1 /*
2  *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #include <math.h>
12 
13 #include "vp9/encoder/vp9_encoder.h"
14 #include "vp9/encoder/vp9_svc_layercontext.h"
15 #include "vp9/encoder/vp9_extend.h"
16 
vp9_init_layer_context(VP9_COMP * const cpi)17 void vp9_init_layer_context(VP9_COMP *const cpi) {
18   SVC *const svc = &cpi->svc;
19   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
20   int layer;
21   int layer_end;
22   int alt_ref_idx = svc->number_spatial_layers;
23 
24   svc->spatial_layer_id = 0;
25   svc->temporal_layer_id = 0;
26 
27   if (svc->number_temporal_layers > 1) {
28     layer_end = svc->number_temporal_layers;
29   } else {
30     layer_end = svc->number_spatial_layers;
31   }
32 
33   for (layer = 0; layer < layer_end; ++layer) {
34     LAYER_CONTEXT *const lc = &svc->layer_context[layer];
35     RATE_CONTROL *const lrc = &lc->rc;
36     int i;
37     lc->current_video_frame_in_layer = 0;
38     lc->layer_size = 0;
39     lrc->ni_av_qi = oxcf->worst_allowed_q;
40     lrc->total_actual_bits = 0;
41     lrc->total_target_vs_actual = 0;
42     lrc->ni_tot_qi = 0;
43     lrc->tot_q = 0.0;
44     lrc->avg_q = 0.0;
45     lrc->ni_frames = 0;
46     lrc->decimation_count = 0;
47     lrc->decimation_factor = 0;
48 
49     for (i = 0; i < RATE_FACTOR_LEVELS; ++i) {
50       lrc->rate_correction_factors[i] = 1.0;
51     }
52 
53     if (svc->number_temporal_layers > 1) {
54       lc->target_bandwidth = oxcf->ts_target_bitrate[layer];
55       lrc->last_q[INTER_FRAME] = oxcf->worst_allowed_q;
56       lrc->avg_frame_qindex[INTER_FRAME] = oxcf->worst_allowed_q;
57     } else {
58       lc->target_bandwidth = oxcf->ss_target_bitrate[layer];
59       lrc->last_q[KEY_FRAME] = oxcf->best_allowed_q;
60       lrc->last_q[INTER_FRAME] = oxcf->best_allowed_q;
61       lrc->avg_frame_qindex[KEY_FRAME] = (oxcf->worst_allowed_q +
62                                           oxcf->best_allowed_q) / 2;
63       lrc->avg_frame_qindex[INTER_FRAME] = (oxcf->worst_allowed_q +
64                                             oxcf->best_allowed_q) / 2;
65       if (oxcf->ss_play_alternate[layer])
66         lc->alt_ref_idx = alt_ref_idx++;
67       else
68         lc->alt_ref_idx = -1;
69       lc->gold_ref_idx = -1;
70     }
71 
72     lrc->buffer_level = vp9_rescale((int)(oxcf->starting_buffer_level_ms),
73                                     lc->target_bandwidth, 1000);
74     lrc->bits_off_target = lrc->buffer_level;
75   }
76 
77   // Still have extra buffer for base layer golden frame
78   if (svc->number_spatial_layers > 1 && alt_ref_idx < REF_FRAMES)
79     svc->layer_context[0].gold_ref_idx = alt_ref_idx;
80 }
81 
82 // Update the layer context from a change_config() call.
vp9_update_layer_context_change_config(VP9_COMP * const cpi,const int target_bandwidth)83 void vp9_update_layer_context_change_config(VP9_COMP *const cpi,
84                                             const int target_bandwidth) {
85   SVC *const svc = &cpi->svc;
86   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
87   const RATE_CONTROL *const rc = &cpi->rc;
88   int layer;
89   int layer_end;
90   float bitrate_alloc = 1.0;
91 
92   if (svc->number_temporal_layers > 1) {
93     layer_end = svc->number_temporal_layers;
94   } else {
95     layer_end = svc->number_spatial_layers;
96   }
97 
98   for (layer = 0; layer < layer_end; ++layer) {
99     LAYER_CONTEXT *const lc = &svc->layer_context[layer];
100     RATE_CONTROL *const lrc = &lc->rc;
101 
102     if (svc->number_temporal_layers > 1) {
103       lc->target_bandwidth = oxcf->ts_target_bitrate[layer];
104     } else {
105       lc->target_bandwidth = oxcf->ss_target_bitrate[layer];
106     }
107     bitrate_alloc = (float)lc->target_bandwidth / target_bandwidth;
108     // Update buffer-related quantities.
