1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3 
4 © Copyright  1995 - 2019 Fraunhofer-Gesellschaft zur Förderung der angewandten
5 Forschung e.V. All rights reserved.
6 
7  1.    INTRODUCTION
8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10 scheme for digital audio. This FDK AAC Codec software is intended to be used on
11 a wide variety of Android devices.
12 
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14 general perceptual audio codecs. AAC-ELD is considered the best-performing
15 full-bandwidth communications codec by independent studies and is widely
16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17 specifications.
18 
19 Patent licenses for necessary patent claims for the FDK AAC Codec (including
20 those of Fraunhofer) may be obtained through Via Licensing
21 (www.vialicensing.com) or through the respective patent owners individually for
22 the purpose of encoding or decoding bit streams in products that are compliant
23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24 Android devices already license these patent claims through Via Licensing or
25 directly from the patent owners, and therefore FDK AAC Codec software may
26 already be covered under those patent licenses when it is used for those
27 licensed purposes only.
28 
29 Commercially-licensed AAC software libraries, including floating-point versions
30 with enhanced sound quality, are also available from Fraunhofer. Users are
31 encouraged to check the Fraunhofer website for additional applications
32 information and documentation.
33 
34 2.    COPYRIGHT LICENSE
35 
36 Redistribution and use in source and binary forms, with or without modification,
37 are permitted without payment of copyright license fees provided that you
38 satisfy the following conditions:
39 
40 You must retain the complete text of this software license in redistributions of
41 the FDK AAC Codec or your modifications thereto in source code form.
42 
43 You must retain the complete text of this software license in the documentation
44 and/or other materials provided with redistributions of the FDK AAC Codec or
45 your modifications thereto in binary form. You must make available free of
46 charge copies of the complete source code of the FDK AAC Codec and your
47 modifications thereto to recipients of copies in binary form.
48 
49 The name of Fraunhofer may not be used to endorse or promote products derived
50 from this library without prior written permission.
51 
52 You may not charge copyright license fees for anyone to use, copy or distribute
53 the FDK AAC Codec software or your modifications thereto.
54 
55 Your modified versions of the FDK AAC Codec must carry prominent notices stating
56 that you changed the software and the date of any change. For modified versions
57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59 AAC Codec Library for Android."
60 
61 3.    NO PATENT LICENSE
62 
63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65 Fraunhofer provides no warranty of patent non-infringement with respect to this
66 software.
67 
68 You may use this FDK AAC Codec software or modifications thereto only for
69 purposes that are authorized by appropriate patent licenses.
70 
71 4.    DISCLAIMER
72 
73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75 including but not limited to the implied warranties of merchantability and
76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78 or consequential damages, including but not limited to procurement of substitute
79 goods or services; loss of use, data, or profits, or business interruption,
80 however caused and on any theory of liability, whether in contract, strict
81 liability, or tort (including negligence), arising in any way out of the use of
82 this software, even if advised of the possibility of such damage.
83 
84 5.    CONTACT INFORMATION
85 
86 Fraunhofer Institute for Integrated Circuits IIS
87 Attention: Audio and Multimedia Departments - FDK AAC LL
88 Am Wolfsmantel 33
89 91058 Erlangen, Germany
90 
91 www.iis.fraunhofer.de/amm
92 amm-info@iis.fraunhofer.de
93 ----------------------------------------------------------------------------- */
94 
95 /******************* Library for basic calculation routines ********************
96 
97    Author(s):
98 
99    Description:
100 
101 *******************************************************************************/
102 
103 /*!
104   \file   qmf.h
105   \brief  Complex qmf analysis/synthesis
106   \author Markus Werner
107 
108 */
109 
110 #ifndef QMF_H
111 #define QMF_H
112 
113 #include "common_fix.h"
114 #include "FDK_tools_rom.h"
115 #include "dct.h"
116 
117 #define FIXP_QAS FIXP_PCM
118 #define QAS_BITS SAMPLE_BITS
119 #define INT_PCM_QMFIN INT_PCM
120 
121 #define FIXP_QSS FIXP_DBL
122 #define QSS_BITS DFRACT_BITS
123 
124 /* Flags for QMF intialization */
125 /* Low Power mode flag */
126 #define QMF_FLAG_LP 1
127 /* Filter is not symmetric. This flag is set internally in the QMF
128  * initialization as required. */
129 /* DO NOT PASS THIS FLAG TO qmfInitAnalysisFilterBank or
130  * qmfInitSynthesisFilterBank */
131 #define QMF_FLAG_NONSYMMETRIC 2
132 /* Complex Low Delay Filter Bank (or std symmetric filter bank) */
133 #define QMF_FLAG_CLDFB 4
134 /* Flag indicating that the states should be kept. */
135 #define QMF_FLAG_KEEP_STATES 8
136 /* Complex Low Delay Filter Bank used in MPEG Surround Encoder */
137 #define QMF_FLAG_MPSLDFB 16
138 /* Complex Low Delay Filter Bank used in MPEG Surround Encoder allows a
139  * optimized calculation of the modulation in qmfForwardModulationHQ() */
140 #define QMF_FLAG_MPSLDFB_OPTIMIZE_MODULATION 32
141 /* Flag to indicate HE-AAC down-sampled SBR mode (decoder) -> adapt analysis
142  * post twiddling */
143 #define QMF_FLAG_DOWNSAMPLED 64
144 
145 #define QMF_MAX_SYNTHESIS_BANDS (64)
146 
147 /*!
