-
Yaowu Xu authored
These contexts need to be saved and restored for recode, otherwise encoder/decoder mismatch happens for some clips (eg._mobcal 720p) Change-Id: Ic65cfa0bf56ed0472ecab962ce31394d59d344bf
31afc770
/* * 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"#define MIN_BPB_FACTOR 0.005#define MAX_BPB_FACTOR 50extern const MB_PREDICTION_MODE vp8_mode_order[MAX_MODES];extern const MV_REFERENCE_FRAME vp8_ref_frame_order[MAX_MODES];#ifdef MODE_STATSextern int y_modes[VP8_YMODES];extern int uv_modes[VP8_UV_MODES];extern int b_modes[B_MODE_COUNT];extern int inter_y_modes[MB_MODE_COUNT];extern int inter_uv_modes[VP8_UV_MODES];extern int inter_b_modes[B_MODE_COUNT];#endif// Bits Per MB at different Q (Multiplied by 512)#define BPER_MB_NORMBITS 9// % adjustment to target kf size based on seperation from previous framestatic const int kf_boost_seperation_adjustment[16] ={ 30, 40, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 100, 100, 100,};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] =7172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140
{
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 };
// These functions use formulaic calculations to make playing with the
// quantizer tables easier. If necessary they can be replaced by lookup
// tables if and when things settle down in the experimental bitstream
double vp8_convert_qindex_to_q( int qindex )
{
// Convert the index to a real Q value (scaled down to match old Q values)
return (double)vp8_ac_yquant( qindex, 0 ) / 4.0;
}
int vp8_gfboost_qadjust( int qindex )
{
int retval;
double q;
q = vp8_convert_qindex_to_q(qindex);
retval = (int)( ( 0.00000828 * q * q * q ) +
( -0.0055 * q * q ) +
( 1.32 * q ) + 79.3 );
return retval;
}
int kfboost_qadjust( int qindex )
{
int retval;
double q;
q = vp8_convert_qindex_to_q(qindex);
retval = (int)( ( 0.00000973 * q * q * q ) +
( -0.00613 * q * q ) +
( 1.316 * q ) + 121.2 );
return retval;
}
int vp8_bits_per_mb( FRAME_TYPE frame_type, int qindex )
{
if ( frame_type == KEY_FRAME )
return (int)(4500000 / vp8_convert_qindex_to_q(qindex));
else
return (int)(2850000 / vp8_convert_qindex_to_q(qindex));
}
void vp8_save_coding_context(VP8_COMP *cpi)
{
CODING_CONTEXT *const cc = & cpi->coding_context;
VP8_COMMON *cm = &cpi->common;
MACROBLOCKD *xd = &cpi->mb.e_mbd;
141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210
// 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.
vp8_copy(cc->mvc, cm->fc.mvc);
vp8_copy(cc->mvcosts, cpi->mb.mvcosts);
#if CONFIG_HIGH_PRECISION_MV
vp8_copy(cc->mvc_hp, cm->fc.mvc_hp);
vp8_copy(cc->mvcosts_hp, cpi->mb.mvcosts_hp);
#endif
vp8_copy( cc->mv_ref_ct, cm->mv_ref_ct );
vp8_copy( cc->mode_context, cm->mode_context );
vp8_copy( cc->mv_ref_ct_a, cm->mv_ref_ct_a );
vp8_copy( cc->mode_context_a, cm->mode_context_a );
vp8_copy( cc->ymode_prob, cm->fc.ymode_prob );
vp8_copy( cc->uv_mode_prob, cm->fc.uv_mode_prob );
// 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
vp8_copy( cc->segment_pred_probs, cm->segment_pred_probs );
vp8_copy( cc->ref_pred_probs_update, cpi->ref_pred_probs_update );
vp8_copy( cc->ref_pred_probs, cm->ref_pred_probs );
vp8_copy( cc->prob_comppred, cm->prob_comppred );
vpx_memcpy( cpi->coding_context.last_frame_seg_map_copy,
cm->last_frame_seg_map, (cm->mb_rows * cm->mb_cols) );
vp8_copy( cc->last_ref_lf_deltas, xd->last_ref_lf_deltas );
vp8_copy( cc->last_mode_lf_deltas, xd->last_mode_lf_deltas );
vp8_copy( cc->coef_probs, cm->fc.coef_probs );
vp8_copy( cc->coef_probs_8x8, cm->fc.coef_probs_8x8 );
}
void vp8_restore_coding_context(VP8_COMP *cpi)
{
CODING_CONTEXT *const cc = & cpi->coding_context;
VP8_COMMON *cm = &cpi->common;
MACROBLOCKD *xd = &cpi->mb.e_mbd;
// Restore key state variables to the snapshot state stored in the
// previous call to vp8_save_coding_context.
