Google Git
Sign in
cobalt / cobalt / 61a8495e1e0485bd40f613004bf29f8a925ab37c / . / src / third_party / libvpx / vp10 / encoder / firstpass.c
blob: 7c5d3c070bc829e45b697d4dec494e8bba99633f [file] [log] [blame]
/*
* 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 <limits.h>
#include <math.h>
#include <stdio.h>
#include "./vpx_dsp_rtcd.h"
#include "./vpx_scale_rtcd.h"
#include "vpx_dsp/vpx_dsp_common.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_ports/mem.h"
#include "vpx_ports/system_state.h"
#include "vpx_scale/vpx_scale.h"
#include "vpx_scale/yv12config.h"
#include "vp10/common/entropymv.h"
#include "vp10/common/quant_common.h"
#include "vp10/common/reconinter.h" // vp10_setup_dst_planes()
#include "vp10/encoder/aq_variance.h"
#include "vp10/encoder/block.h"
#include "vp10/encoder/encodeframe.h"
#include "vp10/encoder/encodemb.h"
#include "vp10/encoder/encodemv.h"
#include "vp10/encoder/encoder.h"
#include "vp10/encoder/extend.h"
#include "vp10/encoder/firstpass.h"
#include "vp10/encoder/mcomp.h"
#include "vp10/encoder/quantize.h"
#include "vp10/encoder/rd.h"
#include "vpx_dsp/variance.h"
#define OUTPUT_FPF 0
#define ARF_STATS_OUTPUT 0
#define GROUP_ADAPTIVE_MAXQ 1
#define BOOST_BREAKOUT 12.5
#define BOOST_FACTOR 12.5
#define FACTOR_PT_LOW 0.70
#define FACTOR_PT_HIGH 0.90
#define FIRST_PASS_Q 10.0
#define GF_MAX_BOOST 96.0
#define INTRA_MODE_PENALTY 1024
#define KF_MAX_BOOST 128.0
#define MIN_ARF_GF_BOOST 240
#define MIN_DECAY_FACTOR 0.01
#define MIN_KF_BOOST 300
#define NEW_MV_MODE_PENALTY 32
#define DARK_THRESH 64
#define DEFAULT_GRP_WEIGHT 1.0
#define RC_FACTOR_MIN 0.75
#define RC_FACTOR_MAX 1.75
#define NCOUNT_INTRA_THRESH 8192
#define NCOUNT_INTRA_FACTOR 3
#define NCOUNT_FRAME_II_THRESH 5.0
#define DOUBLE_DIVIDE_CHECK(x) ((x) < 0 ? (x) - 0.000001 : (x) + 0.000001)
#if ARF_STATS_OUTPUT
unsigned int arf_count = 0;
#endif
// Resets the first pass file to the given position using a relative seek from
// the current position.
static void reset_fpf_position(TWO_PASS *p,
const FIRSTPASS_STATS *position) {
p->stats_in = position;
}
// Read frame stats at an offset from the current position.
static const FIRSTPASS_STATS *read_frame_stats(const TWO_PASS *p, int offset) {
if ((offset >= 0 && p->stats_in + offset >= p->stats_in_end) ||
(offset < 0 && p->stats_in + offset < p->stats_in_start)) {
return NULL;
}
return &p->stats_in[offset];
}
static int input_stats(TWO_PASS *p, FIRSTPASS_STATS *fps) {
if (p->stats_in >= p->stats_in_end)
return EOF;
*fps = *p->stats_in;
++p->stats_in;
return 1;
}
static void output_stats(FIRSTPASS_STATS *stats,
struct vpx_codec_pkt_list *pktlist) {
struct vpx_codec_cx_pkt pkt;
pkt.kind = VPX_CODEC_STATS_PKT;
pkt.data.twopass_stats.buf = stats;
pkt.data.twopass_stats.sz = sizeof(FIRSTPASS_STATS);
vpx_codec_pkt_list_add(pktlist, &pkt);
// TEMP debug code
#if OUTPUT_FPF
{
FILE *fpfile;
fpfile = fopen("firstpass.stt", "a");
fprintf(fpfile, "%12.0lf %12.4lf %12.0lf %12.0lf %12.0lf %12.4lf %12.4lf"
"%12.4lf %12.4lf %12.4lf %12.4lf %12.4lf %12.4lf %12.4lf %12.4lf"
"%12.4lf %12.4lf %12.0lf %12.0lf %12.0lf %12.4lf\n",
stats->frame,
stats->weight,
stats->intra_error,
stats->coded_error,
stats->sr_coded_error,
stats->pcnt_inter,
stats->pcnt_motion,
stats->pcnt_second_ref,
stats->pcnt_neutral,
stats->intra_skip_pct,
stats->inactive_zone_rows,
stats->inactive_zone_cols,
stats->MVr,
stats->mvr_abs,
stats->MVc,
stats->mvc_abs,
stats->MVrv,
stats->MVcv,
stats->mv_in_out_count,
stats->new_mv_count,
stats->count,
stats->duration);
fclose(fpfile);
}
#endif
}
#if CONFIG_FP_MB_STATS
static void output_fpmb_stats(uint8_t *this_frame_mb_stats,
VP10_COMMON *cm,
struct vpx_codec_pkt_list *pktlist) {
struct vpx_codec_cx_pkt pkt;
pkt.kind = VPX_CODEC_FPMB_STATS_PKT;
pkt.data.firstpass_mb_stats.buf = this_frame_mb_stats;
pkt.data.firstpass_mb_stats.sz = cm->initial_mbs * sizeof(uint8_t);
vpx_codec_pkt_list_add(pktlist, &pkt);
}
#endif
static void zero_stats(FIRSTPASS_STATS *section) {
section->frame = 0.0;
section->weight = 0.0;
section->intra_error = 0.0;
section->coded_error = 0.0;
section->sr_coded_error = 0.0;
section->pcnt_inter = 0.0;
section->pcnt_motion = 0.0;
section->pcnt_second_ref = 0.0;
section->pcnt_neutral = 0.0;
section->intra_skip_pct = 0.0;
section->inactive_zone_rows = 0.0;
section->inactive_zone_cols = 0.0;
section->MVr = 0.0;
section->mvr_abs = 0.0;
section->MVc = 0.0;
section->mvc_abs = 0.0;
section->MVrv = 0.0;
section->MVcv = 0.0;
section->mv_in_out_count = 0.0;
section->new_mv_count = 0.0;
section->count = 0.0;
section->duration = 1.0;
}
static void accumulate_stats(FIRSTPASS_STATS *section,
const FIRSTPASS_STATS *frame) {
section->frame += frame->frame;
section->weight += frame->weight;
section->intra_error += frame->intra_error;
section->coded_error += frame->coded_error;
section->sr_coded_error += frame->sr_coded_error;
section->pcnt_inter += frame->pcnt_inter;
section->pcnt_motion += frame->pcnt_motion;
section->pcnt_second_ref += frame->pcnt_second_ref;
section->pcnt_neutral += frame->pcnt_neutral;
section->intra_skip_pct += frame->intra_skip_pct;
section->inactive_zone_rows += frame->inactive_zone_rows;
section->inactive_zone_cols += frame->inactive_zone_cols;
section->MVr += frame->MVr;
section->mvr_abs += frame->mvr_abs;
section->MVc += frame->MVc;
section->mvc_abs += frame->mvc_abs;
section->MVrv += frame->MVrv;
section->MVcv += frame->MVcv;
section->mv_in_out_count += frame->mv_in_out_count;
section->new_mv_count += frame->new_mv_count;
section->count += frame->count;
section->duration += frame->duration;
}
static void subtract_stats(FIRSTPASS_STATS *section,
const FIRSTPASS_STATS *frame) {
section->frame -= frame->frame;
section->weight -= frame->weight;
section->intra_error -= frame->intra_error;
section->coded_error -= frame->coded_error;
section->sr_coded_error -= frame->sr_coded_error;
section->pcnt_inter -= frame->pcnt_inter;
section->pcnt_motion -= frame->pcnt_motion;
section->pcnt_second_ref -= frame->pcnt_second_ref;
section->pcnt_neutral -= frame->pcnt_neutral;
section->intra_skip_pct -= frame->intra_skip_pct;
section->inactive_zone_rows -= frame->inactive_zone_rows;
section->inactive_zone_cols -= frame->inactive_zone_cols;
section->MVr -= frame->MVr;
section->mvr_abs -= frame->mvr_abs;
section->MVc -= frame->MVc;
section->mvc_abs -= frame->mvc_abs;
section->MVrv -= frame->MVrv;
section->MVcv -= frame->MVcv;
section->mv_in_out_count -= frame->mv_in_out_count;
section->new_mv_count -= frame->new_mv_count;
section->count -= frame->count;
section->duration -= frame->duration;
}
// Calculate the linear size relative to a baseline of 1080P
#define BASE_SIZE 2073600.0 // 1920x1080
static double get_linear_size_factor(const VP10_COMP *cpi) {
const double this_area = cpi->initial_width * cpi->initial_height;
return pow(this_area / BASE_SIZE, 0.5);
}
// Calculate an active area of the image that discounts formatting
// bars and partially discounts other 0 energy areas.
#define MIN_ACTIVE_AREA 0.5
#define MAX_ACTIVE_AREA 1.0
static double calculate_active_area(const VP10_COMP *cpi,
const FIRSTPASS_STATS *this_frame)
{
double active_pct;
active_pct = 1.0 -
((this_frame->intra_skip_pct / 2) +
((this_frame->inactive_zone_rows * 2) / (double)cpi->common.mb_rows));
return fclamp(active_pct, MIN_ACTIVE_AREA, MAX_ACTIVE_AREA);
}
// Calculate a modified Error used in distributing bits between easier and
// harder frames.
#define ACT_AREA_CORRECTION 0.5
static double calculate_modified_err(const VP10_COMP *cpi,
const TWO_PASS *twopass,
const VP10EncoderConfig *oxcf,
const FIRSTPASS_STATS *this_frame) {
const FIRSTPASS_STATS *const stats = &twopass->total_stats;
const double av_weight = stats->weight / stats->count;
const double av_err = (stats->coded_error * av_weight) / stats->count;
double modified_error =
av_err * pow(this_frame->coded_error * this_frame->weight /
DOUBLE_DIVIDE_CHECK(av_err), oxcf->two_pass_vbrbias / 100.0);
// Correction for active area. Frames with a reduced active area
// (eg due to formatting bars) have a higher error per mb for the
// remaining active MBs. The correction here assumes that coding
// 0.5N blocks of complexity 2X is a little easier than coding N
// blocks of complexity X.
modified_error *=
pow(calculate_active_area(cpi, this_frame), ACT_AREA_CORRECTION);
return fclamp(modified_error,
twopass->modified_error_min, twopass->modified_error_max);
}
// This function returns the maximum target rate per frame.
static int frame_max_bits(const RATE_CONTROL *rc,
const VP10EncoderConfig *oxcf) {
int64_t max_bits = ((int64_t)rc->avg_frame_bandwidth *
(int64_t)oxcf->two_pass_vbrmax_section) / 100;
if (max_bits < 0)
max_bits = 0;
else if (max_bits > rc->max_frame_bandwidth)
max_bits = rc->max_frame_bandwidth;
return (int)max_bits;
}
void vp10_init_first_pass(VP10_COMP *cpi) {
zero_stats(&cpi->twopass.total_stats);
}
void vp10_end_first_pass(VP10_COMP *cpi) {
output_stats(&cpi->twopass.total_stats, cpi->output_pkt_list);
}
static vpx_variance_fn_t get_block_variance_fn(BLOCK_SIZE bsize) {
switch (bsize) {
case BLOCK_8X8:
return vpx_mse8x8;
case BLOCK_16X8:
return vpx_mse16x8;
case BLOCK_8X16:
return vpx_mse8x16;
default:
return vpx_mse16x16;
}
}
static unsigned int get_prediction_error(BLOCK_SIZE bsize,
const struct buf_2d *src,
const struct buf_2d *ref) {
unsigned int sse;
const vpx_variance_fn_t fn = get_block_variance_fn(bsize);
fn(src->buf, src->stride, ref->buf, ref->stride, &sse);
return sse;
}
#if CONFIG_VP9_HIGHBITDEPTH
static vpx_variance_fn_t highbd_get_block_variance_fn(BLOCK_SIZE bsize,
int bd) {
switch (bd) {
default:
switch (bsize) {
case BLOCK_8X8:
return vpx_highbd_8_mse8x8;
case BLOCK_16X8:
return vpx_highbd_8_mse16x8;
case BLOCK_8X16:
return vpx_highbd_8_mse8x16;
default:
return vpx_highbd_8_mse16x16;
}
break;
case 10:
switch (bsize) {
case BLOCK_8X8:
return vpx_highbd_10_mse8x8;
case BLOCK_16X8:
return vpx_highbd_10_mse16x8;
case BLOCK_8X16:
return vpx_highbd_10_mse8x16;
default:
return vpx_highbd_10_mse16x16;
}
break;
case 12:
switch (bsize) {
case BLOCK_8X8:
return vpx_highbd_12_mse8x8;
case BLOCK_16X8:
return vpx_highbd_12_mse16x8;
case BLOCK_8X16:
return vpx_highbd_12_mse8x16;
default:
return vpx_highbd_12_mse16x16;
}
break;
}
}
static unsigned int highbd_get_prediction_error(BLOCK_SIZE bsize,
const struct buf_2d *src,
const struct buf_2d *ref,
int bd) {
unsigned int sse;
const vpx_variance_fn_t fn = highbd_get_block_variance_fn(bsize, bd);
fn(src->buf, src->stride, ref->buf, ref->stride, &sse);
return sse;
}
#endif // CONFIG_VP9_HIGHBITDEPTH
// Refine the motion search range according to the frame dimension
// for first pass test.