148  * \brief Algorithmic scaling in sbrForwardModulation()
149  *
150  * The scaling in sbrForwardModulation() is caused by:
151  *
152  *   \li 1 R_SHIFT in sbrForwardModulation()
153  *   \li 5/6 R_SHIFT in dct3() if using 32/64 Bands
154  *   \li 1 omitted gain of 2.0 in qmfForwardModulation()
155  */
156 #define ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK 7
157 
158 /*!
159  * \brief Algorithmic scaling in cplxSynthesisQmfFiltering()
160  *
161  * The scaling in cplxSynthesisQmfFiltering() is caused by:
162  *
163  *   \li  5/6 R_SHIFT in dct2() if using 32/64 Bands
164  *   \li  1 omitted gain of 2.0 in qmfInverseModulation()
165  *   \li -6 division by 64 in synthesis filterbank
166  *   \li x bits external influence
167  */
168 #define ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK 1
169 
170 typedef struct {
171   int lb_scale;    /*!< Scale of low band area                   */
172   int ov_lb_scale; /*!< Scale of adjusted overlap low band area  */
173   int hb_scale;    /*!< Scale of high band area                  */
174   int ov_hb_scale; /*!< Scale of adjusted overlap high band area */
175 } QMF_SCALE_FACTOR;
176 
177 struct QMF_FILTER_BANK {
178   const FIXP_PFT *p_filter; /*!< Pointer to filter coefficients */
179 
180   void *FilterStates;    /*!< Pointer to buffer of filter states
181                               FIXP_PCM in analyse and
182                               FIXP_DBL in synthesis filter */
183   int FilterSize;        /*!< Size of prototype filter. */
184   const FIXP_QTW *t_cos; /*!< Modulation tables. */
185   const FIXP_QTW *t_sin;
186   int filterScale; /*!< filter scale */
187 
188   int no_channels; /*!< Total number of channels (subbands) */
189   int no_col;      /*!< Number of time slots       */
190   int lsb;         /*!< Top of low subbands */
191   int usb;         /*!< Top of high subbands */
192 
193   int synScalefactor; /*!< Scale factor of synthesis qmf (syn only) */
194   int outScalefactor; /*!< Scale factor of output data (syn only) */
195   FIXP_DBL outGain_m; /*!< Mantissa of gain output data (syn only) (init with
196                          0x80000000 to ignore) */
197   int outGain_e;      /*!< Exponent of gain output data (syn only) */
198 
199   UINT flags;     /*!< flags */
200   UCHAR p_stride; /*!< Stride Factor of polyphase filters */
201 };
202 
203 typedef struct QMF_FILTER_BANK *HANDLE_QMF_FILTER_BANK;
204 
205 int qmfInitAnalysisFilterBank(
206     HANDLE_QMF_FILTER_BANK h_Qmf, /*!< QMF Handle */
207     FIXP_QAS *pFilterStates,      /*!< Pointer to filter state buffer */
208     int noCols,                   /*!< Number of time slots  */
209     int lsb,                      /*!< Number of lower bands */
210     int usb,                      /*!< Number of upper bands */
211     int no_channels,              /*!< Number of critically sampled bands */
212     int flags);                   /*!< Flags */
213 #if SAMPLE_BITS == 16
214 
215 int qmfInitAnalysisFilterBank(
216     HANDLE_QMF_FILTER_BANK h_Qmf, /*!< QMF Handle */
217     FIXP_DBL *pFilterStates,      /*!< Pointer to filter state buffer */
218     int noCols,                   /*!< Number of time slots  */
219     int lsb,                      /*!< Number of lower bands */
220     int usb,                      /*!< Number of upper bands */
221     int no_channels,              /*!< Number of critically sampled bands */
222     int flags);                   /*!< Flags */
223 #endif
224 
225 void qmfAnalysisFiltering(
226     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Analysis Bank   */
227     FIXP_DBL **qmfReal,            /*!< Pointer to real subband slots */
228     FIXP_DBL **qmfImag,            /*!< Pointer to imag subband slots */
229     QMF_SCALE_FACTOR *scaleFactor, /*!< Scale factors of QMF data     */
230     const INT_PCM *timeIn,         /*!< Time signal */
231     const int timeIn_e,            /*!< Exponent of audio data        */
232     const int stride,              /*!< Stride factor of audio data   */
233     FIXP_DBL *pWorkBuffer          /*!< pointer to temporal working buffer */
234 );
235 #if SAMPLE_BITS == 16
236 
237 void qmfAnalysisFiltering(
238     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Analysis Bank   */
239     FIXP_DBL **qmfReal,            /*!< Pointer to real subband slots */
240     FIXP_DBL **qmfImag,            /*!< Pointer to imag subband slots */
241     QMF_SCALE_FACTOR *scaleFactor, /*!< Scale factors of QMF data     */
242     const LONG *timeIn,            /*!< Time signal */
243     const int timeIn_e,            /*!< Exponent of audio data        */