vp8_copy(cm->fc.mvc, cc->mvc);
vp8_copy(cpi->mb.mvcosts, cc->mvcosts);
#if CONFIG_HIGH_PRECISION_MV
vp8_copy(cm->fc.mvc_hp, cc->mvc_hp);
vp8_copy(cpi->mb.mvcosts_hp, cc->mvcosts_hp);
#endif
vp8_copy( cm->mv_ref_ct, cc->mv_ref_ct );
vp8_copy( cm->mode_context, cc->mode_context );
vp8_copy( cm->mv_ref_ct_a, cc->mv_ref_ct_a );
vp8_copy( cm->mode_context_a, cc->mode_context_a );
vp8_copy( cm->fc.ymode_prob, cc->ymode_prob);
vp8_copy( cm->fc.uv_mode_prob, cc->uv_mode_prob);
// Stats
211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280
#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
vp8_copy( cm->segment_pred_probs, cc->segment_pred_probs );
vp8_copy( cpi->ref_pred_probs_update, cc->ref_pred_probs_update );
vp8_copy( cm->ref_pred_probs, cc->ref_pred_probs );
vp8_copy( cm->prob_comppred, cc->prob_comppred );
vpx_memcpy( cm->last_frame_seg_map,
cpi->coding_context.last_frame_seg_map_copy,
(cm->mb_rows * cm->mb_cols) );
vp8_copy( xd->last_ref_lf_deltas, cc->last_ref_lf_deltas );
vp8_copy( xd->last_mode_lf_deltas, cc->last_mode_lf_deltas );
vp8_copy( cm->fc.coef_probs, cc->coef_probs );
vp8_copy( cm->fc.coef_probs_8x8, cc->coef_probs_8x8 );
}
void vp8_setup_key_frame(VP8_COMP *cpi)
{
// Setup for Key frame:
vp8_default_coef_probs(& cpi->common);
vp8_kf_default_bmode_probs(cpi->common.kf_bmode_prob);
vp8_init_mbmode_probs(& cpi->common);
vpx_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);
}
#if CONFIG_HIGH_PRECISION_MV
vpx_memcpy(cpi->common.fc.mvc_hp, vp8_default_mv_context_hp, sizeof(vp8_default_mv_context_hp));
{
int flag[2] = {1, 1};
vp8_build_component_cost_table_hp(cpi->mb.mvcost_hp, (const MV_CONTEXT_HP *) cpi->common.fc.mvc_hp, flag);
}
#endif
cpi->common.txfm_mode = ONLY_4X4;
if( cpi->common.Width * cpi->common.Height > 640*360
&& vp8_ac_yquant(cpi->common.base_qindex) > 171)
cpi->common.txfm_mode = ALLOW_8X8;
else
cpi->common.txfm_mode = ONLY_4X4;
//cpi->common.filter_level = 0; // Reset every key frame.
