ref: 4a47ef814b57d16787e6331e4ac1bd9dc093459e
dir: /vp9/encoder/vp9_aq_cyclicrefresh.c/
/*
* Copyright (c) 2014 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 "vpx_dsp/vpx_dsp_common.h"
#include "vpx_ports/system_state.h"
#include "vp9/encoder/vp9_aq_cyclicrefresh.h"
#include "vp9/common/vp9_seg_common.h"
#include "vp9/encoder/vp9_ratectrl.h"
#include "vp9/encoder/vp9_segmentation.h"
static const uint8_t VP9_VAR_OFFS[64] = {
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128
};
CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
size_t last_coded_q_map_size;
CYCLIC_REFRESH *const cr = vpx_calloc(1, sizeof(*cr));
if (cr == NULL) return NULL;
cr->map = vpx_calloc(mi_rows * mi_cols, sizeof(*cr->map));
if (cr->map == NULL) {
vp9_cyclic_refresh_free(cr);
return NULL;
}
last_coded_q_map_size = mi_rows * mi_cols * sizeof(*cr->last_coded_q_map);
cr->last_coded_q_map = vpx_malloc(last_coded_q_map_size);
if (cr->last_coded_q_map == NULL) {
vp9_cyclic_refresh_free(cr);
return NULL;
}
assert(MAXQ <= 255);
memset(cr->last_coded_q_map, MAXQ, last_coded_q_map_size);
cr->counter_encode_maxq_scene_change = 0;
return cr;
}
void vp9_cyclic_refresh_free(CYCLIC_REFRESH *cr) {
if (cr != NULL) {
vpx_free(cr->map);
vpx_free(cr->last_coded_q_map);
vpx_free(cr);
}
}
// Check if this coding block, of size bsize, should be considered for refresh
// (lower-qp coding). Decision can be based on various factors, such as
// size of the coding block (i.e., below min_block size rejected), coding
// mode, and rate/distortion.
static int candidate_refresh_aq(const CYCLIC_REFRESH *cr, const MODE_INFO *mi,
int64_t rate, int64_t dist, int bsize) {
MV mv = mi->mv[0].as_mv;
// Reject the block for lower-qp coding if projected distortion
// is above the threshold, and any of the following is true:
// 1) mode uses large mv
// 2) mode is an intra-mode
// Otherwise accept for refresh.
if (dist > cr->thresh_dist_sb &&
(mv.row > cr->motion_thresh || mv.row < -cr->motion_thresh ||
mv.col > cr->motion_thresh || mv.col < -cr->motion_thresh ||
!is_inter_block(mi)))
return CR_SEGMENT_ID_BASE;
else if (bsize >= BLOCK_16X16 && rate < cr->thresh_rate_sb &&
is_inter_block(mi) && mi->mv[0].as_int == 0 &&
cr->rate_boost_fac > 10)
// More aggressive delta-q for bigger blocks with zero motion.
return CR_SEGMENT_ID_BOOST2;
else
return CR_SEGMENT_ID_BOOST1;
}
// Compute delta-q for the segment.
static int compute_deltaq(const VP9_COMP *cpi, int q, double rate_factor) {
const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
const RATE_CONTROL *const rc = &cpi->rc;
int deltaq = vp9_compute_qdelta_by_rate(rc, cpi->common.frame_type, q,
rate_factor, cpi->common.bit_depth);
if ((-deltaq) > cr->max_qdelta_perc * q / 100) {
deltaq = -cr->max_qdelta_perc * q / 100;
}
return deltaq;
}
// For the just encoded frame, estimate the bits, incorporating the delta-q
// from non-base segment. For now ignore effect of multiple segments
// (with different delta-q). Note this function is called in the postencode
// (called from rc_update_rate_correction_factors()).
