ref: 09fbe88631a437bf68cbfe2d5dcf937a42d08c49
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"
#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);
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);
}
/* Make sure we initialize separate contexts for altref,gold, and normal.
* TODO shouldn't need 3 different copies of structure to do this!
*/
vpx_memcpy(&cpi->lfc_a, &cpi->common.fc, sizeof(cpi->common.fc));
vpx_memcpy(&cpi->lfc_g, &cpi->common.fc, sizeof(cpi->common.fc));
vpx_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 = MAX(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))
cpi->this_frame_target += ((cpi->current_gf_interval - 1) * 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;
/* 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;
}