static int get_search_range(const VP10_COMP *cpi) {
int sr = 0;
const int dim = VPXMIN(cpi->initial_width, cpi->initial_height);
while ((dim << sr) < MAX_FULL_PEL_VAL)
++sr;
return sr;
}
static void first_pass_motion_search(VP10_COMP *cpi, MACROBLOCK *x,
const MV *ref_mv, MV *best_mv,
int *best_motion_err) {
MACROBLOCKD *const xd = &x->e_mbd;
MV tmp_mv = {0, 0};
MV ref_mv_full = {ref_mv->row >> 3, ref_mv->col >> 3};
int num00, tmp_err, n;
const BLOCK_SIZE bsize = xd->mi[0]->mbmi.sb_type;
vp9_variance_fn_ptr_t v_fn_ptr = cpi->fn_ptr[bsize];
const int new_mv_mode_penalty = NEW_MV_MODE_PENALTY;
int step_param = 3;
int further_steps = (MAX_MVSEARCH_STEPS - 1) - step_param;
const int sr = get_search_range(cpi);
step_param += sr;
further_steps -= sr;
// Override the default variance function to use MSE.
v_fn_ptr.vf = get_block_variance_fn(bsize);
#if CONFIG_VP9_HIGHBITDEPTH
if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
v_fn_ptr.vf = highbd_get_block_variance_fn(bsize, xd->bd);
}
#endif // CONFIG_VP9_HIGHBITDEPTH
// Center the initial step/diamond search on best mv.
tmp_err = cpi->diamond_search_sad(x, &cpi->ss_cfg, &ref_mv_full, &tmp_mv,
step_param,
x->sadperbit16, &num00, &v_fn_ptr, ref_mv);
if (tmp_err < INT_MAX)
tmp_err = vp10_get_mvpred_var(x, &tmp_mv, ref_mv, &v_fn_ptr, 1);
if (tmp_err < INT_MAX - new_mv_mode_penalty)
tmp_err += new_mv_mode_penalty;
if (tmp_err < *best_motion_err) {
*best_motion_err = tmp_err;
*best_mv = tmp_mv;
}
// Carry out further step/diamond searches as necessary.
n = num00;
num00 = 0;
while (n < further_steps) {
++n;
if (num00) {
--num00;
} else {
tmp_err = cpi->diamond_search_sad(x, &cpi->ss_cfg, &ref_mv_full, &tmp_mv,
step_param + n, x->sadperbit16,
&num00, &v_fn_ptr, ref_mv);
if (tmp_err < INT_MAX)
tmp_err = vp10_get_mvpred_var(x, &tmp_mv, ref_mv, &v_fn_ptr, 1);
if (tmp_err < INT_MAX - new_mv_mode_penalty)
tmp_err += new_mv_mode_penalty;
if (tmp_err < *best_motion_err) {
*best_motion_err = tmp_err;
*best_mv = tmp_mv;
}
}
}
}
static BLOCK_SIZE get_bsize(const VP10_COMMON *cm, int mb_row, int mb_col) {
if (2 * mb_col + 1 < cm->mi_cols) {
return 2 * mb_row + 1 < cm->mi_rows ? BLOCK_16X16
: BLOCK_16X8;
} else {
return 2 * mb_row + 1 < cm->mi_rows ? BLOCK_8X16
: BLOCK_8X8;
}
}
static int find_fp_qindex(vpx_bit_depth_t bit_depth) {
int i;
for (i = 0; i < QINDEX_RANGE; ++i)
if (vp10_convert_qindex_to_q(i, bit_depth) >= FIRST_PASS_Q)
break;
if (i == QINDEX_RANGE)
i--;
return i;
}
static void set_first_pass_params(VP10_COMP *cpi) {
VP10_COMMON *const cm = &cpi->common;
if (!cpi->refresh_alt_ref_frame &&
(cm->current_video_frame == 0 ||
(cpi->frame_flags & FRAMEFLAGS_KEY))) {
cm->frame_type = KEY_FRAME;
} else {
cm->frame_type = INTER_FRAME;
}
// Do not use periodic key frames.
cpi->rc.frames_to_key = INT_MAX;
}
#define UL_INTRA_THRESH 50
#define INVALID_ROW -1
void vp10_first_pass(VP10_COMP *cpi, const struct lookahead_entry *source) {
int mb_row, mb_col;
MACROBLOCK *const x = &cpi->td.mb;
VP10_COMMON *const cm = &cpi->common;
MACROBLOCKD *const xd = &x->e_mbd;
TileInfo tile;
struct macroblock_plane *const p = x->plane;
struct macroblockd_plane *const pd = xd->plane;
const PICK_MODE_CONTEXT *ctx = &cpi->td.pc_root->none;
int i;
int recon_yoffset, recon_uvoffset;
int64_t intra_error = 0;
int64_t coded_error = 0;
int64_t sr_coded_error = 0;
int sum_mvr = 0, sum_mvc = 0;
int sum_mvr_abs = 0, sum_mvc_abs = 0;
int64_t sum_mvrs = 0, sum_mvcs = 0;
int mvcount = 0;
int intercount = 0;
int second_ref_count = 0;
const int intrapenalty = INTRA_MODE_PENALTY;
double neutral_count;
int intra_skip_count = 0;
int image_data_start_row = INVALID_ROW;
int new_mv_count = 0;
int sum_in_vectors = 0;
MV lastmv = {0, 0};
TWO_PASS *twopass = &cpi->twopass;
const MV zero_mv = {0, 0};
int recon_y_stride, recon_uv_stride, uv_mb_height;
YV12_BUFFER_CONFIG *const lst_yv12 = get_ref_frame_buffer(cpi, LAST_FRAME);
YV12_BUFFER_CONFIG *gld_yv12 = get_ref_frame_buffer(cpi, GOLDEN_FRAME);
YV12_BUFFER_CONFIG *const new_yv12 = get_frame_new_buffer(cm);
const YV12_BUFFER_CONFIG *first_ref_buf = lst_yv12;
double intra_factor;
double brightness_factor;
BufferPool *const pool = cm->buffer_pool;
// First pass code requires valid last and new frame buffers.
assert(new_yv12 != NULL);
assert(frame_is_intra_only(cm) || (lst_yv12 != NULL));
#if CONFIG_FP_MB_STATS
if (cpi->use_fp_mb_stats) {
vp10_zero_array(cpi->twopass.frame_mb_stats_buf, cm->initial_mbs);
}
#endif
vpx_clear_system_state();
intra_factor = 0.0;
brightness_factor = 0.0;
neutral_count = 0.0;
set_first_pass_params(cpi);
vp10_set_quantizer(cm, find_fp_qindex(cm->bit_depth));
vp10_setup_block_planes(&x->e_mbd, cm->subsampling_x, cm->subsampling_y);
vp10_setup_src_planes(x, cpi->Source, 0, 0);
vp10_setup_dst_planes(xd->plane, new_yv12, 0, 0);
if (!frame_is_intra_only(cm)) {
vp10_setup_pre_planes(xd, 0, first_ref_buf, 0, 0, NULL);
}
xd->mi = cm->mi_grid_visible;
xd->mi[0] = cm->mi;
vp10_frame_init_quantizer(cpi);
for (i = 0; i < MAX_MB_PLANE; ++i) {
p[i].coeff = ctx->coeff_pbuf[i][1];
p[i].qcoeff = ctx->qcoeff_pbuf[i][1];
pd[i].dqcoeff = ctx->dqcoeff_pbuf[i][1];
p[i].eobs = ctx->eobs_pbuf[i][1];
}
x->skip_recode = 0;
vp10_init_mv_probs(cm);
vp10_initialize_rd_consts(cpi);
// Tiling is ignored in the first pass.
vp10_tile_init(&tile, cm, 0, 0);
recon_y_stride = new_yv12->y_stride;
recon_uv_stride = new_yv12->uv_stride;
uv_mb_height = 16 >> (new_yv12->y_height > new_yv12->uv_height);
for (mb_row = 0; mb_row < cm->mb_rows; ++mb_row) {
MV best_ref_mv = {0, 0};
// Reset above block coeffs.
xd->up_available = (mb_row != 0);
recon_yoffset = (mb_row * recon_y_stride * 16);
recon_uvoffset = (mb_row * recon_uv_stride * uv_mb_height);
// Set up limit values for motion vectors to prevent them extending
// outside the UMV borders.
x->mv_row_min = -((mb_row * 16) + BORDER_MV_PIXELS_B16);
x->mv_row_max = ((cm->mb_rows - 1 - mb_row) * 16)
+ BORDER_MV_PIXELS_B16;
for (mb_col = 0; mb_col < cm->mb_cols; ++mb_col) {
int this_error;
const int use_dc_pred = (mb_col || mb_row) && (!mb_col || !mb_row);
const BLOCK_SIZE bsize = get_bsize(cm, mb_row, mb_col);
double log_intra;
int level_sample;
#if CONFIG_FP_MB_STATS
const int mb_index = mb_row * cm->mb_cols + mb_col;
#endif
vpx_clear_system_state();
xd->plane[0].dst.buf = new_yv12->y_buffer + recon_yoffset;
xd->plane[1].dst.buf = new_yv12->u_buffer + recon_uvoffset;
xd->plane[2].dst.buf = new_yv12->v_buffer + recon_uvoffset;
xd->left_available = (mb_col != 0);
xd->mi[0]->mbmi.sb_type = bsize;
xd->mi[0]->mbmi.ref_frame[0] = INTRA_FRAME;
set_mi_row_col(xd, &tile,
mb_row << 1, num_8x8_blocks_high_lookup[bsize],
mb_col << 1, num_8x8_blocks_wide_lookup[bsize],
cm->mi_rows, cm->mi_cols);
// Do intra 16x16 prediction.
xd->mi[0]->mbmi.segment_id = 0;
xd->mi[0]->mbmi.mode = DC_PRED;
xd->mi[0]->mbmi.tx_size = use_dc_pred ?
(bsize >= BLOCK_16X16 ? TX_16X16 : TX_8X8) : TX_4X4;
vp10_encode_intra_block_plane(x, bsize, 0);
this_error = vpx_get_mb_ss(x->plane[0].src_diff);
// Keep a record of blocks that have almost no intra error residual
// (i.e. are in effect completely flat and untextured in the intra
// domain). In natural videos this is uncommon, but it is much more
// common in animations, graphics and screen content, so may be used
// as a signal to detect these types of content.
if (this_error < UL_INTRA_THRESH) {
++intra_skip_count;
} else if ((mb_col > 0) && (image_data_start_row == INVALID_ROW)) {
image_data_start_row = mb_row;
}
#if CONFIG_VP9_HIGHBITDEPTH
if (cm->use_highbitdepth) {
switch (cm->bit_depth) {
case VPX_BITS_8:
break;
case VPX_BITS_10:
this_error >>= 4;
break;
case VPX_BITS_12:
this_error >>= 8;
break;
default:
assert(0 && "cm->bit_depth should be VPX_BITS_8, "
"VPX_BITS_10 or VPX_BITS_12");
return;
}
}
#endif // CONFIG_VP9_HIGHBITDEPTH
vpx_clear_system_state();
log_intra = log(this_error + 1.0);
if (log_intra < 10.0)
intra_factor += 1.0 + ((10.0 - log_intra) * 0.05);
else
intra_factor += 1.0;
#if CONFIG_VP9_HIGHBITDEPTH
if (cm->use_highbitdepth)
level_sample = CONVERT_TO_SHORTPTR(x->plane[0].src.buf)[0];
else
level_sample = x->plane[0].src.buf[0];
#else
level_sample = x->plane[0].src.buf[0];
#endif
if ((level_sample < DARK_THRESH) && (log_intra < 9.0))
brightness_factor += 1.0 + (0.01 * (DARK_THRESH - level_sample));
else
brightness_factor += 1.0;
// Intrapenalty below deals with situations where the intra and inter
// error scores are very low (e.g. a plain black frame).