int vp9_cyclic_refresh_estimate_bits_at_q(const VP9_COMP *cpi,
double correction_factor) {
const VP9_COMMON *const cm = &cpi->common;
const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
int estimated_bits;
int mbs = cm->MBs;
int num8x8bl = mbs << 2;
// Weight for non-base segments: use actual number of blocks refreshed in
// previous/just encoded frame. Note number of blocks here is in 8x8 units.
double weight_segment1 = (double)cr->actual_num_seg1_blocks / num8x8bl;
double weight_segment2 = (double)cr->actual_num_seg2_blocks / num8x8bl;
// Take segment weighted average for estimated bits.
estimated_bits =
(int)((1.0 - weight_segment1 - weight_segment2) *
vp9_estimate_bits_at_q(cm->frame_type, cm->base_qindex, mbs,
correction_factor, cm->bit_depth) +
weight_segment1 *
vp9_estimate_bits_at_q(cm->frame_type,
cm->base_qindex + cr->qindex_delta[1],
mbs, correction_factor, cm->bit_depth) +
weight_segment2 *
vp9_estimate_bits_at_q(cm->frame_type,
cm->base_qindex + cr->qindex_delta[2],
mbs, correction_factor, cm->bit_depth));
return estimated_bits;
}
// Prior to encoding the frame, estimate the bits per mb, for a given q = i and
// a corresponding delta-q (for segment 1). This function is called in the
// rc_regulate_q() to set the base qp index.
// Note: the segment map is set to either 0/CR_SEGMENT_ID_BASE (no refresh) or
// to 1/CR_SEGMENT_ID_BOOST1 (refresh) for each superblock, prior to encoding.
int vp9_cyclic_refresh_rc_bits_per_mb(const VP9_COMP *cpi, int i,
double correction_factor) {
const VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
int bits_per_mb;
int deltaq = 0;
if (cpi->oxcf.speed < 8)
deltaq = compute_deltaq(cpi, i, cr->rate_ratio_qdelta);
else
deltaq = -(cr->max_qdelta_perc * i) / 200;
// Take segment weighted average for bits per mb.
bits_per_mb = (int)((1.0 - cr->weight_segment) *
vp9_rc_bits_per_mb(cm->frame_type, i,
correction_factor, cm->bit_depth) +
cr->weight_segment *
vp9_rc_bits_per_mb(cm->frame_type, i + deltaq,
correction_factor, cm->bit_depth));
return bits_per_mb;
}
// Prior to coding a given prediction block, of size bsize at (mi_row, mi_col),
// check if we should reset the segment_id, and update the cyclic_refresh map
// and segmentation map.
void vp9_cyclic_refresh_update_segment(VP9_COMP *const cpi, MODE_INFO *const mi,
int mi_row, int mi_col, BLOCK_SIZE bsize,
int64_t rate, int64_t dist, int skip,
struct macroblock_plane *const p) {
const VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
const int bw = num_8x8_blocks_wide_lookup[bsize];
const int bh = num_8x8_blocks_high_lookup[bsize];
const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
const int block_index = mi_row * cm->mi_cols + mi_col;
int refresh_this_block = candidate_refresh_aq(cr, mi, rate, dist, bsize);
// Default is to not update the refresh map.
int new_map_value = cr->map[block_index];
int x = 0;
int y = 0;
int is_skin = 0;
if (refresh_this_block == 0 && bsize <= BLOCK_16X16 &&
cpi->use_skin_detection) {
is_skin =
vp9_compute_skin_block(p[0].src.buf, p[1].src.buf, p[2].src.buf,
p[0].src.stride, p[1].src.stride, bsize, 0, 0);
if (is_skin) refresh_this_block = 1;
}
if (cpi->oxcf.rc_mode == VPX_VBR && mi->ref_frame[0] == GOLDEN_FRAME)
refresh_this_block = 0;
// If this block is labeled for refresh, check if we should reset the
// segment_id.
if (cyclic_refresh_segment_id_boosted(mi->segment_id)) {
mi->segment_id = refresh_this_block;
// Reset segment_id if it will be skipped.