109     lrc->starting_buffer_level =
110         (int64_t)(rc->starting_buffer_level * bitrate_alloc);
111     lrc->optimal_buffer_level =
112         (int64_t)(rc->optimal_buffer_level * bitrate_alloc);
113     lrc->maximum_buffer_size =
114         (int64_t)(rc->maximum_buffer_size * bitrate_alloc);
115     lrc->bits_off_target = MIN(lrc->bits_off_target, lrc->maximum_buffer_size);
116     lrc->buffer_level = MIN(lrc->buffer_level, lrc->maximum_buffer_size);
117     // Update framerate-related quantities.
118     if (svc->number_temporal_layers > 1) {
119       lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
120     } else {
121       lc->framerate = oxcf->framerate;
122     }
123     lrc->avg_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
124     lrc->max_frame_bandwidth = rc->max_frame_bandwidth;
125     // Update qp-related quantities.
126     lrc->worst_quality = rc->worst_quality;
127     lrc->best_quality = rc->best_quality;
128   }
129 }
130 
get_layer_context(SVC * svc)131 static LAYER_CONTEXT *get_layer_context(SVC *svc) {
132   return svc->number_temporal_layers > 1 ?
133          &svc->layer_context[svc->temporal_layer_id] :
134          &svc->layer_context[svc->spatial_layer_id];
135 }
136 
vp9_update_temporal_layer_framerate(VP9_COMP * const cpi)137 void vp9_update_temporal_layer_framerate(VP9_COMP *const cpi) {
138   SVC *const svc = &cpi->svc;
139   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
140   LAYER_CONTEXT *const lc = get_layer_context(svc);
141   RATE_CONTROL *const lrc = &lc->rc;
142   const int layer = svc->temporal_layer_id;
143 
144   lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
145   lrc->avg_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
146   lrc->max_frame_bandwidth = cpi->rc.max_frame_bandwidth;
147   // Update the average layer frame size (non-cumulative per-frame-bw).
148   if (layer == 0) {
149     lc->avg_frame_size = lrc->avg_frame_bandwidth;
150   } else {
151     const double prev_layer_framerate =
152         oxcf->framerate / oxcf->ts_rate_decimator[layer - 1];
153     const int prev_layer_target_bandwidth = oxcf->ts_target_bitrate[layer - 1];
154     lc->avg_frame_size =
155         (int)((lc->target_bandwidth - prev_layer_target_bandwidth) /
156               (lc->framerate - prev_layer_framerate));
157   }
158 }
159 
vp9_update_spatial_layer_framerate(VP9_COMP * const cpi,double framerate)160 void vp9_update_spatial_layer_framerate(VP9_COMP *const cpi, double framerate) {
161   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
162   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
163   RATE_CONTROL *const lrc = &lc->rc;
164 
165   lc->framerate = framerate;
166   lrc->avg_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
167   lrc->min_frame_bandwidth = (int)(lrc->avg_frame_bandwidth *
168                                    oxcf->two_pass_vbrmin_section / 100);
169   lrc->max_frame_bandwidth = (int)(((int64_t)lrc->avg_frame_bandwidth *
170                                    oxcf->two_pass_vbrmax_section) / 100);
171   vp9_rc_set_gf_max_interval(cpi, lrc);
172 }
173 
vp9_restore_layer_context(VP9_COMP * const cpi)174 void vp9_restore_layer_context(VP9_COMP *const cpi) {
175   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
176   const int old_frame_since_key = cpi->rc.frames_since_key;
177   const int old_frame_to_key = cpi->rc.frames_to_key;
178 
179   cpi->rc = lc->rc;
180   cpi->twopass = lc->twopass;
181   cpi->oxcf.target_bandwidth = lc->target_bandwidth;
182   cpi->alt_ref_source = lc->alt_ref_source;
183   // Reset the frames_since_key and frames_to_key counters to their values
184   // before the layer restore. Keep these defined for the stream (not layer).
