAW       2
2262 #define FF_CODER_TYPE_RLE       3
2263 #define FF_CODER_TYPE_DEFLATE   4
2264     /**
2265      * coder type
2266      * - encoding: Set by user.
2267      * - decoding: unused
2268      */
2269     int coder_type;
2270 
2271     /**
2272      * context model
2273      * - encoding: Set by user.
2274      * - decoding: unused
2275      */
2276     int context_model;
2277 
2278     /**
2279      * minimum Lagrange multipler
2280      * - encoding: Set by user.
2281      * - decoding: unused
2282      */
2283     int lmin;
2284 
2285     /**
2286      * maximum Lagrange multipler
2287      * - encoding: Set by user.
2288      * - decoding: unused
2289      */
2290     int lmax;
2291 
2292     /**
2293      * frame skip threshold
2294      * - encoding: Set by user.
2295      * - decoding: unused
2296      */
2297     int frame_skip_threshold;
2298 
2299     /**
2300      * frame skip factor
2301      * - encoding: Set by user.
2302      * - decoding: unused
2303      */
2304     int frame_skip_factor;
2305 
2306     /**
2307      * frame skip exponent
2308      * - encoding: Set by user.
2309      * - decoding: unused
2310      */
2311     int frame_skip_exp;
2312 
2313     /**
2314      * frame skip comparison function
2315      * - encoding: Set by user.
2316      * - decoding: unused
2317      */
2318     int frame_skip_cmp;
2319 
2320     /**
2321      * trellis RD quantization
2322      * - encoding: Set by user.
2323      * - decoding: unused
2324      */
2325     int trellis;
2326 
2327     /**
2328      * - encoding: Set by user.
2329      * - decoding: unused
2330      */
2331     int min_prediction_order;
2332 
2333     /**
2334      * - encoding: Set by user.
2335      * - decoding: unused
2336      */
2337     int max_prediction_order;
2338 
2339     /**
2340      * GOP timecode frame start number
2341      * - encoding: Set by user, in non drop frame format
2342      * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2343      */
2344     int64_t timecode_frame_start;
2345 
2346     /* The RTP callback: This function is called    */
2347     /* every time the encoder has a packet to send. */
2348     /* It depends on the encoder if the data starts */
2349     /* with a Start Code (it should). H.263 does.   */
2350     /* mb_nb contains the number of macroblocks     */
2351     /* encoded in the RTP payload.                  */
2352     void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2353 
2354     int rtp_payload_size;   /* The size of the RTP payload: the coder will  */
2355                             /* do its best to deliver a chunk with size     */
2356                             /* below rtp_payload_size, the chunk will start */
2357                             /* with a start code on some codecs like H.263. */
2358                             /* This doesn't take account of any particular  */
2359                             /* headers inside the transmitted RTP payload.  */
2360 
2361     /* statistics, used for 2-pass encoding */
2362     int mv_bits;
2363     int header_bits;
2364     int i_tex_bits;
2365     int p_tex_bits;
2366     int i_count;
2367     int p_count;
2368     int skip_count;
2369     int misc_bits;
2370 
2371     /**
2372      * number of bits used for the previously encoded frame
2373      * - encoding: Set by libavcodec.
2374      * - decoding: unused
2375      */
2376     int frame_bits;
2377 
2378     /**
2379      * pass1 encoding statistics output buffer
2380      * - encoding: Set by libavcodec.
2381      * - decoding: unused
2382      */
2383     char *stats_out;
2384 
2385     /**
2386      * pass2 encoding statistics input buffer
2387      * Concatenated stuff from stats_out of pass1 should be placed here.
2388      * - encoding: Allocated/set/freed by user.
2389      * - decoding: unused
2390      */
2391     char *stats_in;
2392 
2393     /**
2394      * Work around bugs in encoders which sometimes cannot be detected automatically.
2395      * - encoding: Set by user
2396      * - decoding: Set by user
2397      */
2398     int workaround_bugs;
2399 #define FF_BUG_AUTODETECT       1  ///< autodetection
2400 #define FF_BUG_OLD_MSMPEG4      2
2401 #define FF_BUG_XVID_ILACE       4
2402 #define FF_BUG_UMP4             8
2403 #define FF_BUG_NO_PADDING       16
2404 #define FF_BUG_AMV              32
2405 #define FF_BUG_AC_VLC           0  ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2406 #define FF_BUG_QPEL_CHROMA      64
2407 #define FF_BUG_STD_QPEL         128
2408 #define FF_BUG_QPEL_CHROMA2     256
2409 #define FF_BUG_DIRECT_BLOCKSIZE 512
2410 #define FF_BUG_EDGE             1024
2411 #define FF_BUG_HPEL_CHROMA      2048
2412 #define FF_BUG_DC_CLIP          4096
2413 #define FF_BUG_MS               8192 ///< Work around various bugs in Microsoft's broken decoders.
2414 #define FF_BUG_TRUNCATED       16384
2415 
2416     /**
2417      * strictly follow the standard (MPEG4, ...).
2418      * - encoding: Set by user.
2419      * - decoding: Set by user.
2420      * Setting this to STRICT or higher means the encoder and decoder will
2421      * generally do stupid things, whereas setting it to unofficial or lower
2422      * will mean the encoder might produce output that is not supported by all
2423      * spec-compliant decoders. Decoders don't differentiate between normal,
2424      * unofficial and experimental (that is, they always try to decode things
2425      * when they can) unless they are explicitly asked to behave stupidly
2426      * (=strictly conform to the specs)
2427      */
2428     int strict_std_compliance;
2429 #define FF_COMPLIANCE_VERY_STRICT   2 ///< Strictly conform to an older more strict version of the spec or reference software.
2430 #define FF_COMPLIANCE_STRICT        1 ///< Strictly conform to all the things in the spec no matter what consequences.
2431 #define FF_COMPLIANCE_NORMAL        0
2432 #define FF_COMPLIANCE_UNOFFICIAL   -1 ///< Allow unofficial extensions
2433 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2434 
2435     /**
2436      * error concealment flags
2437      * - encoding: unused
2438      * - decoding: Set by user.
2439      */
2440     int error_concealment;
2441 #define FF_EC_GUESS_MVS   1
2442 #define FF_EC_DEBLOCK     2
2443 
2444     /**
2445      * debug
2446      * - encoding: Set by user.
2447      * - decoding: Set by user.
2448      */
2449     int debug;
2450 #define FF_DEBUG_PICT_INFO   1
2451 #define FF_DEBUG_RC          2
2452 #define FF_DEBUG_BITSTREAM   4
2453 #define FF_DEBUG_MB_TYPE     8
2454 #define FF_DEBUG_QP          16
2455 #define FF_DEBUG_MV          32
2456 #define FF_DEBUG_DCT_COEFF   0x00000040
2457 #define FF_DEBUG_SKIP        0x00000080
2458 #define FF_DEBUG_STARTCODE   0x00000100
2459 #define FF_DEBUG_PTS         0x00000200
2460 #define FF_DEBUG_ER          0x00000400
2461 #define FF_DEBUG_MMCO        0x00000800
2462 #define FF_DEBUG_BUGS        0x00001000
2463 #define FF_DEBUG_VIS_QP      0x00002000
2464 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2465 #define FF_DEBUG_BUFFERS     0x00008000
2466 #define FF_DEBUG_THREADS     0x00010000
2467 
2468     /**
2469      * debug
2470      * - encoding: Set by user.
2471      * - decoding: Set by user.
2472      */
2473     int debug_mv;
2474 #define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
2475 #define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
2476 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2477 
2478     /**
2479      * Error recognition; may misdetect some more or less valid parts as errors.
2480      * - encoding: unused
2481      * - decoding: Set by user.
2482      */
2483     int err_recognition;
2484 #define AV_EF_CRCCHECK  (1<<0)
2485 #define AV_EF_BITSTREAM (1<<1)
2486 #define AV_EF_BUFFER    (1<<2)
2487 #define AV_EF_EXPLODE   (1<<3)
2488 
2489 #define AV_EF_CAREFUL    (1<<16)
2490 #define AV_EF_COMPLIANT  (1<<17)
2491 #define AV_EF_AGGRESSIVE (1<<18)
2492 
2493 
2494     /**
2495      * opaque 64bit number (generally a PTS) that will be reordered and
2496      * output in AVFrame.reordered_opaque
2497      * @deprecated in favor of pkt_pts
2498      * - encoding: unused
2499      * - decoding: Set by user.
2500      */
2501     int64_t reordered_opaque;
2502 
2503     /**
2504      * Hardware accelerator in use
2505      * - encoding: unused.
2506      * - decoding: Set by libavcodec
2507      */
2508     struct AVHWAccel *hwaccel;
2509 
2510     /**
2511      * Hardware accelerator context.
2512      * For some hardware accelerators, a global context needs to be
2513      * provided by the user. In that case, this holds display-dependent
2514      * data FFmpeg cannot instantiate itself. Please refer to the
2515      * FFmpeg HW accelerator documentation to know how to fill this
2516      * is. e.g. for VA API, this is a struct vaapi_context.
2517      * - encoding: unused
2518      * - decoding: Set by user
2519      */
2520     void *hwaccel_context;
2521 
2522     /**
2523      * error
2524      * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2525      * - decoding: unused
2526      */
2527     uint64_t error[AV_NUM_DATA_POINTERS];
2528 
2529     /**
2530      * DCT algorithm, see FF_DCT_* below
2531      * - encoding: Set by user.
2532      * - decoding: unused
2533      */
2534     int dct_algo;
2535 #define FF_DCT_AUTO    0
2536 #define FF_DCT_FASTINT 1
2537 #define FF_DCT_INT     2
2538 #define FF_DCT_MMX     3
2539 #define FF_DCT_ALTIVEC 5
2540 #define FF_DCT_FAAN    6
2541 
2542     /**
2543      * IDCT algorithm, see FF_IDCT_* below.
2544      * - encoding: Set by user.
2545      * - decoding: Set by user.
2546      */
2547     int idct_algo;
2548 #define FF_IDCT_AUTO          0
2549 #define FF_IDCT_INT           1
2550 #define FF_IDCT_SIMPLE        2
2551 #define FF_IDCT_SIMPLEMMX     3
2552 #define FF_IDCT_ARM           7
2553 #define FF_IDCT_ALTIVEC       8
2554 #define FF_IDCT_SH4           9
2555 #define FF_IDCT_SIMPLEARM     10
2556 #define FF_IDCT_IPP           13
2557 #define FF_IDCT_XVIDMMX       14
2558 #define FF_IDCT_SIMPLEARMV5TE 16
2559 #define FF_IDCT_SIMPLEARMV6   17
2560 #define FF_IDCT_SIMPLEVIS     18
2561 #define FF_IDCT_FAAN          20
2562 #define FF_IDCT_SIMPLENEON    22
2563 #define FF_IDCT_SIMPLEALPHA   23
2564 
2565     /**
2566      * bits per sample/pixel from the demuxer (needed for huffyuv).
2567      * - encoding: Set by libavcodec.
2568      * - decoding: Set by user.
2569      */
2570      int bits_per_coded_sample;
2571 
2572     /**
2573      * Bits per sample/pixel of internal libavcodec pixel/sample format.
2574      * - encoding: set by user.
2575      * - decoding: set by libavcodec.
2576      */
2577     int bits_per_raw_sample;
2578 
2579 #if FF_API_LOWRES
2580     /**
2581      * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2582      * - encoding: unused
2583      * - decoding: Set by user.
2584      * Code outside libavcodec should access this field using:
2585      * av_codec_{get,set}_lowres(avctx)
2586      */
2587      int lowres;
2588 #endif
2589 
2590     /**
2591      * the picture in the bitstream
2592      * - encoding: Set by libavcodec.