if (skip) mi->segment_id = CR_SEGMENT_ID_BASE;
}
// Update the cyclic refresh map, to be used for setting segmentation map
// for the next frame. If the block will be refreshed this frame, mark it
// as clean. The magnitude of the -ve influences how long before we consider
// it for refresh again.
if (cyclic_refresh_segment_id_boosted(mi->segment_id)) {
new_map_value = -cr->time_for_refresh;
} else if (refresh_this_block) {
// Else if it is accepted as candidate for refresh, and has not already
// been refreshed (marked as 1) then mark it as a candidate for cleanup
// for future time (marked as 0), otherwise don't update it.
if (cr->map[block_index] == 1) new_map_value = 0;
} else {
// Leave it marked as block that is not candidate for refresh.
new_map_value = 1;
}
// Update entries in the cyclic refresh map with new_map_value, and
// copy mbmi->segment_id into global segmentation map.
for (y = 0; y < ymis; y++)
for (x = 0; x < xmis; x++) {
int map_offset = block_index + y * cm->mi_cols + x;
cr->map[map_offset] = new_map_value;
cpi->segmentation_map[map_offset] = mi->segment_id;
}
}
void vp9_cyclic_refresh_update_sb_postencode(VP9_COMP *const cpi,
const MODE_INFO *const mi,
int mi_row, int mi_col,
BLOCK_SIZE bsize) {
const VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
const int bw = num_8x8_blocks_wide_lookup[bsize];
const int bh = num_8x8_blocks_high_lookup[bsize];
const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
const int block_index = mi_row * cm->mi_cols + mi_col;
int x, y;
for (y = 0; y < ymis; y++)
for (x = 0; x < xmis; x++) {
int map_offset = block_index + y * cm->mi_cols + x;
// Inter skip blocks were clearly not coded at the current qindex, so
// don't update the map for them. For cases where motion is non-zero or
// the reference frame isn't the previous frame, the previous value in
// the map for this spatial location is not entirely correct.
if ((!is_inter_block(mi) || !mi->skip) &&
mi->segment_id <= CR_SEGMENT_ID_BOOST2) {
cr->last_coded_q_map[map_offset] =
clamp(cm->base_qindex + cr->qindex_delta[mi->segment_id], 0, MAXQ);
} else if (is_inter_block(mi) && mi->skip &&
mi->segment_id <= CR_SEGMENT_ID_BOOST2) {
cr->last_coded_q_map[map_offset] = VPXMIN(
clamp(cm->base_qindex + cr->qindex_delta[mi->segment_id], 0, MAXQ),
cr->last_coded_q_map[map_offset]);
}
}
}
// From the just encoded frame: update the actual number of blocks that were
// applied the segment delta q, and the amount of low motion in the frame.
// Also check conditions for forcing golden update, or preventing golden
// update if the period is up.
void vp9_cyclic_refresh_postencode(VP9_COMP *const cpi) {
VP9_COMMON *const cm = &cpi->common;
MODE_INFO **mi = cm->mi_grid_visible;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
RATE_CONTROL *const rc = &cpi->rc;
unsigned char *const seg_map = cpi->segmentation_map;
double fraction_low = 0.0;
int force_gf_refresh = 0;
int low_content_frame = 0;
int mi_row, mi_col;
cr->actual_num_seg1_blocks = 0;
cr->actual_num_seg2_blocks = 0;
for (mi_row = 0; mi_row < cm->mi_rows; mi_row++) {
for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) {
MV mv = mi[0]->mv[0].as_mv;
int map_index = mi_row * cm->mi_cols + mi_col;
if (cyclic_refresh_segment_id(seg_map[map_index]) == CR_SEGMENT_ID_BOOST1)
cr->actual_num_seg1_blocks++;
else if (cyclic_refresh_segment_id(seg_map[map_index]) ==
CR_SEGMENT_ID_BOOST2)
cr->actual_num_seg2_blocks++;
// Accumulate low_content_frame.
