ref: 240726ac85c16792d2bcf656c20248ea24d4734c
dir: /vp8/encoder/ratectrl.c/
/*
* Copyright (c) 2010 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <assert.h>
#include "math.h"
#include "vp8/common/common.h"
#include "ratectrl.h"
#include "vp8/common/entropymode.h"
#include "vpx_mem/vpx_mem.h"
#include "vp8/common/systemdependent.h"
#include "encodemv.h"
#include "vpx_dsp/vpx_dsp_common.h"
#define MIN_BPB_FACTOR 0.01
#define MAX_BPB_FACTOR 50
extern const MB_PREDICTION_MODE vp8_mode_order[MAX_MODES];
#ifdef MODE_STATS
extern int y_modes[5];
extern int uv_modes[4];
extern int b_modes[10];
extern int inter_y_modes[10];
extern int inter_uv_modes[4];
extern int inter_b_modes[10];
#endif
/* Bits Per MB at different Q (Multiplied by 512) */
#define BPER_MB_NORMBITS 9
/* Work in progress recalibration of baseline rate tables based on
* the assumption that bits per mb is inversely proportional to the
* quantizer value.
*/
const int vp8_bits_per_mb[2][QINDEX_RANGE] = {
/* Intra case 450000/Qintra */
{
1125000, 900000, 750000, 642857, 562500, 500000, 450000, 450000, 409090,
375000, 346153, 321428, 300000, 281250, 264705, 264705, 250000, 236842,
225000, 225000, 214285, 214285, 204545, 204545, 195652, 195652, 187500,
180000, 180000, 173076, 166666, 160714, 155172, 150000, 145161, 140625,
136363, 132352, 128571, 125000, 121621, 121621, 118421, 115384, 112500,
109756, 107142, 104651, 102272, 100000, 97826, 97826, 95744, 93750,
91836, 90000, 88235, 86538, 84905, 83333, 81818, 80357, 78947,
77586, 76271, 75000, 73770, 72580, 71428, 70312, 69230, 68181,
67164, 66176, 65217, 64285, 63380, 62500, 61643, 60810, 60000,
59210, 59210, 58441, 57692, 56962, 56250, 55555, 54878, 54216,
53571, 52941, 52325, 51724, 51136, 50561, 49450, 48387, 47368,
46875, 45918, 45000, 44554, 44117, 43269, 42452, 41666, 40909,
40178, 39473, 38793, 38135, 36885, 36290, 35714, 35156, 34615,
34090, 33582, 33088, 32608, 32142, 31468, 31034, 30405, 29801,
29220, 28662,
},
/* Inter case 285000/Qinter */
{
712500, 570000, 475000, 407142, 356250, 316666, 285000, 259090, 237500,
219230, 203571, 190000, 178125, 167647, 158333, 150000, 142500, 135714,
129545, 123913, 118750, 114000, 109615, 105555, 101785, 98275, 95000,
91935, 89062, 86363, 83823, 81428, 79166, 77027, 75000, 73076,
71250, 69512, 67857, 66279, 64772, 63333, 61956, 60638, 59375,
58163, 57000, 55882, 54807, 53773, 52777, 51818, 50892, 50000,
49137, 47500, 45967, 44531, 43181, 41911, 40714, 39583, 38513,
37500, 36538, 35625, 34756, 33928, 33139, 32386, 31666, 30978,
30319, 29687, 29081, 28500, 27941, 27403, 26886, 26388, 25909,
25446, 25000, 24568, 23949, 23360, 22800, 22265, 21755, 21268,
20802, 20357, 19930, 19520, 19127, 18750, 18387, 18037, 17701,
17378, 17065, 16764, 16473, 16101, 15745, 15405, 15079, 14766,
14467, 14179, 13902, 13636, 13380, 13133, 12895, 12666, 12445,
12179, 11924, 11632, 11445, 11220, 11003, 10795, 10594, 10401,
10215, 10035,
}
};
static const int kf_boost_qadjustment[QINDEX_RANGE] = {
128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142,
143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157,
158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172,
173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187,
188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 200, 201,
201, 202, 203, 203, 203, 204, 204, 205, 205, 206, 206, 207, 207, 208, 208,
209, 209, 210, 210, 211, 211, 212, 212, 213, 213, 214, 214, 215, 215, 216,
216, 217, 217, 218, 218, 219, 219, 220, 220, 220, 220, 220, 220, 220, 220,
220, 220, 220, 220, 220, 220, 220, 220,
};
/* #define GFQ_ADJUSTMENT (Q+100) */
#define GFQ_ADJUSTMENT vp8_gf_boost_qadjustment[Q]
const int vp8_gf_boost_qadjustment[QINDEX_RANGE] = {
80, 82, 84, 86, 88, 90, 92, 94, 96, 97, 98, 99, 100, 101, 102,
103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132,
133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147,
148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162,
163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177,
178, 179, 180, 181, 182, 183, 184, 184, 185, 185, 186, 186, 187, 187, 188,
188, 189, 189, 190, 190, 191, 191, 192, 192, 193, 193, 194, 194, 194, 194,
195, 195, 196, 196, 197, 197, 198, 198
};
/*
const int vp8_gf_boost_qadjustment[QINDEX_RANGE] =
{
100,101,102,103,104,105,105,106,
106,107,107,108,109,109,110,111,
112,113,114,115,116,117,118,119,
120,121,122,123,124,125,126,127,
128,129,130,131,132,133,134,135,
136,137,138,139,140,141,142,143,
144,145,146,147,148,149,150,151,
152,153,154,155,156,157,158,159,
160,161,162,163,164,165,166,167,
168,169,170,170,171,171,172,172,
173,173,173,174,174,174,175,175,
175,176,176,176,177,177,177,177,
178,178,179,179,180,180,181,181,
182,182,183,183,184,184,185,185,
186,186,187,187,188,188,189,189,
190,190,191,191,192,192,193,193,
};
*/
static const int kf_gf_boost_qlimits[QINDEX_RANGE] = {
150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220,
225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295,
300, 305, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430,
440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580,
590, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600,
600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600,
600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600,
600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600, 600,
600, 600, 600, 600, 600, 600, 600, 600,
};
static const int gf_adjust_table[101] = {
100, 115, 130, 145, 160, 175, 190, 200, 210, 220, 230, 240, 260, 270, 280,
290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 400, 400, 400,
400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
400, 400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
};
static const int gf_intra_usage_adjustment[20] = {
125, 120, 115, 110, 105, 100, 95, 85, 80, 75,
70, 65, 60, 55, 50, 50, 50, 50, 50, 50,
};
static const int gf_interval_table[101] = {
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
};
static const unsigned int prior_key_frame_weight[KEY_FRAME_CONTEXT] = { 1, 2, 3,
4, 5 };
void vp8_save_coding_context(VP8_COMP *cpi) {
CODING_CONTEXT *const cc = &cpi->coding_context;
/* Stores a snapshot of key state variables which can subsequently be
* restored with a call to vp8_restore_coding_context. These functions are
* intended for use in a re-code loop in vp8_compress_frame where the
* quantizer value is adjusted between loop iterations.
