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Minor Two pass rate control adjustments.

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Alter way in which we identify static scenes.
Remove some redundant code.

Change-Id: I883c2ea2e341770648a8663d8881f720ed099b61
This commit is contained in:
Paul Wilkins 2014-07-25 10:19:19 +01:00
parent 1d9e2b5003
commit ea55e4d26a
3 changed files with 32 additions and 51 deletions
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2
vp9/encoder/vp9_encoder.c
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@ -1663,8 +1663,8 @@ static void output_frame_level_debug_stats(VP9_COMP *cpi) {
cpi->rc.total_actual_bits, cm->base_qindex,
vp9_convert_qindex_to_q(cm->base_qindex),
(double)vp9_dc_quant(cm->base_qindex, 0) / 4.0,
vp9_convert_qindex_to_q(cpi->twopass.active_worst_quality),
cpi->rc.avg_q,
vp9_convert_qindex_to_q(cpi->rc.ni_av_qi),
vp9_convert_qindex_to_q(cpi->oxcf.cq_level),
cpi->refresh_last_frame, cpi->refresh_golden_frame,
cpi->refresh_alt_ref_frame, cm->frame_type, cpi->rc.gfu_boost,

79
vp9/encoder/vp9_firstpass.c
View File

@ -22,7 +22,6 @@
#include "vp9/common/vp9_quant_common.h"
#include "vp9/common/vp9_reconinter.h" // vp9_setup_dst_planes()
#include "vp9/common/vp9_systemdependent.h"
#include "vp9/encoder/vp9_aq_variance.h"
#include "vp9/encoder/vp9_block.h"
#include "vp9/encoder/vp9_encodeframe.h"
@ -56,7 +55,6 @@
#define MIN_KF_BOOST 300
#define MIN_GF_INTERVAL 4
#define LONG_TERM_VBR_CORRECTION
static void swap_yv12(YV12_BUFFER_CONFIG *a, YV12_BUFFER_CONFIG *b) {
YV12_BUFFER_CONFIG temp = *a;
@ -963,7 +961,7 @@ static int get_twopass_worst_quality(const VP9_COMP *cpi,
const double err_per_mb = section_err / num_mbs;
const double speed_term = 1.0 + 0.04 * oxcf->speed;
const int target_norm_bits_per_mb = ((uint64_t)section_target_bandwidth <<
BPER_MB_NORMBITS) / num_mbs;
BPER_MB_NORMBITS) / num_mbs;
int q;
int is_svc_upper_layer = 0;
if (is_spatial_svc(cpi) && cpi->svc.spatial_layer_id > 0)
@ -1081,6 +1079,19 @@ static double get_prediction_decay_rate(const VP9_COMMON *cm,
return MIN(second_ref_decay, next_frame->pcnt_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 VP9_COMMON *cm,
const FIRSTPASS_STATS *frame) {
const double sr_ratio = frame->coded_error /
DOUBLE_DIVIDE_CHECK(frame->sr_coded_error);
const double zero_motion_pct = frame->pcnt_inter -
frame->pcnt_motion;
return MIN(sr_ratio, zero_motion_pct);
}
// 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.
@ -1604,11 +1615,9 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
decay_accumulator = decay_accumulator * loop_decay_rate;
// Monitor for static sections.
if ((next_frame.pcnt_inter - next_frame.pcnt_motion) <
zero_motion_accumulator) {
zero_motion_accumulator = next_frame.pcnt_inter -
next_frame.pcnt_motion;
}
zero_motion_accumulator =
MIN(zero_motion_accumulator,
get_zero_motion_factor(&cpi->common, &next_frame));
// Break clause to detect very still sections after motion. For example,
// a static image after a fade or other transition.
@ -1978,11 +1987,9 @@ static void find_next_key_frame(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
break;
// Monitor for static sections.
if ((next_frame.pcnt_inter - next_frame.pcnt_motion) <
zero_motion_accumulator) {
zero_motion_accumulator = (next_frame.pcnt_inter -
next_frame.pcnt_motion);
}
zero_motion_accumulator =
MIN(zero_motion_accumulator,
get_zero_motion_factor(&cpi->common, &next_frame));
// For the first few frames collect data to decide kf boost.
