ref: 83fd18977fcde783d2e44b248c2dea4a8eb04955
parent: f59cb45e907911b0d4a6e8cb4b355eece1115b5b
author: Marco Paniconi <[email protected]>
date: Wed Apr 2 14:37:04 EDT 2014
Cyclic refresh: factor segment delta-q into rate control. Incorporate segment delta-q into estimated bits. This generally improves the rate control under cyclic refresh (aq=3) mode. Change-Id: I1dc60fb230e7d08357fae18909d8ed27bf58e037
--- a/vp9/encoder/vp9_aq_cyclicrefresh.c
+++ b/vp9/encoder/vp9_aq_cyclicrefresh.c
@@ -19,9 +19,9 @@
#include "vp9/encoder/vp9_segmentation.h"
struct CYCLIC_REFRESH {- // Percentage of super-blocks per frame that are targeted as candidates
+ // Percentage of blocks per frame that are targeted as candidates
// for cyclic refresh.
- int max_sbs_perframe;
+ int percent_refresh;
// Maximum q-delta as percentage of base q.
int max_qdelta_perc;
// Block size below which we don't apply cyclic refresh.
@@ -28,12 +28,14 @@
BLOCK_SIZE min_block_size;
// Superblock starting index for cycling through the frame.
int sb_index;
- // Controls how long a block will need to wait to be refreshed again.
+ // Controls how long block will need to wait to be refreshed again, in
+ // excess of the cycle time, i.e., in the case of all zero motion, block
+ // will be refreshed every (100/percent_refresh + time_for_refresh) frames.
int time_for_refresh;
+ // // Target number of (8x8) blocks that are set for delta-q (segment 1).
+ int target_num_seg_blocks;
// Actual number of (8x8) blocks that were applied delta-q (segment 1).
- int num_seg_blocks;
- // Actual encoding bits for segment 1.
- int actual_seg_bits;
+ int actual_num_seg_blocks;
// RD mult. parameters for segment 1.
int rdmult;
// Cyclic refresh map.
@@ -41,6 +43,8 @@
// Thresholds applied to projected rate/distortion of the superblock.
int64_t thresh_rate_sb;
int64_t thresh_dist_sb;
+ // Rate target ratio to set q delta.
+ double rate_ratio_qdelta;
};
CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {@@ -117,6 +121,73 @@
}
}
+// Compute delta-q for the segment.
+static int compute_deltaq(const VP9_COMP *cpi, int q) {+ 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, cr->rate_ratio_qdelta,
+ 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 segment 1. 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 segment 1: use actual number of blocks refreshed in
+ // previous/just encoded frame. Note number of blocks here is in 8x8 units.
+ double weight_segment = (double)cr->actual_num_seg_blocks / num8x8bl;
+ // Compute delta-q that was used in the just encoded frame.
+ int deltaq = compute_deltaq(cpi, cm->base_qindex);
+ // Take segment weighted average for estimated bits.
+ estimated_bits = (int)((1.0 - weight_segment) *
+ vp9_estimate_bits_at_q(cm->frame_type, cm->base_qindex, mbs,
+ correction_factor, cm->bit_depth) +
+ weight_segment *
+ vp9_estimate_bits_at_q(cm->frame_type, cm->base_qindex + deltaq, 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.
+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 num8x8bl = cm->MBs << 2;
+ // Weight for segment 1 prior to encoding: take the target number for the
+ // frame to be encoded. Number of blocks here is in 8x8 units.
+ // Note that this is called in rc_regulate_q, which is called before the
+ // cyclic_refresh_setup (which sets cr->target_num_seg_blocks). So a mismatch
+ // may occur between the cr->target_num_seg_blocks value here and the
+ // cr->target_num_seg_block set for encoding the frame. For the current use
+ // case of fixed cr->percent_refresh and cr->time_for_refresh = 0, mismatch
+ // does not occur/is very small.
+ double weight_segment = (double)cr->target_num_seg_blocks / num8x8bl;
+ // Compute delta-q corresponding to qindex i.
+ int deltaq = compute_deltaq(cpi, i);
+ // Take segment weighted average for bits per mb.
+ bits_per_mb = (int)((1.0 - weight_segment) *
+ vp9_rc_bits_per_mb(cm->frame_type, i, correction_factor, cm->bit_depth) +
+ 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.