*/
cc->frames_since_key = cpi->frames_since_key;
cc->filter_level = cpi->common.filter_level;
cc->frames_till_gf_update_due = cpi->frames_till_gf_update_due;
cc->frames_since_golden = cpi->frames_since_golden;
vp8_copy(cc->mvc, cpi->common.fc.mvc);
vp8_copy(cc->mvcosts, cpi->rd_costs.mvcosts);
vp8_copy(cc->ymode_prob, cpi->common.fc.ymode_prob);
vp8_copy(cc->uv_mode_prob, cpi->common.fc.uv_mode_prob);
vp8_copy(cc->ymode_count, cpi->mb.ymode_count);
vp8_copy(cc->uv_mode_count, cpi->mb.uv_mode_count);
/* Stats */
#ifdef MODE_STATS
vp8_copy(cc->y_modes, y_modes);
vp8_copy(cc->uv_modes, uv_modes);
vp8_copy(cc->b_modes, b_modes);
vp8_copy(cc->inter_y_modes, inter_y_modes);
vp8_copy(cc->inter_uv_modes, inter_uv_modes);
vp8_copy(cc->inter_b_modes, inter_b_modes);
#endif
cc->this_frame_percent_intra = cpi->this_frame_percent_intra;
}
void vp8_restore_coding_context(VP8_COMP *cpi) {
CODING_CONTEXT *const cc = &cpi->coding_context;
/* Restore key state variables to the snapshot state stored in the
* previous call to vp8_save_coding_context.
*/
cpi->frames_since_key = cc->frames_since_key;
cpi->common.filter_level = cc->filter_level;
cpi->frames_till_gf_update_due = cc->frames_till_gf_update_due;
cpi->frames_since_golden = cc->frames_since_golden;
vp8_copy(cpi->common.fc.mvc, cc->mvc);
vp8_copy(cpi->rd_costs.mvcosts, cc->mvcosts);
vp8_copy(cpi->common.fc.ymode_prob, cc->ymode_prob);
vp8_copy(cpi->common.fc.uv_mode_prob, cc->uv_mode_prob);
vp8_copy(cpi->mb.ymode_count, cc->ymode_count);
vp8_copy(cpi->mb.uv_mode_count, cc->uv_mode_count);
/* Stats */
#ifdef MODE_STATS
vp8_copy(y_modes, cc->y_modes);
vp8_copy(uv_modes, cc->uv_modes);
vp8_copy(b_modes, cc->b_modes);
vp8_copy(inter_y_modes, cc->inter_y_modes);
vp8_copy(inter_uv_modes, cc->inter_uv_modes);
vp8_copy(inter_b_modes, cc->inter_b_modes);
#endif
cpi->this_frame_percent_intra = cc->this_frame_percent_intra;
}
void vp8_setup_key_frame(VP8_COMP *cpi) {
/* Setup for Key frame: */
vp8_default_coef_probs(&cpi->common);
memcpy(cpi->common.fc.mvc, vp8_default_mv_context,
sizeof(vp8_default_mv_context));
{
int flag[2] = { 1, 1 };
vp8_build_component_cost_table(
cpi->mb.mvcost, (const MV_CONTEXT *)cpi->common.fc.mvc, flag);
}
/* Make sure we initialize separate contexts for altref,gold, and normal.
* TODO shouldn't need 3 different copies of structure to do this!
*/
memcpy(&cpi->lfc_a, &cpi->common.fc, sizeof(cpi->common.fc));
memcpy(&cpi->lfc_g, &cpi->common.fc, sizeof(cpi->common.fc));
memcpy(&cpi->lfc_n, &cpi->common.fc, sizeof(cpi->common.fc));
cpi->common.filter_level = cpi->common.base_qindex * 3 / 8;
/* Provisional interval before next GF */
if (cpi->auto_gold) {
cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
} else {
cpi->frames_till_gf_update_due = DEFAULT_GF_INTERVAL;
}
cpi->common.refresh_golden_frame = 1;
cpi->common.refresh_alt_ref_frame = 1;
}
static int estimate_bits_at_q(int frame_kind, int Q, int MBs,
double correction_factor) {
int Bpm = (int)(.5 + correction_factor * vp8_bits_per_mb[frame_kind][Q]);
/* Attempt to retain reasonable accuracy without overflow. The cutoff is
* chosen such that the maximum product of Bpm and MBs fits 31 bits. The
* largest Bpm takes 20 bits.
*/
if (MBs > (1 << 11)) {
return (Bpm >> BPER_MB_NORMBITS) * MBs;
} else {
return (Bpm * MBs) >> BPER_MB_NORMBITS;
}
}
static void calc_iframe_target_size(VP8_COMP *cpi) {
/* boost defaults to half second */
int kf_boost;
uint64_t target;
/* Clear down mmx registers to allow floating point in what follows */
vp8_clear_system_state();
if (cpi->oxcf.fixed_q >= 0) {
int Q = cpi->oxcf.key_q;
target = estimate_bits_at_q(INTRA_FRAME, Q, cpi->common.MBs,
cpi->key_frame_rate_correction_factor);
} else if (cpi->pass == 2) {
/* New Two pass RC */
target = cpi->per_frame_bandwidth;
}
/* First Frame is a special case */
else if (cpi->common.current_video_frame == 0) {
/* 1 Pass there is no information on which to base size so use
* bandwidth per second * fraction of the initial buffer
* level
*/
target = cpi->oxcf.starting_buffer_level / 2;
if (target > cpi->oxcf.target_bandwidth * 3 / 2) {
target = cpi->oxcf.target_bandwidth * 3 / 2;
}
} else {
/* if this keyframe was forced, use a more recent Q estimate */
int Q = (cpi->common.frame_flags & FRAMEFLAGS_KEY) ? cpi->avg_frame_qindex
: cpi->ni_av_qi;
int initial_boost = 32; /* |3.0 * per_frame_bandwidth| */
/* Boost depends somewhat on frame rate: only used for 1 layer case. */
if (cpi->oxcf.number_of_layers == 1) {
kf_boost = VPXMAX(initial_boost, (int)(2 * cpi->output_framerate - 16));
} else {
/* Initial factor: set target size to: |3.0 * per_frame_bandwidth|. */
kf_boost = initial_boost;
}
/* adjustment up based on q: this factor ranges from ~1.2 to 2.2. */
kf_boost = kf_boost * kf_boost_qadjustment[Q] / 100;
/* frame separation adjustment ( down) */
if (cpi->frames_since_key < cpi->output_framerate / 2) {
kf_boost =
(int)(kf_boost * cpi->frames_since_key / (cpi->output_framerate / 2));
}
/* Minimal target size is |2* per_frame_bandwidth|. */
if (kf_boost < 16) kf_boost = 16;
target = ((16 + kf_boost) * cpi->per_frame_bandwidth) >> 4;
}
if (cpi->oxcf.rc_max_intra_bitrate_pct) {
unsigned int max_rate =
cpi->per_frame_bandwidth * cpi->oxcf.rc_max_intra_bitrate_pct / 100;
if (target > max_rate) target = max_rate;
}
cpi->this_frame_target = (int)target;
/* TODO: if we separate rate targeting from Q targetting, move this.