// We do not have special cases in first pass for 0,0 and nearest etc so
// all inter modes carry an overhead cost estimate for the mv.
// When the error score is very low this causes us to pick all or lots of
// INTRA modes and throw lots of key frames.
// This penalty adds a cost matching that of a 0,0 mv to the intra case.
this_error += intrapenalty;
// Accumulate the intra error.
intra_error += (int64_t)this_error;
#if CONFIG_FP_MB_STATS
if (cpi->use_fp_mb_stats) {
// initialization
cpi->twopass.frame_mb_stats_buf[mb_index] = 0;
}
#endif
// Set up limit values for motion vectors to prevent them extending
// outside the UMV borders.
x->mv_col_min = -((mb_col * 16) + BORDER_MV_PIXELS_B16);
x->mv_col_max = ((cm->mb_cols - 1 - mb_col) * 16) + BORDER_MV_PIXELS_B16;
// Other than for the first frame do a motion search.
if (cm->current_video_frame > 0) {
int tmp_err, motion_error, raw_motion_error;
// Assume 0,0 motion with no mv overhead.
MV mv = {0, 0} , tmp_mv = {0, 0};
struct buf_2d unscaled_last_source_buf_2d;
xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset;
#if CONFIG_VP9_HIGHBITDEPTH
if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
motion_error = highbd_get_prediction_error(
bsize, &x->plane[0].src, &xd->plane[0].pre[0], xd->bd);
} else {
motion_error = get_prediction_error(
bsize, &x->plane[0].src, &xd->plane[0].pre[0]);
}
#else
motion_error = get_prediction_error(
bsize, &x->plane[0].src, &xd->plane[0].pre[0]);
#endif // CONFIG_VP9_HIGHBITDEPTH
// Compute the motion error of the 0,0 motion using the last source
// frame as the reference. Skip the further motion search on
// reconstructed frame if this error is small.
unscaled_last_source_buf_2d.buf =
cpi->unscaled_last_source->y_buffer + recon_yoffset;
unscaled_last_source_buf_2d.stride =
cpi->unscaled_last_source->y_stride;
#if CONFIG_VP9_HIGHBITDEPTH
if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
raw_motion_error = highbd_get_prediction_error(
bsize, &x->plane[0].src, &unscaled_last_source_buf_2d, xd->bd);
} else {
raw_motion_error = get_prediction_error(
bsize, &x->plane[0].src, &unscaled_last_source_buf_2d);
}
#else
raw_motion_error = get_prediction_error(
bsize, &x->plane[0].src, &unscaled_last_source_buf_2d);
#endif // CONFIG_VP9_HIGHBITDEPTH
// TODO(pengchong): Replace the hard-coded threshold
if (raw_motion_error > 25) {
// Test last reference frame using the previous best mv as the
// starting point (best reference) for the search.
first_pass_motion_search(cpi, x, &best_ref_mv, &mv, &motion_error);
// If the current best reference mv is not centered on 0,0 then do a
// 0,0 based search as well.
if (!is_zero_mv(&best_ref_mv)) {
tmp_err = INT_MAX;
first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv, &tmp_err);
if (tmp_err < motion_error) {
motion_error = tmp_err;
mv = tmp_mv;
}
}
// Search in an older reference frame.
if ((cm->current_video_frame > 1) && gld_yv12 != NULL) {
// Assume 0,0 motion with no mv overhead.
int gf_motion_error;
xd->plane[0].pre[0].buf = gld_yv12->y_buffer + recon_yoffset;
#if CONFIG_VP9_HIGHBITDEPTH
if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
gf_motion_error = highbd_get_prediction_error(
bsize, &x->plane[0].src, &xd->plane[0].pre[0], xd->bd);
} else {
gf_motion_error = get_prediction_error(
bsize, &x->plane[0].src, &xd->plane[0].pre[0]);
}
#else
gf_motion_error = get_prediction_error(
bsize, &x->plane[0].src, &xd->plane[0].pre[0]);
#endif // CONFIG_VP9_HIGHBITDEPTH
first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv,
&gf_motion_error);
if (gf_motion_error < motion_error && gf_motion_error < this_error)
++second_ref_count;
// Reset to last frame as reference buffer.
xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset;
xd->plane[1].pre[0].buf = first_ref_buf->u_buffer + recon_uvoffset;
xd->plane[2].pre[0].buf = first_ref_buf->v_buffer + recon_uvoffset;
// In accumulating a score for the older reference frame take the
// best of the motion predicted score and the intra coded error
// (just as will be done for) accumulation of "coded_error" for
// the last frame.
if (gf_motion_error < this_error)
sr_coded_error += gf_motion_error;
else
sr_coded_error += this_error;
} else {
sr_coded_error += motion_error;
}
} else {
sr_coded_error += motion_error;
}
// Start by assuming that intra mode is best.
best_ref_mv.row = 0;
best_ref_mv.col = 0;
#if CONFIG_FP_MB_STATS
if (cpi->use_fp_mb_stats) {
// intra predication statistics
cpi->twopass.frame_mb_stats_buf[mb_index] = 0;
cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_DCINTRA_MASK;
cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_ZERO_MASK;
if (this_error > FPMB_ERROR_LARGE_TH) {
cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_ERROR_LARGE_MASK;
} else if (this_error < FPMB_ERROR_SMALL_TH) {
cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_ERROR_SMALL_MASK;
}
}
#endif
if (motion_error <= this_error) {
vpx_clear_system_state();
// Keep a count of cases where the inter and intra were very close
// and very low. This helps with scene cut detection for example in
// cropped clips with black bars at the sides or top and bottom.
if (((this_error - intrapenalty) * 9 <= motion_error * 10) &&
(this_error < (2 * intrapenalty))) {
neutral_count += 1.0;
// Also track cases where the intra is not much worse than the inter
// and use this in limiting the GF/arf group length.
} else if ((this_error > NCOUNT_INTRA_THRESH) &&
(this_error < (NCOUNT_INTRA_FACTOR * motion_error))) {
neutral_count += (double)motion_error /
DOUBLE_DIVIDE_CHECK((double)this_error);
}
mv.row *= 8;
mv.col *= 8;
this_error = motion_error;
xd->mi[0]->mbmi.mode = NEWMV;
xd->mi[0]->mbmi.mv[0].as_mv = mv;
xd->mi[0]->mbmi.tx_size = TX_4X4;
xd->mi[0]->mbmi.ref_frame[0] = LAST_FRAME;
xd->mi[0]->mbmi.ref_frame[1] = NONE;
vp10_build_inter_predictors_sby(xd, mb_row << 1, mb_col << 1, bsize);
vp10_encode_sby_pass1(x, bsize);
sum_mvr += mv.row;
sum_mvr_abs += abs(mv.row);
sum_mvc += mv.col;
sum_mvc_abs += abs(mv.col);
sum_mvrs += mv.row * mv.row;
sum_mvcs += mv.col * mv.col;
++intercount;
best_ref_mv = mv;
#if CONFIG_FP_MB_STATS
if (cpi->use_fp_mb_stats) {
// inter predication statistics
cpi->twopass.frame_mb_stats_buf[mb_index] = 0;
cpi->twopass.frame_mb_stats_buf[mb_index] &= ~FPMB_DCINTRA_MASK;
cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_ZERO_MASK;
if (this_error > FPMB_ERROR_LARGE_TH) {
cpi->twopass.frame_mb_stats_buf[mb_index] |=
FPMB_ERROR_LARGE_MASK;
} else if (this_error < FPMB_ERROR_SMALL_TH) {
cpi->twopass.frame_mb_stats_buf[mb_index] |=
FPMB_ERROR_SMALL_MASK;
}
}
#endif
if (!is_zero_mv(&mv)) {
++mvcount;
#if CONFIG_FP_MB_STATS
if (cpi->use_fp_mb_stats) {
cpi->twopass.frame_mb_stats_buf[mb_index] &=
~FPMB_MOTION_ZERO_MASK;
// check estimated motion direction
if (mv.as_mv.col > 0 && mv.as_mv.col >= abs(mv.as_mv.row)) {
// right direction
cpi->twopass.frame_mb_stats_buf[mb_index] |=
FPMB_MOTION_RIGHT_MASK;
} else if (mv.as_mv.row < 0 &&
abs(mv.as_mv.row) >= abs(mv.as_mv.col)) {
// up direction
cpi->twopass.frame_mb_stats_buf[mb_index] |=
FPMB_MOTION_UP_MASK;
} else if (mv.as_mv.col < 0 &&
abs(mv.as_mv.col) >= abs(mv.as_mv.row)) {
// left direction
cpi->twopass.frame_mb_stats_buf[mb_index] |=
FPMB_MOTION_LEFT_MASK;
} else {
// down direction
cpi->twopass.frame_mb_stats_buf[mb_index] |=
FPMB_MOTION_DOWN_MASK;
}
}
#endif
// Non-zero vector, was it different from the last non zero vector?
if (!is_equal_mv(&mv, &lastmv))
++new_mv_count;
lastmv = mv;
// Does the row vector point inwards or outwards?
if (mb_row < cm->mb_rows / 2) {
if (mv.row > 0)
--sum_in_vectors;
else if (mv.row < 0)
++sum_in_vectors;
} else if (mb_row > cm->mb_rows / 2) {
if (mv.row > 0)
++sum_in_vectors;
else if (mv.row < 0)
--sum_in_vectors;
}
// Does the col vector point inwards or outwards?
if (mb_col < cm->mb_cols / 2) {
if (mv.col > 0)
--sum_in_vectors;
else if (mv.col < 0)
++sum_in_vectors;
} else if (mb_col > cm->mb_cols / 2) {
if (mv.col > 0)
++sum_in_vectors;
else if (mv.col < 0)
--sum_in_vectors;
}
}
}
} else {
sr_coded_error += (int64_t)this_error;
}
coded_error += (int64_t)this_error;
// Adjust to the next column of MBs.
x->plane[0].src.buf += 16;
x->plane[1].src.buf += uv_mb_height;
x->plane[2].src.buf += uv_mb_height;
recon_yoffset += 16;
recon_uvoffset += uv_mb_height;
}
// Adjust to the next row of MBs.
x->plane[0].src.buf += 16 * x->plane[0].src.stride - 16 * cm->mb_cols;
x->plane[1].src.buf += uv_mb_height * x->plane[1].src.stride -
uv_mb_height * cm->mb_cols;
x->plane[2].src.buf += uv_mb_height * x->plane[1].src.stride -
uv_mb_height * cm->mb_cols;
vpx_clear_system_state();
}
// Clamp the image start to rows/2. This number of rows is discarded top
// and bottom as dead data so rows / 2 means the frame is blank.
if ((image_data_start_row > cm->mb_rows / 2) ||
(image_data_start_row == INVALID_ROW)) {
image_data_start_row = cm->mb_rows / 2;
}
// Exclude any image dead zone
if (image_data_start_row > 0) {
intra_skip_count =
VPXMAX(0, intra_skip_count - (image_data_start_row * cm->mb_cols * 2));
}
{
FIRSTPASS_STATS fps;
// The minimum error here insures some bit allocation to frames even
// in static regions. The allocation per MB declines for larger formats
// where the typical "real" energy per MB also falls.
