ref: ed30c8eff2dec9b065d00dc7a9d639eba251a9b7
dir: /vp9/encoder/vp9_svc_layercontext.c/
/*
* Copyright (c) 2014 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <math.h>
#include "vp9/encoder/vp9_encoder.h"
#include "vp9/encoder/vp9_svc_layercontext.h"
void vp9_init_layer_context(VP9_COMP *const cpi) {
SVC *const svc = &cpi->svc;
const VP9EncoderConfig *const oxcf = &cpi->oxcf;
int layer;
int layer_end;
svc->spatial_layer_id = 0;
svc->temporal_layer_id = 0;
if (svc->number_temporal_layers > 1) {
layer_end = svc->number_temporal_layers;
} else {
layer_end = svc->number_spatial_layers;
}
for (layer = 0; layer < layer_end; ++layer) {
LAYER_CONTEXT *const lc = &svc->layer_context[layer];
RATE_CONTROL *const lrc = &lc->rc;
lc->current_video_frame_in_layer = 0;
lrc->avg_frame_qindex[INTER_FRAME] = oxcf->worst_allowed_q;
lrc->ni_av_qi = oxcf->worst_allowed_q;
lrc->total_actual_bits = 0;
lrc->total_target_vs_actual = 0;
lrc->ni_tot_qi = 0;
lrc->tot_q = 0.0;
lrc->avg_q = 0.0;
lrc->ni_frames = 0;
lrc->decimation_count = 0;
lrc->decimation_factor = 0;
lrc->rate_correction_factor = 1.0;
lrc->key_frame_rate_correction_factor = 1.0;
if (svc->number_temporal_layers > 1) {
lc->target_bandwidth = oxcf->ts_target_bitrate[layer] * 1000;
lrc->last_q[INTER_FRAME] = oxcf->worst_allowed_q;
} else {
lc->target_bandwidth = oxcf->ss_target_bitrate[layer] * 1000;
lrc->last_q[0] = oxcf->best_allowed_q;
lrc->last_q[1] = oxcf->best_allowed_q;
lrc->last_q[2] = oxcf->best_allowed_q;
}
lrc->buffer_level = vp9_rescale((int)(oxcf->starting_buffer_level),
lc->target_bandwidth, 1000);
lrc->bits_off_target = lrc->buffer_level;
}
}
// Update the layer context from a change_config() call.
void vp9_update_layer_context_change_config(VP9_COMP *const cpi,
const int target_bandwidth) {
SVC *const svc = &cpi->svc;
const VP9EncoderConfig *const oxcf = &cpi->oxcf;
const RATE_CONTROL *const rc = &cpi->rc;
int layer;
int layer_end;
float bitrate_alloc = 1.0;
if (svc->number_temporal_layers > 1) {
layer_end = svc->number_temporal_layers;
} else {
layer_end = svc->number_spatial_layers;
}
for (layer = 0; layer < layer_end; ++layer) {
LAYER_CONTEXT *const lc = &svc->layer_context[layer];
RATE_CONTROL *const lrc = &lc->rc;
if (svc->number_temporal_layers > 1) {
lc->target_bandwidth = oxcf->ts_target_bitrate[layer] * 1000;
} else {
lc->target_bandwidth = oxcf->ss_target_bitrate[layer] * 1000;
}
bitrate_alloc = (float)lc->target_bandwidth / target_bandwidth;
// Update buffer-related quantities.
lc->starting_buffer_level =
(int64_t)(oxcf->starting_buffer_level * bitrate_alloc);
lc->optimal_buffer_level =
(int64_t)(oxcf->optimal_buffer_level * bitrate_alloc);
lc->maximum_buffer_size =
(int64_t)(oxcf->maximum_buffer_size * bitrate_alloc);
lrc->bits_off_target = MIN(lrc->bits_off_target, lc->maximum_buffer_size);
lrc->buffer_level = MIN(lrc->buffer_level, lc->maximum_buffer_size);
// Update framerate-related quantities.
if (svc->number_temporal_layers > 1) {
lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
} else {
lc->framerate = oxcf->framerate;
}
lrc->avg_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
lrc->max_frame_bandwidth = rc->max_frame_bandwidth;
// Update qp-related quantities.
lrc->worst_quality = rc->worst_quality;
lrc->best_quality = rc->best_quality;
}
}
static LAYER_CONTEXT *get_layer_context(SVC *svc) {
return svc->number_temporal_layers > 1 ?