* Reset the active worst quality to the baseline value for key frames.
*/
if (cpi->pass != 2) cpi->active_worst_quality = cpi->worst_quality;
#if 0
{
FILE *f;
f = fopen("kf_boost.stt", "a");
fprintf(f, " %8u %10d %10d %10d\n",
cpi->common.current_video_frame, cpi->gfu_boost, cpi->baseline_gf_interval, cpi->source_alt_ref_pending);
fclose(f);
}
#endif
}
/* Do the best we can to define the parameters for the next GF based on what
* information we have available.
*/
static void calc_gf_params(VP8_COMP *cpi) {
int Q =
(cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
int Boost = 0;
int gf_frame_useage = 0; /* Golden frame useage since last GF */
int tot_mbs = cpi->recent_ref_frame_usage[INTRA_FRAME] +
cpi->recent_ref_frame_usage[LAST_FRAME] +
cpi->recent_ref_frame_usage[GOLDEN_FRAME] +
cpi->recent_ref_frame_usage[ALTREF_FRAME];
int pct_gf_active = (100 * cpi->gf_active_count) /
(cpi->common.mb_rows * cpi->common.mb_cols);
if (tot_mbs) {
gf_frame_useage = (cpi->recent_ref_frame_usage[GOLDEN_FRAME] +
cpi->recent_ref_frame_usage[ALTREF_FRAME]) *
100 / tot_mbs;
}
if (pct_gf_active > gf_frame_useage) gf_frame_useage = pct_gf_active;
/* Not two pass */
if (cpi->pass != 2) {
/* Single Pass lagged mode: TBD */
if (0) {
}
/* Single Pass compression: Has to use current and historical data */
else {
#if 0
/* Experimental code */
int index = cpi->one_pass_frame_index;
int frames_to_scan = (cpi->max_gf_interval <= MAX_LAG_BUFFERS) ? cpi->max_gf_interval : MAX_LAG_BUFFERS;
/* ************** Experimental code - incomplete */
/*
double decay_val = 1.0;
double IIAccumulator = 0.0;
double last_iiaccumulator = 0.0;
double IIRatio;
cpi->one_pass_frame_index = cpi->common.current_video_frame%MAX_LAG_BUFFERS;
for ( i = 0; i < (frames_to_scan - 1); i++ )
{
if ( index < 0 )
index = MAX_LAG_BUFFERS;
index --;
if ( cpi->one_pass_frame_stats[index].frame_coded_error > 0.0 )
{
IIRatio = cpi->one_pass_frame_stats[index].frame_intra_error / cpi->one_pass_frame_stats[index].frame_coded_error;
if ( IIRatio > 30.0 )
IIRatio = 30.0;
}
else
IIRatio = 30.0;
IIAccumulator += IIRatio * decay_val;
decay_val = decay_val * cpi->one_pass_frame_stats[index].frame_pcnt_inter;
if ( (i > MIN_GF_INTERVAL) &&
((IIAccumulator - last_iiaccumulator) < 2.0) )
{
break;
}
last_iiaccumulator = IIAccumulator;
}
Boost = IIAccumulator*100.0/16.0;
cpi->baseline_gf_interval = i;
*/
#else
/*************************************************************/
/* OLD code */
/* Adjust boost based upon ambient Q */
Boost = GFQ_ADJUSTMENT;
/* Adjust based upon most recently measure intra useage */
Boost = Boost *
gf_intra_usage_adjustment[(cpi->this_frame_percent_intra < 15)
? cpi->this_frame_percent_intra
: 14] /
100;
/* Adjust gf boost based upon GF usage since last GF */
Boost = Boost * gf_adjust_table[gf_frame_useage] / 100;
#endif
}
/* golden frame boost without recode loop often goes awry. be
* safe by keeping numbers down.
*/
if (!cpi->sf.recode_loop) {
if (cpi->compressor_speed == 2) Boost = Boost / 2;
}
/* Apply an upper limit based on Q for 1 pass encodes */
if (Boost > kf_gf_boost_qlimits[Q] && (cpi->pass == 0)) {
Boost = kf_gf_boost_qlimits[Q];
/* Apply lower limits to boost. */
} else if (Boost < 110) {
Boost = 110;
}
/* Note the boost used */
cpi->last_boost = Boost;
}
/* Estimate next interval
* This is updated once the real frame size/boost is known.