// Initial estimate here uses sqrt(mbs) to define the min_err, where the
// number of mbs is proportional to the image area.
const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE)
? cpi->initial_mbs : cpi->common.MBs;
const double min_err = 200 * sqrt(num_mbs);
intra_factor = intra_factor / (double)num_mbs;
brightness_factor = brightness_factor / (double)num_mbs;
fps.weight = intra_factor * brightness_factor;
fps.frame = cm->current_video_frame;
fps.coded_error = (double)(coded_error >> 8) + min_err;
fps.sr_coded_error = (double)(sr_coded_error >> 8) + min_err;
fps.intra_error = (double)(intra_error >> 8) + min_err;
fps.count = 1.0;
fps.pcnt_inter = (double)intercount / num_mbs;
fps.pcnt_second_ref = (double)second_ref_count / num_mbs;
fps.pcnt_neutral = (double)neutral_count / num_mbs;
fps.intra_skip_pct = (double)intra_skip_count / num_mbs;
fps.inactive_zone_rows = (double)image_data_start_row;
fps.inactive_zone_cols = (double)0; // TODO(paulwilkins): fix
if (mvcount > 0) {
fps.MVr = (double)sum_mvr / mvcount;
fps.mvr_abs = (double)sum_mvr_abs / mvcount;
fps.MVc = (double)sum_mvc / mvcount;
fps.mvc_abs = (double)sum_mvc_abs / mvcount;
fps.MVrv = ((double)sum_mvrs -
((double)sum_mvr * sum_mvr / mvcount)) / mvcount;
fps.MVcv = ((double)sum_mvcs -
((double)sum_mvc * sum_mvc / mvcount)) / mvcount;
fps.mv_in_out_count = (double)sum_in_vectors / (mvcount * 2);
fps.new_mv_count = new_mv_count;
fps.pcnt_motion = (double)mvcount / num_mbs;
} else {
fps.MVr = 0.0;
fps.mvr_abs = 0.0;
fps.MVc = 0.0;
fps.mvc_abs = 0.0;
fps.MVrv = 0.0;
fps.MVcv = 0.0;
fps.mv_in_out_count = 0.0;
fps.new_mv_count = 0.0;
fps.pcnt_motion = 0.0;
}
// TODO(paulwilkins): Handle the case when duration is set to 0, or
// something less than the full time between subsequent values of
// cpi->source_time_stamp.
fps.duration = (double)(source->ts_end - source->ts_start);
// Don't want to do output stats with a stack variable!
twopass->this_frame_stats = fps;
output_stats(&twopass->this_frame_stats, cpi->output_pkt_list);
accumulate_stats(&twopass->total_stats, &fps);
#if CONFIG_FP_MB_STATS
if (cpi->use_fp_mb_stats) {
output_fpmb_stats(twopass->frame_mb_stats_buf, cm, cpi->output_pkt_list);
}
#endif
}
// Copy the previous Last Frame back into gf and and arf buffers if
// the prediction is good enough... but also don't allow it to lag too far.
if ((twopass->sr_update_lag > 3) ||
((cm->current_video_frame > 0) &&
(twopass->this_frame_stats.pcnt_inter > 0.20) &&
((twopass->this_frame_stats.intra_error /
DOUBLE_DIVIDE_CHECK(twopass->this_frame_stats.coded_error)) > 2.0))) {
if (gld_yv12 != NULL) {
ref_cnt_fb(pool->frame_bufs, &cm->ref_frame_map[cpi->gld_fb_idx],
cm->ref_frame_map[cpi->lst_fb_idx]);
}
twopass->sr_update_lag = 1;
} else {
++twopass->sr_update_lag;
}
vpx_extend_frame_borders(new_yv12);
// The frame we just compressed now becomes the last frame.
ref_cnt_fb(pool->frame_bufs, &cm->ref_frame_map[cpi->lst_fb_idx],
cm->new_fb_idx);
// Special case for the first frame. Copy into the GF buffer as a second
// reference.
if (cm->current_video_frame == 0 && cpi->gld_fb_idx != INVALID_IDX) {
ref_cnt_fb(pool->frame_bufs, &cm->ref_frame_map[cpi->gld_fb_idx],
cm->ref_frame_map[cpi->lst_fb_idx]);
}
// Use this to see what the first pass reconstruction looks like.
if (0) {
char filename[512];
FILE *recon_file;
snprintf(filename, sizeof(filename), "enc%04d.yuv",
(int)cm->current_video_frame);
if (cm->current_video_frame == 0)
recon_file = fopen(filename, "wb");
else
recon_file = fopen(filename, "ab");
(void)fwrite(lst_yv12->buffer_alloc, lst_yv12->frame_size, 1, recon_file);
fclose(recon_file);
}
++cm->current_video_frame;
}
static double calc_correction_factor(double err_per_mb,
double err_divisor,
double pt_low,
double pt_high,
int q,
vpx_bit_depth_t bit_depth) {
const double error_term = err_per_mb / err_divisor;
// Adjustment based on actual quantizer to power term.
const double power_term =
VPXMIN(vp10_convert_qindex_to_q(q, bit_depth) * 0.01 + pt_low, pt_high);
// Calculate correction factor.
if (power_term < 1.0)
assert(error_term >= 0.0);
return fclamp(pow(error_term, power_term), 0.05, 5.0);
}
#define ERR_DIVISOR 100.0
static int get_twopass_worst_quality(const VP10_COMP *cpi,
const double section_err,
double inactive_zone,
int section_target_bandwidth,
double group_weight_factor) {
const RATE_CONTROL *const rc = &cpi->rc;
const VP10EncoderConfig *const oxcf = &cpi->oxcf;
inactive_zone = fclamp(inactive_zone, 0.0, 1.0);
if (section_target_bandwidth <= 0) {
return rc->worst_quality; // Highest value allowed
} else {
const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE)
? cpi->initial_mbs : cpi->common.MBs;
const int active_mbs = VPXMAX(1, num_mbs - (int)(num_mbs * inactive_zone));
const double av_err_per_mb = section_err / active_mbs;
const double speed_term = 1.0 + 0.04 * oxcf->speed;
double ediv_size_correction;
const int target_norm_bits_per_mb = ((uint64_t)section_target_bandwidth <<
BPER_MB_NORMBITS) / active_mbs;
int q;
// Larger image formats are expected to be a little harder to code
// relatively given the same prediction error score. This in part at
// least relates to the increased size and hence coding overheads of
// motion vectors. Some account of this is made through adjustment of
// the error divisor.
ediv_size_correction =
VPXMAX(0.2, VPXMIN(5.0, get_linear_size_factor(cpi)));
if (ediv_size_correction < 1.0)
ediv_size_correction = -(1.0 / ediv_size_correction);
ediv_size_correction *= 4.0;
// Try and pick a max Q that will be high enough to encode the
// content at the given rate.
for (q = rc->best_quality; q < rc->worst_quality; ++q) {
const double factor =
calc_correction_factor(av_err_per_mb,
ERR_DIVISOR - ediv_size_correction,
FACTOR_PT_LOW, FACTOR_PT_HIGH, q,
cpi->common.bit_depth);
const int bits_per_mb =
vp10_rc_bits_per_mb(INTER_FRAME, q,
factor * speed_term * group_weight_factor,
cpi->common.bit_depth);
if (bits_per_mb <= target_norm_bits_per_mb)
break;
}
// Restriction on active max q for constrained quality mode.
if (cpi->oxcf.rc_mode == VPX_CQ)
q = VPXMAX(q, oxcf->cq_level);
return q;
}
}
static void setup_rf_level_maxq(VP10_COMP *cpi) {
int i;
RATE_CONTROL *const rc = &cpi->rc;
for (i = INTER_NORMAL; i < RATE_FACTOR_LEVELS; ++i) {
int qdelta = vp10_frame_type_qdelta(cpi, i, rc->worst_quality);
rc->rf_level_maxq[i] = VPXMAX(rc->worst_quality + qdelta, rc->best_quality);
}
}
void vp10_init_subsampling(VP10_COMP *cpi) {
const VP10_COMMON *const cm = &cpi->common;
RATE_CONTROL *const rc = &cpi->rc;
const int w = cm->width;
const int h = cm->height;
int i;
for (i = 0; i < FRAME_SCALE_STEPS; ++i) {
// Note: Frames with odd-sized dimensions may result from this scaling.
rc->frame_width[i] = (w * 16) / frame_scale_factor[i];
rc->frame_height[i] = (h * 16) / frame_scale_factor[i];
}
setup_rf_level_maxq(cpi);
}
void vp10_calculate_coded_size(VP10_COMP *cpi,
int *scaled_frame_width,
int *scaled_frame_height) {
RATE_CONTROL *const rc = &cpi->rc;
*scaled_frame_width = rc->frame_width[rc->frame_size_selector];
*scaled_frame_height = rc->frame_height[rc->frame_size_selector];
}
void vp10_init_second_pass(VP10_COMP *cpi) {
const VP10EncoderConfig *const oxcf = &cpi->oxcf;
TWO_PASS *const twopass = &cpi->twopass;
double frame_rate;
FIRSTPASS_STATS *stats;
zero_stats(&twopass->total_stats);
zero_stats(&twopass->total_left_stats);
if (!twopass->stats_in_end)
return;
stats = &twopass->total_stats;
*stats = *twopass->stats_in_end;
twopass->total_left_stats = *stats;
frame_rate = 10000000.0 * stats->count / stats->duration;
// Each frame can have a different duration, as the frame rate in the source
// isn't guaranteed to be constant. The frame rate prior to the first frame
// encoded in the second pass is a guess. However, the sum duration is not.
// It is calculated based on the actual durations of all frames from the
// first pass.
vp10_new_framerate(cpi, frame_rate);
twopass->bits_left = (int64_t)(stats->duration * oxcf->target_bandwidth /
10000000.0);
// This variable monitors how far behind the second ref update is lagging.
twopass->sr_update_lag = 1;
// Scan the first pass file and calculate a modified total error based upon
// the bias/power function used to allocate bits.
{
const double avg_error = stats->coded_error /
DOUBLE_DIVIDE_CHECK(stats->count);
const FIRSTPASS_STATS *s = twopass->stats_in;
double modified_error_total = 0.0;
twopass->modified_error_min = (avg_error *
oxcf->two_pass_vbrmin_section) / 100;
twopass->modified_error_max = (avg_error *
oxcf->two_pass_vbrmax_section) / 100;
while (s < twopass->stats_in_end) {
modified_error_total += calculate_modified_err(cpi, twopass, oxcf, s);
++s;
}
twopass->modified_error_left = modified_error_total;
}
// Reset the vbr bits off target counters
cpi->rc.vbr_bits_off_target = 0;
cpi->rc.vbr_bits_off_target_fast = 0;
cpi->rc.rate_error_estimate = 0;
// Static sequence monitor variables.
twopass->kf_zeromotion_pct = 100;
twopass->last_kfgroup_zeromotion_pct = 100;
if (oxcf->resize_mode != RESIZE_NONE) {
vp10_init_subsampling(cpi);
}
}
#define SR_DIFF_PART 0.0015
#define MOTION_AMP_PART 0.003
#define INTRA_PART 0.005
#define DEFAULT_DECAY_LIMIT 0.75
#define LOW_SR_DIFF_TRHESH 0.1
#define SR_DIFF_MAX 128.0
static double get_sr_decay_rate(const VP10_COMP *cpi,
const FIRSTPASS_STATS *frame) {
const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE)
? cpi->initial_mbs : cpi->common.MBs;
double sr_diff =
(frame->sr_coded_error - frame->coded_error) / num_mbs;
double sr_decay = 1.0;
double modified_pct_inter;
double modified_pcnt_intra;
const double motion_amplitude_factor =
frame->pcnt_motion * ((frame->mvc_abs + frame->mvr_abs) / 2);
modified_pct_inter = frame->pcnt_inter;
if ((frame->intra_error / DOUBLE_DIVIDE_CHECK(frame->coded_error)) <
(double)NCOUNT_FRAME_II_THRESH) {
modified_pct_inter = frame->pcnt_inter - frame->pcnt_neutral;
}
modified_pcnt_intra = 100 * (1.0 - modified_pct_inter);
if ((sr_diff > LOW_SR_DIFF_TRHESH)) {
sr_diff = VPXMIN(sr_diff, SR_DIFF_MAX);
sr_decay = 1.0 - (SR_DIFF_PART * sr_diff) -
(MOTION_AMP_PART * motion_amplitude_factor) -
(INTRA_PART * modified_pcnt_intra);
}
return VPXMAX(sr_decay, VPXMIN(DEFAULT_DECAY_LIMIT, modified_pct_inter));
}
// This function gives an estimate of how badly we believe the prediction
// quality is decaying from frame to frame.
static double get_zero_motion_factor(const VP10_COMP *cpi,
const FIRSTPASS_STATS *frame) {
const double zero_motion_pct = frame->pcnt_inter -
frame->pcnt_motion;
double sr_decay = get_sr_decay_rate(cpi, frame);
return VPXMIN(sr_decay, zero_motion_pct);
}
#define ZM_POWER_FACTOR 0.75
static double get_prediction_decay_rate(const VP10_COMP *cpi,
const FIRSTPASS_STATS *next_frame) {
const double sr_decay_rate = get_sr_decay_rate(cpi, next_frame);
const double zero_motion_factor =
(0.95 * pow((next_frame->pcnt_inter - next_frame->pcnt_motion),
ZM_POWER_FACTOR));
return VPXMAX(zero_motion_factor,
(sr_decay_rate + ((1.0 - sr_decay_rate) * zero_motion_factor)));
}
// Function to test for a condition where a complex transition is followed
// by a static section. For example in slide shows where there is a fade
// between slides. This is to help with more optimal kf and gf positioning.
static int detect_transition_to_still(VP10_COMP *cpi,
int frame_interval, int still_interval,
double loop_decay_rate,
double last_decay_rate) {
TWO_PASS *const twopass = &cpi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
// Break clause to detect very still sections after motion
// For example a static image after a fade or other transition
// instead of a clean scene cut.
if (frame_interval > rc->min_gf_interval &&
loop_decay_rate >= 0.999 &&
last_decay_rate < 0.9) {
int j;
// Look ahead a few frames to see if static condition persists...
for (j = 0; j < still_interval; ++j) {
const FIRSTPASS_STATS *stats = &twopass->stats_in[j];
if (stats >= twopass->stats_in_end)
break;
if (stats->pcnt_inter - stats->pcnt_motion < 0.999)
break;
}
// Only if it does do we signal a transition to still.
return j == still_interval;
}
return 0;
}
// This function detects a flash through the high relative pcnt_second_ref
// score in the frame following a flash frame. The offset passed in should
// reflect this.
static int detect_flash(const TWO_PASS *twopass, int offset) {
const FIRSTPASS_STATS *const next_frame = read_frame_stats(twopass, offset);
// What we are looking for here is a situation where there is a
// brief break in prediction (such as a flash) but subsequent frames
// are reasonably well predicted by an earlier (pre flash) frame.
