Index: source/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c |
=================================================================== |
--- source/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c (revision 0) |
+++ source/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c (revision 0) |
@@ -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; |
+} |