if (is_inter_block(mi[0]) && abs(mv.row) < 16 && abs(mv.col) < 16)
low_content_frame++;
mi++;
}
mi += 8;
}
// Check for golden frame update: only for non-SVC and non-golden boost.
if (!cpi->use_svc && cpi->ext_refresh_frame_flags_pending == 0 &&
!cpi->oxcf.gf_cbr_boost_pct) {
// Force this frame as a golden update frame if this frame changes the
// resolution (resize_pending != 0).
if (cpi->resize_pending != 0) {
vp9_cyclic_refresh_set_golden_update(cpi);
rc->frames_till_gf_update_due = rc->baseline_gf_interval;
if (rc->frames_till_gf_update_due > rc->frames_to_key)
rc->frames_till_gf_update_due = rc->frames_to_key;
cpi->refresh_golden_frame = 1;
force_gf_refresh = 1;
}
// Update average of low content/motion in the frame.
fraction_low = (double)low_content_frame / (cm->mi_rows * cm->mi_cols);
cr->low_content_avg = (fraction_low + 3 * cr->low_content_avg) / 4;
if (!force_gf_refresh && cpi->refresh_golden_frame == 1 &&
rc->frames_since_key > rc->frames_since_golden + 1) {
// Don't update golden reference if the amount of low_content for the
// current encoded frame is small, or if the recursive average of the
// low_content over the update interval window falls below threshold.
if (fraction_low < 0.65 || cr->low_content_avg < 0.6) {
cpi->refresh_golden_frame = 0;
}
// Reset for next internal.
cr->low_content_avg = fraction_low;
}
}
}
// Set golden frame update interval, for non-svc 1 pass CBR mode.
void vp9_cyclic_refresh_set_golden_update(VP9_COMP *const cpi) {
RATE_CONTROL *const rc = &cpi->rc;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
// Set minimum gf_interval for GF update to a multiple of the refresh period,
// with some max limit. Depending on past encoding stats, GF flag may be
// reset and update may not occur until next baseline_gf_interval.
if (cr->percent_refresh > 0)
rc->baseline_gf_interval = VPXMIN(4 * (100 / cr->percent_refresh), 40);
else
rc->baseline_gf_interval = 40;
if (cpi->oxcf.rc_mode == VPX_VBR) rc->baseline_gf_interval = 20;
if (rc->avg_frame_low_motion < 50 && rc->frames_since_key > 40)
rc->baseline_gf_interval = 10;
}
static int is_superblock_flat_static(VP9_COMP *const cpi, int sb_row_index,
int sb_col_index) {
unsigned int source_variance;
const uint8_t *src_y = cpi->Source->y_buffer;
const int ystride = cpi->Source->y_stride;
unsigned int sse;
const BLOCK_SIZE bsize = BLOCK_64X64;
src_y += (sb_row_index << 6) * ystride + (sb_col_index << 6);
source_variance =
cpi->fn_ptr[bsize].vf(src_y, ystride, VP9_VAR_OFFS, 0, &sse);
if (source_variance == 0) {
uint64_t block_sad;
const uint8_t *last_src_y = cpi->Last_Source->y_buffer;
const int last_ystride = cpi->Last_Source->y_stride;
last_src_y += (sb_row_index << 6) * ystride + (sb_col_index << 6);
block_sad =
cpi->fn_ptr[bsize].sdf(src_y, ystride, last_src_y, last_ystride);
if (block_sad == 0) return 1;
}
return 0;
}
// Update the segmentation map, and related quantities: cyclic refresh map,
// refresh sb_index, and target number of blocks to be refreshed.
// The map is set to either 0/CR_SEGMENT_ID_BASE (no refresh) or to
// 1/CR_SEGMENT_ID_BOOST1 (refresh) for each superblock.