185   if (cpi->svc.number_temporal_layers > 1) {
186     cpi->rc.frames_since_key = old_frame_since_key;
187     cpi->rc.frames_to_key = old_frame_to_key;
188   }
189 }
190 
vp9_save_layer_context(VP9_COMP * const cpi)191 void vp9_save_layer_context(VP9_COMP *const cpi) {
192   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
193   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
194 
195   lc->rc = cpi->rc;
196   lc->twopass = cpi->twopass;
197   lc->target_bandwidth = (int)oxcf->target_bandwidth;
198   lc->alt_ref_source = cpi->alt_ref_source;
199 }
200 
vp9_init_second_pass_spatial_svc(VP9_COMP * cpi)201 void vp9_init_second_pass_spatial_svc(VP9_COMP *cpi) {
202   SVC *const svc = &cpi->svc;
203   int i;
204 
205   for (i = 0; i < svc->number_spatial_layers; ++i) {
206     TWO_PASS *const twopass = &svc->layer_context[i].twopass;
207 
208     svc->spatial_layer_id = i;
209     vp9_init_second_pass(cpi);
210 
211     twopass->total_stats.spatial_layer_id = i;
212     twopass->total_left_stats.spatial_layer_id = i;
213   }
214   svc->spatial_layer_id = 0;
215 }
216 
vp9_inc_frame_in_layer(SVC * svc)217 void vp9_inc_frame_in_layer(SVC *svc) {
218   LAYER_CONTEXT *const lc = (svc->number_temporal_layers > 1)
219       ? &svc->layer_context[svc->temporal_layer_id]
220       : &svc->layer_context[svc->spatial_layer_id];
221   ++lc->current_video_frame_in_layer;
222 }
223 
vp9_is_upper_layer_key_frame(const VP9_COMP * const cpi)224 int vp9_is_upper_layer_key_frame(const VP9_COMP *const cpi) {
225   return is_spatial_svc(cpi) &&
226          cpi->svc.spatial_layer_id > 0 &&
227          cpi->svc.layer_context[cpi->svc.spatial_layer_id].is_key_frame;
228 }
229 
230 #if CONFIG_SPATIAL_SVC
vp9_svc_lookahead_push(const VP9_COMP * const cpi,struct lookahead_ctx * ctx,YV12_BUFFER_CONFIG * src,int64_t ts_start,int64_t ts_end,unsigned int flags)231 int vp9_svc_lookahead_push(const VP9_COMP *const cpi, struct lookahead_ctx *ctx,
232                            YV12_BUFFER_CONFIG *src, int64_t ts_start,
233                            int64_t ts_end, unsigned int flags) {
234   struct lookahead_entry *buf;
235   int i, index;
236 
237   if (vp9_lookahead_push(ctx, src, ts_start, ts_end, flags))
238     return 1;
239 
240   index = ctx->write_idx - 1;
241   if (index < 0)
242     index += ctx->max_sz;
243 
244   buf = ctx->buf + index;
245 
246   if (buf == NULL)
247     return 1;
248 
249   // Store svc parameters for each layer
250   for (i = 0; i < cpi->svc.number_spatial_layers; ++i)
251     buf->svc_params[i] = cpi->svc.layer_context[i].svc_params_received;
252 
253   return 0;
254 }
255 
copy_svc_params(VP9_COMP * const cpi,struct lookahead_entry * buf)256 static int copy_svc_params(VP9_COMP *const cpi, struct lookahead_entry *buf) {
257   int layer_id;
258   vpx_svc_parameters_t *layer_param;
259   LAYER_CONTEXT *lc;
260 
261   // Find the next layer to be encoded
262   for (layer_id = 0; layer_id < cpi->svc.number_spatial_layers; ++layer_id) {
263     if (buf->svc_params[layer_id].spatial_layer >=0)
264       break;
265   }
266 
267   if (layer_id == cpi->svc.number_spatial_layers)
268     return 1;
269 
270   layer_param = &buf->svc_params[layer_id];
271   cpi->svc.spatial_layer_id = layer_param->spatial_layer;
272   cpi->svc.temporal_layer_id = layer_param->temporal_layer;
273   cpi->ref_frame_flags = VP9_ALT_FLAG | VP9_GOLD_FLAG | VP9_LAST_FLAG;
274 
275   lc = &cpi->svc.layer_context[cpi->svc.spatial_layer_id];
276 
277   cpi->lst_fb_idx = cpi->svc.spatial_layer_id;
278 
279   if (cpi->svc.spatial_layer_id < 1)
280       cpi->gld_fb_idx = lc->gold_ref_idx >= 0 ?