*/
if (cpi->oxcf.fixed_q == -1) {
if (cpi->pass == 2) /* 2 Pass */
{
cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
} else /* 1 Pass */
{
cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
if (cpi->last_boost > 750) cpi->frames_till_gf_update_due++;
if (cpi->last_boost > 1000) cpi->frames_till_gf_update_due++;
if (cpi->last_boost > 1250) cpi->frames_till_gf_update_due++;
if (cpi->last_boost >= 1500) cpi->frames_till_gf_update_due++;
if (gf_interval_table[gf_frame_useage] > cpi->frames_till_gf_update_due) {
cpi->frames_till_gf_update_due = gf_interval_table[gf_frame_useage];
}
if (cpi->frames_till_gf_update_due > cpi->max_gf_interval) {
cpi->frames_till_gf_update_due = cpi->max_gf_interval;
}
}
} else {
cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
}
/* ARF on or off */
if (cpi->pass != 2) {
/* For now Alt ref is not allowed except in 2 pass modes. */
cpi->source_alt_ref_pending = 0;
/*if ( cpi->oxcf.fixed_q == -1)
{
if ( cpi->oxcf.play_alternate && (cpi->last_boost > (100 +
(AF_THRESH*cpi->frames_till_gf_update_due)) ) )
cpi->source_alt_ref_pending = 1;
else
cpi->source_alt_ref_pending = 0;
}*/
}
}
static void calc_pframe_target_size(VP8_COMP *cpi) {
int min_frame_target;
int old_per_frame_bandwidth = cpi->per_frame_bandwidth;
if (cpi->current_layer > 0) {
cpi->per_frame_bandwidth =
cpi->layer_context[cpi->current_layer].avg_frame_size_for_layer;
}
min_frame_target = 0;
if (cpi->pass == 2) {
min_frame_target = cpi->min_frame_bandwidth;
if (min_frame_target < (cpi->av_per_frame_bandwidth >> 5)) {
min_frame_target = cpi->av_per_frame_bandwidth >> 5;
}
} else if (min_frame_target < cpi->per_frame_bandwidth / 4) {
min_frame_target = cpi->per_frame_bandwidth / 4;
}
/* Special alt reference frame case */
if ((cpi->common.refresh_alt_ref_frame) &&
(cpi->oxcf.number_of_layers == 1)) {
if (cpi->pass == 2) {
/* Per frame bit target for the alt ref frame */
cpi->per_frame_bandwidth = cpi->twopass.gf_bits;
cpi->this_frame_target = cpi->per_frame_bandwidth;
}
/* One Pass ??? TBD */
}
/* Normal frames (gf,and inter) */
else {
/* 2 pass */
if (cpi->pass == 2) {
cpi->this_frame_target = cpi->per_frame_bandwidth;
}
/* 1 pass */
else {
int Adjustment;
/* Make rate adjustment to recover bits spent in key frame
* Test to see if the key frame inter data rate correction
* should still be in force
*/
if (cpi->kf_overspend_bits > 0) {
Adjustment = (cpi->kf_bitrate_adjustment <= cpi->kf_overspend_bits)
? cpi->kf_bitrate_adjustment
: cpi->kf_overspend_bits;
if (Adjustment > (cpi->per_frame_bandwidth - min_frame_target)) {
Adjustment = (cpi->per_frame_bandwidth - min_frame_target);
}
cpi->kf_overspend_bits -= Adjustment;
/* Calculate an inter frame bandwidth target for the next
* few frames designed to recover any extra bits spent on
* the key frame.
*/
cpi->this_frame_target = cpi->per_frame_bandwidth - Adjustment;
if (cpi->this_frame_target < min_frame_target) {
cpi->this_frame_target = min_frame_target;
}
} else {
cpi->this_frame_target = cpi->per_frame_bandwidth;
}
/* If appropriate make an adjustment to recover bits spent on a
* recent GF
*/
if ((cpi->gf_overspend_bits > 0) &&
(cpi->this_frame_target > min_frame_target)) {
Adjustment = (cpi->non_gf_bitrate_adjustment <= cpi->gf_overspend_bits)
? cpi->non_gf_bitrate_adjustment
: cpi->gf_overspend_bits;
if (Adjustment > (cpi->this_frame_target - min_frame_target)) {
Adjustment = (cpi->this_frame_target - min_frame_target);
}
cpi->gf_overspend_bits -= Adjustment;
cpi->this_frame_target -= Adjustment;
}
/* Apply small + and - boosts for non gf frames */
if ((cpi->last_boost > 150) && (cpi->frames_till_gf_update_due > 0) &&
(cpi->current_gf_interval >= (MIN_GF_INTERVAL << 1))) {
/* % Adjustment limited to the range 1% to 10% */
Adjustment = (cpi->last_boost - 100) >> 5;
if (Adjustment < 1) {
Adjustment = 1;
} else if (Adjustment > 10) {
Adjustment = 10;
}
/* Convert to bits */
Adjustment = (cpi->this_frame_target * Adjustment) / 100;
if (Adjustment > (cpi->this_frame_target - min_frame_target)) {
Adjustment = (cpi->this_frame_target - min_frame_target);
}
if (cpi->frames_since_golden == (cpi->current_gf_interval >> 1)) {
Adjustment = (cpi->current_gf_interval - 1) * Adjustment;
// Limit adjustment to 10% of current target.
if (Adjustment > (10 * cpi->this_frame_target) / 100) {
Adjustment = (10 * cpi->this_frame_target) / 100;
}
cpi->this_frame_target += Adjustment;
} else {
cpi->this_frame_target -= Adjustment;
}
}
}
}
/* Sanity check that the total sum of adjustments is not above the
* maximum allowed That is that having allowed for KF and GF penalties
* we have not pushed the current interframe target to low. If the
* adjustment we apply here is not capable of recovering all the extra
* bits we have spent in the KF or GF then the remainder will have to
* be recovered over a longer time span via other buffer / rate control
* mechanisms.
*/
if (cpi->this_frame_target < min_frame_target) {
cpi->this_frame_target = min_frame_target;
}
if (!cpi->common.refresh_alt_ref_frame) {
/* Note the baseline target data rate for this inter frame. */
cpi->inter_frame_target = cpi->this_frame_target;
}
/* One Pass specific code */
if (cpi->pass == 0) {
/* Adapt target frame size with respect to any buffering constraints: */
if (cpi->buffered_mode) {
int one_percent_bits = (int)(1 + cpi->oxcf.optimal_buffer_level / 100);
if ((cpi->buffer_level < cpi->oxcf.optimal_buffer_level) ||
(cpi->bits_off_target < cpi->oxcf.optimal_buffer_level)) {
int percent_low = 0;
/* Decide whether or not we need to adjust the frame data
* rate target.
*
* If we are are below the optimal buffer fullness level
* and adherence to buffering constraints is important to
* the end usage then adjust the per frame target.
*/
if ((cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
(cpi->buffer_level < cpi->oxcf.optimal_buffer_level)) {
percent_low =
(int)((cpi->oxcf.optimal_buffer_level - cpi->buffer_level) /
one_percent_bits);
}
/* Are we overshooting the long term clip data rate... */
else if (cpi->bits_off_target < 0) {
/* Adjust per frame data target downwards to compensate. */
percent_low =
(int)(100 * -cpi->bits_off_target / (cpi->total_byte_count * 8));
}
if (percent_low > cpi->oxcf.under_shoot_pct) {
percent_low = cpi->oxcf.under_shoot_pct;
} else if (percent_low < 0) {
percent_low = 0;
}
/* lower the target bandwidth for this frame. */
cpi->this_frame_target -= (cpi->this_frame_target * percent_low) / 200;
/* Are we using allowing control of active_worst_allowed_q
* according to buffer level.
*/
if (cpi->auto_worst_q && cpi->ni_frames > 150) {
int64_t critical_buffer_level;
/* For streaming applications the most important factor is
* cpi->buffer_level as this takes into account the
* specified short term buffering constraints. However,
* hitting the long term clip data rate target is also
* important.