2593      * - decoding: Set by libavcodec.
2594      */
2595     AVFrame *coded_frame;
2596 
2597     /**
2598      * thread count
2599      * is used to decide how many independent tasks should be passed to execute()
2600      * - encoding: Set by user.
2601      * - decoding: Set by user.
2602      */
2603     int thread_count;
2604 
2605     /**
2606      * Which multithreading methods to use.
2607      * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2608      * so clients which cannot provide future frames should not use it.
2609      *
2610      * - encoding: Set by user, otherwise the default is used.
2611      * - decoding: Set by user, otherwise the default is used.
2612      */
2613     int thread_type;
2614 #define FF_THREAD_FRAME   1 ///< Decode more than one frame at once
2615 #define FF_THREAD_SLICE   2 ///< Decode more than one part of a single frame at once
2616 
2617     /**
2618      * Which multithreading methods are in use by the codec.
2619      * - encoding: Set by libavcodec.
2620      * - decoding: Set by libavcodec.
2621      */
2622     int active_thread_type;
2623 
2624     /**
2625      * Set by the client if its custom get_buffer() callback can be called
2626      * synchronously from another thread, which allows faster multithreaded decoding.
2627      * draw_horiz_band() will be called from other threads regardless of this setting.
2628      * Ignored if the default get_buffer() is used.
2629      * - encoding: Set by user.
2630      * - decoding: Set by user.
2631      */
2632     int thread_safe_callbacks;
2633 
2634     /**
2635      * The codec may call this to execute several independent things.
2636      * It will return only after finishing all tasks.
2637      * The user may replace this with some multithreaded implementation,
2638      * the default implementation will execute the parts serially.
2639      * @param count the number of things to execute
2640      * - encoding: Set by libavcodec, user can override.
2641      * - decoding: Set by libavcodec, user can override.
2642      */
2643     int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2644 
2645     /**
2646      * The codec may call this to execute several independent things.
2647      * It will return only after finishing all tasks.
2648      * The user may replace this with some multithreaded implementation,
2649      * the default implementation will execute the parts serially.
2650      * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2651      * @param c context passed also to func
2652      * @param count the number of things to execute
2653      * @param arg2 argument passed unchanged to func
2654      * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2655      * @param func function that will be called count times, with jobnr from 0 to count-1.
2656      *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2657      *             two instances of func executing at the same time will have the same threadnr.
2658      * @return always 0 currently, but code should handle a future improvement where when any call to func
2659      *         returns < 0 no further calls to func may be done and < 0 is returned.
2660      * - encoding: Set by libavcodec, user can override.
2661      * - decoding: Set by libavcodec, user can override.
2662      */
2663     int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2664 
2665     /**
2666      * thread opaque
2667      * Can be used by execute() to store some per AVCodecContext stuff.
2668      * - encoding: set by execute()
2669      * - decoding: set by execute()
2670      */
2671     void *thread_opaque;
2672 
2673     /**
2674      * noise vs. sse weight for the nsse comparsion function
2675      * - encoding: Set by user.
2676      * - decoding: unused
2677      */
2678      int nsse_weight;
2679 
2680     /**
2681      * profile
2682      * - encoding: Set by user.
2683      * - decoding: Set by libavcodec.
2684      */
2685      int profile;
2686 #define FF_PROFILE_UNKNOWN -99
2687 #define FF_PROFILE_RESERVED -100
2688 
2689 #define FF_PROFILE_AAC_MAIN 0
2690 #define FF_PROFILE_AAC_LOW  1
2691 #define FF_PROFILE_AAC_SSR  2
2692 #define FF_PROFILE_AAC_LTP  3
2693 #define FF_PROFILE_AAC_HE   4
2694 #define FF_PROFILE_AAC_HE_V2 28
2695 #define FF_PROFILE_AAC_LD   22
2696 #define FF_PROFILE_AAC_ELD  38
2697 #define FF_PROFILE_MPEG2_AAC_LOW 128
2698 #define FF_PROFILE_MPEG2_AAC_HE  131
2699 
2700 #define FF_PROFILE_DTS         20
2701 #define FF_PROFILE_DTS_ES      30
2702 #define FF_PROFILE_DTS_96_24   40
2703 #define FF_PROFILE_DTS_HD_HRA  50
2704 #define FF_PROFILE_DTS_HD_MA   60
2705 
2706 #define FF_PROFILE_MPEG2_422    0
2707 #define FF_PROFILE_MPEG2_HIGH   1
2708 #define FF_PROFILE_MPEG2_SS     2
2709 #define FF_PROFILE_MPEG2_SNR_SCALABLE  3
2710 #define FF_PROFILE_MPEG2_MAIN   4
2711 #define FF_PROFILE_MPEG2_SIMPLE 5
2712 
2713 #define FF_PROFILE_H264_CONSTRAINED  (1<<9)  // 8+1; constraint_set1_flag
2714 #define FF_PROFILE_H264_INTRA        (1<<11) // 8+3; constraint_set3_flag
2715 
2716 #define FF_PROFILE_H264_BASELINE             66
2717 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2718 #define FF_PROFILE_H264_MAIN                 77
2719 #define FF_PROFILE_H264_EXTENDED             88
2720 #define FF_PROFILE_H264_HIGH                 100
2721 #define FF_PROFILE_H264_HIGH_10              110
2722 #define FF_PROFILE_H264_HIGH_10_INTRA        (110|FF_PROFILE_H264_INTRA)
2723 #define FF_PROFILE_H264_HIGH_422             122
2724 #define FF_PROFILE_H264_HIGH_422_INTRA       (122|FF_PROFILE_H264_INTRA)
2725 #define FF_PROFILE_H264_HIGH_444             144
2726 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE  244
2727 #define FF_PROFILE_H264_HIGH_444_INTRA       (244|FF_PROFILE_H264_INTRA)
2728 #define FF_PROFILE_H264_CAVLC_444            44
2729 
2730 #define FF_PROFILE_VC1_SIMPLE   0
2731 #define FF_PROFILE_VC1_MAIN     1
2732 #define FF_PROFILE_VC1_COMPLEX  2
2733 #define FF_PROFILE_VC1_ADVANCED 3
2734 
2735 #define FF_PROFILE_MPEG4_SIMPLE                     0
2736 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE            1
2737 #define FF_PROFILE_MPEG4_CORE                       2
2738 #define FF_PROFILE_MPEG4_MAIN                       3
2739 #define FF_PROFILE_MPEG4_N_BIT                      4
2740 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE           5
2741 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION      6
2742 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE     7
2743 #define FF_PROFILE_MPEG4_HYBRID                     8
2744 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME         9
2745 #define FF_PROFILE_MPEG4_CORE_SCALABLE             10
2746 #define FF_PROFILE_MPEG4_ADVANCED_CODING           11
2747 #define FF_PROFILE_MPEG4_ADVANCED_CORE             12
2748 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2749 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO             14
2750 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE           15
2751 
2752 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0   0
2753 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1   1
2754 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION  2
2755 #define FF_PROFILE_JPEG2000_DCINEMA_2K              3
2756 #define FF_PROFILE_JPEG2000_DCINEMA_4K              4
2757 
2758     /**
2759      * level
2760      * - encoding: Set by user.
2761      * - decoding: Set by libavcodec.
2762      */
2763      int level;
2764 #define FF_LEVEL_UNKNOWN -99
2765 
2766     /**
2767      * Skip loop filtering for selected frames.
2768      * - encoding: unused
2769      * - decoding: Set by user.
2770      */
2771     enum AVDiscard skip_loop_filter;
2772 
2773     /**
2774      * Skip IDCT/dequantization for selected frames.
2775      * - encoding: unused
2776      * - decoding: Set by user.
2777      */
2778     enum AVDiscard skip_idct;
2779 
2780     /**
2781      * Skip decoding for selected frames.
2782      * - encoding: unused
2783      * - decoding: Set by user.
2784      */
2785     enum AVDiscard skip_frame;
2786 
2787     /**
2788      * Header containing style information for text subtitles.
2789      * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2790      * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2791      * the Format line following. It shouldn't include any Dialogue line.
2792      * - encoding: Set/allocated/freed by user (before avcodec_open2())
2793      * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2794      */
2795     uint8_t *subtitle_header;
2796     int subtitle_header_size;
2797 
2798     /**
2799      * Simulates errors in the bitstream to test error concealment.
2800      * - encoding: Set by user.
2801      * - decoding: unused
2802      */
2803     int error_rate;
2804 
2805     /**
2806      * Current packet as passed into the decoder, to avoid having
2807      * to pass the packet into every function. Currently only valid
2808      * inside lavc and get/release_buffer callbacks.
2809      * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
2810      * - encoding: unused
2811      */
2812     AVPacket *pkt;
2813 
2814     /**
2815      * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2816      * Used for compliant TS muxing.
2817      * - encoding: Set by libavcodec.
2818      * - decoding: unused.
2819      */
2820     uint64_t vbv_delay;
2821 
2822     /**
2823      * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
2824      * Code outside libavcodec should access this field using:
2825      * av_codec_{get,set}_pkt_timebase(avctx)
2826      * - encoding unused.
2827      * - decoding set by user.
2828      */
2829     AVRational pkt_timebase;
2830 
2831     /**
2832      * AVCodecDescriptor
2833      * Code outside libavcodec should access this field using:
2834      * av_codec_{get,set}_codec_descriptor(avctx)
2835      * - encoding: unused.
2836      * - decoding: set by libavcodec.
2837      */
2838     const AVCodecDescriptor *codec_descriptor;
2839 
2840 #if !FF_API_LOWRES
2841     /**
2842      * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2843      * - encoding: unused
2844      * - decoding: Set by user.
2845      * Code outside libavcodec should access this field using:
2846      * av_codec_{get,set}_lowres(avctx)
2847      */
2848      int lowres;
2849 #endif
2850 
2851     /**
2852      * Current statistics for PTS correction.
2853      * - decoding: maintained and used by libavcodec, not intended to be used by user apps
2854      * - encoding: unused
2855      */
2856     int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
2857     int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
2858     int64_t pts_correction_last_pts;       /// PTS of the last frame
2859     int64_t pts_correction_last_dts;       /// DTS of the last frame
2860 
2861     /**
2862      * Character encoding of the input subtitles file.
2863      * - decoding: set by user
2864      * - encoding: unused
2865      */
2866     char *sub_charenc;
2867 
2868     /**
2869      * Subtitles character encoding mode. Formats or codecs might be adjusting
2870      * this setting (if they are doing the conversion themselves for instance).
2871      * - decoding: set by libavcodec
2872      * - encoding: unused
2873      */
2874     int sub_charenc_mode;
2875 #define FF_SUB_CHARENC_MODE_DO_NOTHING  -1  ///< do nothing (demuxer outputs a stream supposed to be already in UTF-8, or the codec is bitmap for instance)
2876 #define FF_SUB_CHARENC_MODE_AUTOMATIC    0  ///< libavcodec will select the mode itself
2877 #define FF_SUB_CHARENC_MODE_PRE_DECODER  1  ///< the AVPacket data needs to be recoded to UTF-8 before being fed to the decoder, requires iconv
2878 
2879 } AVCodecContext;
2880 
2881 AVRational av_codec_get_pkt_timebase         (const AVCodecContext *avctx);
2882 void       av_codec_set_pkt_timebase         (AVCodecContext *avctx, AVRational val);
2883 
2884 const AVCodecDescriptor *av_codec_get_codec_descriptor(const AVCodecContext *avctx);
2885 void                     av_codec_set_codec_descriptor(AVCodecContext *avctx, const AVCodecDescriptor *desc);
2886 
2887 int  av_codec_get_lowres(const AVCodecContext *avctx);
2888 void av_codec_set_lowres(AVCodecContext *avctx, int val);
2889 
2890 /**
2891  * AVProfile.
