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_onyx_int.h"
14 #include "vp9/encoder/vp9_svc_layercontext.h"
15 
vp9_init_layer_context(VP9_COMP * const cpi)16 void vp9_init_layer_context(VP9_COMP *const cpi) {
17   const VP9_CONFIG *const oxcf = &cpi->oxcf;
18   int layer;
19   int layer_end;
20 
21   cpi->svc.spatial_layer_id = 0;
22   cpi->svc.temporal_layer_id = 0;
23 
24   if (cpi->svc.number_temporal_layers > 1) {
25     layer_end = cpi->svc.number_temporal_layers;
26   } else {
27     layer_end = cpi->svc.number_spatial_layers;
28   }
29 
30   for (layer = 0; layer < layer_end; ++layer) {
31     LAYER_CONTEXT *const lc = &cpi->svc.layer_context[layer];
32     RATE_CONTROL *const lrc = &lc->rc;
33     lc->current_video_frame_in_layer = 0;
34     lrc->avg_frame_qindex[INTER_FRAME] = q_trans[oxcf->worst_allowed_q];
35     lrc->ni_av_qi = q_trans[oxcf->worst_allowed_q];
36     lrc->total_actual_bits = 0;
37     lrc->total_target_vs_actual = 0;
38     lrc->ni_tot_qi = 0;
39     lrc->tot_q = 0.0;
40     lrc->avg_q = 0.0;
41     lrc->ni_frames = 0;
42     lrc->decimation_count = 0;
43     lrc->decimation_factor = 0;
44     lrc->rate_correction_factor = 1.0;
45     lrc->key_frame_rate_correction_factor = 1.0;
46 
47     if (cpi->svc.number_temporal_layers > 1) {
48       lc->target_bandwidth = oxcf->ts_target_bitrate[layer] * 1000;
49       lrc->last_q[INTER_FRAME] = q_trans[oxcf->worst_allowed_q];
50     } else {
51       lc->target_bandwidth = oxcf->ss_target_bitrate[layer] * 1000;
52       lrc->last_q[0] = q_trans[oxcf->best_allowed_q];
53       lrc->last_q[1] = q_trans[oxcf->best_allowed_q];
54       lrc->last_q[2] = q_trans[oxcf->best_allowed_q];
55     }
56 
57     lrc->buffer_level = vp9_rescale((int)(oxcf->starting_buffer_level),
58                                     lc->target_bandwidth, 1000);
59     lrc->bits_off_target = lrc->buffer_level;
60   }
61 }
62 
63 // Update the layer context from a change_config() call.
vp9_update_layer_context_change_config(VP9_COMP * const cpi,const int target_bandwidth)64 void vp9_update_layer_context_change_config(VP9_COMP *const cpi,
65                                             const int target_bandwidth) {
66   const VP9_CONFIG *const oxcf = &cpi->oxcf;
67   const RATE_CONTROL *const rc = &cpi->rc;
68   int layer;
69   int layer_end;
70   float bitrate_alloc = 1.0;
71 
72   if (cpi->svc.number_temporal_layers > 1) {
73     layer_end = cpi->svc.number_temporal_layers;
74   } else {
75     layer_end = cpi->svc.number_spatial_layers;
76   }
77 
78   for (layer = 0; layer < layer_end; ++layer) {
79     LAYER_CONTEXT *const lc = &cpi->svc.layer_context[layer];
80     RATE_CONTROL *const lrc = &lc->rc;
81 
82     if (cpi->svc.number_temporal_layers > 1) {
83       lc->target_bandwidth = oxcf->ts_target_bitrate[layer] * 1000;
84     } else {
85       lc->target_bandwidth = oxcf->ss_target_bitrate[layer] * 1000;
86     }
87     bitrate_alloc = (float)lc->target_bandwidth / target_bandwidth;
88     // Update buffer-related quantities.
89     lc->starting_buffer_level =
90         (int64_t)(oxcf->starting_buffer_level * bitrate_alloc);
91     lc->optimal_buffer_level =
92         (int64_t)(oxcf->optimal_buffer_level * bitrate_alloc);
93     lc->maximum_buffer_size =
94         (int64_t)(oxcf->maximum_buffer_size * bitrate_alloc);
95     lrc->bits_off_target = MIN(lrc->bits_off_target, lc->maximum_buffer_size);
96     lrc->buffer_level = MIN(lrc->buffer_level, lc->maximum_buffer_size);
97     // Update framerate-related quantities.
98     if (cpi->svc.number_temporal_layers > 1) {
99       lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
100     } else {
101       lc->framerate = oxcf->framerate;
102     }
103     lrc->av_per_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
104     lrc->max_frame_bandwidth = rc->max_frame_bandwidth;
105     // Update qp-related quantities.
106     lrc->worst_quality = rc->worst_quality;
107     lrc->best_quality = rc->best_quality;
108   }
109 }
110 
get_layer_context(SVC * svc)111 static LAYER_CONTEXT *get_layer_context(SVC *svc) {
112   return svc->number_temporal_layers > 1 ?