// Blocks labeled as BOOST1 may later get set to BOOST2 (during the
// encoding of the superblock).
static void cyclic_refresh_update_map(VP9_COMP *const cpi) {
VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
unsigned char *const seg_map = cpi->segmentation_map;
int i, block_count, bl_index, sb_rows, sb_cols, sbs_in_frame;
int xmis, ymis, x, y;
int consec_zero_mv_thresh = 0;
int qindex_thresh = 0;
int count_sel = 0;
int count_tot = 0;
memset(seg_map, CR_SEGMENT_ID_BASE, cm->mi_rows * cm->mi_cols);
sb_cols = (cm->mi_cols + MI_BLOCK_SIZE - 1) / MI_BLOCK_SIZE;
sb_rows = (cm->mi_rows + MI_BLOCK_SIZE - 1) / MI_BLOCK_SIZE;
sbs_in_frame = sb_cols * sb_rows;
// Number of target blocks to get the q delta (segment 1).
block_count = cr->percent_refresh * cm->mi_rows * cm->mi_cols / 100;
// Set the segmentation map: cycle through the superblocks, starting at
// cr->mb_index, and stopping when either block_count blocks have been found
// to be refreshed, or we have passed through whole frame.
assert(cr->sb_index < sbs_in_frame);
i = cr->sb_index;
cr->target_num_seg_blocks = 0;
if (cpi->oxcf.content != VP9E_CONTENT_SCREEN) {
consec_zero_mv_thresh = 100;
}
qindex_thresh =
cpi->oxcf.content == VP9E_CONTENT_SCREEN
? vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST2, cm->base_qindex)
: vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST1, cm->base_qindex);
// More aggressive settings for noisy content.
if (cpi->noise_estimate.enabled && cpi->noise_estimate.level >= kMedium) {
consec_zero_mv_thresh = 60;
qindex_thresh =
VPXMAX(vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST1, cm->base_qindex),
cm->base_qindex);
}
do {
int sum_map = 0;
int consec_zero_mv_thresh_block = consec_zero_mv_thresh;
// Get the mi_row/mi_col corresponding to superblock index i.
int sb_row_index = (i / sb_cols);
int sb_col_index = i - sb_row_index * sb_cols;
int mi_row = sb_row_index * MI_BLOCK_SIZE;
int mi_col = sb_col_index * MI_BLOCK_SIZE;
int flat_static_blocks = 0;
int compute_content = 1;
assert(mi_row >= 0 && mi_row < cm->mi_rows);
assert(mi_col >= 0 && mi_col < cm->mi_cols);
#if CONFIG_VP9_HIGHBITDEPTH
if (cpi->common.use_highbitdepth) compute_content = 0;
#endif
if (cpi->Last_Source == NULL ||
cpi->Last_Source->y_width != cpi->Source->y_width ||
cpi->Last_Source->y_height != cpi->Source->y_height)
compute_content = 0;
bl_index = mi_row * cm->mi_cols + mi_col;
// Loop through all 8x8 blocks in superblock and update map.
xmis =
VPXMIN(cm->mi_cols - mi_col, num_8x8_blocks_wide_lookup[BLOCK_64X64]);
ymis =
VPXMIN(cm->mi_rows - mi_row, num_8x8_blocks_high_lookup[BLOCK_64X64]);
if (cpi->noise_estimate.enabled && cpi->noise_estimate.level >= kMedium &&
(xmis <= 2 || ymis <= 2))
consec_zero_mv_thresh_block = 4;
for (y = 0; y < ymis; y++) {
for (x = 0; x < xmis; x++) {
const int bl_index2 = bl_index + y * cm->mi_cols + x;
// If the block is as a candidate for clean up then mark it
// for possible boost/refresh (segment 1). The segment id may get
// reset to 0 later depending on the coding mode.
if (cr->map[bl_index2] == 0) {
count_tot++;
if (cr->last_coded_q_map[bl_index2] > qindex_thresh ||
cpi->consec_zero_mv[bl_index2] < consec_zero_mv_thresh_block) {
sum_map++;
count_sel++;
}
} else if (cr->map[bl_index2] < 0) {
cr->map[bl_index2]++;
}
}
}
// Enforce constant segment over superblock.
