vp9/encoder/vp9_aq_cyclicrefresh.c - aom - Git at Google

 /*
  *  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_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 = avg_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->avg_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 = cpi->mb.in_static_area ||
                                  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;
     const double q = vp9_convert_qindex_to_q(cm->base_qindex);
     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)(q * q);
     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)(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.
     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;
 }
	/*
	* 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_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 = avg_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->avg_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 = cpi->mb.in_static_area \|\|
	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;
	const double q = vp9_convert_qindex_to_q(cm->base_qindex);
	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)(q * q);
	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)(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.
	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;
	}