2892  */
2893 typedef struct AVProfile {
2894     int profile;
2895     const char *name; ///< short name for the profile
2896 } AVProfile;
2897 
2898 typedef struct AVCodecDefault AVCodecDefault;
2899 
2900 struct AVSubtitle;
2901 
2902 /**
2903  * AVCodec.
2904  */
2905 typedef struct AVCodec {
2906     /**
2907      * Name of the codec implementation.
2908      * The name is globally unique among encoders and among decoders (but an
2909      * encoder and a decoder can share the same name).
2910      * This is the primary way to find a codec from the user perspective.
2911      */
2912     const char *name;
2913     /**
2914      * Descriptive name for the codec, meant to be more human readable than name.
2915      * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
2916      */
2917     const char *long_name;
2918     enum AVMediaType type;
2919     enum AVCodecID id;
2920     /**
2921      * Codec capabilities.
2922      * see CODEC_CAP_*
2923      */
2924     int capabilities;
2925     const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
2926     const enum AVPixelFormat *pix_fmts;     ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
2927     const int *supported_samplerates;       ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
2928     const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
2929     const uint64_t *channel_layouts;         ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
2930     uint8_t max_lowres;                     ///< maximum value for lowres supported by the decoder
2931     const AVClass *priv_class;              ///< AVClass for the private context
2932     const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
2933 
2934     /*****************************************************************
2935      * No fields below this line are part of the public API. They
2936      * may not be used outside of libavcodec and can be changed and
2937      * removed at will.
2938      * New public fields should be added right above.
2939      *****************************************************************
2940      */
2941     int priv_data_size;
2942     struct AVCodec *next;
2943     /**
2944      * @name Frame-level threading support functions
2945      * @{
2946      */
2947     /**
2948      * If defined, called on thread contexts when they are created.
2949      * If the codec allocates writable tables in init(), re-allocate them here.
2950      * priv_data will be set to a copy of the original.
2951      */
2952     int (*init_thread_copy)(AVCodecContext *);
2953     /**
2954      * Copy necessary context variables from a previous thread context to the current one.
2955      * If not defined, the next thread will start automatically; otherwise, the codec
2956      * must call ff_thread_finish_setup().
2957      *
2958      * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
2959      */
2960     int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
2961     /** @} */
2962 
2963     /**
2964      * Private codec-specific defaults.
2965      */
2966     const AVCodecDefault *defaults;
2967 
2968     /**
2969      * Initialize codec static data, called from avcodec_register().
2970      */
2971     void (*init_static_data)(struct AVCodec *codec);
2972 
2973     int (*init)(AVCodecContext *);
2974     int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
2975                       const struct AVSubtitle *sub);
2976     /**
2977      * Encode data to an AVPacket.
2978      *
2979      * @param      avctx          codec context
2980      * @param      avpkt          output AVPacket (may contain a user-provided buffer)
2981      * @param[in]  frame          AVFrame containing the raw data to be encoded
2982      * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
2983      *                            non-empty packet was returned in avpkt.
2984      * @return 0 on success, negative error code on failure
2985      */
2986     int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
2987                    int *got_packet_ptr);
2988     int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
2989     int (*close)(AVCodecContext *);
2990     /**
2991      * Flush buffers.
2992      * Will be called when seeking
2993      */
2994     void (*flush)(AVCodecContext *);
2995 } AVCodec;
2996 
2997 /**
2998  * AVHWAccel.
2999  */
3000 typedef struct AVHWAccel {
3001     /**
3002      * Name of the hardware accelerated codec.
3003      * The name is globally unique among encoders and among decoders (but an
3004      * encoder and a decoder can share the same name).
3005      */
3006     const char *name;
3007 
3008     /**
3009      * Type of codec implemented by the hardware accelerator.
3010      *
3011      * See AVMEDIA_TYPE_xxx
3012      */
3013     enum AVMediaType type;
3014 
3015     /**
3016      * Codec implemented by the hardware accelerator.
3017      *
3018      * See AV_CODEC_ID_xxx
3019      */
3020     enum AVCodecID id;
3021 
3022     /**
3023      * Supported pixel format.
3024      *
3025      * Only hardware accelerated formats are supported here.
3026      */
3027     enum AVPixelFormat pix_fmt;
3028 
3029     /**
3030      * Hardware accelerated codec capabilities.
3031      * see FF_HWACCEL_CODEC_CAP_*
3032      */
3033     int capabilities;
3034 
3035     struct AVHWAccel *next;
3036 
3037     /**
3038      * Called at the beginning of each frame or field picture.
3039      *
3040      * Meaningful frame information (codec specific) is guaranteed to
3041      * be parsed at this point. This function is mandatory.
3042      *
3043      * Note that buf can be NULL along with buf_size set to 0.
3044      * Otherwise, this means the whole frame is available at this point.
3045      *
3046      * @param avctx the codec context
3047      * @param buf the frame data buffer base
3048      * @param buf_size the size of the frame in bytes
3049      * @return zero if successful, a negative value otherwise
3050      */
3051     int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3052 
3053     /**
3054      * Callback for each slice.
3055      *
3056      * Meaningful slice information (codec specific) is guaranteed to
3057      * be parsed at this point. This function is mandatory.
3058      *
3059      * @param avctx the codec context
3060      * @param buf the slice data buffer base
3061      * @param buf_size the size of the slice in bytes
3062      * @return zero if successful, a negative value otherwise
3063      */
3064     int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3065 
3066     /**
3067      * Called at the end of each frame or field picture.
3068      *
3069      * The whole picture is parsed at this point and can now be sent
3070      * to the hardware accelerator. This function is mandatory.
3071      *
3072      * @param avctx the codec context
3073      * @return zero if successful, a negative value otherwise
3074      */
3075     int (*end_frame)(AVCodecContext *avctx);
3076 
3077     /**
3078      * Size of HW accelerator private data.
3079      *
3080      * Private data is allocated with av_mallocz() before
3081      * AVCodecContext.get_buffer() and deallocated after
3082      * AVCodecContext.release_buffer().
3083      */
3084     int priv_data_size;
3085 } AVHWAccel;
3086 
3087 /**
3088  * @defgroup lavc_picture AVPicture
3089  *
3090  * Functions for working with AVPicture
3091  * @{
3092  */
3093 
3094 /**
3095  * four components are given, that's all.
3096  * the last component is alpha
3097  */
3098 typedef struct AVPicture {
3099     uint8_t *data[AV_NUM_DATA_POINTERS];
3100     int linesize[AV_NUM_DATA_POINTERS];     ///< number of bytes per line
3101 } AVPicture;
3102 
3103 /**
3104  * @}
3105  */
3106 
3107 enum AVSubtitleType {
3108     SUBTITLE_NONE,
3109 
3110     SUBTITLE_BITMAP,                ///< A bitmap, pict will be set
3111 
3112     /**
3113      * Plain text, the text field must be set by the decoder and is
3114      * authoritative. ass and pict fields may contain approximations.
3115      */
3116     SUBTITLE_TEXT,
3117 
3118     /**
3119      * Formatted text, the ass field must be set by the decoder and is
3120      * authoritative. pict and text fields may contain approximations.
3121      */
3122     SUBTITLE_ASS,
3123 };
3124 
3125 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3126 
3127 typedef struct AVSubtitleRect {
3128     int x;         ///< top left corner  of pict, undefined when pict is not set
3129     int y;         ///< top left corner  of pict, undefined when pict is not set
3130     int w;         ///< width            of pict, undefined when pict is not set
3131     int h;         ///< height           of pict, undefined when pict is not set
3132     int nb_colors; ///< number of colors in pict, undefined when pict is not set
3133 
3134     /**
3135      * data+linesize for the bitmap of this subtitle.
3136      * can be set for text/ass as well once they where rendered
3137      */
3138     AVPicture pict;
3139     enum AVSubtitleType type;
3140 
3141     char *text;                     ///< 0 terminated plain UTF-8 text
3142 
3143     /**
3144      * 0 terminated ASS/SSA compatible event line.
3145      * The presentation of this is unaffected by the other values in this
3146      * struct.
3147      */
3148     char *ass;
3149 
3150     int flags;
3151 } AVSubtitleRect;
3152 
3153 typedef struct AVSubtitle {
3154     uint16_t format; /* 0 = graphics */
3155     uint32_t start_display_time; /* relative to packet pts, in ms */
3156     uint32_t end_display_time; /* relative to packet pts, in ms */
3157     unsigned num_rects;
3158     AVSubtitleRect **rects;
3159     int64_t pts;    ///< Same as packet pts, in AV_TIME_BASE
3160 } AVSubtitle;
3161 
3162 /**
3163  * If c is NULL, returns the first registered codec,
3164  * if c is non-NULL, returns the next registered codec after c,
3165  * or NULL if c is the last one.
3166  */
3167 AVCodec *av_codec_next(const AVCodec *c);
3168 
3169 /**
3170  * Return the LIBAVCODEC_VERSION_INT constant.
3171  */
3172 unsigned avcodec_version(void);
3173 
3174 /**
3175  * Return the libavcodec build-time configuration.
3176  */
3177 const char *avcodec_configuration(void);
3178 
3179 /**
3180  * Return the libavcodec license.
3181  */
3182 const char *avcodec_license(void);
3183 
3184 /**
3185  * Register the codec codec and initialize libavcodec.
3186  *
3187  * @warning either this function or avcodec_register_all() must be called
3188  * before any other libavcodec functions.
3189  *
3190  * @see avcodec_register_all()
3191  */
3192 void avcodec_register(AVCodec *codec);
3193 
3194 /**
3195  * Register all the codecs, parsers and bitstream filters which were enabled at
3196  * configuration time. If you do not call this function you can select exactly
3197  * which formats you want to support, by using the individual registration
3198  * functions.
3199  *
3200  * @see avcodec_register
3201  * @see av_register_codec_parser
3202  * @see av_register_bitstream_filter
3203  */
3204 void avcodec_register_all(void);
3205 
3206 
3207 #if FF_API_ALLOC_CONTEXT
3208 /**
3209  * Allocate an AVCodecContext and set its fields to default values.  The
3210  * resulting struct can be deallocated by simply calling av_free().
3211  *
3212  * @return An AVCodecContext filled with default values or NULL on failure.
3213  * @see avcodec_get_context_defaults
3214  *
3215  * @deprecated use avcodec_alloc_context3()
3216  */
3217 attribute_deprecated
3218 AVCodecContext *avcodec_alloc_context(void);
3219 
3220 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3221  *  we WILL change its arguments and name a few times! */
3222 attribute_deprecated
3223 AVCodecContext *avcodec_alloc_context2(enum AVMediaType);
3224 
3225 /**
3226  * Set the fields of the given AVCodecContext to default values.
3227  *
3228  * @param s The AVCodecContext of which the fields should be set to default values.
3229  * @deprecated use avcodec_get_context_defaults3
3230  */
3231 attribute_deprecated
3232 void avcodec_get_context_defaults(AVCodecContext *s);
3233 
3234 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3235  *  we WILL change its arguments and name a few times! */
3236 attribute_deprecated
3237 void avcodec_get_context_defaults2(AVCodecContext *s, enum AVMediaType);
3238 #endif
3239 
3240 /**
3241  * Allocate an AVCodecContext and set its fields to default values.  The
3242  * resulting struct can be deallocated by calling avcodec_close() on it followed
3243  * by av_free().
3244  *
3245  * @param codec if non-NULL, allocate private data and initialize defaults
3246  *              for the given codec. It is illegal to then call avcodec_open2()
3247  *              with a different codec.