// If segment is at least half of superblock, set to 1.
if (sum_map >= xmis * ymis / 2) {
// This superblock is a candidate for refresh:
// compute spatial variance and exclude blocks that are spatially flat
// and stationary. Note: this is currently only done for screne content
// mode.
if (compute_content && cr->skip_flat_static_blocks)
flat_static_blocks =
is_superblock_flat_static(cpi, sb_row_index, sb_col_index);
if (!flat_static_blocks) {
// Label this superblock as segment 1.
for (y = 0; y < ymis; y++)
for (x = 0; x < xmis; x++) {
seg_map[bl_index + y * cm->mi_cols + x] = CR_SEGMENT_ID_BOOST1;
}
cr->target_num_seg_blocks += xmis * ymis;
}
}
i++;
if (i == sbs_in_frame) {
i = 0;
}
} while (cr->target_num_seg_blocks < block_count && i != cr->sb_index);
cr->sb_index = i;
cr->reduce_refresh = 0;
if (cpi->oxcf.content != VP9E_CONTENT_SCREEN)
if (count_sel<(3 * count_tot)>> 2) cr->reduce_refresh = 1;
}
// Set cyclic refresh parameters.
void vp9_cyclic_refresh_update_parameters(VP9_COMP *const cpi) {
const RATE_CONTROL *const rc = &cpi->rc;
const VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
int num8x8bl = cm->MBs << 2;
int target_refresh = 0;
double weight_segment_target = 0;
double weight_segment = 0;
int thresh_low_motion = (cm->width < 720) ? 55 : 20;
int qp_thresh = VPXMIN(20, rc->best_quality << 1);
cr->apply_cyclic_refresh = 1;
if (frame_is_intra_only(cm) || cpi->svc.temporal_layer_id > 0 ||
is_lossless_requested(&cpi->oxcf) ||
rc->avg_frame_qindex[INTER_FRAME] < qp_thresh ||
(cpi->use_svc &&
cpi->svc.layer_context[cpi->svc.temporal_layer_id].is_key_frame) ||
(!cpi->use_svc && rc->avg_frame_low_motion < thresh_low_motion &&
rc->frames_since_key > 40)) {
cr->apply_cyclic_refresh = 0;
return;
}
cr->percent_refresh = 10;
if (cr->reduce_refresh) cr->percent_refresh = 5;
cr->max_qdelta_perc = 60;
cr->time_for_refresh = 0;
cr->motion_thresh = 32;
cr->rate_boost_fac = 15;
// Use larger delta-qp (increase rate_ratio_qdelta) for first few (~4)
// periods of the refresh cycle, after a key frame.
// Account for larger interval on base layer for temporal layers.
if (cr->percent_refresh > 0 &&
rc->frames_since_key <
(4 * cpi->svc.number_temporal_layers) * (100 / cr->percent_refresh)) {
cr->rate_ratio_qdelta = 3.0;
} else {
cr->rate_ratio_qdelta = 2.0;
if (cpi->noise_estimate.enabled && cpi->noise_estimate.level >= kMedium) {
// Reduce the delta-qp if the estimated source noise is above threshold.
cr->rate_ratio_qdelta = 1.7;
cr->rate_boost_fac = 13;
}
}
// For screen-content: keep rate_ratio_qdelta to 2.0 (segment#1 boost) and
// percent_refresh (refresh rate) to 10. But reduce rate boost for segment#2
// (rate_boost_fac = 10 disables segment#2).
if (cpi->oxcf.content == VP9E_CONTENT_SCREEN) {
// Only enable feature of skipping flat_static blocks for top layer
// under screen content mode.