// The recovery after a flash is indicated by a high pcnt_second_ref
// compared to pcnt_inter.
return next_frame != NULL &&
next_frame->pcnt_second_ref > next_frame->pcnt_inter &&
next_frame->pcnt_second_ref >= 0.5;
}
// Update the motion related elements to the GF arf boost calculation.
static void accumulate_frame_motion_stats(const FIRSTPASS_STATS *stats,
double *mv_in_out,
double *mv_in_out_accumulator,
double *abs_mv_in_out_accumulator,
double *mv_ratio_accumulator) {
const double pct = stats->pcnt_motion;
// Accumulate Motion In/Out of frame stats.
*mv_in_out = stats->mv_in_out_count * pct;
*mv_in_out_accumulator += *mv_in_out;
*abs_mv_in_out_accumulator += fabs(*mv_in_out);
// Accumulate a measure of how uniform (or conversely how random) the motion
// field is (a ratio of abs(mv) / mv).
if (pct > 0.05) {
const double mvr_ratio = fabs(stats->mvr_abs) /
DOUBLE_DIVIDE_CHECK(fabs(stats->MVr));
const double mvc_ratio = fabs(stats->mvc_abs) /
DOUBLE_DIVIDE_CHECK(fabs(stats->MVc));
*mv_ratio_accumulator += pct * (mvr_ratio < stats->mvr_abs ?
mvr_ratio : stats->mvr_abs);
*mv_ratio_accumulator += pct * (mvc_ratio < stats->mvc_abs ?
mvc_ratio : stats->mvc_abs);
}
}
#define BASELINE_ERR_PER_MB 1000.0
static double calc_frame_boost(VP10_COMP *cpi,
const FIRSTPASS_STATS *this_frame,
double this_frame_mv_in_out,
double max_boost) {
double frame_boost;
const double lq =
vp10_convert_qindex_to_q(cpi->rc.avg_frame_qindex[INTER_FRAME],
cpi->common.bit_depth);
const double boost_q_correction = VPXMIN((0.5 + (lq * 0.015)), 1.5);
int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE)
? cpi->initial_mbs : cpi->common.MBs;
// Correct for any inactive region in the image
num_mbs = (int)VPXMAX(1, num_mbs * calculate_active_area(cpi, this_frame));
// Underlying boost factor is based on inter error ratio.
frame_boost = (BASELINE_ERR_PER_MB * num_mbs) /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error);
frame_boost = frame_boost * BOOST_FACTOR * boost_q_correction;
// Increase boost for frames where new data coming into frame (e.g. zoom out).
// Slightly reduce boost if there is a net balance of motion out of the frame
// (zoom in). The range for this_frame_mv_in_out is -1.0 to +1.0.
if (this_frame_mv_in_out > 0.0)
frame_boost += frame_boost * (this_frame_mv_in_out * 2.0);
// In the extreme case the boost is halved.
else
frame_boost += frame_boost * (this_frame_mv_in_out / 2.0);
return VPXMIN(frame_boost, max_boost * boost_q_correction);
}
static int calc_arf_boost(VP10_COMP *cpi, int offset,
int f_frames, int b_frames,
int *f_boost, int *b_boost) {
TWO_PASS *const twopass = &cpi->twopass;
int i;
double boost_score = 0.0;
double mv_ratio_accumulator = 0.0;
double decay_accumulator = 1.0;
double this_frame_mv_in_out = 0.0;
double mv_in_out_accumulator = 0.0;
double abs_mv_in_out_accumulator = 0.0;
int arf_boost;
int flash_detected = 0;
// Search forward from the proposed arf/next gf position.
for (i = 0; i < f_frames; ++i) {
const FIRSTPASS_STATS *this_frame = read_frame_stats(twopass, i + offset);
if (this_frame == NULL)
break;
// Update the motion related elements to the boost calculation.
accumulate_frame_motion_stats(this_frame,
&this_frame_mv_in_out, &mv_in_out_accumulator,
&abs_mv_in_out_accumulator,
&mv_ratio_accumulator);
// We want to discount the flash frame itself and the recovery
// frame that follows as both will have poor scores.
flash_detected = detect_flash(twopass, i + offset) ||
detect_flash(twopass, i + offset + 1);
// Accumulate the effect of prediction quality decay.
if (!flash_detected) {
decay_accumulator *= get_prediction_decay_rate(cpi, this_frame);
decay_accumulator = decay_accumulator < MIN_DECAY_FACTOR
? MIN_DECAY_FACTOR : decay_accumulator;
}
boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame,
this_frame_mv_in_out,
GF_MAX_BOOST);
}
*f_boost = (int)boost_score;
// Reset for backward looking loop.
boost_score = 0.0;
mv_ratio_accumulator = 0.0;
decay_accumulator = 1.0;
this_frame_mv_in_out = 0.0;
mv_in_out_accumulator = 0.0;
abs_mv_in_out_accumulator = 0.0;
// Search backward towards last gf position.
for (i = -1; i >= -b_frames; --i) {
const FIRSTPASS_STATS *this_frame = read_frame_stats(twopass, i + offset);
if (this_frame == NULL)
break;
// Update the motion related elements to the boost calculation.
accumulate_frame_motion_stats(this_frame,
&this_frame_mv_in_out, &mv_in_out_accumulator,
&abs_mv_in_out_accumulator,
&mv_ratio_accumulator);
// We want to discount the the flash frame itself and the recovery
// frame that follows as both will have poor scores.
flash_detected = detect_flash(twopass, i + offset) ||
detect_flash(twopass, i + offset + 1);
// Cumulative effect of prediction quality decay.
if (!flash_detected) {
decay_accumulator *= get_prediction_decay_rate(cpi, this_frame);
decay_accumulator = decay_accumulator < MIN_DECAY_FACTOR
? MIN_DECAY_FACTOR : decay_accumulator;
}
boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame,
this_frame_mv_in_out,
GF_MAX_BOOST);
}
*b_boost = (int)boost_score;
arf_boost = (*f_boost + *b_boost);
if (arf_boost < ((b_frames + f_frames) * 20))
arf_boost = ((b_frames + f_frames) * 20);
arf_boost = VPXMAX(arf_boost, MIN_ARF_GF_BOOST);
return arf_boost;
}
// Calculate a section intra ratio used in setting max loop filter.
static int calculate_section_intra_ratio(const FIRSTPASS_STATS *begin,
const FIRSTPASS_STATS *end,
int section_length) {
const FIRSTPASS_STATS *s = begin;
double intra_error = 0.0;
double coded_error = 0.0;
int i = 0;
while (s < end && i < section_length) {
intra_error += s->intra_error;
coded_error += s->coded_error;
++s;
++i;
}
return (int)(intra_error / DOUBLE_DIVIDE_CHECK(coded_error));
}
// Calculate the total bits to allocate in this GF/ARF group.
static int64_t calculate_total_gf_group_bits(VP10_COMP *cpi,
double gf_group_err) {
const RATE_CONTROL *const rc = &cpi->rc;
const TWO_PASS *const twopass = &cpi->twopass;
const int max_bits = frame_max_bits(rc, &cpi->oxcf);
int64_t total_group_bits;
// Calculate the bits to be allocated to the group as a whole.
if ((twopass->kf_group_bits > 0) && (twopass->kf_group_error_left > 0)) {
total_group_bits = (int64_t)(twopass->kf_group_bits *
(gf_group_err / twopass->kf_group_error_left));
} else {
total_group_bits = 0;
}
// Clamp odd edge cases.
total_group_bits = (total_group_bits < 0) ?
0 : (total_group_bits > twopass->kf_group_bits) ?
twopass->kf_group_bits : total_group_bits;
// Clip based on user supplied data rate variability limit.
if (total_group_bits > (int64_t)max_bits * rc->baseline_gf_interval)
total_group_bits = (int64_t)max_bits * rc->baseline_gf_interval;
return total_group_bits;
}
// Calculate the number bits extra to assign to boosted frames in a group.
static int calculate_boost_bits(int frame_count,
int boost, int64_t total_group_bits) {
int allocation_chunks;
// return 0 for invalid inputs (could arise e.g. through rounding errors)
if (!boost || (total_group_bits <= 0) || (frame_count <= 0) )
return 0;
allocation_chunks = (frame_count * 100) + boost;
// Prevent overflow.
if (boost > 1023) {
int divisor = boost >> 10;
boost /= divisor;
allocation_chunks /= divisor;
}
// Calculate the number of extra bits for use in the boosted frame or frames.
return VPXMAX((int)(((int64_t)boost * total_group_bits) / allocation_chunks),
0);
}
// Current limit on maximum number of active arfs in a GF/ARF group.
#define MAX_ACTIVE_ARFS 2
#define ARF_SLOT1 2
#define ARF_SLOT2 3
// This function indirects the choice of buffers for arfs.
// At the moment the values are fixed but this may change as part of
// the integration process with other codec features that swap buffers around.
static void get_arf_buffer_indices(unsigned char *arf_buffer_indices) {
arf_buffer_indices[0] = ARF_SLOT1;
arf_buffer_indices[1] = ARF_SLOT2;
}
static void allocate_gf_group_bits(VP10_COMP *cpi, int64_t gf_group_bits,
double group_error, int gf_arf_bits) {
RATE_CONTROL *const rc = &cpi->rc;
const VP10EncoderConfig *const oxcf = &cpi->oxcf;
TWO_PASS *const twopass = &cpi->twopass;
GF_GROUP *const gf_group = &twopass->gf_group;
FIRSTPASS_STATS frame_stats;
int i;
int frame_index = 1;
int target_frame_size;
int key_frame;
const int max_bits = frame_max_bits(&cpi->rc, &cpi->oxcf);
int64_t total_group_bits = gf_group_bits;
double modified_err = 0.0;
double err_fraction;
int mid_boost_bits = 0;
int mid_frame_idx;
unsigned char arf_buffer_indices[MAX_ACTIVE_ARFS];
key_frame = cpi->common.frame_type == KEY_FRAME;
get_arf_buffer_indices(arf_buffer_indices);
// For key frames the frame target rate is already set and it
// is also the golden frame.
if (!key_frame) {
if (rc->source_alt_ref_active) {
gf_group->update_type[0] = OVERLAY_UPDATE;
gf_group->rf_level[0] = INTER_NORMAL;
gf_group->bit_allocation[0] = 0;
} else {
gf_group->update_type[0] = GF_UPDATE;
gf_group->rf_level[0] = GF_ARF_STD;
gf_group->bit_allocation[0] = gf_arf_bits;
}
gf_group->arf_update_idx[0] = arf_buffer_indices[0];
gf_group->arf_ref_idx[0] = arf_buffer_indices[0];
// Step over the golden frame / overlay frame
if (EOF == input_stats(twopass, &frame_stats))
return;
}
// Deduct the boost bits for arf (or gf if it is not a key frame)
// from the group total.
if (rc->source_alt_ref_pending || !key_frame)
total_group_bits -= gf_arf_bits;
// Store the bits to spend on the ARF if there is one.
if (rc->source_alt_ref_pending) {
gf_group->update_type[frame_index] = ARF_UPDATE;
gf_group->rf_level[frame_index] = GF_ARF_STD;
gf_group->bit_allocation[frame_index] = gf_arf_bits;
gf_group->arf_src_offset[frame_index] =
(unsigned char)(rc->baseline_gf_interval - 1);
gf_group->arf_update_idx[frame_index] = arf_buffer_indices[0];
gf_group->arf_ref_idx[frame_index] =
arf_buffer_indices[cpi->multi_arf_last_grp_enabled &&
rc->source_alt_ref_active];
++frame_index;
if (cpi->multi_arf_enabled) {
// Set aside a slot for a level 1 arf.
gf_group->update_type[frame_index] = ARF_UPDATE;
gf_group->rf_level[frame_index] = GF_ARF_LOW;
gf_group->arf_src_offset[frame_index] =
(unsigned char)((rc->baseline_gf_interval >> 1) - 1);
gf_group->arf_update_idx[frame_index] = arf_buffer_indices[1];
gf_group->arf_ref_idx[frame_index] = arf_buffer_indices[0];
++frame_index;
}
}
// Define middle frame
mid_frame_idx = frame_index + (rc->baseline_gf_interval >> 1) - 1;
// Allocate bits to the other frames in the group.