*/
if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) {
/* Take the smaller of cpi->buffer_level and
* cpi->bits_off_target
*/
critical_buffer_level = (cpi->buffer_level < cpi->bits_off_target)
? cpi->buffer_level
: cpi->bits_off_target;
}
/* For local file playback short term buffering constraints
* are less of an issue
*/
else {
/* Consider only how we are doing for the clip as a
* whole
*/
critical_buffer_level = cpi->bits_off_target;
}
/* Set the active worst quality based upon the selected
* buffer fullness number.
*/
if (critical_buffer_level < cpi->oxcf.optimal_buffer_level) {
if (critical_buffer_level > (cpi->oxcf.optimal_buffer_level >> 2)) {
int64_t qadjustment_range = cpi->worst_quality - cpi->ni_av_qi;
int64_t above_base = (critical_buffer_level -
(cpi->oxcf.optimal_buffer_level >> 2));
/* Step active worst quality down from
* cpi->ni_av_qi when (critical_buffer_level ==
* cpi->optimal_buffer_level) to
* cpi->worst_quality when
* (critical_buffer_level ==
* cpi->optimal_buffer_level >> 2)
*/
cpi->active_worst_quality =
cpi->worst_quality -
(int)((qadjustment_range * above_base) /
(cpi->oxcf.optimal_buffer_level * 3 >> 2));
} else {
cpi->active_worst_quality = cpi->worst_quality;
}
} else {
cpi->active_worst_quality = cpi->ni_av_qi;
}
} else {
cpi->active_worst_quality = cpi->worst_quality;
}
} else {
int percent_high = 0;
if ((cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
(cpi->buffer_level > cpi->oxcf.optimal_buffer_level)) {
percent_high =
(int)((cpi->buffer_level - cpi->oxcf.optimal_buffer_level) /
one_percent_bits);
} else if (cpi->bits_off_target > cpi->oxcf.optimal_buffer_level) {
percent_high =
(int)((100 * cpi->bits_off_target) / (cpi->total_byte_count * 8));
}
if (percent_high > cpi->oxcf.over_shoot_pct) {
percent_high = cpi->oxcf.over_shoot_pct;
} else if (percent_high < 0) {
percent_high = 0;
}
cpi->this_frame_target += (cpi->this_frame_target * percent_high) / 200;
/* Are we allowing control of active_worst_allowed_q according
* to buffer level.
*/
if (cpi->auto_worst_q && cpi->ni_frames > 150) {
/* When using the relaxed buffer model stick to the
* user specified value
*/
cpi->active_worst_quality = cpi->ni_av_qi;
} else {
cpi->active_worst_quality = cpi->worst_quality;
}
}
/* Set active_best_quality to prevent quality rising too high */
cpi->active_best_quality = cpi->best_quality;
/* Worst quality obviously must not be better than best quality */
if (cpi->active_worst_quality <= cpi->active_best_quality) {
cpi->active_worst_quality = cpi->active_best_quality + 1;
}
if (cpi->active_worst_quality > 127) cpi->active_worst_quality = 127;
}
/* Unbuffered mode (eg. video conferencing) */
else {
/* Set the active worst quality */
cpi->active_worst_quality = cpi->worst_quality;
}
/* Special trap for constrained quality mode
* "active_worst_quality" may never drop below cq level
* for any frame type.
*/
if (cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY &&
cpi->active_worst_quality < cpi->cq_target_quality) {
cpi->active_worst_quality = cpi->cq_target_quality;
}
}
/* Test to see if we have to drop a frame
* The auto-drop frame code is only used in buffered mode.
* In unbufferd mode (eg vide conferencing) the descision to
* code or drop a frame is made outside the codec in response to real
* world comms or buffer considerations.
*/
if (cpi->drop_frames_allowed &&
(cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
((cpi->common.frame_type != KEY_FRAME))) {
/* Check for a buffer underun-crisis in which case we have to drop
* a frame
*/
if ((cpi->buffer_level < 0)) {
#if 0
FILE *f = fopen("dec.stt", "a");
fprintf(f, "%10d %10d %10d %10d ***** BUFFER EMPTY\n",
(int) cpi->common.current_video_frame,
cpi->decimation_factor, cpi->common.horiz_scale,
(cpi->buffer_level * 100) / cpi->oxcf.optimal_buffer_level);
fclose(f);
#endif
cpi->drop_frame = 1;
/* Update the buffer level variable. */
cpi->bits_off_target += cpi->av_per_frame_bandwidth;
if (cpi->bits_off_target > cpi->oxcf.maximum_buffer_size) {
cpi->bits_off_target = (int)cpi->oxcf.maximum_buffer_size;
}
cpi->buffer_level = cpi->bits_off_target;
if (cpi->oxcf.number_of_layers > 1) {
unsigned int i;
// Propagate bits saved by dropping the frame to higher layers.
