summaryrefslogtreecommitdiffstats
path: root/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c
diff options
context:
space:
mode:
Diffstat (limited to 'libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c')
-rw-r--r--libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c b/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c
new file mode 100644
index 0000000..7879091
--- /dev/null
+++ b/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c
@@ -0,0 +1,324 @@
+/*
+ * 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 "vp9/encoder/vp9_aq_cyclicrefresh.h"
+
+#include "vp9/common/vp9_seg_common.h"
+
+#include "vp9/encoder/vp9_ratectrl.h"
+#include "vp9/encoder/vp9_rdopt.h"
+#include "vp9/encoder/vp9_segmentation.h"
+
+struct CYCLIC_REFRESH {
+ // Percentage of super-blocks per frame that are targeted as candidates
+ // for cyclic refresh.
+ int max_sbs_perframe;
+ // Maximum q-delta as percentage of base q.
+ int max_qdelta_perc;
+ // Block size below which we don't apply cyclic refresh.
+ 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.
+ int time_for_refresh;
+ // 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;
+ // RD mult. parameters for segment 1.
+ int rdmult;
+ // Cyclic refresh map.
+ signed char *map;
+ // Projected rate and distortion for the current superblock.
+ int64_t projected_rate_sb;
+ int64_t projected_dist_sb;
+ // Thresholds applied to projected rate/distortion of the superblock.
+ int64_t thresh_rate_sb;
+ int64_t thresh_dist_sb;
+};
+
+CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
+ 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) {
+ vpx_free(cr);
+ return NULL;
+ }
+
+ return cr;
+}
+
+void vp9_cyclic_refresh_free(CYCLIC_REFRESH *cr) {
+ vpx_free(cr->map);
+ vpx_free(cr);
+}
+
+// Check if we should turn off cyclic refresh based on bitrate condition.
+static int apply_cyclic_refresh_bitrate(const VP9_COMMON *cm,
+ const RATE_CONTROL *rc) {
+ // Turn off cyclic refresh if bits available per frame is not sufficiently
+ // larger than bit cost of segmentation. Segment map bit cost should scale
+ // with number of seg blocks, so compare available bits to number of blocks.
+ // Average bits available per frame = av_per_frame_bandwidth
+ // Number of (8x8) blocks in frame = mi_rows * mi_cols;
+ const float factor = 0.5;
+ const int number_blocks = cm->mi_rows * cm->mi_cols;
+ // The condition below corresponds to turning off at target bitrates:
+ // ~24kbps for CIF, 72kbps for VGA (at 30fps).
+ // Also turn off at very small frame sizes, to avoid too large fraction of
+ // superblocks to be refreshed per frame. Threshold below is less than QCIF.
+ if (rc->av_per_frame_bandwidth < factor * number_blocks ||
+ number_blocks / 64 < 5)
+ return 0;
+ else
+ return 1;
+}
+
+// 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 MB_MODE_INFO *mbmi,
+ BLOCK_SIZE bsize, int use_rd) {
+ if (use_rd) {
+ // If projected rate is below the thresh_rate (well below target,
+ // so undershoot expected), accept it for lower-qp coding.
+ if (cr->projected_rate_sb < cr->thresh_rate_sb)
+ return 1;
+ // Otherwise, reject the block for lower-qp coding if any of the following:
+ // 1) prediction block size is below min_block_size
+ // 2) mode is non-zero mv and projected distortion is above thresh_dist
+ // 3) mode is an intra-mode (we may want to allow some of this under
+ // another thresh_dist)
+ else if (bsize < cr->min_block_size ||
+ (mbmi->mv[0].as_int != 0 &&
+ cr->projected_dist_sb > cr->thresh_dist_sb) ||
+ !is_inter_block(mbmi))
+ return 0;
+ else
+ return 1;
+ } else {
+ // Rate/distortion not used for update.
+ if (bsize < cr->min_block_size ||
+ mbmi->mv[0].as_int != 0 ||
+ !is_inter_block(mbmi))
+ return 0;
+ else
+ return 1;
+ }
+}
+
+// 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,
+ MB_MODE_INFO *const mbmi,
+ int mi_row, int mi_col,
+ BLOCK_SIZE bsize, int use_rd) {
+ 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 = MIN(cm->mi_cols - mi_col, bw);
+ const int ymis = MIN(cm->mi_rows - mi_row, bh);
+ const int block_index = mi_row * cm->mi_cols + mi_col;
+ const int refresh_this_block = candidate_refresh_aq(cr, mbmi, bsize, use_rd);
+ // Default is to not update the refresh map.
+ int new_map_value = cr->map[block_index];
+ int x = 0; int y = 0;
+
+ // Check if we should reset the segment_id for this block.
+ if (mbmi->segment_id > 0 && !refresh_this_block)
+ mbmi->segment_id = 0;
+
+ // 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 (mbmi->segment_id == 1) {
+ 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++) {
+ cr->map[block_index + y * cm->mi_cols + x] = new_map_value;
+ 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;
+}
+
+// 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;
+ 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 ||
+ (cm->frame_type == KEY_FRAME) ||
+ (cpi->svc.temporal_layer_id > 0)) {
+ // Set segmentation map to 0 and disable.
+ vpx_memset(seg_map, 0, cm->mi_rows * cm->mi_cols);
+ vp9_disable_segmentation(&cm->seg);
+ if (cm->frame_type == KEY_FRAME)
+ cr->sb_index = 0;
+ 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;
+ vp9_clear_system_state();
+ // Some of these parameters may be set via codec-control function later.
+ cr->max_sbs_perframe = 10;
+ cr->max_qdelta_perc = 50;
+ cr->min_block_size = BLOCK_8X8;
+ cr->time_for_refresh = 1;
+ // 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.
+ cr->thresh_dist_sb = 8 * (int)(vp9_convert_qindex_to_q(cm->base_qindex) *
+ vp9_convert_qindex_to_q(cm->base_qindex));
+ if (cpi->sf.use_nonrd_pick_mode) {
+ // May want to be more conservative with thresholds in non-rd mode for now
+ // as rate/distortion are derived from model based on prediction residual.
+ cr->thresh_rate_sb = (rc->sb64_target_rate * 256) >> 3;
+ cr->thresh_dist_sb = 4 * (int)(vp9_convert_qindex_to_q(cm->base_qindex) *
+ vp9_convert_qindex_to_q(cm->base_qindex));
+ }
+
+ 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.
+ 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 0 "Q" feature is disabled so it defaults to the baseline Q.
+ vp9_disable_segfeature(seg, 0, SEG_LVL_ALT_Q);
+ // Use segment 1 for in-frame Q adjustment.
+ 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);
+ // 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;
+
+ // Compute rd-mult for segment 1.
+ 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, 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;
+ }
+}
+
+void vp9_cyclic_refresh_set_rate_and_dist_sb(CYCLIC_REFRESH *cr,
+ int64_t rate_sb, int64_t dist_sb) {
+ cr->projected_rate_sb = rate_sb;
+ cr->projected_dist_sb = dist_sb;
+}
+
+int vp9_cyclic_refresh_get_rdmult(const CYCLIC_REFRESH *cr) {
+ return cr->rdmult;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-25 01:11:06 +0000