if (cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1)
cr->skip_flat_static_blocks = 1;
cr->percent_refresh = (cr->skip_flat_static_blocks) ? 5 : 10;
// Increase the amount of refresh on scene change that is encoded at max Q,
// increase for a few cycles of the refresh period (~100 / percent_refresh).
if (cr->counter_encode_maxq_scene_change < 30)
cr->percent_refresh = (cr->skip_flat_static_blocks) ? 10 : 15;
cr->rate_ratio_qdelta = 2.0;
cr->rate_boost_fac = 10;
}
// Adjust some parameters for low resolutions.
if (cm->width <= 352 && cm->height <= 288) {
if (rc->avg_frame_bandwidth < 3000) {
cr->motion_thresh = 16;
cr->rate_boost_fac = 13;
} else {
cr->max_qdelta_perc = 70;
cr->rate_ratio_qdelta = VPXMAX(cr->rate_ratio_qdelta, 2.5);
}
}
if (cpi->oxcf.rc_mode == VPX_VBR) {
// To be adjusted for VBR mode, e.g., based on gf period and boost.
// For now use smaller qp-delta (than CBR), no second boosted seg, and
// turn-off (no refresh) on golden refresh (since it's already boosted).
cr->percent_refresh = 10;
cr->rate_ratio_qdelta = 1.5;
cr->rate_boost_fac = 10;
if (cpi->refresh_golden_frame == 1) {
cr->percent_refresh = 0;
cr->rate_ratio_qdelta = 1.0;
}
}
// Weight for segment prior to encoding: take the average of the target
// number for the frame to be encoded and the actual from the previous frame.
// Use the target if its less. To be used for setting the base qp for the
// frame in vp9_rc_regulate_q.
target_refresh = cr->percent_refresh * cm->mi_rows * cm->mi_cols / 100;
weight_segment_target = (double)(target_refresh) / num8x8bl;
weight_segment = (double)((target_refresh + cr->actual_num_seg1_blocks +
cr->actual_num_seg2_blocks) >>
1) /
num8x8bl;
if (weight_segment_target < 7 * weight_segment / 8)
weight_segment = weight_segment_target;
// For screen-content: don't include target for the weight segment,
// since for all flat areas the segment is reset, so its more accurate
// to just use the previous actual number of seg blocks for the weight.
if (cpi->oxcf.content == VP9E_CONTENT_SCREEN)
weight_segment =
(double)(cr->actual_num_seg1_blocks + cr->actual_num_seg2_blocks) /
num8x8bl;
cr->weight_segment = weight_segment;
}
// Setup cyclic background refresh: set delta q and segmentation map.
void vp9_cyclic_refresh_setup(VP9_COMP *const cpi) {
VP9_COMMON *const cm = &cpi->common;
const RATE_CONTROL *const rc = &cpi->rc;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
struct segmentation *const seg = &cm->seg;
int scene_change_detected =
cpi->rc.high_source_sad ||
(cpi->use_svc && cpi->svc.high_source_sad_superframe);
if (cm->current_video_frame == 0) cr->low_content_avg = 0.0;
// Reset if resoluton change has occurred.
if (cpi->resize_pending != 0) vp9_cyclic_refresh_reset_resize(cpi);
if (!cr->apply_cyclic_refresh || (cpi->force_update_segmentation) ||
scene_change_detected) {
// Set segmentation map to 0 and disable.
unsigned char *const seg_map = cpi->segmentation_map;
memset(seg_map, 0, cm->mi_rows * cm->mi_cols);
vp9_disable_segmentation(&cm->seg);
if (cm->frame_type == KEY_FRAME || scene_change_detected) {
memset(cr->last_coded_q_map, MAXQ,
cm->mi_rows * cm->mi_cols * sizeof(*cr->last_coded_q_map));
cr->sb_index = 0;
cr->reduce_refresh = 0;
cr->counter_encode_maxq_scene_change = 0;
}
return;
} else {
int qindex_delta = 0;
int qindex2;
const double q = vp9_convert_qindex_to_q(cm->base_qindex, cm->bit_depth);
cr->counter_encode_maxq_scene_change++;
vpx_clear_system_state();
// Set rate threshold to some multiple (set to 2 for now) of the target
// rate (target is given by sb64_target_rate and scaled by 256).
cr->thresh_rate_sb = ((int64_t)(rc->sb64_target_rate) << 8) << 2;
// Distortion threshold, quadratic in Q, scale factor to be adjusted.