3248  *              If NULL, then the codec-specific defaults won't be initialized,
3249  *              which may result in suboptimal default settings (this is
3250  *              important mainly for encoders, e.g. libx264).
3251  *
3252  * @return An AVCodecContext filled with default values or NULL on failure.
3253  * @see avcodec_get_context_defaults
3254  */
3255 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
3256 
3257 /**
3258  * Set the fields of the given AVCodecContext to default values corresponding
3259  * to the given codec (defaults may be codec-dependent).
3260  *
3261  * Do not call this function if a non-NULL codec has been passed
3262  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3263  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3264  * different codec on this AVCodecContext.
3265  */
3266 int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec);
3267 
3268 /**
3269  * Get the AVClass for AVCodecContext. It can be used in combination with
3270  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3271  *
3272  * @see av_opt_find().
3273  */
3274 const AVClass *avcodec_get_class(void);
3275 
3276 /**
3277  * Get the AVClass for AVFrame. It can be used in combination with
3278  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3279  *
3280  * @see av_opt_find().
3281  */
3282 const AVClass *avcodec_get_frame_class(void);
3283 
3284 /**
3285  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3286  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3287  *
3288  * @see av_opt_find().
3289  */
3290 const AVClass *avcodec_get_subtitle_rect_class(void);
3291 
3292 /**
3293  * Copy the settings of the source AVCodecContext into the destination
3294  * AVCodecContext. The resulting destination codec context will be
3295  * unopened, i.e. you are required to call avcodec_open2() before you
3296  * can use this AVCodecContext to decode/encode video/audio data.
3297  *
3298  * @param dest target codec context, should be initialized with
3299  *             avcodec_alloc_context3(), but otherwise uninitialized
3300  * @param src source codec context
3301  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3302  */
3303 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
3304 
3305 /**
3306  * Allocate an AVFrame and set its fields to default values.  The resulting
3307  * struct must be freed using avcodec_free_frame().
3308  *
3309  * @return An AVFrame filled with default values or NULL on failure.
3310  * @see avcodec_get_frame_defaults
3311  */
3312 AVFrame *avcodec_alloc_frame(void);
3313 
3314 /**
3315  * Set the fields of the given AVFrame to default values.
3316  *
3317  * @param frame The AVFrame of which the fields should be set to default values.
3318  */
3319 void avcodec_get_frame_defaults(AVFrame *frame);
3320 
3321 /**
3322  * Free the frame and any dynamically allocated objects in it,
3323  * e.g. extended_data.
3324  *
3325  * @param frame frame to be freed. The pointer will be set to NULL.
3326  *
3327  * @warning this function does NOT free the data buffers themselves
3328  * (it does not know how, since they might have been allocated with
3329  *  a custom get_buffer()).
3330  */
3331 void avcodec_free_frame(AVFrame **frame);
3332 
3333 #if FF_API_AVCODEC_OPEN
3334 /**
3335  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3336  * function the context has to be allocated.
3337  *
3338  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3339  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3340  * retrieving a codec.
3341  *
3342  * @warning This function is not thread safe!
3343  *
3344  * @code
3345  * avcodec_register_all();
3346  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3347  * if (!codec)
3348  *     exit(1);
3349  *
3350  * context = avcodec_alloc_context3(codec);
3351  *
3352  * if (avcodec_open(context, codec) < 0)
3353  *     exit(1);
3354  * @endcode
3355  *
3356  * @param avctx The context which will be set up to use the given codec.
3357  * @param codec The codec to use within the context.
3358  * @return zero on success, a negative value on error
3359  * @see avcodec_alloc_context3, avcodec_find_decoder, avcodec_find_encoder, avcodec_close
3360  *
3361  * @deprecated use avcodec_open2
3362  */
3363 attribute_deprecated
3364 int avcodec_open(AVCodecContext *avctx, AVCodec *codec);
3365 #endif
3366 
3367 /**
3368  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3369  * function the context has to be allocated with avcodec_alloc_context3().
3370  *
3371  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3372  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3373  * retrieving a codec.
3374  *
3375  * @warning This function is not thread safe!
3376  *
3377  * @code
3378  * avcodec_register_all();
3379  * av_dict_set(&opts, "b", "2.5M", 0);
3380  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3381  * if (!codec)
3382  *     exit(1);
3383  *
3384  * context = avcodec_alloc_context3(codec);
3385  *
3386  * if (avcodec_open2(context, codec, opts) < 0)
3387  *     exit(1);
3388  * @endcode
3389  *
3390  * @param avctx The context to initialize.
3391  * @param codec The codec to open this context for. If a non-NULL codec has been
3392  *              previously passed to avcodec_alloc_context3() or
3393  *              avcodec_get_context_defaults3() for this context, then this
3394  *              parameter MUST be either NULL or equal to the previously passed
3395  *              codec.
3396  * @param options A dictionary filled with AVCodecContext and codec-private options.
3397  *                On return this object will be filled with options that were not found.
3398  *
3399  * @return zero on success, a negative value on error
3400  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3401  *      av_dict_set(), av_opt_find().
3402  */
3403 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3404 
3405 /**
3406  * Close a given AVCodecContext and free all the data associated with it
3407  * (but not the AVCodecContext itself).
3408  *
3409  * Calling this function on an AVCodecContext that hasn't been opened will free
3410  * the codec-specific data allocated in avcodec_alloc_context3() /
3411  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3412  * do nothing.
3413  */
3414 int avcodec_close(AVCodecContext *avctx);
3415 
3416 /**
3417  * Free all allocated data in the given subtitle struct.
3418  *
3419  * @param sub AVSubtitle to free.
3420  */
3421 void avsubtitle_free(AVSubtitle *sub);
3422 
3423 /**
3424  * @}
3425  */
3426 
3427 /**
3428  * @addtogroup lavc_packet
3429  * @{
3430  */
3431 
3432 #if FF_API_DESTRUCT_PACKET
3433 /**
3434  * Default packet destructor.
3435  * @deprecated use the AVBuffer API instead
3436  */
3437 attribute_deprecated
3438 void av_destruct_packet(AVPacket *pkt);
3439 #endif
3440 
3441 /**
3442  * Initialize optional fields of a packet with default values.
3443  *
3444  * Note, this does not touch the data and size members, which have to be
3445  * initialized separately.
3446  *
3447  * @param pkt packet
3448  */
3449 void av_init_packet(AVPacket *pkt);
3450 
3451 /**
3452  * Allocate the payload of a packet and initialize its fields with
3453  * default values.
3454  *
3455  * @param pkt packet
3456  * @param size wanted payload size
3457  * @return 0 if OK, AVERROR_xxx otherwise
3458  */
3459 int av_new_packet(AVPacket *pkt, int size);
3460 
3461 /**
3462  * Reduce packet size, correctly zeroing padding
3463  *
3464  * @param pkt packet
3465  * @param size new size
3466  */
3467 void av_shrink_packet(AVPacket *pkt, int size);
3468 
3469 /**
3470  * Increase packet size, correctly zeroing padding
3471  *
3472  * @param pkt packet
3473  * @param grow_by number of bytes by which to increase the size of the packet
3474  */
3475 int av_grow_packet(AVPacket *pkt, int grow_by);
3476 
3477 /**
3478  * Initialize a reference-counted packet from av_malloc()ed data.
3479  *
3480  * @param pkt packet to be initialized. This function will set the data, size,
3481  *        buf and destruct fields, all others are left untouched.
3482  * @param data Data allocated by av_malloc() to be used as packet data. If this
3483  *        function returns successfully, the data is owned by the underlying AVBuffer.
3484  *        The caller may not access the data through other means.
3485  * @param size size of data in bytes, without the padding. I.e. the full buffer
3486  *        size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3487  *
3488  * @return 0 on success, a negative AVERROR on error
3489  */
3490 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size);
3491 
3492 /**
3493  * @warning This is a hack - the packet memory allocation stuff is broken. The
3494  * packet is allocated if it was not really allocated.
3495  */
3496 int av_dup_packet(AVPacket *pkt);
3497 
3498 /**
3499  * Copy packet, including contents
3500  *
3501  * @return 0 on success, negative AVERROR on fail
3502  */
3503 int av_copy_packet(AVPacket *dst, AVPacket *src);
3504 
3505 /**
3506  * Copy packet side data
3507  *
3508  * @return 0 on success, negative AVERROR on fail
3509  */
3510 int av_copy_packet_side_data(AVPacket *dst, AVPacket *src);
3511 
3512 /**
3513  * Free a packet.
3514  *
3515  * @param pkt packet to free
3516  */
3517 void av_free_packet(AVPacket *pkt);
3518 
3519 /**
3520  * Allocate new information of a packet.
3521  *
3522  * @param pkt packet
3523  * @param type side information type
3524  * @param size side information size
3525  * @return pointer to fresh allocated data or NULL otherwise
3526  */
3527 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3528                                  int size);
3529 
3530 /**
3531  * Shrink the already allocated side data buffer
3532  *
3533  * @param pkt packet
3534  * @param type side information type
3535  * @param size new side information size
3536  * @return 0 on success, < 0 on failure
3537  */
3538 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3539                                int size);
3540 
3541 /**
3542  * Get side information from packet.
3543  *
3544  * @param pkt packet
3545  * @param type desired side information type
3546  * @param size pointer for side information size to store (optional)
3547  * @return pointer to data if present or NULL otherwise
3548  */
3549 uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3550                                  int *size);
3551 
3552 int av_packet_merge_side_data(AVPacket *pkt);
3553 
3554 int av_packet_split_side_data(AVPacket *pkt);
3555 
3556 
3557 /**
3558  * @}
3559  */
3560 
3561 /**
3562  * @addtogroup lavc_decoding
3563  * @{
3564  */
3565 
3566 /**
3567  * Find a registered decoder with a matching codec ID.
3568  *
3569  * @param id AVCodecID of the requested decoder
3570  * @return A decoder if one was found, NULL otherwise.
3571  */
3572 AVCodec *avcodec_find_decoder(enum AVCodecID id);
3573 
3574 /**
3575  * Find a registered decoder with the specified name.
3576  *
3577  * @param name name of the requested decoder
3578  * @return A decoder if one was found, NULL otherwise.
3579  */
3580 AVCodec *avcodec_find_decoder_by_name(const char *name);
3581 
3582 #if FF_API_GET_BUFFER
3583 attribute_deprecated int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
3584 attribute_deprecated void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
3585 attribute_deprecated int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
3586 #endif
3587 
3588 /**
3589  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3590  * it can be called by custom get_buffer2() implementations for decoders without
3591  * CODEC_CAP_DR1 set.
3592  */
3593 int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags);
3594 
3595 /**
3596  * Return the amount of padding in pixels which the get_buffer callback must
3597  * provide around the edge of the image for codecs which do not have the
3598  * CODEC_FLAG_EMU_EDGE flag.
3599  *
3600  * @return Required padding in pixels.
3601  */
3602 unsigned avcodec_get_edge_width(void);
3603 
3604 /**
3605  * Modify width and height values so that they will result in a memory
3606  * buffer that is acceptable for the codec if you do not use any horizontal
3607  * padding.
3608  *
3609  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3610  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3611  * according to avcodec_get_edge_width() before.
3612  */
3613 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
3614 
3615 /**
3616  * Modify width and height values so that they will result in a memory
3617  * buffer that is acceptable for the codec if you also ensure that all
3618  * line sizes are a multiple of the respective linesize_align[i].
3619  *
3620  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3621  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3622  * according to avcodec_get_edge_width() before.