for (i = 0; i < rc->baseline_gf_interval - rc->source_alt_ref_pending; ++i) {
int arf_idx = 0;
if (EOF == input_stats(twopass, &frame_stats))
break;
modified_err = calculate_modified_err(cpi, twopass, oxcf, &frame_stats);
if (group_error > 0)
err_fraction = modified_err / DOUBLE_DIVIDE_CHECK(group_error);
else
err_fraction = 0.0;
target_frame_size = (int)((double)total_group_bits * err_fraction);
if (rc->source_alt_ref_pending && cpi->multi_arf_enabled) {
mid_boost_bits += (target_frame_size >> 4);
target_frame_size -= (target_frame_size >> 4);
if (frame_index <= mid_frame_idx)
arf_idx = 1;
}
gf_group->arf_update_idx[frame_index] = arf_buffer_indices[arf_idx];
gf_group->arf_ref_idx[frame_index] = arf_buffer_indices[arf_idx];
target_frame_size = clamp(target_frame_size, 0,
VPXMIN(max_bits, (int)total_group_bits));
gf_group->update_type[frame_index] = LF_UPDATE;
gf_group->rf_level[frame_index] = INTER_NORMAL;
gf_group->bit_allocation[frame_index] = target_frame_size;
++frame_index;
}
// Note:
// We need to configure the frame at the end of the sequence + 1 that will be
// the start frame for the next group. Otherwise prior to the call to
// vp10_rc_get_second_pass_params() the data will be undefined.
gf_group->arf_update_idx[frame_index] = arf_buffer_indices[0];
gf_group->arf_ref_idx[frame_index] = arf_buffer_indices[0];
if (rc->source_alt_ref_pending) {
gf_group->update_type[frame_index] = OVERLAY_UPDATE;
gf_group->rf_level[frame_index] = INTER_NORMAL;
// Final setup for second arf and its overlay.
if (cpi->multi_arf_enabled) {
gf_group->bit_allocation[2] =
gf_group->bit_allocation[mid_frame_idx] + mid_boost_bits;
gf_group->update_type[mid_frame_idx] = OVERLAY_UPDATE;
gf_group->bit_allocation[mid_frame_idx] = 0;
}
} else {
gf_group->update_type[frame_index] = GF_UPDATE;
gf_group->rf_level[frame_index] = GF_ARF_STD;
}
// Note whether multi-arf was enabled this group for next time.
cpi->multi_arf_last_grp_enabled = cpi->multi_arf_enabled;
}
// Analyse and define a gf/arf group.
static void define_gf_group(VP10_COMP *cpi, FIRSTPASS_STATS *this_frame) {
VP10_COMMON *const cm = &cpi->common;
RATE_CONTROL *const rc = &cpi->rc;
VP10EncoderConfig *const oxcf = &cpi->oxcf;
TWO_PASS *const twopass = &cpi->twopass;
FIRSTPASS_STATS next_frame;
const FIRSTPASS_STATS *const start_pos = twopass->stats_in;
int i;
double boost_score = 0.0;
double old_boost_score = 0.0;
double gf_group_err = 0.0;
#if GROUP_ADAPTIVE_MAXQ
double gf_group_raw_error = 0.0;
#endif
double gf_group_skip_pct = 0.0;
double gf_group_inactive_zone_rows = 0.0;
double gf_first_frame_err = 0.0;
double mod_frame_err = 0.0;
double mv_ratio_accumulator = 0.0;
double decay_accumulator = 1.0;
double zero_motion_accumulator = 1.0;
double loop_decay_rate = 1.00;
double last_loop_decay_rate = 1.00;
double this_frame_mv_in_out = 0.0;
double mv_in_out_accumulator = 0.0;
double abs_mv_in_out_accumulator = 0.0;
double mv_ratio_accumulator_thresh;
unsigned int allow_alt_ref = is_altref_enabled(cpi);
int f_boost = 0;
int b_boost = 0;
int flash_detected;
int active_max_gf_interval;
int active_min_gf_interval;
int64_t gf_group_bits;
double gf_group_error_left;
int gf_arf_bits;
const int is_key_frame = frame_is_intra_only(cm);
const int arf_active_or_kf = is_key_frame || rc->source_alt_ref_active;
// Reset the GF group data structures unless this is a key
// frame in which case it will already have been done.
if (is_key_frame == 0) {
vp10_zero(twopass->gf_group);
}
vpx_clear_system_state();
vp10_zero(next_frame);
// Load stats for the current frame.
mod_frame_err = calculate_modified_err(cpi, twopass, oxcf, this_frame);
// Note the error of the frame at the start of the group. This will be
// the GF frame error if we code a normal gf.
gf_first_frame_err = mod_frame_err;
// If this is a key frame or the overlay from a previous arf then
// the error score / cost of this frame has already been accounted for.
if (arf_active_or_kf) {
gf_group_err -= gf_first_frame_err;
#if GROUP_ADAPTIVE_MAXQ
gf_group_raw_error -= this_frame->coded_error;
#endif
gf_group_skip_pct -= this_frame->intra_skip_pct;
gf_group_inactive_zone_rows -= this_frame->inactive_zone_rows;
}
// Motion breakout threshold for loop below depends on image size.
mv_ratio_accumulator_thresh =
(cpi->initial_height + cpi->initial_width) / 4.0;
// Set a maximum and minimum interval for the GF group.
// If the image appears almost completely static we can extend beyond this.
{
int int_max_q =
(int)(vp10_convert_qindex_to_q(twopass->active_worst_quality,
cpi->common.bit_depth));
int int_lbq =
(int)(vp10_convert_qindex_to_q(rc->last_boosted_qindex,
cpi->common.bit_depth));
active_min_gf_interval = rc->min_gf_interval + VPXMIN(2, int_max_q / 200);
if (active_min_gf_interval > rc->max_gf_interval)
active_min_gf_interval = rc->max_gf_interval;
if (cpi->multi_arf_allowed) {
active_max_gf_interval = rc->max_gf_interval;
} else {
// The value chosen depends on the active Q range. At low Q we have
// bits to spare and are better with a smaller interval and smaller boost.
// At high Q when there are few bits to spare we are better with a longer
// interval to spread the cost of the GF.
active_max_gf_interval = 12 + VPXMIN(4, (int_lbq / 6));
// We have: active_min_gf_interval <= rc->max_gf_interval
if (active_max_gf_interval < active_min_gf_interval)
active_max_gf_interval = active_min_gf_interval;
else if (active_max_gf_interval > rc->max_gf_interval)
active_max_gf_interval = rc->max_gf_interval;
}
}
i = 0;
while (i < rc->static_scene_max_gf_interval && i < rc->frames_to_key) {
++i;
// Accumulate error score of frames in this gf group.
mod_frame_err = calculate_modified_err(cpi, twopass, oxcf, this_frame);
gf_group_err += mod_frame_err;
#if GROUP_ADAPTIVE_MAXQ
gf_group_raw_error += this_frame->coded_error;
#endif
gf_group_skip_pct += this_frame->intra_skip_pct;
gf_group_inactive_zone_rows += this_frame->inactive_zone_rows;
if (EOF == input_stats(twopass, &next_frame))
break;
// Test for the case where there is a brief flash but the prediction
// quality back to an earlier frame is then restored.
flash_detected = detect_flash(twopass, 0);
// Update the motion related elements to the boost calculation.
accumulate_frame_motion_stats(&next_frame,
&this_frame_mv_in_out, &mv_in_out_accumulator,
&abs_mv_in_out_accumulator,
&mv_ratio_accumulator);
// Accumulate the effect of prediction quality decay.
if (!flash_detected) {
last_loop_decay_rate = loop_decay_rate;
loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame);
decay_accumulator = decay_accumulator * loop_decay_rate;
// Monitor for static sections.
zero_motion_accumulator = VPXMIN(
zero_motion_accumulator, get_zero_motion_factor(cpi, &next_frame));
// Break clause to detect very still sections after motion. For example,
// a static image after a fade or other transition.
if (detect_transition_to_still(cpi, i, 5, loop_decay_rate,
last_loop_decay_rate)) {
allow_alt_ref = 0;
break;
}
}
// Calculate a boost number for this frame.
boost_score += decay_accumulator * calc_frame_boost(cpi, &next_frame,
this_frame_mv_in_out,
GF_MAX_BOOST);
// Break out conditions.
if (
// Break at active_max_gf_interval unless almost totally static.
(i >= (active_max_gf_interval + arf_active_or_kf) &&
zero_motion_accumulator < 0.995) ||
(
// Don't break out with a very short interval.
(i >= active_min_gf_interval + arf_active_or_kf) &&
(!flash_detected) &&
((mv_ratio_accumulator > mv_ratio_accumulator_thresh) ||
(abs_mv_in_out_accumulator > 3.0) ||
(mv_in_out_accumulator < -2.0) ||
((boost_score - old_boost_score) < BOOST_BREAKOUT)))) {
boost_score = old_boost_score;
break;
}
*this_frame = next_frame;
old_boost_score = boost_score;
}
twopass->gf_zeromotion_pct = (int)(zero_motion_accumulator * 1000.0);
// Was the group length constrained by the requirement for a new KF?
rc->constrained_gf_group = (i >= rc->frames_to_key) ? 1 : 0;
// Should we use the alternate reference frame.
if (allow_alt_ref &&
(i < cpi->oxcf.lag_in_frames) &&
(i >= rc->min_gf_interval)) {
// Calculate the boost for alt ref.
rc->gfu_boost = calc_arf_boost(cpi, 0, (i - 1), (i - 1), &f_boost,
&b_boost);
rc->source_alt_ref_pending = 1;
// Test to see if multi arf is appropriate.
cpi->multi_arf_enabled =
(cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) &&
(zero_motion_accumulator < 0.995)) ? 1 : 0;
} else {
rc->gfu_boost = VPXMAX((int)boost_score, MIN_ARF_GF_BOOST);
rc->source_alt_ref_pending = 0;
}
// Set the interval until the next gf.
rc->baseline_gf_interval = i - (is_key_frame || rc->source_alt_ref_pending);
rc->frames_till_gf_update_due = rc->baseline_gf_interval;
// Reset the file position.
reset_fpf_position(twopass, start_pos);
// Calculate the bits to be allocated to the gf/arf group as a whole
gf_group_bits = calculate_total_gf_group_bits(cpi, gf_group_err);
#if GROUP_ADAPTIVE_MAXQ
// Calculate an estimate of the maxq needed for the group.
// We are more agressive about correcting for sections
// where there could be significant overshoot than for easier
// sections where we do not wish to risk creating an overshoot
// of the allocated bit budget.
if ((cpi->oxcf.rc_mode != VPX_Q) && (rc->baseline_gf_interval > 1)) {
const int vbr_group_bits_per_frame =
(int)(gf_group_bits / rc->baseline_gf_interval);
const double group_av_err = gf_group_raw_error / rc->baseline_gf_interval;
const double group_av_skip_pct =
gf_group_skip_pct / rc->baseline_gf_interval;
const double group_av_inactive_zone =
((gf_group_inactive_zone_rows * 2) /
(rc->baseline_gf_interval * (double)cm->mb_rows));
int tmp_q;
// rc factor is a weight factor that corrects for local rate control drift.
double rc_factor = 1.0;
if (rc->rate_error_estimate > 0) {
rc_factor = VPXMAX(RC_FACTOR_MIN,
(double)(100 - rc->rate_error_estimate) / 100.0);
} else {
rc_factor = VPXMIN(RC_FACTOR_MAX,
(double)(100 - rc->rate_error_estimate) / 100.0);
}
tmp_q =
get_twopass_worst_quality(cpi, group_av_err,
(group_av_skip_pct + group_av_inactive_zone),
vbr_group_bits_per_frame,
twopass->kfgroup_inter_fraction * rc_factor);
twopass->active_worst_quality =
VPXMAX(tmp_q, twopass->active_worst_quality >> 1);
}
#endif
// Calculate the extra bits to be used for boosted frame(s)
gf_arf_bits = calculate_boost_bits(rc->baseline_gf_interval,
rc->gfu_boost, gf_group_bits);
// Adjust KF group bits and error remaining.
twopass->kf_group_error_left -= (int64_t)gf_group_err;
// If this is an arf update we want to remove the score for the overlay
// frame at the end which will usually be very cheap to code.
// The overlay frame has already, in effect, been coded so we want to spread
// the remaining bits among the other frames.