&svc->layer_context[svc->temporal_layer_id] :
&svc->layer_context[svc->spatial_layer_id];
}
void vp9_update_temporal_layer_framerate(VP9_COMP *const cpi) {
SVC *const svc = &cpi->svc;
const VP9EncoderConfig *const oxcf = &cpi->oxcf;
LAYER_CONTEXT *const lc = get_layer_context(svc);
RATE_CONTROL *const lrc = &lc->rc;
const int layer = svc->temporal_layer_id;
lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
lrc->avg_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
lrc->max_frame_bandwidth = cpi->rc.max_frame_bandwidth;
// Update the average layer frame size (non-cumulative per-frame-bw).
if (layer == 0) {
lc->avg_frame_size = lrc->avg_frame_bandwidth;
} else {
const double prev_layer_framerate =
oxcf->framerate / oxcf->ts_rate_decimator[layer - 1];
const int prev_layer_target_bandwidth =
oxcf->ts_target_bitrate[layer - 1] * 1000;
lc->avg_frame_size =
(int)((lc->target_bandwidth - prev_layer_target_bandwidth) /
(lc->framerate - prev_layer_framerate));
}
}
void vp9_update_spatial_layer_framerate(VP9_COMP *const cpi, double framerate) {
const VP9EncoderConfig *const oxcf = &cpi->oxcf;
LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
RATE_CONTROL *const lrc = &lc->rc;
lc->framerate = framerate;
lrc->avg_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
lrc->min_frame_bandwidth = (int)(lrc->avg_frame_bandwidth *
oxcf->two_pass_vbrmin_section / 100);
lrc->max_frame_bandwidth = (int)(((int64_t)lrc->avg_frame_bandwidth *
oxcf->two_pass_vbrmax_section) / 100);
lrc->max_gf_interval = 16;
lrc->static_scene_max_gf_interval = cpi->oxcf.key_freq >> 1;
if (oxcf->play_alternate && oxcf->lag_in_frames) {
if (lrc->max_gf_interval > oxcf->lag_in_frames - 1)
lrc->max_gf_interval = oxcf->lag_in_frames - 1;
if (lrc->static_scene_max_gf_interval > oxcf->lag_in_frames - 1)
lrc->static_scene_max_gf_interval = oxcf->lag_in_frames - 1;
}
if (lrc->max_gf_interval > lrc->static_scene_max_gf_interval)
lrc->max_gf_interval = lrc->static_scene_max_gf_interval;
}
void vp9_restore_layer_context(VP9_COMP *const cpi) {
LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
const int old_frame_since_key = cpi->rc.frames_since_key;
const int old_frame_to_key = cpi->rc.frames_to_key;
cpi->rc = lc->rc;
cpi->twopass = lc->twopass;
cpi->oxcf.target_bandwidth = lc->target_bandwidth;
cpi->oxcf.starting_buffer_level = lc->starting_buffer_level;
cpi->oxcf.optimal_buffer_level = lc->optimal_buffer_level;
cpi->oxcf.maximum_buffer_size = lc->maximum_buffer_size;
// Reset the frames_since_key and frames_to_key counters to their values
// before the layer restore. Keep these defined for the stream (not layer).
if (cpi->svc.number_temporal_layers > 1) {
cpi->rc.frames_since_key = old_frame_since_key;
cpi->rc.frames_to_key = old_frame_to_key;
}
}
void vp9_save_layer_context(VP9_COMP *const cpi) {
const VP9EncoderConfig *const oxcf = &cpi->oxcf;
LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
lc->rc = cpi->rc;
lc->twopass = cpi->twopass;
lc->target_bandwidth = (int)oxcf->target_bandwidth;
lc->starting_buffer_level = oxcf->starting_buffer_level;
lc->optimal_buffer_level = oxcf->optimal_buffer_level;
lc->maximum_buffer_size = oxcf->maximum_buffer_size;
}
void vp9_init_second_pass_spatial_svc(VP9_COMP *cpi) {
SVC *const svc = &cpi->svc;
int i;
for (i = 0; i < svc->number_spatial_layers; ++i) {
struct twopass_rc *const twopass = &svc->layer_context[i].twopass;
svc->spatial_layer_id = i;
vp9_init_second_pass(cpi);
twopass->total_stats.spatial_layer_id = i;
twopass->total_left_stats.spatial_layer_id = i;
}
svc->spatial_layer_id = 0;
}
void vp9_inc_frame_in_layer(SVC *svc) {
LAYER_CONTEXT *const lc = (svc->number_temporal_layers > 1)
? &svc->layer_context[svc->temporal_layer_id]
: &svc->layer_context[svc->spatial_layer_id];
++lc->current_video_frame_in_layer;
}
int vp9_is_upper_layer_key_frame(const VP9_COMP *cpi) {
return cpi->use_svc &&
cpi->svc.number_temporal_layers == 1 &&
cpi->svc.spatial_layer_id > 0 &&
cpi->svc.layer_context[cpi->svc.spatial_layer_id].is_key_frame;
}