3623  */
3624 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
3625                                int linesize_align[AV_NUM_DATA_POINTERS]);
3626 
3627 #if FF_API_OLD_DECODE_AUDIO
3628 /**
3629  * Wrapper function which calls avcodec_decode_audio4.
3630  *
3631  * @deprecated Use avcodec_decode_audio4 instead.
3632  *
3633  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3634  * Some decoders may support multiple frames in a single AVPacket, such
3635  * decoders would then just decode the first frame. In this case,
3636  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3637  * the remaining data in order to decode the second frame etc.
3638  * If no frame
3639  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3640  * decompressed frame size in bytes.
3641  *
3642  * @warning You must set frame_size_ptr to the allocated size of the
3643  * output buffer before calling avcodec_decode_audio3().
3644  *
3645  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3646  * the actual read bytes because some optimized bitstream readers read 32 or 64
3647  * bits at once and could read over the end.
3648  *
3649  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3650  * no overreading happens for damaged MPEG streams.
3651  *
3652  * @warning You must not provide a custom get_buffer() when using
3653  * avcodec_decode_audio3().  Doing so will override it with
3654  * avcodec_default_get_buffer.  Use avcodec_decode_audio4() instead,
3655  * which does allow the application to provide a custom get_buffer().
3656  *
3657  * @note You might have to align the input buffer avpkt->data and output buffer
3658  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3659  * necessary at all, on others it won't work at all if not aligned and on others
3660  * it will work but it will have an impact on performance.
3661  *
3662  * In practice, avpkt->data should have 4 byte alignment at minimum and
3663  * samples should be 16 byte aligned unless the CPU doesn't need it
3664  * (AltiVec and SSE do).
3665  *
3666  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3667  * between input and output, these need to be fed with avpkt->data=NULL,
3668  * avpkt->size=0 at the end to return the remaining frames.
3669  *
3670  * @param avctx the codec context
3671  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3672  *                     If the sample format is planar, each channel plane will
3673  *                     be the same size, with no padding between channels.
3674  * @param[in,out] frame_size_ptr the output buffer size in bytes
3675  * @param[in] avpkt The input AVPacket containing the input buffer.
3676  *            You can create such packet with av_init_packet() and by then setting
3677  *            data and size, some decoders might in addition need other fields.
3678  *            All decoders are designed to use the least fields possible though.
3679  * @return On error a negative value is returned, otherwise the number of bytes
3680  * used or zero if no frame data was decompressed (used) from the input AVPacket.
3681  */
3682 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3683                          int *frame_size_ptr,
3684                          AVPacket *avpkt);
3685 #endif
3686 
3687 /**
3688  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3689  *
3690  * Some decoders may support multiple frames in a single AVPacket. Such
3691  * decoders would then just decode the first frame. In this case,
3692  * avcodec_decode_audio4 has to be called again with an AVPacket containing
3693  * the remaining data in order to decode the second frame, etc...
3694  * Even if no frames are returned, the packet needs to be fed to the decoder
3695  * with remaining data until it is completely consumed or an error occurs.
3696  *
3697  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3698  *          larger than the actual read bytes because some optimized bitstream
3699  *          readers read 32 or 64 bits at once and could read over the end.
3700  *
3701  * @note You might have to align the input buffer. The alignment requirements
3702  *       depend on the CPU and the decoder.
3703  *
3704  * @param      avctx the codec context
3705  * @param[out] frame The AVFrame in which to store decoded audio samples.
3706  *                   The decoder will allocate a buffer for the decoded frame by
3707  *                   calling the AVCodecContext.get_buffer2() callback.
3708  *                   When AVCodecContext.refcounted_frames is set to 1, the frame is
3709  *                   reference counted and the returned reference belongs to the
3710  *                   caller. The caller must release the frame using av_frame_unref()
3711  *                   when the frame is no longer needed. The caller may safely write
3712  *                   to the frame if av_frame_is_writable() returns 1.
3713  *                   When AVCodecContext.refcounted_frames is set to 0, the returned
3714  *                   reference belongs to the decoder and is valid only until the
3715  *                   next call to this function or until closing the decoder.
3716  *                   The caller may not write to it.
3717  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
3718  *                           non-zero.
3719  * @param[in]  avpkt The input AVPacket containing the input buffer.
3720  *                   At least avpkt->data and avpkt->size should be set. Some
3721  *                   decoders might also require additional fields to be set.
3722  * @return A negative error code is returned if an error occurred during
3723  *         decoding, otherwise the number of bytes consumed from the input
3724  *         AVPacket is returned.
3725  */
3726 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
3727                           int *got_frame_ptr, const AVPacket *avpkt);
3728 
3729 /**
3730  * Decode the video frame of size avpkt->size from avpkt->data into picture.
3731  * Some decoders may support multiple frames in a single AVPacket, such
3732  * decoders would then just decode the first frame.
3733  *
3734  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3735  * the actual read bytes because some optimized bitstream readers read 32 or 64
3736  * bits at once and could read over the end.
3737  *
3738  * @warning The end of the input buffer buf should be set to 0 to ensure that
3739  * no overreading happens for damaged MPEG streams.
3740  *
3741  * @note You might have to align the input buffer avpkt->data.
3742  * The alignment requirements depend on the CPU: on some CPUs it isn't
3743  * necessary at all, on others it won't work at all if not aligned and on others
3744  * it will work but it will have an impact on performance.
3745  *
3746  * In practice, avpkt->data should have 4 byte alignment at minimum.
3747  *
3748  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3749  * between input and output, these need to be fed with avpkt->data=NULL,
3750  * avpkt->size=0 at the end to return the remaining frames.
3751  *
3752  * @param avctx the codec context
3753  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3754  *             Use av_frame_alloc() to get an AVFrame. The codec will
3755  *             allocate memory for the actual bitmap by calling the
3756  *             AVCodecContext.get_buffer2() callback.
3757  *             When AVCodecContext.refcounted_frames is set to 1, the frame is
3758  *             reference counted and the returned reference belongs to the
3759  *             caller. The caller must release the frame using av_frame_unref()
3760  *             when the frame is no longer needed. The caller may safely write
3761  *             to the frame if av_frame_is_writable() returns 1.
3762  *             When AVCodecContext.refcounted_frames is set to 0, the returned
3763  *             reference belongs to the decoder and is valid only until the
3764  *             next call to this function or until closing the decoder. The
3765  *             caller may not write to it.
3766  *
3767  * @param[in] avpkt The input AVpacket containing the input buffer.
3768  *            You can create such packet with av_init_packet() and by then setting
3769  *            data and size, some decoders might in addition need other fields like
3770  *            flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
3771  *            fields possible.
3772  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3773  * @return On error a negative value is returned, otherwise the number of bytes
3774  * used or zero if no frame could be decompressed.
3775  */
3776 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
3777                          int *got_picture_ptr,
3778                          const AVPacket *avpkt);
3779 
3780 /**
3781  * Decode a subtitle message.
3782  * Return a negative value on error, otherwise return the number of bytes used.
3783  * If no subtitle could be decompressed, got_sub_ptr is zero.
3784  * Otherwise, the subtitle is stored in *sub.
3785  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
3786  * simplicity, because the performance difference is expect to be negligible
3787  * and reusing a get_buffer written for video codecs would probably perform badly
3788  * due to a potentially very different allocation pattern.
3789  *
3790  * @param avctx the codec context
3791  * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
3792                    freed with avsubtitle_free if *got_sub_ptr is set.
3793  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3794  * @param[in] avpkt The input AVPacket containing the input buffer.
3795  */
3796 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
3797                             int *got_sub_ptr,
3798                             AVPacket *avpkt);
3799 
3800 /**
3801  * @defgroup lavc_parsing Frame parsing
3802  * @{
3803  */
3804 
3805 enum AVPictureStructure {
3806     AV_PICTURE_STRUCTURE_UNKNOWN,      //< unknown
3807     AV_PICTURE_STRUCTURE_TOP_FIELD,    //< coded as top field
3808     AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
3809     AV_PICTURE_STRUCTURE_FRAME,        //< coded as frame
3810 };
3811 
3812 typedef struct AVCodecParserContext {
3813     void *priv_data;
3814     struct AVCodecParser *parser;
3815     int64_t frame_offset; /* offset of the current frame */
3816     int64_t cur_offset; /* current offset
3817                            (incremented by each av_parser_parse()) */
3818     int64_t next_frame_offset; /* offset of the next frame */
3819     /* video info */
3820     int pict_type; /* XXX: Put it back in AVCodecContext. */
3821     /**
3822      * This field is used for proper frame duration computation in lavf.
3823      * It signals, how much longer the frame duration of the current frame
3824      * is compared to normal frame duration.
3825      *
3826      * frame_duration = (1 + repeat_pict) * time_base
3827      *
3828      * It is used by codecs like H.264 to display telecined material.
3829      */
3830     int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3831     int64_t pts;     /* pts of the current frame */
3832     int64_t dts;     /* dts of the current frame */
3833 
3834     /* private data */
3835     int64_t last_pts;
3836     int64_t last_dts;
3837     int fetch_timestamp;
3838 
3839 #define AV_PARSER_PTS_NB 4
3840     int cur_frame_start_index;
3841     int64_t cur_frame_offset[AV_PARSER_PTS_NB];
3842     int64_t cur_frame_pts[AV_PARSER_PTS_NB];
3843     int64_t cur_frame_dts[AV_PARSER_PTS_NB];
3844 
3845     int flags;
3846 #define PARSER_FLAG_COMPLETE_FRAMES           0x0001
3847 #define PARSER_FLAG_ONCE                      0x0002
3848 /// Set if the parser has a valid file offset
3849 #define PARSER_FLAG_FETCHED_OFFSET            0x0004
3850 #define PARSER_FLAG_USE_CODEC_TS              0x1000
3851 
3852     int64_t offset;      ///< byte offset from starting packet start
3853     int64_t cur_frame_end[AV_PARSER_PTS_NB];
3854 
3855     /**
3856      * Set by parser to 1 for key frames and 0 for non-key frames.
3857      * It is initialized to -1, so if the parser doesn't set this flag,
3858      * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3859      * will be used.
3860      */
3861     int key_frame;
3862 
3863     /**
3864      * Time difference in stream time base units from the pts of this
3865      * packet to the point at which the output from the decoder has converged
3866      * independent from the availability of previous frames. That is, the
3867      * frames are virtually identical no matter if decoding started from
3868      * the very first frame or from this keyframe.
3869      * Is AV_NOPTS_VALUE if unknown.
3870      * This field is not the display duration of the current frame.
3871      * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
3872      * set.
3873      *
3874      * The purpose of this field is to allow seeking in streams that have no
3875      * keyframes in the conventional sense. It corresponds to the
3876      * recovery point SEI in H.264 and match_time_delta in NUT. It is also
3877      * essential for some types of subtitle streams to ensure that all
3878      * subtitles are correctly displayed after seeking.
3879      */
3880     int64_t convergence_duration;
3881 
3882     // Timestamp generation support:
3883     /**
3884      * Synchronization point for start of timestamp generation.
3885      *
3886      * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3887      * (default).
3888      *
3889      * For example, this corresponds to presence of H.264 buffering period
3890      * SEI message.
3891      */
3892     int dts_sync_point;
3893 
3894     /**
3895      * Offset of the current timestamp against last timestamp sync point in
3896      * units of AVCodecContext.time_base.
3897      *
3898      * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3899      * contain a valid timestamp offset.
3900      *
3901      * Note that the timestamp of sync point has usually a nonzero
3902      * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3903      * the next frame after timestamp sync point will be usually 1.
3904      *
3905      * For example, this corresponds to H.264 cpb_removal_delay.