@@ -167,12 +238,87 @@
cpi->segmentation_map[block_index + y * cm->mi_cols + x] =
mbmi->segment_id;
}
- // Keep track of actual number (in units of 8x8) of blocks in segment 1 used
- // for encoding this frame.
- if (mbmi->segment_id)
- cr->num_seg_blocks += xmis * ymis;
}
+// Update the actual number of blocks that were applied the segment delta q.
+void vp9_cyclic_refresh_update_actual_count(struct 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 mi_row, mi_col;
+ cr->actual_num_seg_blocks = 0;
+ for (mi_row = 0; mi_row < cm->mi_rows; mi_row++)
+ for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) {+ if (seg_map[mi_row * cm->mi_cols + mi_col] == 1)
+ cr->actual_num_seg_blocks++;
+ }
+}
+
+// Update the segmentation map, and related quantities: cyclic refresh map,
+// refresh sb_index, and target number of blocks to be refreshed.
+void vp9_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;
+ vpx_memset(seg_map, 0, 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;
+ do {+ int sum_map = 0;
+ // 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;
+ assert(mi_row >= 0 && mi_row < cm->mi_rows);
+ assert(mi_col >= 0 && mi_col < cm->mi_cols);
+ bl_index = mi_row * cm->mi_cols + mi_col;
+ // Loop through all 8x8 blocks in superblock and update map.
+ xmis = MIN(cm->mi_cols - mi_col,
+ num_8x8_blocks_wide_lookup[BLOCK_64X64]);
+ ymis = MIN(cm->mi_rows - mi_row,
+ num_8x8_blocks_high_lookup[BLOCK_64X64]);
+ 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 if block gets coded anything other than ZEROMV.
+ if (cr->map[bl_index2] == 0) {+ sum_map++;
+ } 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) {+ for (y = 0; y < ymis; y++)
+ for (x = 0; x < xmis; x++) {+ seg_map[bl_index + y * cm->mi_cols + x] = 1;
+ }
+ 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;
+}
+
// 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;
@@ -179,7 +325,6 @@
const RATE_CONTROL *const rc = &cpi->rc;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
struct segmentation *const seg = &cm->seg;
- unsigned char *const seg_map = cpi->segmentation_map;
const int apply_cyclic_refresh = apply_cyclic_refresh_bitrate(cm, rc);
// Don't apply refresh on key frame or enhancement layer frames.
if (!apply_cyclic_refresh ||
@@ -187,6 +332,7 @@
(cpi->svc.temporal_layer_id > 0) ||
(cpi->svc.spatial_layer_id > 0)) {// Set segmentation map to 0 and disable.
+ unsigned char *const seg_map = cpi->segmentation_map;
vpx_memset(seg_map, 0, cm->mi_rows * cm->mi_cols);
vp9_disable_segmentation(&cm->seg);
if (cm->frame_type == KEY_FRAME)
@@ -194,18 +340,15 @@
return;
} else {int qindex_delta = 0;
- int i, block_count, bl_index, sb_rows, sb_cols, sbs_in_frame;
- int xmis, ymis, x, y, qindex2;
-
- // Rate target ratio to set q delta.
- const float rate_ratio_qdelta = 2.0;
+ int qindex2;
const double q = vp9_convert_qindex_to_q(cm->base_qindex, cm->bit_depth);
vp9_clear_system_state();
// Some of these parameters may be set via codec-control function later.
- cr->max_sbs_perframe = 10;
+ cr->percent_refresh = 10;
+ cr->rate_ratio_qdelta = 2.0;
cr->max_qdelta_perc = 50;
cr->min_block_size = BLOCK_8X8;
- cr->time_for_refresh = 1;
+ cr->time_for_refresh = 0;
// Set rate threshold to some fraction of target (and scaled by 256).
cr->thresh_rate_sb = (rc->sb64_target_rate * 256) >> 2;
// Distortion threshold, quadratic in Q, scale factor to be adjusted.
@@ -217,10 +360,8 @@
cr->thresh_dist_sb = 16 * (int)(q * q);
}
- cr->num_seg_blocks = 0;
// Set up segmentation.
// Clear down the segment map.