cpi->common.filter_level = cpi->common.base_qindex * 3 / 8 ;
// interval before next GF
cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
cpi->common.refresh_golden_frame = TRUE;
cpi->common.refresh_alt_ref_frame = TRUE;
vpx_memcpy(&cpi->common.lfc, &cpi->common.fc, sizeof(cpi->common.fc));
vpx_memcpy(&cpi->common.lfc_a, &cpi->common.fc, sizeof(cpi->common.fc));
vp8_init_mode_contexts(&cpi->common);
vpx_memcpy( cpi->common.vp8_mode_contexts,
cpi->common.mode_context,
281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350
sizeof(cpi->common.mode_context));
vpx_memcpy( cpi->common.vp8_mode_contexts,
default_vp8_mode_contexts,
sizeof(default_vp8_mode_contexts));
}
void vp8_setup_inter_frame(VP8_COMP *cpi)
{
if(cpi->common.Width * cpi->common.Height > 640*360)
cpi->common.txfm_mode = ALLOW_8X8;
else
cpi->common.txfm_mode = ONLY_4X4;
if(cpi->common.refresh_alt_ref_frame)
{
vpx_memcpy( &cpi->common.fc,
&cpi->common.lfc_a,
sizeof(cpi->common.fc));
vpx_memcpy( cpi->common.vp8_mode_contexts,
cpi->common.mode_context_a,
sizeof(cpi->common.vp8_mode_contexts));
}
else
{
vpx_memcpy( &cpi->common.fc,
&cpi->common.lfc,
sizeof(cpi->common.fc));
vpx_memcpy( cpi->common.vp8_mode_contexts,
cpi->common.mode_context,
sizeof(cpi->common.vp8_mode_contexts));
}
}
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;
int target;
// Clear down mmx registers to allow floating point in what follows
vp8_clear_system_state(); //__asm emms;
// New Two pass RC
target = cpi->per_frame_bandwidth;
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;
351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420
}
cpi->this_frame_target = target;
}
// Do the best we can to define the parameteres for the next GF based
// on what information we have available.
//
// In this experimental code only two pass is supported
// so we just use the interval determined in the two pass code.
static void calc_gf_params(VP8_COMP *cpi)
{
// Set the gf interval
cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
}
static void calc_pframe_target_size(VP8_COMP *cpi)
{
int min_frame_target;
int Adjustment;
min_frame_target = 0;
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;
// Special alt reference frame case
if (cpi->common.refresh_alt_ref_frame)
{
// 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;
}
// Normal frames (gf,and inter)
else
{
cpi->this_frame_target = cpi->per_frame_bandwidth;
}
// 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;
// Adjust target frame size for Golden Frames:
if ( cpi->frames_till_gf_update_due == 0 )
{
//int Boost = 0;
int Q = (cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
cpi->common.refresh_golden_frame = TRUE;
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
421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490
// Jims modified boost
if (!cpi->source_alt_ref_active)
{
if (cpi->oxcf.fixed_q < 0)
{
// 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
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;
}
}
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(); //__asm emms;
if (cpi->common.frame_type == KEY_FRAME)
{
rate_correction_factor = cpi->key_frame_rate_correction_factor;
}
else
{
if (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->zbin_over_quant > 0)
{
int Z = cpi->zbin_over_quant;
double Factor = 0.99;
double factor_adjustment = 0.01 / 256.0; //(double)ZBIN_OQ_MAX;
while (Z > 0)
{
Z --;
491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560
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 ( cpi->this_frame_target > 0 )
// correction_factor = (100 * cpi->projected_frame_size) / cpi->this_frame_target;
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) && (Q < cpi->active_worst_quality) )
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) && (Q > cpi->active_best_quality) )
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->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;
int i;
561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630
int last_error = INT_MAX;
int target_bits_per_mb;
int bits_per_mb_at_this_q;
double correction_factor;
// Reset Zbin OQ value
cpi->zbin_over_quant = 0;
// 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->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))
target_bits_per_mb = (target_bits_per_frame / cpi->common.MBs) << BPER_MB_NORMBITS; // Case where we would overflow int
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; //(double)ZBIN_OQ_MAX;
if (cpi->common.frame_type == KEY_FRAME)
zbin_oqmax = 0; //ZBIN_OQ_MAX/16
else if (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;
// 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->zbin_over_quant < zbin_oqmax)
{
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cpi->zbin_over_quant ++;
if (cpi->zbin_over_quant > zbin_oqmax)
cpi->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;
if (bits_per_mb_at_this_q <= target_bits_per_mb) // Break out if we get down to the target rate
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 = (int)cpi->output_frame_rate * 2;
if (cpi->oxcf.auto_key && av_key_frame_frequency > key_freq)
av_key_frame_frequency = cpi->oxcf.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;
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}
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();
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->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
{
// 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;
771772773774775776777778
if (cm->frame_type == KEY_FRAME)
calc_iframe_target_size(cpi);
else
calc_pframe_target_size(cpi);
return 1;
}