3906      */
3907     int dts_ref_dts_delta;
3908 
3909     /**
3910      * Presentation delay of current frame in units of AVCodecContext.time_base.
3911      *
3912      * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3913      * contain valid non-negative timestamp delta (presentation time of a frame
3914      * must not lie in the past).
3915      *
3916      * This delay represents the difference between decoding and presentation
3917      * time of the frame.
3918      *
3919      * For example, this corresponds to H.264 dpb_output_delay.
3920      */
3921     int pts_dts_delta;
3922 
3923     /**
3924      * Position of the packet in file.
3925      *
3926      * Analogous to cur_frame_pts/dts
3927      */
3928     int64_t cur_frame_pos[AV_PARSER_PTS_NB];
3929 
3930     /**
3931      * Byte position of currently parsed frame in stream.
3932      */
3933     int64_t pos;
3934 
3935     /**
3936      * Previous frame byte position.
3937      */
3938     int64_t last_pos;
3939 
3940     /**
3941      * Duration of the current frame.
3942      * For audio, this is in units of 1 / AVCodecContext.sample_rate.
3943      * For all other types, this is in units of AVCodecContext.time_base.
3944      */
3945     int duration;
3946 
3947     enum AVFieldOrder field_order;
3948 
3949     /**
3950      * Indicate whether a picture is coded as a frame, top field or bottom field.
3951      *
3952      * For example, H.264 field_pic_flag equal to 0 corresponds to
3953      * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
3954      * equal to 1 and bottom_field_flag equal to 0 corresponds to
3955      * AV_PICTURE_STRUCTURE_TOP_FIELD.
3956      */
3957     enum AVPictureStructure picture_structure;
3958 } AVCodecParserContext;
3959 
3960 typedef struct AVCodecParser {
3961     int codec_ids[5]; /* several codec IDs are permitted */
3962     int priv_data_size;
3963     int (*parser_init)(AVCodecParserContext *s);
3964     int (*parser_parse)(AVCodecParserContext *s,
3965                         AVCodecContext *avctx,
3966                         const uint8_t **poutbuf, int *poutbuf_size,
3967                         const uint8_t *buf, int buf_size);
3968     void (*parser_close)(AVCodecParserContext *s);
3969     int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
3970     struct AVCodecParser *next;
3971 } AVCodecParser;
3972 
3973 AVCodecParser *av_parser_next(AVCodecParser *c);
3974 
3975 void av_register_codec_parser(AVCodecParser *parser);
3976 AVCodecParserContext *av_parser_init(int codec_id);
3977 
3978 /**
3979  * Parse a packet.
3980  *
3981  * @param s             parser context.
3982  * @param avctx         codec context.
3983  * @param poutbuf       set to pointer to parsed buffer or NULL if not yet finished.
3984  * @param poutbuf_size  set to size of parsed buffer or zero if not yet finished.
3985  * @param buf           input buffer.
3986  * @param buf_size      input length, to signal EOF, this should be 0 (so that the last frame can be output).
3987  * @param pts           input presentation timestamp.
3988  * @param dts           input decoding timestamp.
3989  * @param pos           input byte position in stream.
3990  * @return the number of bytes of the input bitstream used.
3991  *
3992  * Example:
3993  * @code
3994  *   while(in_len){
3995  *       len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3996  *                                        in_data, in_len,
3997  *                                        pts, dts, pos);
3998  *       in_data += len;
3999  *       in_len  -= len;
4000  *
4001  *       if(size)
4002  *          decode_frame(data, size);
4003  *   }
4004  * @endcode
4005  */
4006 int av_parser_parse2(AVCodecParserContext *s,
4007                      AVCodecContext *avctx,
4008                      uint8_t **poutbuf, int *poutbuf_size,
4009                      const uint8_t *buf, int buf_size,
4010                      int64_t pts, int64_t dts,
4011                      int64_t pos);
4012 
4013 /**
4014  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4015  * @deprecated use AVBitStreamFilter
4016  */
4017 int av_parser_change(AVCodecParserContext *s,
4018                      AVCodecContext *avctx,
4019                      uint8_t **poutbuf, int *poutbuf_size,
4020                      const uint8_t *buf, int buf_size, int keyframe);
4021 void av_parser_close(AVCodecParserContext *s);
4022 
4023 /**
4024  * @}
4025  * @}
4026  */
4027 
4028 /**
4029  * @addtogroup lavc_encoding
4030  * @{
4031  */
4032 
4033 /**
4034  * Find a registered encoder with a matching codec ID.
4035  *
4036  * @param id AVCodecID of the requested encoder
4037  * @return An encoder if one was found, NULL otherwise.
4038  */
4039 AVCodec *avcodec_find_encoder(enum AVCodecID id);
4040 
4041 /**
4042  * Find a registered encoder with the specified name.
4043  *
4044  * @param name name of the requested encoder
4045  * @return An encoder if one was found, NULL otherwise.
4046  */
4047 AVCodec *avcodec_find_encoder_by_name(const char *name);
4048 
4049 #if FF_API_OLD_ENCODE_AUDIO
4050 /**
4051  * Encode an audio frame from samples into buf.
4052  *
4053  * @deprecated Use avcodec_encode_audio2 instead.
4054  *
4055  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4056  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4057  * will know how much space is needed because it depends on the value passed
4058  * in buf_size as described below. In that case a lower value can be used.
4059  *
4060  * @param avctx the codec context
4061  * @param[out] buf the output buffer
4062  * @param[in] buf_size the output buffer size
4063  * @param[in] samples the input buffer containing the samples
4064  * The number of samples read from this buffer is frame_size*channels,
4065  * both of which are defined in avctx.
4066  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4067  * samples read from samples is equal to:
4068  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4069  * This also implies that av_get_bits_per_sample() must not return 0 for these
4070  * codecs.
4071  * @return On error a negative value is returned, on success zero or the number
4072  * of bytes used to encode the data read from the input buffer.
4073  */
4074 int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
4075                                               uint8_t *buf, int buf_size,
4076                                               const short *samples);
4077 #endif
4078 
4079 /**
4080  * Encode a frame of audio.
4081  *
4082  * Takes input samples from frame and writes the next output packet, if
4083  * available, to avpkt. The output packet does not necessarily contain data for
4084  * the most recent frame, as encoders can delay, split, and combine input frames
4085  * internally as needed.
4086  *
4087  * @param avctx     codec context
4088  * @param avpkt     output AVPacket.
4089  *                  The user can supply an output buffer by setting
4090  *                  avpkt->data and avpkt->size prior to calling the
4091  *                  function, but if the size of the user-provided data is not
4092  *                  large enough, encoding will fail. If avpkt->data and
4093  *                  avpkt->size are set, avpkt->destruct must also be set. All
4094  *                  other AVPacket fields will be reset by the encoder using
4095  *                  av_init_packet(). If avpkt->data is NULL, the encoder will
4096  *                  allocate it. The encoder will set avpkt->size to the size
4097  *                  of the output packet.
4098  *
4099  *                  If this function fails or produces no output, avpkt will be
4100  *                  freed using av_free_packet() (i.e. avpkt->destruct will be
4101  *                  called to free the user supplied buffer).
4102  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4103  *                  May be NULL when flushing an encoder that has the
4104  *                  CODEC_CAP_DELAY capability set.
4105  *                  If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4106  *                  can have any number of samples.
4107  *                  If it is not set, frame->nb_samples must be equal to
4108  *                  avctx->frame_size for all frames except the last.
4109  *                  The final frame may be smaller than avctx->frame_size.
4110  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4111  *                            output packet is non-empty, and to 0 if it is
4112  *                            empty. If the function returns an error, the
4113  *                            packet can be assumed to be invalid, and the
4114  *                            value of got_packet_ptr is undefined and should
4115  *                            not be used.
4116  * @return          0 on success, negative error code on failure
4117  */
4118 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4119                           const AVFrame *frame, int *got_packet_ptr);
4120 
4121 #if FF_API_OLD_ENCODE_VIDEO
4122 /**
4123  * @deprecated use avcodec_encode_video2() instead.
4124  *
4125  * Encode a video frame from pict into buf.
4126  * The input picture should be
4127  * stored using a specific format, namely avctx.pix_fmt.
4128  *
4129  * @param avctx the codec context
4130  * @param[out] buf the output buffer for the bitstream of encoded frame
4131  * @param[in] buf_size the size of the output buffer in bytes
4132  * @param[in] pict the input picture to encode
4133  * @return On error a negative value is returned, on success zero or the number
4134  * of bytes used from the output buffer.
4135  */
4136 attribute_deprecated
4137 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4138                          const AVFrame *pict);
4139 #endif
4140 
4141 /**
4142  * Encode a frame of video.
4143  *
4144  * Takes input raw video data from frame and writes the next output packet, if
4145  * available, to avpkt. The output packet does not necessarily contain data for
4146  * the most recent frame, as encoders can delay and reorder input frames
4147  * internally as needed.
4148  *
4149  * @param avctx     codec context
4150  * @param avpkt     output AVPacket.
4151  *                  The user can supply an output buffer by setting
4152  *                  avpkt->data and avpkt->size prior to calling the
4153  *                  function, but if the size of the user-provided data is not
4154  *                  large enough, encoding will fail. All other AVPacket fields
4155  *                  will be reset by the encoder using av_init_packet(). If
4156  *                  avpkt->data is NULL, the encoder will allocate it.
4157  *                  The encoder will set avpkt->size to the size of the
4158  *                  output packet. The returned data (if any) belongs to the
4159  *                  caller, he is responsible for freeing it.
4160  *
4161  *                  If this function fails or produces no output, avpkt will be
4162  *                  freed using av_free_packet() (i.e. avpkt->destruct will be
4163  *                  called to free the user supplied buffer).
4164  * @param[in] frame AVFrame containing the raw video data to be encoded.
4165  *                  May be NULL when flushing an encoder that has the
4166  *                  CODEC_CAP_DELAY capability set.
4167  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4168  *                            output packet is non-empty, and to 0 if it is
4169  *                            empty. If the function returns an error, the
4170  *                            packet can be assumed to be invalid, and the
4171  *                            value of got_packet_ptr is undefined and should
4172  *                            not be used.
4173  * @return          0 on success, negative error code on failure
4174  */
4175 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4176                           const AVFrame *frame, int *got_packet_ptr);
4177 
4178 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4179                             const AVSubtitle *sub);
4180 
4181 
4182 /**
4183  * @}
4184  */
4185 
4186 #if FF_API_AVCODEC_RESAMPLE
4187 /**
4188  * @defgroup lavc_resample Audio resampling
4189  * @ingroup libavc
4190  * @deprecated use libswresample instead
4191  *
4192  * @{
4193  */
4194 struct ReSampleContext;
4195 struct AVResampleContext;
4196 
4197 typedef struct ReSampleContext ReSampleContext;
4198 
4199 /**
4200  *  Initialize audio resampling context.
4201  *
4202  * @param output_channels  number of output channels
4203  * @param input_channels   number of input channels
4204  * @param output_rate      output sample rate
4205  * @param input_rate       input sample rate
4206  * @param sample_fmt_out   requested output sample format
4207  * @param sample_fmt_in    input sample format
4208  * @param filter_length    length of each FIR filter in the filterbank relative to the cutoff frequency
4209  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4210  * @param linear           if 1 then the used FIR filter will be linearly interpolated
4211                            between the 2 closest, if 0 the closest will be used
4212  * @param cutoff           cutoff frequency, 1.0 corresponds to half the output sampling rate
4213  * @return allocated ReSampleContext, NULL if error occurred
4214  */
4215 attribute_deprecated
4216 ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
4217                                         int output_rate, int input_rate,
4218                                         enum AVSampleFormat sample_fmt_out,
4219                                         enum AVSampleFormat sample_fmt_in,
4220                                         int filter_length, int log2_phase_count,
4221                                         int linear, double cutoff);
4222 
4223 attribute_deprecated
4224 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4225 
4226 /**
4227  * Free resample context.