// For normal GFs remove the score for the GF itself unless this is
// also a key frame in which case it has already been accounted for.
if (rc->source_alt_ref_pending) {
gf_group_error_left = gf_group_err - mod_frame_err;
} else if (is_key_frame == 0) {
gf_group_error_left = gf_group_err - gf_first_frame_err;
} else {
gf_group_error_left = gf_group_err;
}
// Allocate bits to each of the frames in the GF group.
allocate_gf_group_bits(cpi, gf_group_bits, gf_group_error_left, gf_arf_bits);
// Reset the file position.
reset_fpf_position(twopass, start_pos);
// Calculate a section intra ratio used in setting max loop filter.
if (cpi->common.frame_type != KEY_FRAME) {
twopass->section_intra_rating =
calculate_section_intra_ratio(start_pos, twopass->stats_in_end,
rc->baseline_gf_interval);
}
if (oxcf->resize_mode == RESIZE_DYNAMIC) {
// Default to starting GF groups at normal frame size.
cpi->rc.next_frame_size_selector = UNSCALED;
}
}
// Threshold for use of the lagging second reference frame. High second ref
// usage may point to a transient event like a flash or occlusion rather than
// a real scene cut.
#define SECOND_REF_USEAGE_THRESH 0.1
// Minimum % intra coding observed in first pass (1.0 = 100%)
#define MIN_INTRA_LEVEL 0.25
// Minimum ratio between the % of intra coding and inter coding in the first
// pass after discounting neutral blocks (discounting neutral blocks in this
// way helps catch scene cuts in clips with very flat areas or letter box
// format clips with image padding.
#define INTRA_VS_INTER_THRESH 2.0
// Hard threshold where the first pass chooses intra for almost all blocks.
// In such a case even if the frame is not a scene cut coding a key frame
// may be a good option.
#define VERY_LOW_INTER_THRESH 0.05
// Maximum threshold for the relative ratio of intra error score vs best
// inter error score.
#define KF_II_ERR_THRESHOLD 2.5
// In real scene cuts there is almost always a sharp change in the intra
// or inter error score.
#define ERR_CHANGE_THRESHOLD 0.4
// For real scene cuts we expect an improvment in the intra inter error
// ratio in the next frame.
#define II_IMPROVEMENT_THRESHOLD 3.5
#define KF_II_MAX 128.0
static int test_candidate_kf(TWO_PASS *twopass,
const FIRSTPASS_STATS *last_frame,
const FIRSTPASS_STATS *this_frame,
const FIRSTPASS_STATS *next_frame) {
int is_viable_kf = 0;
double pcnt_intra = 1.0 - this_frame->pcnt_inter;
double modified_pcnt_inter =
this_frame->pcnt_inter - this_frame->pcnt_neutral;
// Does the frame satisfy the primary criteria of a key frame?
// See above for an explanation of the test criteria.
// If so, then examine how well it predicts subsequent frames.
if ((this_frame->pcnt_second_ref < SECOND_REF_USEAGE_THRESH) &&
(next_frame->pcnt_second_ref < SECOND_REF_USEAGE_THRESH) &&
((this_frame->pcnt_inter < VERY_LOW_INTER_THRESH) ||
((pcnt_intra > MIN_INTRA_LEVEL) &&
(pcnt_intra > (INTRA_VS_INTER_THRESH * modified_pcnt_inter)) &&
((this_frame->intra_error /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error)) <
KF_II_ERR_THRESHOLD) &&
((fabs(last_frame->coded_error - this_frame->coded_error) /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error) >
ERR_CHANGE_THRESHOLD) ||
(fabs(last_frame->intra_error - this_frame->intra_error) /
DOUBLE_DIVIDE_CHECK(this_frame->intra_error) >
ERR_CHANGE_THRESHOLD) ||
((next_frame->intra_error /
DOUBLE_DIVIDE_CHECK(next_frame->coded_error)) >
II_IMPROVEMENT_THRESHOLD))))) {
int i;
const FIRSTPASS_STATS *start_pos = twopass->stats_in;
FIRSTPASS_STATS local_next_frame = *next_frame;
double boost_score = 0.0;
double old_boost_score = 0.0;
double decay_accumulator = 1.0;
// Examine how well the key frame predicts subsequent frames.
for (i = 0; i < 16; ++i) {
double next_iiratio = (BOOST_FACTOR * local_next_frame.intra_error /
DOUBLE_DIVIDE_CHECK(local_next_frame.coded_error));
if (next_iiratio > KF_II_MAX)
next_iiratio = KF_II_MAX;
// Cumulative effect of decay in prediction quality.
if (local_next_frame.pcnt_inter > 0.85)
decay_accumulator *= local_next_frame.pcnt_inter;
else
decay_accumulator *= (0.85 + local_next_frame.pcnt_inter) / 2.0;
// Keep a running total.
boost_score += (decay_accumulator * next_iiratio);
// Test various breakout clauses.
if ((local_next_frame.pcnt_inter < 0.05) ||
(next_iiratio < 1.5) ||
(((local_next_frame.pcnt_inter -
local_next_frame.pcnt_neutral) < 0.20) &&
(next_iiratio < 3.0)) ||
((boost_score - old_boost_score) < 3.0) ||
(local_next_frame.intra_error < 200)) {
break;
}
old_boost_score = boost_score;
// Get the next frame details
if (EOF == input_stats(twopass, &local_next_frame))
break;
}
// If there is tolerable prediction for at least the next 3 frames then
// break out else discard this potential key frame and move on
if (boost_score > 30.0 && (i > 3)) {
is_viable_kf = 1;
} else {
// Reset the file position
reset_fpf_position(twopass, start_pos);
is_viable_kf = 0;
}
}
return is_viable_kf;
}
#define FRAMES_TO_CHECK_DECAY 8
static void find_next_key_frame(VP10_COMP *cpi, FIRSTPASS_STATS *this_frame) {
int i, j;
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->twopass;
GF_GROUP *const gf_group = &twopass->gf_group;
const VP10EncoderConfig *const oxcf = &cpi->oxcf;
const FIRSTPASS_STATS first_frame = *this_frame;
const FIRSTPASS_STATS *const start_position = twopass->stats_in;
FIRSTPASS_STATS next_frame;
FIRSTPASS_STATS last_frame;
int kf_bits = 0;
int loop_decay_counter = 0;
double decay_accumulator = 1.0;
double av_decay_accumulator = 0.0;
double zero_motion_accumulator = 1.0;
double boost_score = 0.0;
double kf_mod_err = 0.0;
double kf_group_err = 0.0;
double recent_loop_decay[FRAMES_TO_CHECK_DECAY];
vp10_zero(next_frame);
cpi->common.frame_type = KEY_FRAME;
// Reset the GF group data structures.
vp10_zero(*gf_group);
// Is this a forced key frame by interval.
rc->this_key_frame_forced = rc->next_key_frame_forced;
// Clear the alt ref active flag and last group multi arf flags as they
// can never be set for a key frame.
rc->source_alt_ref_active = 0;
cpi->multi_arf_last_grp_enabled = 0;
// KF is always a GF so clear frames till next gf counter.
rc->frames_till_gf_update_due = 0;
rc->frames_to_key = 1;
twopass->kf_group_bits = 0; // Total bits available to kf group
twopass->kf_group_error_left = 0; // Group modified error score.
kf_mod_err = calculate_modified_err(cpi, twopass, oxcf, this_frame);
// Initialize the decay rates for the recent frames to check
for (j = 0; j < FRAMES_TO_CHECK_DECAY; ++j)
recent_loop_decay[j] = 1.0;
// Find the next keyframe.
i = 0;
while (twopass->stats_in < twopass->stats_in_end &&
rc->frames_to_key < cpi->oxcf.key_freq) {
// Accumulate kf group error.
kf_group_err += calculate_modified_err(cpi, twopass, oxcf, this_frame);
// Load the next frame's stats.
last_frame = *this_frame;
input_stats(twopass, this_frame);
// Provided that we are not at the end of the file...
if (cpi->oxcf.auto_key && twopass->stats_in < twopass->stats_in_end) {
double loop_decay_rate;
// Check for a scene cut.
if (test_candidate_kf(twopass, &last_frame, this_frame,
twopass->stats_in))
break;
// How fast is the prediction quality decaying?
loop_decay_rate = get_prediction_decay_rate(cpi, twopass->stats_in);
// We want to know something about the recent past... rather than
// as used elsewhere where we are concerned with decay in prediction
// quality since the last GF or KF.
recent_loop_decay[i % FRAMES_TO_CHECK_DECAY] = loop_decay_rate;
decay_accumulator = 1.0;
for (j = 0; j < FRAMES_TO_CHECK_DECAY; ++j)
decay_accumulator *= recent_loop_decay[j];
// Special check for transition or high motion followed by a
// static scene.
if (detect_transition_to_still(cpi, i, cpi->oxcf.key_freq - i,
loop_decay_rate, decay_accumulator))
break;
// Step on to the next frame.
++rc->frames_to_key;
// If we don't have a real key frame within the next two
// key_freq intervals then break out of the loop.
if (rc->frames_to_key >= 2 * cpi->oxcf.key_freq)
break;
} else {
++rc->frames_to_key;
}
++i;
}
// If there is a max kf interval set by the user we must obey it.
// We already breakout of the loop above at 2x max.
// This code centers the extra kf if the actual natural interval
// is between 1x and 2x.
if (cpi->oxcf.auto_key &&
rc->frames_to_key > cpi->oxcf.key_freq) {
FIRSTPASS_STATS tmp_frame = first_frame;
rc->frames_to_key /= 2;
// Reset to the start of the group.
reset_fpf_position(twopass, start_position);
kf_group_err = 0.0;
// Rescan to get the correct error data for the forced kf group.
for (i = 0; i < rc->frames_to_key; ++i) {
kf_group_err += calculate_modified_err(cpi, twopass, oxcf, &tmp_frame);
input_stats(twopass, &tmp_frame);
}
rc->next_key_frame_forced = 1;
} else if (twopass->stats_in == twopass->stats_in_end ||
rc->frames_to_key >= cpi->oxcf.key_freq) {
rc->next_key_frame_forced = 1;
} else {
rc->next_key_frame_forced = 0;
}
// Special case for the last key frame of the file.
if (twopass->stats_in >= twopass->stats_in_end) {
// Accumulate kf group error.
kf_group_err += calculate_modified_err(cpi, twopass, oxcf, this_frame);
}
// Calculate the number of bits that should be assigned to the kf group.
if (twopass->bits_left > 0 && twopass->modified_error_left > 0.0) {
// Maximum number of bits for a single normal frame (not key frame).
const int max_bits = frame_max_bits(rc, &cpi->oxcf);
// Maximum number of bits allocated to the key frame group.
int64_t max_grp_bits;
// Default allocation based on bits left and relative
// complexity of the section.
twopass->kf_group_bits = (int64_t)(twopass->bits_left *
(kf_group_err / twopass->modified_error_left));
// Clip based on maximum per frame rate defined by the user.
max_grp_bits = (int64_t)max_bits * (int64_t)rc->frames_to_key;
if (twopass->kf_group_bits > max_grp_bits)
twopass->kf_group_bits = max_grp_bits;
} else {
twopass->kf_group_bits = 0;
}
twopass->kf_group_bits = VPXMAX(0, twopass->kf_group_bits);
// Reset the first pass file position.
reset_fpf_position(twopass, start_position);
// Scan through the kf group collating various stats used to determine
// how many bits to spend on it.
decay_accumulator = 1.0;
boost_score = 0.0;
for (i = 0; i < (rc->frames_to_key - 1); ++i) {
if (EOF == input_stats(twopass, &next_frame))
break;
// Monitor for static sections.
zero_motion_accumulator = VPXMIN(
zero_motion_accumulator, get_zero_motion_factor(cpi, &next_frame));
// Not all frames in the group are necessarily used in calculating boost.
if ((i <= rc->max_gf_interval) ||
((i <= (rc->max_gf_interval * 4)) && (decay_accumulator > 0.5))) {
const double frame_boost =
calc_frame_boost(cpi, this_frame, 0, KF_MAX_BOOST);
// How fast is prediction quality decaying.
if (!detect_flash(twopass, 0)) {
const double loop_decay_rate =
get_prediction_decay_rate(cpi, &next_frame);
decay_accumulator *= loop_decay_rate;
decay_accumulator = VPXMAX(decay_accumulator, MIN_DECAY_FACTOR);
av_decay_accumulator += decay_accumulator;
++loop_decay_counter;
}
boost_score += (decay_accumulator * frame_boost);
}
}
av_decay_accumulator /= (double)loop_decay_counter;
reset_fpf_position(twopass, start_position);
// Store the zero motion percentage
twopass->kf_zeromotion_pct = (int)(zero_motion_accumulator * 100.0);
// Calculate a section intra ratio used in setting max loop filter.
twopass->section_intra_rating =
calculate_section_intra_ratio(start_position, twopass->stats_in_end,
rc->frames_to_key);
// Apply various clamps for min and max boost
rc->kf_boost = (int)(av_decay_accumulator * boost_score);
rc->kf_boost = VPXMAX(rc->kf_boost, (rc->frames_to_key * 3));
rc->kf_boost = VPXMAX(rc->kf_boost, MIN_KF_BOOST);
// Work out how many bits to allocate for the key frame itself.
kf_bits = calculate_boost_bits((rc->frames_to_key - 1),
rc->kf_boost, twopass->kf_group_bits);
// Work out the fraction of the kf group bits reserved for the inter frames
// within the group after discounting the bits for the kf itself.
if (twopass->kf_group_bits) {
twopass->kfgroup_inter_fraction =
(double)(twopass->kf_group_bits - kf_bits) /
(double)twopass->kf_group_bits;
} else {
twopass->kfgroup_inter_fraction = 1.0;
}
twopass->kf_group_bits -= kf_bits;
// Save the bits to spend on the key frame.
gf_group->bit_allocation[0] = kf_bits;
gf_group->update_type[0] = KF_UPDATE;
gf_group->rf_level[0] = KF_STD;
// Note the total error score of the kf group minus the key frame itself.
twopass->kf_group_error_left = (int)(kf_group_err - kf_mod_err);
// Adjust the count of total modified error left.