- vpx_memset(seg_map, 0, cm->mi_rows * cm->mi_cols);
vp9_enable_segmentation(&cm->seg);
vp9_clearall_segfeatures(seg);
// Select delta coding method.
@@ -239,14 +380,7 @@
vp9_enable_segfeature(seg, 1, SEG_LVL_ALT_Q);
// Set the q delta for segment 1.
- qindex_delta = vp9_compute_qdelta_by_rate(rc, cm->frame_type,
- cm->base_qindex,
- rate_ratio_qdelta,
- cm->bit_depth);
- // TODO(marpan): Incorporate the actual-vs-target rate over/undershoot from
- // previous encoded frame.
- if (-qindex_delta > cr->max_qdelta_perc * cm->base_qindex / 100)
- qindex_delta = -cr->max_qdelta_perc * cm->base_qindex / 100;
+ qindex_delta = compute_deltaq(cpi, cm->base_qindex);
// Compute rd-mult for segment 1.
qindex2 = clamp(cm->base_qindex + cm->y_dc_delta_q + qindex_delta, 0, MAXQ);
@@ -254,61 +388,8 @@
vp9_set_segdata(seg, 1, SEG_LVL_ALT_Q, qindex_delta);
- 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 superblocks to get the q delta (segment 1).
- block_count = cr->max_sbs_perframe * sbs_in_frame / 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;
- do {- int sum_map = 0;
- // 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;
- assert(mi_row >= 0 && mi_row < cm->mi_rows);
- assert(mi_col >= 0 && mi_col < cm->mi_cols);
- bl_index = mi_row * cm->mi_cols + mi_col;
- // Loop through all 8x8 blocks in superblock and update map.
- xmis = MIN(cm->mi_cols - mi_col,
- num_8x8_blocks_wide_lookup[BLOCK_64X64]);
- ymis = MIN(cm->mi_rows - mi_row,
- num_8x8_blocks_high_lookup[BLOCK_64X64]);
- 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 if block gets coded anything other than ZEROMV.
- if (cr->map[bl_index2] == 0) {- seg_map[bl_index2] = 1;
- sum_map++;
- } else if (cr->map[bl_index2] < 0) {- cr->map[bl_index2]++;
- }
- }
- }
- // Enforce constant segment over superblock.
- // If segment is partial over superblock, reset to either all 1 or 0.
- if (sum_map > 0 && sum_map < xmis * ymis) {- const int new_value = (sum_map >= xmis * ymis / 2);
- for (y = 0; y < ymis; y++)
- for (x = 0; x < xmis; x++)
- seg_map[bl_index + y * cm->mi_cols + x] = new_value;
- }
- i++;
- if (i == sbs_in_frame) {- i = 0;
- }
- if (sum_map >= xmis * ymis /2)
- block_count--;
- } while (block_count && i != cr->sb_index);
- cr->sb_index = i;
+ // Update the segmentation and refresh map.
+ vp9_cyclic_refresh_update_map(cpi);
}
}
--- a/vp9/encoder/vp9_aq_cyclicrefresh.h
+++ b/vp9/encoder/vp9_aq_cyclicrefresh.h
@@ -27,6 +27,16 @@
void vp9_cyclic_refresh_free(CYCLIC_REFRESH *cr);
+// Estimate the bits, incorporating the delta-q from segment 1, after encoding
+// the frame.
+int vp9_cyclic_refresh_estimate_bits_at_q(const struct VP9_COMP *cpi,
+ double correction_factor);
+
+// Estimate the bits per mb, for a given q = i and a corresponding delta-q
+// (for segment 1), prior to encoding the frame.
+int vp9_cyclic_refresh_rc_bits_per_mb(const struct VP9_COMP *cpi, int i,
+ double correction_factor);
+
// 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.
@@ -35,6 +45,13 @@
int mi_row, int mi_col,
BLOCK_SIZE bsize, int use_rd,
int64_t rate_sb);
+
+// Update the segmentation map, and related quantities: cyclic refresh map,
+// refresh sb_index, and target number of blocks to be refreshed.
+void vp9_cyclic_refresh_update__map(struct VP9_COMP *const cpi);
+
+// Update the actual number of blocks that were applied the segment delta q.