if (i <= (rc->max_gf_interval * 2)) {
@ -2139,11 +2146,11 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
target_rate = twopass->gf_group.bit_allocation[twopass->gf_group.index];
target_rate = vp9_rc_clamp_pframe_target_size(cpi, target_rate);
rc->base_frame_target = target_rate;
#ifdef LONG_TERM_VBR_CORRECTION
// Correction to rate target based on prior over or under shoot.
if (cpi->oxcf.rc_mode == VPX_VBR)
vbr_rate_correction(&target_rate, rc->vbr_bits_off_target);
#endif
vp9_rc_set_frame_target(cpi, target_rate);
cm->frame_type = INTER_FRAME;
@ -2242,11 +2249,11 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
target_rate = vp9_rc_clamp_pframe_target_size(cpi, target_rate);
rc->base_frame_target = target_rate;
#ifdef LONG_TERM_VBR_CORRECTION
// Correction to rate target based on prior over or under shoot.
if (cpi->oxcf.rc_mode == VPX_VBR)
vbr_rate_correction(&target_rate, rc->vbr_bits_off_target);
#endif
vp9_rc_set_frame_target(cpi, target_rate);
// Update the total stats remaining structure.
@ -2256,45 +2263,19 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
void vp9_twopass_postencode_update(VP9_COMP *cpi) {
TWO_PASS *const twopass = &cpi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
#ifdef LONG_TERM_VBR_CORRECTION
// In this experimental mode, the VBR correction is done exclusively 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 mode is less likely to suffer from
// extreme behaviour at the end of a clip or group of frames.
// 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.
const int bits_used = rc->base_frame_target;
rc->vbr_bits_off_target += rc->base_frame_target - rc->projected_frame_size;
#else
// In this mode, VBR correction is acheived by altering bits_left,
// kf_group_bits & gf_group_bits to reflect any deviation from the target
// rate in this frame. This alters the allocation of bits to the
// remaning frames in the group / clip.
//
// This method can give rise to unstable behaviour near the end of a clip
// or kf/gf group of frames where any accumulated error is corrected over an
// ever decreasing number of frames. Hence we change the balance of target
// vs. actual bitrate gradually as we progress towards the end of the
// sequence in order to mitigate this effect.
const double progress =
(double)(twopass->stats_in - twopass->stats_in_start) /
(twopass->stats_in_end - twopass->stats_in_start);
const int bits_used = (int)(progress * rc->this_frame_target +
(1.0 - progress) * rc->projected_frame_size);
#endif
twopass->bits_left = MAX(twopass->bits_left - bits_used, 0);
#ifdef LONG_TERM_VBR_CORRECTION
if (cpi->common.frame_type != KEY_FRAME &&
!vp9_is_upper_layer_key_frame(cpi)) {
#else
if (cpi->common.frame_type == KEY_FRAME ||
vp9_is_upper_layer_key_frame(cpi)) {
// For key frames kf_group_bits already had the target bits subtracted out.
// So now update to the correct value based on the actual bits used.
twopass->kf_group_bits += rc->this_frame_target - bits_used;
} else {
#endif
twopass->kf_group_bits -= bits_used;
}
twopass->kf_group_bits = MAX(twopass->kf_group_bits, 0);

2
vp9/encoder/vp9_ratectrl.c
View File

@ -104,7 +104,7 @@ int vp9_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,
// q based adjustment to baseline enumerator
enumerator += (int)(enumerator * q) >> 12;
return (int)(0.5 + (enumerator * correction_factor / q));
return (int)(enumerator * correction_factor / q);
}
static int estimate_bits_at_q(FRAME_TYPE frame_type, int q, int mbs,