for (i = cpi->current_layer + 1; i < cpi->oxcf.number_of_layers; ++i) {
LAYER_CONTEXT *lc = &cpi->layer_context[i];
lc->bits_off_target += (int)(lc->target_bandwidth / lc->framerate);
if (lc->bits_off_target > lc->maximum_buffer_size) {
lc->bits_off_target = lc->maximum_buffer_size;
}
lc->buffer_level = lc->bits_off_target;
}
}
}
}
/* Adjust target frame size for Golden Frames: */
if (cpi->oxcf.error_resilient_mode == 0 &&
(cpi->frames_till_gf_update_due == 0) && !cpi->drop_frame) {
int Q =
(cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
int gf_frame_useage = 0; /* Golden frame useage since last GF */
int tot_mbs = cpi->recent_ref_frame_usage[INTRA_FRAME] +
cpi->recent_ref_frame_usage[LAST_FRAME] +
cpi->recent_ref_frame_usage[GOLDEN_FRAME] +
cpi->recent_ref_frame_usage[ALTREF_FRAME];
int pct_gf_active = (100 * cpi->gf_active_count) /
(cpi->common.mb_rows * cpi->common.mb_cols);
if (tot_mbs) {
gf_frame_useage = (cpi->recent_ref_frame_usage[GOLDEN_FRAME] +
cpi->recent_ref_frame_usage[ALTREF_FRAME]) *
100 / tot_mbs;
}
if (pct_gf_active > gf_frame_useage) gf_frame_useage = pct_gf_active;
/* Is a fixed manual GF frequency being used */
if (cpi->auto_gold) {
/* For one pass throw a GF if recent frame intra useage is
* low or the GF useage is high
*/
if ((cpi->pass == 0) &&
(cpi->this_frame_percent_intra < 15 || gf_frame_useage >= 5)) {
cpi->common.refresh_golden_frame = 1;
/* Two pass GF descision */
} else if (cpi->pass == 2) {
cpi->common.refresh_golden_frame = 1;
}
}
#if 0
/* Debug stats */
if (0)
{
FILE *f;
f = fopen("gf_useaget.stt", "a");
fprintf(f, " %8ld %10ld %10ld %10ld %10ld\n",
cpi->common.current_video_frame, cpi->gfu_boost, GFQ_ADJUSTMENT, cpi->gfu_boost, gf_frame_useage);
fclose(f);
}
#endif
if (cpi->common.refresh_golden_frame == 1) {
#if 0
if (0)
{
FILE *f;
f = fopen("GFexit.stt", "a");
fprintf(f, "%8ld GF coded\n", cpi->common.current_video_frame);
fclose(f);
}
#endif
if (cpi->auto_adjust_gold_quantizer) {
calc_gf_params(cpi);
}
/* If we are using alternate ref instead of gf then do not apply the
* boost It will instead be applied to the altref update Jims
* modified boost
*/
if (!cpi->source_alt_ref_active) {
if (cpi->oxcf.fixed_q < 0) {
if (cpi->pass == 2) {
/* The spend on the GF is defined in the two pass
* code for two pass encodes
*/
cpi->this_frame_target = cpi->per_frame_bandwidth;
} else {
int Boost = cpi->last_boost;
int frames_in_section = cpi->frames_till_gf_update_due + 1;
int allocation_chunks = (frames_in_section * 100) + (Boost - 100);
int bits_in_section = cpi->inter_frame_target * frames_in_section;
/* Normalize Altboost and allocations chunck down to
* prevent overflow
*/
while (Boost > 1000) {
Boost /= 2;
allocation_chunks /= 2;
}
/* Avoid loss of precision but avoid overflow */
if ((bits_in_section >> 7) > allocation_chunks) {
cpi->this_frame_target =
Boost * (bits_in_section / allocation_chunks);
} else {
cpi->this_frame_target =
(Boost * bits_in_section) / allocation_chunks;
}
}
} else {
cpi->this_frame_target =
(estimate_bits_at_q(1, Q, cpi->common.MBs, 1.0) *
cpi->last_boost) /
100;
}
}
/* If there is an active ARF at this location use the minimum
* bits on this frame even if it is a contructed arf.
* The active maximum quantizer insures that an appropriate
* number of bits will be spent if needed for contstructed ARFs.
*/
else {
cpi->this_frame_target = 0;
}
cpi->current_gf_interval = cpi->frames_till_gf_update_due;
}
}
cpi->per_frame_bandwidth = old_per_frame_bandwidth;
}
void vp8_update_rate_correction_factors(VP8_COMP *cpi, int damp_var) {
int Q = cpi->common.base_qindex;
int correction_factor = 100;
double rate_correction_factor;
double adjustment_limit;
int projected_size_based_on_q = 0;
/* Clear down mmx registers to allow floating point in what follows */
vp8_clear_system_state();
if (cpi->common.frame_type == KEY_FRAME) {
rate_correction_factor = cpi->key_frame_rate_correction_factor;
} else {
if (cpi->oxcf.number_of_layers == 1 && (cpi->common.refresh_alt_ref_frame ||
cpi->common.refresh_golden_frame)) {
rate_correction_factor = cpi->gf_rate_correction_factor;
} else {
rate_correction_factor = cpi->rate_correction_factor;
}
}
/* Work out how big we would have expected the frame to be at this Q
* given the current correction factor. Stay in double to avoid int
* overflow when values are large
*/
projected_size_based_on_q =
(int)(((.5 +
rate_correction_factor *
vp8_bits_per_mb[cpi->common.frame_type][Q]) *
cpi->common.MBs) /
(1 << BPER_MB_NORMBITS));
/* Make some allowance for cpi->zbin_over_quant */
if (cpi->mb.zbin_over_quant > 0) {
int Z = cpi->mb.zbin_over_quant;
double Factor = 0.99;
double factor_adjustment = 0.01 / 256.0;
while (Z > 0) {
Z--;
projected_size_based_on_q = (int)(Factor * projected_size_based_on_q);
Factor += factor_adjustment;
if (Factor >= 0.999) Factor = 0.999;
}
}
/* Work out a size correction factor. */
if (projected_size_based_on_q > 0) {
correction_factor =
(100 * cpi->projected_frame_size) / projected_size_based_on_q;
}
/* More heavily damped adjustment used if we have been oscillating
* either side of target
*/
switch (damp_var) {
case 0: adjustment_limit = 0.75; break;
case 1: adjustment_limit = 0.375; break;
case 2:
default: adjustment_limit = 0.25; break;
}
if (correction_factor > 102) {
/* We are not already at the worst allowable quality */
correction_factor =
(int)(100.5 + ((correction_factor - 100) * adjustment_limit));
rate_correction_factor =
((rate_correction_factor * correction_factor) / 100);
/* Keep rate_correction_factor within limits */
if (rate_correction_factor > MAX_BPB_FACTOR) {
rate_correction_factor = MAX_BPB_FACTOR;
}
} else if (correction_factor < 99) {
/* We are not already at the best allowable quality */
correction_factor =
(int)(100.5 - ((100 - correction_factor) * adjustment_limit));
rate_correction_factor =
((rate_correction_factor * correction_factor) / 100);
/* Keep rate_correction_factor within limits */
if (rate_correction_factor < MIN_BPB_FACTOR) {