4228  *
4229  * @param s a non-NULL pointer to a resample context previously
4230  *          created with av_audio_resample_init()
4231  */
4232 attribute_deprecated
4233 void audio_resample_close(ReSampleContext *s);
4234 
4235 
4236 /**
4237  * Initialize an audio resampler.
4238  * Note, if either rate is not an integer then simply scale both rates up so they are.
4239  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4240  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4241  * @param linear If 1 then the used FIR filter will be linearly interpolated
4242                  between the 2 closest, if 0 the closest will be used
4243  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4244  */
4245 attribute_deprecated
4246 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4247 
4248 /**
4249  * Resample an array of samples using a previously configured context.
4250  * @param src an array of unconsumed samples
4251  * @param consumed the number of samples of src which have been consumed are returned here
4252  * @param src_size the number of unconsumed samples available
4253  * @param dst_size the amount of space in samples available in dst
4254  * @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
4255  * @return the number of samples written in dst or -1 if an error occurred
4256  */
4257 attribute_deprecated
4258 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4259 
4260 
4261 /**
4262  * Compensate samplerate/timestamp drift. The compensation is done by changing
4263  * the resampler parameters, so no audible clicks or similar distortions occur
4264  * @param compensation_distance distance in output samples over which the compensation should be performed
4265  * @param sample_delta number of output samples which should be output less
4266  *
4267  * example: av_resample_compensate(c, 10, 500)
4268  * here instead of 510 samples only 500 samples would be output
4269  *
4270  * note, due to rounding the actual compensation might be slightly different,
4271  * especially if the compensation_distance is large and the in_rate used during init is small
4272  */
4273 attribute_deprecated
4274 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4275 attribute_deprecated
4276 void av_resample_close(struct AVResampleContext *c);
4277 
4278 /**
4279  * @}
4280  */
4281 #endif
4282 
4283 /**
4284  * @addtogroup lavc_picture
4285  * @{
4286  */
4287 
4288 /**
4289  * Allocate memory for a picture.  Call avpicture_free() to free it.
4290  *
4291  * @see avpicture_fill()
4292  *
4293  * @param picture the picture to be filled in
4294  * @param pix_fmt the format of the picture
4295  * @param width the width of the picture
4296  * @param height the height of the picture
4297  * @return zero if successful, a negative value if not
4298  */
4299 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4300 
4301 /**
4302  * Free a picture previously allocated by avpicture_alloc().
4303  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4304  * itself is not.
4305  *
4306  * @param picture the AVPicture to be freed
4307  */
4308 void avpicture_free(AVPicture *picture);
4309 
4310 /**
4311  * Fill in the AVPicture fields, always assume a linesize alignment of
4312  * 1.
4313  *
4314  * @see av_image_fill_arrays()
4315  */
4316 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4317                    enum AVPixelFormat pix_fmt, int width, int height);
4318 
4319 /**
4320  * Copy pixel data from an AVPicture into a buffer, always assume a
4321  * linesize alignment of 1.
4322  *
4323  * @see av_image_copy_to_buffer()
4324  */
4325 int avpicture_layout(const AVPicture* src, enum AVPixelFormat pix_fmt,
4326                      int width, int height,
4327                      unsigned char *dest, int dest_size);
4328 
4329 /**
4330  * Calculate the size in bytes that a picture of the given width and height
4331  * would occupy if stored in the given picture format.
4332  * Always assume a linesize alignment of 1.
4333  *
4334  * @see av_image_get_buffer_size().
4335  */
4336 int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
4337 
4338 #if FF_API_DEINTERLACE
4339 /**
4340  *  deinterlace - if not supported return -1
4341  *
4342  * @deprecated - use yadif (in libavfilter) instead
4343  */
4344 attribute_deprecated
4345 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4346                           enum AVPixelFormat pix_fmt, int width, int height);
4347 #endif
4348 /**
4349  * Copy image src to dst. Wraps av_image_copy().
4350  */
4351 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4352                      enum AVPixelFormat pix_fmt, int width, int height);
4353 
4354 /**
4355  * Crop image top and left side.
4356  */
4357 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4358                     enum AVPixelFormat pix_fmt, int top_band, int left_band);
4359 
4360 /**
4361  * Pad image.
4362  */
4363 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4364             int padtop, int padbottom, int padleft, int padright, int *color);
4365 
4366 /**
4367  * @}
4368  */
4369 
4370 /**
4371  * @defgroup lavc_misc Utility functions
4372  * @ingroup libavc
4373  *
4374  * Miscellaneous utility functions related to both encoding and decoding
4375  * (or neither).
4376  * @{
4377  */
4378 
4379 /**
4380  * @defgroup lavc_misc_pixfmt Pixel formats
4381  *
4382  * Functions for working with pixel formats.
4383  * @{
4384  */
4385 
4386 /**
4387  * Utility function to access log2_chroma_w log2_chroma_h from
4388  * the pixel format AVPixFmtDescriptor.
4389  *
4390  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4391  * for one that returns a failure code and continues in case of invalid
4392  * pix_fmts.
4393  *
4394  * @param[in]  pix_fmt the pixel format
4395  * @param[out] h_shift store log2_chroma_w
4396  * @param[out] v_shift store log2_chroma_h
4397  *
4398  * @see av_pix_fmt_get_chroma_sub_sample
4399  */
4400 
4401 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4402 
4403 /**
4404  * Return a value representing the fourCC code associated to the
4405  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4406  * found.
4407  */
4408 unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
4409 
4410 #define FF_LOSS_RESOLUTION  0x0001 /**< loss due to resolution change */
4411 #define FF_LOSS_DEPTH       0x0002 /**< loss due to color depth change */
4412 #define FF_LOSS_COLORSPACE  0x0004 /**< loss due to color space conversion */
4413 #define FF_LOSS_ALPHA       0x0008 /**< loss of alpha bits */
4414 #define FF_LOSS_COLORQUANT  0x0010 /**< loss due to color quantization */
4415 #define FF_LOSS_CHROMA      0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
4416 
4417 /**
4418  * Compute what kind of losses will occur when converting from one specific
4419  * pixel format to another.
4420  * When converting from one pixel format to another, information loss may occur.
4421  * For example, when converting from RGB24 to GRAY, the color information will
4422  * be lost. Similarly, other losses occur when converting from some formats to
4423  * other formats. These losses can involve loss of chroma, but also loss of
4424  * resolution, loss of color depth, loss due to the color space conversion, loss
4425  * of the alpha bits or loss due to color quantization.
4426  * avcodec_get_fix_fmt_loss() informs you about the various types of losses
4427  * which will occur when converting from one pixel format to another.
4428  *
4429  * @param[in] dst_pix_fmt destination pixel format
4430  * @param[in] src_pix_fmt source pixel format
4431  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4432  * @return Combination of flags informing you what kind of losses will occur
4433  * (maximum loss for an invalid dst_pix_fmt).
4434  */
4435 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4436                              int has_alpha);
4437 
4438 /**
4439  * Find the best pixel format to convert to given a certain source pixel
4440  * format.  When converting from one pixel format to another, information loss
4441  * may occur.  For example, when converting from RGB24 to GRAY, the color
4442  * information will be lost. Similarly, other losses occur when converting from
4443  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4444  * the given pixel formats should be used to suffer the least amount of loss.
4445  * The pixel formats from which it chooses one, are determined by the
4446  * pix_fmt_list parameter.
4447  *
4448  *
4449  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4450  * @param[in] src_pix_fmt source pixel format
4451  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4452  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4453  * @return The best pixel format to convert to or -1 if none was found.
4454  */
4455 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(enum AVPixelFormat *pix_fmt_list,
4456                                             enum AVPixelFormat src_pix_fmt,
4457                                             int has_alpha, int *loss_ptr);
4458 
4459 /**
4460  * Find the best pixel format to convert to given a certain source pixel
4461  * format and a selection of two destination pixel formats. When converting from
4462  * one pixel format to another, information loss may occur.  For example, when converting
4463  * from RGB24 to GRAY, the color information will be lost. Similarly, other losses occur when
4464  * converting from some formats to other formats. avcodec_find_best_pix_fmt_of_2() selects which of
4465  * the given pixel formats should be used to suffer the least amount of loss.
4466  *
4467  * If one of the destination formats is AV_PIX_FMT_NONE the other pixel format (if valid) will be
4468  * returned.
4469  *
4470  * @code
4471  * src_pix_fmt = AV_PIX_FMT_YUV420P;
4472  * dst_pix_fmt1= AV_PIX_FMT_RGB24;
4473  * dst_pix_fmt2= AV_PIX_FMT_GRAY8;
4474  * dst_pix_fmt3= AV_PIX_FMT_RGB8;
4475  * loss= FF_LOSS_CHROMA; // don't care about chroma loss, so chroma loss will be ignored.
4476  * dst_pix_fmt = avcodec_find_best_pix_fmt_of_2(dst_pix_fmt1, dst_pix_fmt2, src_pix_fmt, alpha, &loss);
4477  * dst_pix_fmt = avcodec_find_best_pix_fmt_of_2(dst_pix_fmt, dst_pix_fmt3, src_pix_fmt, alpha, &loss);
4478  * @endcode
4479  *
4480  * @param[in] dst_pix_fmt1 One of the two destination pixel formats to choose from
4481  * @param[in] dst_pix_fmt2 The other of the two destination pixel formats to choose from
4482  * @param[in] src_pix_fmt Source pixel format
4483  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4484  * @param[in, out] loss_ptr Combination of loss flags. In: selects which of the losses to ignore, i.e.
4485  *                               NULL or value of zero means we care about all losses. Out: the loss
4486  *                               that occurs when converting from src to selected dst pixel format.
4487  * @return The best pixel format to convert to or -1 if none was found.
4488  */
4489 enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4490                                             enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4491 
4492 attribute_deprecated
4493 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
4494 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
4495                                               enum AVPixelFormat src_pix_fmt,
4496                                               int has_alpha, int *loss_ptr);
4497 #else
4498 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4499                                             enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4500 #endif
4501 
4502 
4503 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
4504 
4505 /**
4506  * @}
4507  */
4508 
4509 void avcodec_set_dimensions(AVCodecContext *s, int width, int height);
4510 
4511 /**
4512  * Put a string representing the codec tag codec_tag in buf.
4513  *
4514  * @param buf_size size in bytes of buf
4515  * @return the length of the string that would have been generated if
4516  * enough space had been available, excluding the trailing null
4517  */
4518 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
4519 
4520 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
4521 
4522 /**
4523  * Return a name for the specified profile, if available.
4524  *
4525  * @param codec the codec that is searched for the given profile
4526  * @param profile the profile value for which a name is requested
4527  * @return A name for the profile if found, NULL otherwise.
4528  */
4529 const char *av_get_profile_name(const AVCodec *codec, int profile);
4530 
4531 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
4532 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
4533 //FIXME func typedef
4534 
4535 /**
4536  * Fill AVFrame audio data and linesize pointers.
4537  *
4538  * The buffer buf must be a preallocated buffer with a size big enough
4539  * to contain the specified samples amount. The filled AVFrame data
4540  * pointers will point to this buffer.
4541  *
4542  * AVFrame extended_data channel pointers are allocated if necessary for
4543  * planar audio.
4544  *
4545  * @param frame       the AVFrame
4546  *                    frame->nb_samples must be set prior to calling the
4547  *                    function. This function fills in frame->data,
4548  *                    frame->extended_data, frame->linesize[0].