244     const int stride,              /*!< Stride factor of audio data   */
245     FIXP_DBL *pWorkBuffer          /*!< pointer to temporary working buffer */
246 );
247 #endif
248 
249 void qmfAnalysisFilteringSlot(
250     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Synthesis Bank  */
251     FIXP_DBL *qmfReal,             /*!< Low and High band, real */
252     FIXP_DBL *qmfImag,             /*!< Low and High band, imag */
253     const INT_PCM *timeIn,         /*!< Pointer to input */
254     const int stride,              /*!< stride factor of input */
255     FIXP_DBL *pWorkBuffer          /*!< pointer to temporal working buffer */
256 );
257 #if SAMPLE_BITS == 16
258 
259 void qmfAnalysisFilteringSlot(
260     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Synthesis Bank  */
261     FIXP_DBL *qmfReal,             /*!< Low and High band, real */
262     FIXP_DBL *qmfImag,             /*!< Low and High band, imag */
263     const LONG *timeIn,            /*!< Pointer to input */
264     const int stride,              /*!< stride factor of input */
265     FIXP_DBL *pWorkBuffer          /*!< pointer to temporary working buffer */
266 );
267 #endif
268 
269 int qmfInitSynthesisFilterBank(
270     HANDLE_QMF_FILTER_BANK h_Qmf, /*!< QMF Handle */
271     FIXP_QSS *pFilterStates,      /*!< Pointer to filter state buffer */
272     int noCols,                   /*!< Number of time slots  */
273     int lsb,                      /*!< Number of lower bands */
274     int usb,                      /*!< Number of upper bands */
275     int no_channels,              /*!< Number of critically sampled bands */
276     int flags);                   /*!< Flags */
277 
278 void qmfSynthesisFiltering(
279     HANDLE_QMF_FILTER_BANK synQmf,       /*!< Handle of Qmf Synthesis Bank  */
280     FIXP_DBL **QmfBufferReal,            /*!< Pointer to real subband slots */
281     FIXP_DBL **QmfBufferImag,            /*!< Pointer to imag subband slots */
282     const QMF_SCALE_FACTOR *scaleFactor, /*!< Scale factors of QMF data     */
283     const int ov_len,                    /*!< Length of band overlap        */
284     INT_PCM *timeOut,                    /*!< Time signal */
285     const INT stride,                    /*!< Stride factor of audio data   */
286     FIXP_DBL *pWorkBuffer /*!< pointer to temporary working buffer. It must be
287                              aligned */
288 );
289 #if SAMPLE_BITS == 16
290 
291 void qmfSynthesisFiltering(
292     HANDLE_QMF_FILTER_BANK synQmf,       /*!< Handle of Qmf Synthesis Bank  */
293     FIXP_DBL **QmfBufferReal,            /*!< Pointer to real subband slots */
294     FIXP_DBL **QmfBufferImag,            /*!< Pointer to imag subband slots */
295     const QMF_SCALE_FACTOR *scaleFactor, /*!< Scale factors of QMF data     */
296     const int ov_len,                    /*!< Length of band overlap        */
297     LONG *timeOut,                       /*!< Time signal */
298     const int timeOut_e,                 /*!< Target exponent for timeOut  */
299     FIXP_DBL *pWorkBuffer /*!< pointer to temporary working buffer */
300 );
301 #endif
302 
303 void qmfSynthesisFilteringSlot(HANDLE_QMF_FILTER_BANK synQmf,
304                                const FIXP_DBL *realSlot,
305                                const FIXP_DBL *imagSlot,
306                                const int scaleFactorLowBand,
307                                const int scaleFactorHighBand, INT_PCM *timeOut,
308                                const int timeOut_e, FIXP_DBL *pWorkBuffer);
309 #if SAMPLE_BITS == 16
310 
311 void qmfSynthesisFilteringSlot(HANDLE_QMF_FILTER_BANK synQmf,
312                                const FIXP_DBL *realSlot,
313                                const FIXP_DBL *imagSlot,
314                                const int scaleFactorLowBand,
315                                const int scaleFactorHighBand, LONG *timeOut,
316                                const int timeOut_e, FIXP_DBL *pWorkBuffer);
317 #endif
318 
319 void qmfChangeOutScalefactor(
320     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank */
321     int outScalefactor             /*!< New scaling factor for output data */
322 );
323 
324 int qmfGetOutScalefactor(
325     HANDLE_QMF_FILTER_BANK synQmf /*!< Handle of Qmf Synthesis Bank */
326 );
327 
328 void qmfChangeOutGain(
329     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank */
330     FIXP_DBL outputGain,           /*!< New gain for output data (mantissa) */
331     int outputGainScale            /*!< New gain for output data (exponent) */
332 );
333 
334 #endif /*ifndef QMF_H       */
335