rate_correction_factor = MIN_BPB_FACTOR;
}
}
if (cpi->common.frame_type == KEY_FRAME) {
cpi->key_frame_rate_correction_factor = rate_correction_factor;
} else {
if (cpi->oxcf.number_of_layers == 1 && (cpi->common.refresh_alt_ref_frame ||
cpi->common.refresh_golden_frame)) {
cpi->gf_rate_correction_factor = rate_correction_factor;
} else {
cpi->rate_correction_factor = rate_correction_factor;
}
}
}
int vp8_regulate_q(VP8_COMP *cpi, int target_bits_per_frame) {
int Q = cpi->active_worst_quality;
if (cpi->force_maxqp == 1) {
cpi->active_worst_quality = cpi->worst_quality;
return cpi->worst_quality;
}
/* Reset Zbin OQ value */
cpi->mb.zbin_over_quant = 0;
if (cpi->oxcf.fixed_q >= 0) {
Q = cpi->oxcf.fixed_q;
if (cpi->common.frame_type == KEY_FRAME) {
Q = cpi->oxcf.key_q;
} else if (cpi->oxcf.number_of_layers == 1 &&
cpi->common.refresh_alt_ref_frame) {
Q = cpi->oxcf.alt_q;
} else if (cpi->oxcf.number_of_layers == 1 &&
cpi->common.refresh_golden_frame) {
Q = cpi->oxcf.gold_q;
}
} else {
int i;
int last_error = INT_MAX;
int target_bits_per_mb;
int bits_per_mb_at_this_q;
double correction_factor;
/* Select the appropriate correction factor based upon type of frame. */
if (cpi->common.frame_type == KEY_FRAME) {
correction_factor = cpi->key_frame_rate_correction_factor;
} else {
if (cpi->oxcf.number_of_layers == 1 &&
(cpi->common.refresh_alt_ref_frame ||
cpi->common.refresh_golden_frame)) {
correction_factor = cpi->gf_rate_correction_factor;
} else {
correction_factor = cpi->rate_correction_factor;
}
}
/* Calculate required scaling factor based on target frame size and
* size of frame produced using previous Q
*/
if (target_bits_per_frame >= (INT_MAX >> BPER_MB_NORMBITS)) {
/* Case where we would overflow int */
target_bits_per_mb = (target_bits_per_frame / cpi->common.MBs)
<< BPER_MB_NORMBITS;
} else {
target_bits_per_mb =
(target_bits_per_frame << BPER_MB_NORMBITS) / cpi->common.MBs;
}
i = cpi->active_best_quality;
do {
bits_per_mb_at_this_q =
(int)(.5 +
correction_factor * vp8_bits_per_mb[cpi->common.frame_type][i]);
if (bits_per_mb_at_this_q <= target_bits_per_mb) {
if ((target_bits_per_mb - bits_per_mb_at_this_q) <= last_error) {
Q = i;
} else {
Q = i - 1;
}
break;
} else {
last_error = bits_per_mb_at_this_q - target_bits_per_mb;
}
} while (++i <= cpi->active_worst_quality);
/* If we are at MAXQ then enable Q over-run which seeks to claw
* back additional bits through things like the RD multiplier
* and zero bin size.
*/
if (Q >= MAXQ) {
int zbin_oqmax;
double Factor = 0.99;
double factor_adjustment = 0.01 / 256.0;
if (cpi->common.frame_type == KEY_FRAME) {
zbin_oqmax = 0;
} else if (cpi->oxcf.number_of_layers == 1 &&
(cpi->common.refresh_alt_ref_frame ||
(cpi->common.refresh_golden_frame &&
!cpi->source_alt_ref_active))) {
zbin_oqmax = 16;
} else {
zbin_oqmax = ZBIN_OQ_MAX;
}
/*{
double Factor =
(double)target_bits_per_mb/(double)bits_per_mb_at_this_q;
double Oq;
Factor = Factor/1.2683;
Oq = pow( Factor, (1.0/-0.165) );
if ( Oq > zbin_oqmax )
Oq = zbin_oqmax;
cpi->zbin_over_quant = (int)Oq;
}*/
/* Each incrment in the zbin is assumed to have a fixed effect
* on bitrate. This is not of course true. The effect will be
* highly clip dependent and may well have sudden steps. The
* idea here is to acheive higher effective quantizers than the
* normal maximum by expanding the zero bin and hence
* decreasing the number of low magnitude non zero coefficients.
*/
while (cpi->mb.zbin_over_quant < zbin_oqmax) {
cpi->mb.zbin_over_quant++;
if (cpi->mb.zbin_over_quant > zbin_oqmax) {
cpi->mb.zbin_over_quant = zbin_oqmax;
}
/* Adjust bits_per_mb_at_this_q estimate */
bits_per_mb_at_this_q = (int)(Factor * bits_per_mb_at_this_q);
Factor += factor_adjustment;
if (Factor >= 0.999) Factor = 0.999;
/* Break out if we get down to the target rate */
if (bits_per_mb_at_this_q <= target_bits_per_mb) break;
}
}
}
return Q;
}
static int estimate_keyframe_frequency(VP8_COMP *cpi) {
int i;
/* Average key frame frequency */
int av_key_frame_frequency = 0;
/* First key frame at start of sequence is a special case. We have no
* frequency data.
*/
if (cpi->key_frame_count == 1) {
/* Assume a default of 1 kf every 2 seconds, or the max kf interval,
* whichever is smaller.
*/
int key_freq = cpi->oxcf.key_freq > 0 ? cpi->oxcf.key_freq : 1;
av_key_frame_frequency = 1 + (int)cpi->output_framerate * 2;
if (cpi->oxcf.auto_key && av_key_frame_frequency > key_freq) {
av_key_frame_frequency = key_freq;
}
cpi->prior_key_frame_distance[KEY_FRAME_CONTEXT - 1] =
av_key_frame_frequency;
} else {
unsigned int total_weight = 0;
int last_kf_interval =
(cpi->frames_since_key > 0) ? cpi->frames_since_key : 1;
/* reset keyframe context and calculate weighted average of last
* KEY_FRAME_CONTEXT keyframes
*/
for (i = 0; i < KEY_FRAME_CONTEXT; ++i) {
if (i < KEY_FRAME_CONTEXT - 1) {
cpi->prior_key_frame_distance[i] = cpi->prior_key_frame_distance[i + 1];
} else {
cpi->prior_key_frame_distance[i] = last_kf_interval;
}
av_key_frame_frequency +=
prior_key_frame_weight[i] * cpi->prior_key_frame_distance[i];
total_weight += prior_key_frame_weight[i];
}
av_key_frame_frequency /= total_weight;
}
// TODO (marpan): Given the checks above, |av_key_frame_frequency|
// should always be above 0. But for now we keep the sanity check in.
if (av_key_frame_frequency == 0) av_key_frame_frequency = 1;
return av_key_frame_frequency;
}
void vp8_adjust_key_frame_context(VP8_COMP *cpi) {
/* Clear down mmx registers to allow floating point in what follows */
vp8_clear_system_state();
/* Do we have any key frame overspend to recover? */
/* Two-pass overspend handled elsewhere. */
if ((cpi->pass != 2) &&
(cpi->projected_frame_size > cpi->per_frame_bandwidth)) {
int overspend;
/* Update the count of key frame overspend to be recovered in
* subsequent frames. A portion of the KF overspend is treated as gf
* overspend (and hence recovered more quickly) as the kf is also a
* gf. Otherwise the few frames following each kf tend to get more
* bits allocated than those following other gfs.