// q will not exceed 457, so (q * q) is within 32bit; see:
// vp9_convert_qindex_to_q(), vp9_ac_quant(), ac_qlookup*[].
cr->thresh_dist_sb = ((int64_t)(q * q)) << 2;
// Set up segmentation.
// Clear down the segment map.
vp9_enable_segmentation(&cm->seg);
vp9_clearall_segfeatures(seg);
// Select delta coding method.
seg->abs_delta = SEGMENT_DELTADATA;
// Note: setting temporal_update has no effect, as the seg-map coding method
// (temporal or spatial) is determined in vp9_choose_segmap_coding_method(),
// based on the coding cost of each method. For error_resilient mode on the
// last_frame_seg_map is set to 0, so if temporal coding is used, it is
// relative to 0 previous map.
// seg->temporal_update = 0;
// Segment BASE "Q" feature is disabled so it defaults to the baseline Q.
vp9_disable_segfeature(seg, CR_SEGMENT_ID_BASE, SEG_LVL_ALT_Q);
// Use segment BOOST1 for in-frame Q adjustment.
vp9_enable_segfeature(seg, CR_SEGMENT_ID_BOOST1, SEG_LVL_ALT_Q);
// Use segment BOOST2 for more aggressive in-frame Q adjustment.
vp9_enable_segfeature(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q);
// Set the q delta for segment BOOST1.
qindex_delta = compute_deltaq(cpi, cm->base_qindex, cr->rate_ratio_qdelta);
cr->qindex_delta[1] = qindex_delta;
// Compute rd-mult for segment BOOST1.
qindex2 = clamp(cm->base_qindex + cm->y_dc_delta_q + qindex_delta, 0, MAXQ);
cr->rdmult = vp9_compute_rd_mult(cpi, qindex2);
vp9_set_segdata(seg, CR_SEGMENT_ID_BOOST1, SEG_LVL_ALT_Q, qindex_delta);
// Set a more aggressive (higher) q delta for segment BOOST2.
qindex_delta = compute_deltaq(
cpi, cm->base_qindex,
VPXMIN(CR_MAX_RATE_TARGET_RATIO,
0.1 * cr->rate_boost_fac * cr->rate_ratio_qdelta));
cr->qindex_delta[2] = qindex_delta;
vp9_set_segdata(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q, qindex_delta);
// Update the segmentation and refresh map.
cyclic_refresh_update_map(cpi);
}
}
int vp9_cyclic_refresh_get_rdmult(const CYCLIC_REFRESH *cr) {
return cr->rdmult;
}
void vp9_cyclic_refresh_reset_resize(VP9_COMP *const cpi) {
const VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
memset(cr->map, 0, cm->mi_rows * cm->mi_cols);
memset(cr->last_coded_q_map, MAXQ,
cm->mi_rows * cm->mi_cols * sizeof(*cr->last_coded_q_map));
cr->sb_index = 0;
cpi->refresh_golden_frame = 1;
cpi->refresh_alt_ref_frame = 1;
cr->counter_encode_maxq_scene_change = 0;
}
void vp9_cyclic_refresh_limit_q(const VP9_COMP *cpi, int *q) {
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
// For now apply hard limit to frame-level decrease in q, if the cyclic
// refresh is active (percent_refresh > 0).
if (cr->percent_refresh > 0 && cpi->rc.q_1_frame - *q > 8) {
*q = cpi->rc.q_1_frame - 8;
}
}