281                         lc->gold_ref_idx : cpi->lst_fb_idx;
282   else
283     cpi->gld_fb_idx = cpi->svc.spatial_layer_id - 1;
284 
285   if (lc->current_video_frame_in_layer == 0) {
286     if (cpi->svc.spatial_layer_id >= 2) {
287       cpi->alt_fb_idx = cpi->svc.spatial_layer_id - 2;
288     } else {
289       cpi->alt_fb_idx = cpi->lst_fb_idx;
290       cpi->ref_frame_flags &= (~VP9_LAST_FLAG & ~VP9_ALT_FLAG);
291     }
292   } else {
293     if (cpi->oxcf.ss_play_alternate[cpi->svc.spatial_layer_id]) {
294       cpi->alt_fb_idx = lc->alt_ref_idx;
295       if (!lc->has_alt_frame)
296         cpi->ref_frame_flags &= (~VP9_ALT_FLAG);
297     } else {
298       // Find a proper alt_fb_idx for layers that don't have alt ref frame
299       if (cpi->svc.spatial_layer_id == 0) {
300         cpi->alt_fb_idx = cpi->lst_fb_idx;
301       } else {
302         LAYER_CONTEXT *lc_lower =
303             &cpi->svc.layer_context[cpi->svc.spatial_layer_id - 1];
304 
305         if (cpi->oxcf.ss_play_alternate[cpi->svc.spatial_layer_id - 1] &&
306             lc_lower->alt_ref_source != NULL)
307           cpi->alt_fb_idx = lc_lower->alt_ref_idx;
308         else if (cpi->svc.spatial_layer_id >= 2)
309           cpi->alt_fb_idx = cpi->svc.spatial_layer_id - 2;
310         else
311           cpi->alt_fb_idx = cpi->lst_fb_idx;
312       }
313     }
314   }
315 
316   if (vp9_set_size_literal(cpi, layer_param->width, layer_param->height) != 0)
317     return VPX_CODEC_INVALID_PARAM;
318 
319   cpi->oxcf.worst_allowed_q =
320       vp9_quantizer_to_qindex(layer_param->max_quantizer);
321   cpi->oxcf.best_allowed_q =
322       vp9_quantizer_to_qindex(layer_param->min_quantizer);
323 
324   vp9_change_config(cpi, &cpi->oxcf);
325 
326   vp9_set_high_precision_mv(cpi, 1);
327 
328   cpi->alt_ref_source = get_layer_context(&cpi->svc)->alt_ref_source;
329 
330   return 0;
331 }
332 
vp9_svc_lookahead_peek(VP9_COMP * const cpi,struct lookahead_ctx * ctx,int index,int copy_params)333 struct lookahead_entry *vp9_svc_lookahead_peek(VP9_COMP *const cpi,
334                                                struct lookahead_ctx *ctx,
335                                                int index, int copy_params) {
336   struct lookahead_entry *buf = vp9_lookahead_peek(ctx, index);
337 
338   if (buf != NULL && copy_params != 0) {
339     if (copy_svc_params(cpi, buf) != 0)
340       return NULL;
341   }
342   return buf;
343 }
344 
vp9_svc_lookahead_pop(VP9_COMP * const cpi,struct lookahead_ctx * ctx,int drain)345 struct lookahead_entry *vp9_svc_lookahead_pop(VP9_COMP *const cpi,
346                                               struct lookahead_ctx *ctx,
347                                               int drain) {
348   struct lookahead_entry *buf = NULL;
349 
350   if (ctx->sz && (drain || ctx->sz == ctx->max_sz - MAX_PRE_FRAMES)) {
351     buf = vp9_svc_lookahead_peek(cpi, ctx, 0, 1);
352     if (buf != NULL) {
353       // Only remove the buffer when pop the highest layer. Simply set the
354       // spatial_layer to -1 for lower layers.
355       buf->svc_params[cpi->svc.spatial_layer_id].spatial_layer = -1;
356       if (cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1) {
357         vp9_lookahead_pop(ctx, drain);
358       }
359     }
360   }
361 
362   return buf;
363 }
364 #endif
365