*/
overspend = (cpi->projected_frame_size - cpi->per_frame_bandwidth);
if (cpi->oxcf.number_of_layers > 1) {
cpi->kf_overspend_bits += overspend;
} else {
cpi->kf_overspend_bits += overspend * 7 / 8;
cpi->gf_overspend_bits += overspend * 1 / 8;
}
/* Work out how much to try and recover per frame. */
cpi->kf_bitrate_adjustment =
cpi->kf_overspend_bits / estimate_keyframe_frequency(cpi);
}
cpi->frames_since_key = 0;
cpi->key_frame_count++;
}
void vp8_compute_frame_size_bounds(VP8_COMP *cpi, int *frame_under_shoot_limit,
int *frame_over_shoot_limit) {
/* Set-up bounds on acceptable frame size: */
if (cpi->oxcf.fixed_q >= 0) {
/* Fixed Q scenario: frame size never outranges target
* (there is no target!)
*/
*frame_under_shoot_limit = 0;
*frame_over_shoot_limit = INT_MAX;
} else {
if (cpi->common.frame_type == KEY_FRAME) {
*frame_over_shoot_limit = cpi->this_frame_target * 9 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 7 / 8;
} else {
if (cpi->oxcf.number_of_layers > 1 || cpi->common.refresh_alt_ref_frame ||
cpi->common.refresh_golden_frame) {
*frame_over_shoot_limit = cpi->this_frame_target * 9 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 7 / 8;
} else {
/* For CBR take buffer fullness into account */
if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) {
if (cpi->buffer_level >= ((cpi->oxcf.optimal_buffer_level +
cpi->oxcf.maximum_buffer_size) >>
1)) {
/* Buffer is too full so relax overshoot and tighten
* undershoot
*/
*frame_over_shoot_limit = cpi->this_frame_target * 12 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 6 / 8;
} else if (cpi->buffer_level <=
(cpi->oxcf.optimal_buffer_level >> 1)) {
/* Buffer is too low so relax undershoot and tighten
* overshoot
*/
*frame_over_shoot_limit = cpi->this_frame_target * 10 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 4 / 8;
} else {
*frame_over_shoot_limit = cpi->this_frame_target * 11 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 5 / 8;
}
}
/* VBR and CQ mode */
/* Note that tighter restrictions here can help quality
* but hurt encode speed
*/
else {
/* Stron overshoot limit for constrained quality */
if (cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY) {
*frame_over_shoot_limit = cpi->this_frame_target * 11 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 2 / 8;
} else {
*frame_over_shoot_limit = cpi->this_frame_target * 11 / 8;
*frame_under_shoot_limit = cpi->this_frame_target * 5 / 8;
}
}
}
}
/* For very small rate targets where the fractional adjustment
* (eg * 7/8) may be tiny make sure there is at least a minimum
* range.
*/
*frame_over_shoot_limit += 200;
*frame_under_shoot_limit -= 200;
if (*frame_under_shoot_limit < 0) *frame_under_shoot_limit = 0;
}
}
/* return of 0 means drop frame */
int vp8_pick_frame_size(VP8_COMP *cpi) {
VP8_COMMON *cm = &cpi->common;
if (cm->frame_type == KEY_FRAME) {
calc_iframe_target_size(cpi);
} else {
calc_pframe_target_size(cpi);
/* Check if we're dropping the frame: */
if (cpi->drop_frame) {
cpi->drop_frame = 0;
return 0;
}
}
return 1;
}
// If this just encoded frame (mcomp/transform/quant, but before loopfilter and
// pack_bitstream) has large overshoot, and was not being encoded close to the
// max QP, then drop this frame and force next frame to be encoded at max QP.
// Condition this on 1 pass CBR with screen content mode and frame dropper off.
// TODO(marpan): Should do this exit condition during the encode_frame
// (i.e., halfway during the encoding of the frame) to save cycles.
int vp8_drop_encodedframe_overshoot(VP8_COMP *cpi, int Q) {
if (cpi->pass == 0 && cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER &&
cpi->drop_frames_allowed == 0 && cpi->common.frame_type != KEY_FRAME) {
// Note: the "projected_frame_size" from encode_frame() only gives estimate
// of mode/motion vector rate (in non-rd mode): so below we only require
// that projected_frame_size is somewhat greater than per-frame-bandwidth,
// but add additional condition with high threshold on prediction residual.
// QP threshold: only allow dropping if we are not close to qp_max.
int thresh_qp = 3 * cpi->worst_quality >> 2;
// Rate threshold, in bytes.
int thresh_rate = 2 * (cpi->av_per_frame_bandwidth >> 3);
// Threshold for the average (over all macroblocks) of the pixel-sum
// residual error over 16x16 block. Should add QP dependence on threshold?
int thresh_pred_err_mb = (256 << 4);
int pred_err_mb = (int)(cpi->mb.prediction_error / cpi->common.MBs);
if (Q < thresh_qp && cpi->projected_frame_size > thresh_rate &&
pred_err_mb > thresh_pred_err_mb) {
double new_correction_factor;
const int target_size = cpi->av_per_frame_bandwidth;
int target_bits_per_mb;
// Drop this frame: advance frame counters, and set force_maxqp flag.
cpi->common.current_video_frame++;
cpi->frames_since_key++;
// Flag to indicate we will force next frame to be encoded at max QP.
cpi->force_maxqp = 1;
// Reset the buffer levels.
cpi->buffer_level = cpi->oxcf.optimal_buffer_level;
cpi->bits_off_target = cpi->oxcf.optimal_buffer_level;
// Compute a new rate correction factor, corresponding to the current
// target frame size and max_QP, and adjust the rate correction factor
// upwards, if needed.
// This is to prevent a bad state where the re-encoded frame at max_QP
// undershoots significantly, and then we end up dropping every other
// frame because the QP/rate_correction_factor may have been too low
// before the drop and then takes too long to come up.
if (target_size >= (INT_MAX >> BPER_MB_NORMBITS)) {
target_bits_per_mb = (target_size / cpi->common.MBs)
<< BPER_MB_NORMBITS;
} else {
target_bits_per_mb =
(target_size << BPER_MB_NORMBITS) / cpi->common.MBs;
}
// Rate correction factor based on target_size_per_mb and max_QP.
new_correction_factor =
(double)target_bits_per_mb /
(double)vp8_bits_per_mb[INTER_FRAME][cpi->worst_quality];
if (new_correction_factor > cpi->rate_correction_factor) {
cpi->rate_correction_factor =
VPXMIN(2.0 * cpi->rate_correction_factor, new_correction_factor);
}
if (cpi->rate_correction_factor > MAX_BPB_FACTOR) {
cpi->rate_correction_factor = MAX_BPB_FACTOR;
}
return 1;
} else {
cpi->force_maxqp = 0;
return 0;
}
cpi->force_maxqp = 0;
return 0;
}
cpi->force_maxqp = 0;
return 0;
}