113          &svc->layer_context[svc->temporal_layer_id] :
114          &svc->layer_context[svc->spatial_layer_id];
115 }
116 
vp9_update_temporal_layer_framerate(VP9_COMP * const cpi)117 void vp9_update_temporal_layer_framerate(VP9_COMP *const cpi) {
118   const int layer = cpi->svc.temporal_layer_id;
119   const VP9_CONFIG *const oxcf = &cpi->oxcf;
120   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
121   RATE_CONTROL *const lrc = &lc->rc;
122 
123   lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
124   lrc->av_per_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
125   lrc->max_frame_bandwidth = cpi->rc.max_frame_bandwidth;
126   // Update the average layer frame size (non-cumulative per-frame-bw).
127   if (layer == 0) {
128     lc->avg_frame_size = lrc->av_per_frame_bandwidth;
129   } else {
130     const double prev_layer_framerate =
131         oxcf->framerate / oxcf->ts_rate_decimator[layer - 1];
132     const int prev_layer_target_bandwidth =
133         oxcf->ts_target_bitrate[layer - 1] * 1000;
134     lc->avg_frame_size =
135         (int)((lc->target_bandwidth - prev_layer_target_bandwidth) /
136               (lc->framerate - prev_layer_framerate));
137   }
138 }
139 
vp9_update_spatial_layer_framerate(VP9_COMP * const cpi,double framerate)140 void vp9_update_spatial_layer_framerate(VP9_COMP *const cpi, double framerate) {
141   const VP9_CONFIG *const oxcf = &cpi->oxcf;
142   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
143   RATE_CONTROL *const lrc = &lc->rc;
144 
145   lc->framerate = framerate;
146   lrc->av_per_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
147   lrc->min_frame_bandwidth = (int)(lrc->av_per_frame_bandwidth *
148                                    oxcf->two_pass_vbrmin_section / 100);
149   lrc->max_frame_bandwidth = (int)(((int64_t)lrc->av_per_frame_bandwidth *
150                                    oxcf->two_pass_vbrmax_section) / 100);
151   lrc->max_gf_interval = 16;
152 
153   lrc->static_scene_max_gf_interval = cpi->key_frame_frequency >> 1;
154 
155   if (oxcf->play_alternate && oxcf->lag_in_frames) {
156     if (lrc->max_gf_interval > oxcf->lag_in_frames - 1)
157       lrc->max_gf_interval = oxcf->lag_in_frames - 1;
158 
159     if (lrc->static_scene_max_gf_interval > oxcf->lag_in_frames - 1)
160       lrc->static_scene_max_gf_interval = oxcf->lag_in_frames - 1;
161   }
162 
163   if (lrc->max_gf_interval > lrc->static_scene_max_gf_interval)
164     lrc->max_gf_interval = lrc->static_scene_max_gf_interval;
165 }
166 
vp9_restore_layer_context(VP9_COMP * const cpi)167 void vp9_restore_layer_context(VP9_COMP *const cpi) {
168   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
169   const int old_frame_since_key = cpi->rc.frames_since_key;
170   const int old_frame_to_key = cpi->rc.frames_to_key;
171 
172   cpi->rc = lc->rc;
173   cpi->twopass = lc->twopass;
174   cpi->oxcf.target_bandwidth = lc->target_bandwidth;
175   cpi->oxcf.starting_buffer_level = lc->starting_buffer_level;
176   cpi->oxcf.optimal_buffer_level = lc->optimal_buffer_level;
177   cpi->oxcf.maximum_buffer_size = lc->maximum_buffer_size;
178   cpi->output_framerate = lc->framerate;
179   // Reset the frames_since_key and frames_to_key counters to their values
180   // before the layer restore. Keep these defined for the stream (not layer).
181   if (cpi->svc.number_temporal_layers > 1) {
182     cpi->rc.frames_since_key = old_frame_since_key;
183     cpi->rc.frames_to_key = old_frame_to_key;
184   }
185 }
186 
vp9_save_layer_context(VP9_COMP * const cpi)187 void vp9_save_layer_context(VP9_COMP *const cpi) {
188   const VP9_CONFIG *const oxcf = &cpi->oxcf;
189   LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
190 
191   lc->rc = cpi->rc;
192   lc->twopass = cpi->twopass;
193   lc->target_bandwidth = (int)oxcf->target_bandwidth;
194   lc->starting_buffer_level = oxcf->starting_buffer_level;
195   lc->optimal_buffer_level = oxcf->optimal_buffer_level;
196   lc->maximum_buffer_size = oxcf->maximum_buffer_size;
197   lc->framerate = cpi->output_framerate;
198 }
199 
vp9_init_second_pass_spatial_svc(VP9_COMP * cpi)200 void vp9_init_second_pass_spatial_svc(VP9_COMP *cpi) {
201   int i;
202   for (i = 0; i < cpi->svc.number_spatial_layers; ++i) {
203     struct twopass_rc *const twopass = &cpi->svc.layer_context[i].twopass;
204 
205     cpi->svc.spatial_layer_id = i;
206     vp9_init_second_pass(cpi);
207 
208     twopass->total_stats.spatial_layer_id = i;
209     twopass->total_left_stats.spatial_layer_id = i;
210   }
211   cpi->svc.spatial_layer_id = 0;
212 }
213