+void vp9_cyclic_refresh_update_actual_count(struct VP9_COMP *const cpi);
// Setup cyclic background refresh: set delta q and segmentation map.
void vp9_cyclic_refresh_setup(struct VP9_COMP *const cpi);
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -18,6 +18,7 @@
#include "vpx_mem/vpx_mem.h"
#include "vp9/common/vp9_alloccommon.h"
+#include "vp9/encoder/vp9_aq_cyclicrefresh.h"
#include "vp9/common/vp9_common.h"
#include "vp9/common/vp9_entropymode.h"
#include "vp9/common/vp9_quant_common.h"
@@ -185,9 +186,9 @@
return (int)(enumerator * correction_factor / q);
}
-static int estimate_bits_at_q(FRAME_TYPE frame_type, int q, int mbs,
- double correction_factor,
- vpx_bit_depth_t bit_depth) {+int vp9_estimate_bits_at_q(FRAME_TYPE frame_type, int q, int mbs,
+ double correction_factor,
+ vpx_bit_depth_t bit_depth) {const int bpm = (int)(vp9_rc_bits_per_mb(frame_type, q, correction_factor,
bit_depth));
return MAX(FRAME_OVERHEAD_BITS,
@@ -232,7 +233,6 @@
return target;
}
-
// Update the buffer level for higher layers, given the encoded current layer.
static void update_layer_buffer_level(SVC *svc, int encoded_frame_size) {int temporal_layer = 0;
@@ -414,10 +414,16 @@
// Work out how big we would have expected the frame to be at this Q given
// the current correction factor.
// Stay in double to avoid int overflow when values are large
- projected_size_based_on_q = estimate_bits_at_q(cm->frame_type,
- cm->base_qindex, cm->MBs,
- rate_correction_factor,
- cm->bit_depth);
+ if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cpi->common.seg.enabled) {+ projected_size_based_on_q =
+ vp9_cyclic_refresh_estimate_bits_at_q(cpi, rate_correction_factor);
+ } else {+ projected_size_based_on_q = vp9_estimate_bits_at_q(cpi->common.frame_type,
+ cm->base_qindex,
+ cm->MBs,
+ rate_correction_factor,
+ cm->bit_depth);
+ }
// Work out a size correction factor.
if (projected_size_based_on_q > FRAME_OVERHEAD_BITS)
correction_factor = (100 * cpi->rc.projected_frame_size) /
@@ -477,7 +483,7 @@
const VP9_COMMON *const cm = &cpi->common;
int q = active_worst_quality;
int last_error = INT_MAX;
- int i, target_bits_per_mb;
+ int i, target_bits_per_mb, bits_per_mb_at_this_q;
const double correction_factor = get_rate_correction_factor(cpi);
// Calculate required scaling factor based on target frame size and size of
@@ -488,9 +494,14 @@
i = active_best_quality;
do {- const int bits_per_mb_at_this_q = (int)vp9_rc_bits_per_mb(cm->frame_type, i,
- correction_factor,
- cm->bit_depth);
+ if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cm->seg.enabled) {+ bits_per_mb_at_this_q =
+ (int)vp9_cyclic_refresh_rc_bits_per_mb(cpi, i, correction_factor);
+ } else {+ bits_per_mb_at_this_q = (int)vp9_rc_bits_per_mb(cm->frame_type, i,
+ correction_factor,
+ cm->bit_depth);
+ }
if (bits_per_mb_at_this_q <= target_bits_per_mb) {if ((target_bits_per_mb - bits_per_mb_at_this_q) <= last_error)
@@ -1202,6 +1213,10 @@
const VP9EncoderConfig *const oxcf = &cpi->oxcf;
RATE_CONTROL *const rc = &cpi->rc;
const int qindex = cm->base_qindex;
+
+ if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cm->seg.enabled) {+ vp9_cyclic_refresh_update_actual_count(cpi);
+ }
// Update rate control heuristics
rc->projected_frame_size = (int)(bytes_used << 3);
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -115,6 +115,10 @@
void vp9_rc_init(const struct VP9EncoderConfig *oxcf, int pass,
RATE_CONTROL *rc);
+int vp9_estimate_bits_at_q(FRAME_TYPE frame_kind, int q, int mbs,
+ double correction_factor,
+ vpx_bit_depth_t bit_depth);
+
double vp9_convert_qindex_to_q(int qindex, vpx_bit_depth_t bit_depth);
void vp9_rc_init_minq_luts();