// The count of bits left is adjusted elsewhere based on real coded frame
// sizes.
twopass->modified_error_left -= kf_group_err;
if (oxcf->resize_mode == RESIZE_DYNAMIC) {
// Default to normal-sized frame on keyframes.
cpi->rc.next_frame_size_selector = UNSCALED;
}
}
// Define the reference buffers that will be updated post encode.
static void configure_buffer_updates(VP10_COMP *cpi) {
TWO_PASS *const twopass = &cpi->twopass;
cpi->rc.is_src_frame_alt_ref = 0;
switch (twopass->gf_group.update_type[twopass->gf_group.index]) {
case KF_UPDATE:
cpi->refresh_last_frame = 1;
cpi->refresh_golden_frame = 1;
cpi->refresh_alt_ref_frame = 1;
break;
case LF_UPDATE:
cpi->refresh_last_frame = 1;
cpi->refresh_golden_frame = 0;
cpi->refresh_alt_ref_frame = 0;
break;
case GF_UPDATE:
cpi->refresh_last_frame = 1;
cpi->refresh_golden_frame = 1;
cpi->refresh_alt_ref_frame = 0;
break;
case OVERLAY_UPDATE:
cpi->refresh_last_frame = 0;
cpi->refresh_golden_frame = 1;
cpi->refresh_alt_ref_frame = 0;
cpi->rc.is_src_frame_alt_ref = 1;
break;
case ARF_UPDATE:
cpi->refresh_last_frame = 0;
cpi->refresh_golden_frame = 0;
cpi->refresh_alt_ref_frame = 1;
break;
default:
assert(0);
break;
}
}
static int is_skippable_frame(const VP10_COMP *cpi) {
// If the current frame does not have non-zero motion vector detected in the
// first pass, and so do its previous and forward frames, then this frame
// can be skipped for partition check, and the partition size is assigned
// according to the variance
const TWO_PASS *const twopass = &cpi->twopass;
return (!frame_is_intra_only(&cpi->common) &&
twopass->stats_in - 2 > twopass->stats_in_start &&
twopass->stats_in < twopass->stats_in_end &&
(twopass->stats_in - 1)->pcnt_inter - (twopass->stats_in - 1)->pcnt_motion
== 1 &&
(twopass->stats_in - 2)->pcnt_inter - (twopass->stats_in - 2)->pcnt_motion
== 1 &&
twopass->stats_in->pcnt_inter - twopass->stats_in->pcnt_motion == 1);
}
void vp10_rc_get_second_pass_params(VP10_COMP *cpi) {
VP10_COMMON *const cm = &cpi->common;
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->twopass;
GF_GROUP *const gf_group = &twopass->gf_group;
int frames_left;
FIRSTPASS_STATS this_frame;
int target_rate;
frames_left = (int)(twopass->total_stats.count -
cm->current_video_frame);
if (!twopass->stats_in)
return;
// If this is an arf frame then we dont want to read the stats file or
// advance the input pointer as we already have what we need.
if (gf_group->update_type[gf_group->index] == ARF_UPDATE) {
int target_rate;
configure_buffer_updates(cpi);
target_rate = gf_group->bit_allocation[gf_group->index];
target_rate = vp10_rc_clamp_pframe_target_size(cpi, target_rate);
rc->base_frame_target = target_rate;
cm->frame_type = INTER_FRAME;
// Do the firstpass stats indicate that this frame is skippable for the
// partition search?
if (cpi->sf.allow_partition_search_skip && cpi->oxcf.pass == 2) {
cpi->partition_search_skippable_frame = is_skippable_frame(cpi);
}
return;
}
vpx_clear_system_state();
if (cpi->oxcf.rc_mode == VPX_Q) {
twopass->active_worst_quality = cpi->oxcf.cq_level;
} else if (cm->current_video_frame == 0) {
// Special case code for first frame.
const int section_target_bandwidth = (int)(twopass->bits_left /
frames_left);
const double section_length = twopass->total_left_stats.count;
const double section_error =
twopass->total_left_stats.coded_error / section_length;
const double section_intra_skip =
twopass->total_left_stats.intra_skip_pct / section_length;
const double section_inactive_zone =
(twopass->total_left_stats.inactive_zone_rows * 2) /
((double)cm->mb_rows * section_length);
const int tmp_q =
get_twopass_worst_quality(cpi, section_error,
section_intra_skip + section_inactive_zone,
section_target_bandwidth, DEFAULT_GRP_WEIGHT);
twopass->active_worst_quality = tmp_q;
twopass->baseline_active_worst_quality = tmp_q;
rc->ni_av_qi = tmp_q;
rc->last_q[INTER_FRAME] = tmp_q;
rc->avg_q = vp10_convert_qindex_to_q(tmp_q, cm->bit_depth);
rc->avg_frame_qindex[INTER_FRAME] = tmp_q;
rc->last_q[KEY_FRAME] = (tmp_q + cpi->oxcf.best_allowed_q) / 2;
rc->avg_frame_qindex[KEY_FRAME] = rc->last_q[KEY_FRAME];
}
vp10_zero(this_frame);
if (EOF == input_stats(twopass, &this_frame))
return;
// Set the frame content type flag.
if (this_frame.intra_skip_pct >= FC_ANIMATION_THRESH)
twopass->fr_content_type = FC_GRAPHICS_ANIMATION;
else
twopass->fr_content_type = FC_NORMAL;
// Keyframe and section processing.
if (rc->frames_to_key == 0 || (cpi->frame_flags & FRAMEFLAGS_KEY)) {
FIRSTPASS_STATS this_frame_copy;
this_frame_copy = this_frame;
// Define next KF group and assign bits to it.
find_next_key_frame(cpi, &this_frame);
this_frame = this_frame_copy;
} else {
cm->frame_type = INTER_FRAME;
}
// Define a new GF/ARF group. (Should always enter here for key frames).
if (rc->frames_till_gf_update_due == 0) {
define_gf_group(cpi, &this_frame);
rc->frames_till_gf_update_due = rc->baseline_gf_interval;
#if ARF_STATS_OUTPUT
{
FILE *fpfile;
fpfile = fopen("arf.stt", "a");
++arf_count;
fprintf(fpfile, "%10d %10ld %10d %10d %10ld\n",
cm->current_video_frame, rc->frames_till_gf_update_due,
rc->kf_boost, arf_count, rc->gfu_boost);
fclose(fpfile);
}
#endif
}
configure_buffer_updates(cpi);
// Do the firstpass stats indicate that this frame is skippable for the
// partition search?
if (cpi->sf.allow_partition_search_skip && cpi->oxcf.pass == 2) {
cpi->partition_search_skippable_frame = is_skippable_frame(cpi);
}
target_rate = gf_group->bit_allocation[gf_group->index];
if (cpi->common.frame_type == KEY_FRAME)
target_rate = vp10_rc_clamp_iframe_target_size(cpi, target_rate);
else
target_rate = vp10_rc_clamp_pframe_target_size(cpi, target_rate);
rc->base_frame_target = target_rate;
{
const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE)
? cpi->initial_mbs : cpi->common.MBs;
// The multiplication by 256 reverses a scaling factor of (>> 8)
// applied when combining MB error values for the frame.
twopass->mb_av_energy =
log(((this_frame.intra_error * 256.0) / num_mbs) + 1.0);
}
// Update the total stats remaining structure.
subtract_stats(&twopass->total_left_stats, &this_frame);
}
#define MINQ_ADJ_LIMIT 48
#define MINQ_ADJ_LIMIT_CQ 20
#define HIGH_UNDERSHOOT_RATIO 2
void vp10_twopass_postencode_update(VP10_COMP *cpi) {
TWO_PASS *const twopass = &cpi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
const int bits_used = rc->base_frame_target;
// VBR correction is done through rc->vbr_bits_off_target. Based on the
// sign of this value, a limited % adjustment is made to the target rate
// of subsequent frames, to try and push it back towards 0. This method
// is designed to prevent extreme behaviour at the end of a clip
// or group of frames.
rc->vbr_bits_off_target += rc->base_frame_target - rc->projected_frame_size;
twopass->bits_left = VPXMAX(twopass->bits_left - bits_used, 0);
// Calculate the pct rc error.
if (rc->total_actual_bits) {
rc->rate_error_estimate =
(int)((rc->vbr_bits_off_target * 100) / rc->total_actual_bits);
rc->rate_error_estimate = clamp(rc->rate_error_estimate, -100, 100);
} else {
rc->rate_error_estimate = 0;
}
if (cpi->common.frame_type != KEY_FRAME) {
twopass->kf_group_bits -= bits_used;
twopass->last_kfgroup_zeromotion_pct = twopass->kf_zeromotion_pct;
}
twopass->kf_group_bits = VPXMAX(twopass->kf_group_bits, 0);
// Increment the gf group index ready for the next frame.
++twopass->gf_group.index;
// If the rate control is drifting consider adjustment to min or maxq.
if ((cpi->oxcf.rc_mode != VPX_Q) &&
(cpi->twopass.gf_zeromotion_pct < VLOW_MOTION_THRESHOLD) &&
!cpi->rc.is_src_frame_alt_ref) {
const int maxq_adj_limit =
rc->worst_quality - twopass->active_worst_quality;
const int minq_adj_limit =
(cpi->oxcf.rc_mode == VPX_CQ ? MINQ_ADJ_LIMIT_CQ : MINQ_ADJ_LIMIT);
// Undershoot.
if (rc->rate_error_estimate > cpi->oxcf.under_shoot_pct) {
--twopass->extend_maxq;
if (rc->rolling_target_bits >= rc->rolling_actual_bits)
++twopass->extend_minq;
// Overshoot.
} else if (rc->rate_error_estimate < -cpi->oxcf.over_shoot_pct) {
--twopass->extend_minq;
if (rc->rolling_target_bits < rc->rolling_actual_bits)
++twopass->extend_maxq;
} else {
// Adjustment for extreme local overshoot.
if (rc->projected_frame_size > (2 * rc->base_frame_target) &&
rc->projected_frame_size > (2 * rc->avg_frame_bandwidth))
++twopass->extend_maxq;
// Unwind undershoot or overshoot adjustment.
if (rc->rolling_target_bits < rc->rolling_actual_bits)
--twopass->extend_minq;
else if (rc->rolling_target_bits > rc->rolling_actual_bits)
--twopass->extend_maxq;
}
twopass->extend_minq = clamp(twopass->extend_minq, 0, minq_adj_limit);
twopass->extend_maxq = clamp(twopass->extend_maxq, 0, maxq_adj_limit);
// If there is a big and undexpected undershoot then feed the extra
// bits back in quickly. One situation where this may happen is if a
// frame is unexpectedly almost perfectly predicted by the ARF or GF
// but not very well predcited by the previous frame.
if (!frame_is_kf_gf_arf(cpi) && !cpi->rc.is_src_frame_alt_ref) {
int fast_extra_thresh = rc->base_frame_target / HIGH_UNDERSHOOT_RATIO;
if (rc->projected_frame_size < fast_extra_thresh) {
rc->vbr_bits_off_target_fast +=
fast_extra_thresh - rc->projected_frame_size;
rc->vbr_bits_off_target_fast =
VPXMIN(rc->vbr_bits_off_target_fast, (4 * rc->avg_frame_bandwidth));
// Fast adaptation of minQ if necessary to use up the extra bits.
if (rc->avg_frame_bandwidth) {
twopass->extend_minq_fast =
(int)(rc->vbr_bits_off_target_fast * 8 / rc->avg_frame_bandwidth);
}
twopass->extend_minq_fast = VPXMIN(
twopass->extend_minq_fast, minq_adj_limit - twopass->extend_minq);
} else if (rc->vbr_bits_off_target_fast) {
twopass->extend_minq_fast = VPXMIN(
twopass->extend_minq_fast, minq_adj_limit - twopass->extend_minq);
} else {
twopass->extend_minq_fast = 0;
}
}
}
}