4549  * @param nb_channels channel count
4550  * @param sample_fmt  sample format
4551  * @param buf         buffer to use for frame data
4552  * @param buf_size    size of buffer
4553  * @param align       plane size sample alignment (0 = default)
4554  * @return            >=0 on success, negative error code on failure
4555  * @todo return the size in bytes required to store the samples in
4556  * case of success, at the next libavutil bump
4557  */
4558 int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
4559                              enum AVSampleFormat sample_fmt, const uint8_t *buf,
4560                              int buf_size, int align);
4561 
4562 /**
4563  * Flush buffers, should be called when seeking or when switching to a different stream.
4564  */
4565 void avcodec_flush_buffers(AVCodecContext *avctx);
4566 
4567 /**
4568  * Return codec bits per sample.
4569  *
4570  * @param[in] codec_id the codec
4571  * @return Number of bits per sample or zero if unknown for the given codec.
4572  */
4573 int av_get_bits_per_sample(enum AVCodecID codec_id);
4574 
4575 /**
4576  * Return the PCM codec associated with a sample format.
4577  * @param be  endianness, 0 for little, 1 for big,
4578  *            -1 (or anything else) for native
4579  * @return  AV_CODEC_ID_PCM_* or AV_CODEC_ID_NONE
4580  */
4581 enum AVCodecID av_get_pcm_codec(enum AVSampleFormat fmt, int be);
4582 
4583 /**
4584  * Return codec bits per sample.
4585  * Only return non-zero if the bits per sample is exactly correct, not an
4586  * approximation.
4587  *
4588  * @param[in] codec_id the codec
4589  * @return Number of bits per sample or zero if unknown for the given codec.
4590  */
4591 int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
4592 
4593 /**
4594  * Return audio frame duration.
4595  *
4596  * @param avctx        codec context
4597  * @param frame_bytes  size of the frame, or 0 if unknown
4598  * @return             frame duration, in samples, if known. 0 if not able to
4599  *                     determine.
4600  */
4601 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
4602 
4603 
4604 typedef struct AVBitStreamFilterContext {
4605     void *priv_data;
4606     struct AVBitStreamFilter *filter;
4607     AVCodecParserContext *parser;
4608     struct AVBitStreamFilterContext *next;
4609 } AVBitStreamFilterContext;
4610 
4611 
4612 typedef struct AVBitStreamFilter {
4613     const char *name;
4614     int priv_data_size;
4615     int (*filter)(AVBitStreamFilterContext *bsfc,
4616                   AVCodecContext *avctx, const char *args,
4617                   uint8_t **poutbuf, int *poutbuf_size,
4618                   const uint8_t *buf, int buf_size, int keyframe);
4619     void (*close)(AVBitStreamFilterContext *bsfc);
4620     struct AVBitStreamFilter *next;
4621 } AVBitStreamFilter;
4622 
4623 /**
4624  * Register a bitstream filter.
4625  *
4626  * The filter will be accessible to the application code through
4627  * av_bitstream_filter_next() or can be directly initialized with
4628  * av_bitstream_filter_init().
4629  *
4630  * @see avcodec_register_all()
4631  */
4632 void av_register_bitstream_filter(AVBitStreamFilter *bsf);
4633 
4634 /**
4635  * Create and initialize a bitstream filter context given a bitstream
4636  * filter name.
4637  *
4638  * The returned context must be freed with av_bitstream_filter_close().
4639  *
4640  * @param name    the name of the bitstream filter
4641  * @return a bitstream filter context if a matching filter was found
4642  * and successfully initialized, NULL otherwise
4643  */
4644 AVBitStreamFilterContext *av_bitstream_filter_init(const char *name);
4645 
4646 /**
4647  * Filter bitstream.
4648  *
4649  * This function filters the buffer buf with size buf_size, and places the
4650  * filtered buffer in the buffer pointed to by poutbuf.
4651  *
4652  * The output buffer must be freed by the caller.
4653  *
4654  * @param bsfc            bitstream filter context created by av_bitstream_filter_init()
4655  * @param avctx           AVCodecContext accessed by the filter, may be NULL.
4656  *                        If specified, this must point to the encoder context of the
4657  *                        output stream the packet is sent to.
4658  * @param args            arguments which specify the filter configuration, may be NULL
4659  * @param poutbuf         pointer which is updated to point to the filtered buffer
4660  * @param poutbuf_size    pointer which is updated to the filtered buffer size in bytes
4661  * @param buf             buffer containing the data to filter
4662  * @param buf_size        size in bytes of buf
4663  * @param keyframe        set to non-zero if the buffer to filter corresponds to a key-frame packet data
4664  * @return >= 0 in case of success, or a negative error code in case of failure
4665  *
4666  * If the return value is positive, an output buffer is allocated and
4667  * is availble in *poutbuf, and is distinct from the input buffer.
4668  *
4669  * If the return value is 0, the output output buffer is not allocated
4670  * and the output buffer should be considered identical to the input
4671  * buffer, or in case *poutbuf was set it points to the input buffer
4672  * (not necessarily to its starting address).
4673  */
4674 int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
4675                                AVCodecContext *avctx, const char *args,
4676                                uint8_t **poutbuf, int *poutbuf_size,
4677                                const uint8_t *buf, int buf_size, int keyframe);
4678 
4679 /**
4680  * Release bitstream filter context.
4681  *
4682  * @param bsf the bitstream filter context created with
4683  * av_bitstream_filter_init(), can be NULL
4684  */
4685 void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
4686 
4687 /**
4688  * If f is NULL, return the first registered bitstream filter,
4689  * if f is non-NULL, return the next registered bitstream filter
4690  * after f, or NULL if f is the last one.
4691  *
4692  * This function can be used to iterate over all registered bitstream
4693  * filters.
4694  */
4695 AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);
4696 
4697 /* memory */
4698 
4699 /**
4700  * Reallocate the given block if it is not large enough, otherwise do nothing.
4701  *
4702  * @see av_realloc
4703  */
4704 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
4705 
4706 /**
4707  * Allocate a buffer, reusing the given one if large enough.
4708  *
4709  * Contrary to av_fast_realloc the current buffer contents might not be
4710  * preserved and on error the old buffer is freed, thus no special
4711  * handling to avoid memleaks is necessary.
4712  *
4713  * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
4714  * @param size size of the buffer *ptr points to
4715  * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
4716  *                 *size 0 if an error occurred.
4717  */
4718 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
4719 
4720 /**
4721  * Same behaviour av_fast_malloc but the buffer has additional
4722  * FF_INPUT_BUFFER_PADDING_SIZE at the end which will will always be 0.
4723  *
4724  * In addition the whole buffer will initially and after resizes
4725  * be 0-initialized so that no uninitialized data will ever appear.
4726  */
4727 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
4728 
4729 /**
4730  * Same behaviour av_fast_padded_malloc except that buffer will always
4731  * be 0-initialized after call.
4732  */
4733 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
4734 
4735 /**
4736  * Encode extradata length to a buffer. Used by xiph codecs.
4737  *
4738  * @param s buffer to write to; must be at least (v/255+1) bytes long
4739  * @param v size of extradata in bytes
4740  * @return number of bytes written to the buffer.
4741  */
4742 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
4743 
4744 #if FF_API_MISSING_SAMPLE
4745 /**
4746  * Log a generic warning message about a missing feature. This function is
4747  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
4748  * only, and would normally not be used by applications.
4749  * @param[in] avc a pointer to an arbitrary struct of which the first field is
4750  * a pointer to an AVClass struct
4751  * @param[in] feature string containing the name of the missing feature
4752  * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
4753  * If want_sample is non-zero, additional verbage will be added to the log
4754  * message which tells the user how to report samples to the development
4755  * mailing list.
4756  * @deprecated Use avpriv_report_missing_feature() instead.
4757  */
4758 attribute_deprecated
4759 void av_log_missing_feature(void *avc, const char *feature, int want_sample);
4760 
4761 /**
4762  * Log a generic warning message asking for a sample. This function is
4763  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
4764  * only, and would normally not be used by applications.
4765  * @param[in] avc a pointer to an arbitrary struct of which the first field is
4766  * a pointer to an AVClass struct
4767  * @param[in] msg string containing an optional message, or NULL if no message
4768  * @deprecated Use avpriv_request_sample() instead.
4769  */
4770 attribute_deprecated
4771 void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
4772 #endif /* FF_API_MISSING_SAMPLE */
4773 
4774 /**
4775  * Register the hardware accelerator hwaccel.
4776  */
4777 void av_register_hwaccel(AVHWAccel *hwaccel);
4778 
4779 /**
4780  * If hwaccel is NULL, returns the first registered hardware accelerator,
4781  * if hwaccel is non-NULL, returns the next registered hardware accelerator
4782  * after hwaccel, or NULL if hwaccel is the last one.
4783  */
4784 AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel);
4785 
4786 
4787 /**
4788  * Lock operation used by lockmgr
4789  */
4790 enum AVLockOp {
4791   AV_LOCK_CREATE,  ///< Create a mutex
4792   AV_LOCK_OBTAIN,  ///< Lock the mutex
4793   AV_LOCK_RELEASE, ///< Unlock the mutex
4794   AV_LOCK_DESTROY, ///< Free mutex resources
4795 };
4796 
4797 /**
4798  * Register a user provided lock manager supporting the operations
4799  * specified by AVLockOp. mutex points to a (void *) where the
4800  * lockmgr should store/get a pointer to a user allocated mutex. It's
4801  * NULL upon AV_LOCK_CREATE and != NULL for all other ops.
4802  *
4803  * @param cb User defined callback. Note: FFmpeg may invoke calls to this
4804  *           callback during the call to av_lockmgr_register().
4805  *           Thus, the application must be prepared to handle that.
4806  *           If cb is set to NULL the lockmgr will be unregistered.
4807  *           Also note that during unregistration the previously registered
4808  *           lockmgr callback may also be invoked.
4809  */
4810 int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
4811 
4812 /**
4813  * Get the type of the given codec.
4814  */
4815 enum AVMediaType avcodec_get_type(enum AVCodecID codec_id);
4816 
4817 /**
4818  * Get the name of a codec.
4819  * @return  a static string identifying the codec; never NULL
4820  */
4821 const char *avcodec_get_name(enum AVCodecID id);
4822 
4823 /**
4824  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
4825  * with no corresponding avcodec_close()), 0 otherwise.
4826  */
4827 int avcodec_is_open(AVCodecContext *s);
4828 
4829 /**
4830  * @return a non-zero number if codec is an encoder, zero otherwise
4831  */
4832 int av_codec_is_encoder(const AVCodec *codec);
4833 
4834 /**
4835  * @return a non-zero number if codec is a decoder, zero otherwise
4836  */
4837 int av_codec_is_decoder(const AVCodec *codec);
4838 
4839 /**
4840  * @return descriptor for given codec ID or NULL if no descriptor exists.
4841  */
4842 const AVCodecDescriptor *avcodec_descriptor_get(enum AVCodecID id);
4843 
4844 /**
4845  * Iterate over all codec descriptors known to libavcodec.
4846  *
4847  * @param prev previous descriptor. NULL to get the first descriptor.
4848  *
4849  * @return next descriptor or NULL after the last descriptor
4850  */
4851 const AVCodecDescriptor *avcodec_descriptor_next(const AVCodecDescriptor *prev);
4852 
4853 /**
4854  * @return codec descriptor with the given name or NULL if no such descriptor
4855  *         exists.
4856  */
4857 const AVCodecDescriptor *avcodec_descriptor_get_by_name(const char *name);
4858 
4859 /**
4860  * @}
4861  */
4862 
4863 #endif /* AVCODEC_AVCODEC_H */
4864