1/*
2 *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include <limits.h>
12#include <math.h>
13
14#include "vpx_dsp/vpx_dsp_common.h"
15#include "vpx_ports/system_state.h"
16
17#include "vp9/encoder/vp9_aq_cyclicrefresh.h"
18
19#include "vp9/common/vp9_seg_common.h"
20
21#include "vp9/encoder/vp9_ratectrl.h"
22#include "vp9/encoder/vp9_segmentation.h"
23
24CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
25  size_t last_coded_q_map_size;
26  CYCLIC_REFRESH *const cr = vpx_calloc(1, sizeof(*cr));
27  if (cr == NULL) return NULL;
28
29  cr->map = vpx_calloc(mi_rows * mi_cols, sizeof(*cr->map));
30  if (cr->map == NULL) {
31    vp9_cyclic_refresh_free(cr);
32    return NULL;
33  }
34  last_coded_q_map_size = mi_rows * mi_cols * sizeof(*cr->last_coded_q_map);
35  cr->last_coded_q_map = vpx_malloc(last_coded_q_map_size);
36  if (cr->last_coded_q_map == NULL) {
37    vp9_cyclic_refresh_free(cr);
38    return NULL;
39  }
40  assert(MAXQ <= 255);
41  memset(cr->last_coded_q_map, MAXQ, last_coded_q_map_size);
42  return cr;
43}
44
45void vp9_cyclic_refresh_free(CYCLIC_REFRESH *cr) {
46  vpx_free(cr->map);
47  vpx_free(cr->last_coded_q_map);
48  vpx_free(cr);
49}
50
51// Check if this coding block, of size bsize, should be considered for refresh
52// (lower-qp coding). Decision can be based on various factors, such as
53// size of the coding block (i.e., below min_block size rejected), coding
54// mode, and rate/distortion.
55static int candidate_refresh_aq(const CYCLIC_REFRESH *cr, const MODE_INFO *mi,
56                                int64_t rate, int64_t dist, int bsize) {
57  MV mv = mi->mv[0].as_mv;
58  // Reject the block for lower-qp coding if projected distortion
59  // is above the threshold, and any of the following is true:
60  // 1) mode uses large mv
61  // 2) mode is an intra-mode
62  // Otherwise accept for refresh.
63  if (dist > cr->thresh_dist_sb &&
64      (mv.row > cr->motion_thresh || mv.row < -cr->motion_thresh ||
65       mv.col > cr->motion_thresh || mv.col < -cr->motion_thresh ||
66       !is_inter_block(mi)))
67    return CR_SEGMENT_ID_BASE;
68  else if (bsize >= BLOCK_16X16 && rate < cr->thresh_rate_sb &&
69           is_inter_block(mi) && mi->mv[0].as_int == 0 &&
70           cr->rate_boost_fac > 10)
71    // More aggressive delta-q for bigger blocks with zero motion.
72    return CR_SEGMENT_ID_BOOST2;
73  else
74    return CR_SEGMENT_ID_BOOST1;
75}
76
77// Compute delta-q for the segment.
78static int compute_deltaq(const VP9_COMP *cpi, int q, double rate_factor) {
79  const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
80  const RATE_CONTROL *const rc = &cpi->rc;
81  int deltaq = vp9_compute_qdelta_by_rate(rc, cpi->common.frame_type, q,
82                                          rate_factor, cpi->common.bit_depth);
83  if ((-deltaq) > cr->max_qdelta_perc * q / 100) {
84    deltaq = -cr->max_qdelta_perc * q / 100;
85  }
86  return deltaq;
87}
88
89// For the just encoded frame, estimate the bits, incorporating the delta-q
90// from non-base segment. For now ignore effect of multiple segments
91// (with different delta-q). Note this function is called in the postencode
92// (called from rc_update_rate_correction_factors()).
93int vp9_cyclic_refresh_estimate_bits_at_q(const VP9_COMP *cpi,
94                                          double correction_factor) {
95  const VP9_COMMON *const cm = &cpi->common;
96  const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
97  int estimated_bits;
98  int mbs = cm->MBs;
99  int num8x8bl = mbs << 2;
100  // Weight for non-base segments: use actual number of blocks refreshed in
101  // previous/just encoded frame. Note number of blocks here is in 8x8 units.
102  double weight_segment1 = (double)cr->actual_num_seg1_blocks / num8x8bl;
103  double weight_segment2 = (double)cr->actual_num_seg2_blocks / num8x8bl;
104  // Take segment weighted average for estimated bits.
105  estimated_bits =
106      (int)((1.0 - weight_segment1 - weight_segment2) *
107                vp9_estimate_bits_at_q(cm->frame_type, cm->base_qindex, mbs,
108                                       correction_factor, cm->bit_depth) +
109            weight_segment1 *
110                vp9_estimate_bits_at_q(cm->frame_type,
111                                       cm->base_qindex + cr->qindex_delta[1],
112                                       mbs, correction_factor, cm->bit_depth) +
113            weight_segment2 *
114                vp9_estimate_bits_at_q(cm->frame_type,
115                                       cm->base_qindex + cr->qindex_delta[2],
116                                       mbs, correction_factor, cm->bit_depth));
117  return estimated_bits;
118}
119
120// Prior to encoding the frame, estimate the bits per mb, for a given q = i and
121// a corresponding delta-q (for segment 1). This function is called in the
122// rc_regulate_q() to set the base qp index.
123// Note: the segment map is set to either 0/CR_SEGMENT_ID_BASE (no refresh) or
124// to 1/CR_SEGMENT_ID_BOOST1 (refresh) for each superblock, prior to encoding.
125int vp9_cyclic_refresh_rc_bits_per_mb(const VP9_COMP *cpi, int i,
126                                      double correction_factor) {
127  const VP9_COMMON *const cm = &cpi->common;
128  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
129  int bits_per_mb;
130  int deltaq = 0;
131  if (cpi->oxcf.speed < 8)
132    deltaq = compute_deltaq(cpi, i, cr->rate_ratio_qdelta);
133  else
134    deltaq = -(cr->max_qdelta_perc * i) / 200;
135  // Take segment weighted average for bits per mb.
136  bits_per_mb = (int)((1.0 - cr->weight_segment) *
137                          vp9_rc_bits_per_mb(cm->frame_type, i,
138                                             correction_factor, cm->bit_depth) +
139                      cr->weight_segment *
140                          vp9_rc_bits_per_mb(cm->frame_type, i + deltaq,
141                                             correction_factor, cm->bit_depth));
142  return bits_per_mb;
143}
144
145// Prior to coding a given prediction block, of size bsize at (mi_row, mi_col),
146// check if we should reset the segment_id, and update the cyclic_refresh map
147// and segmentation map.
148void vp9_cyclic_refresh_update_segment(VP9_COMP *const cpi, MODE_INFO *const mi,
149                                       int mi_row, int mi_col, BLOCK_SIZE bsize,
150                                       int64_t rate, int64_t dist, int skip,
151                                       struct macroblock_plane *const p) {
152  const VP9_COMMON *const cm = &cpi->common;
153  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
154  const int bw = num_8x8_blocks_wide_lookup[bsize];
155  const int bh = num_8x8_blocks_high_lookup[bsize];
156  const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
157  const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
158  const int block_index = mi_row * cm->mi_cols + mi_col;
159  int refresh_this_block = candidate_refresh_aq(cr, mi, rate, dist, bsize);
160  // Default is to not update the refresh map.
161  int new_map_value = cr->map[block_index];
162  int x = 0;
163  int y = 0;
164
165  int is_skin = 0;
166  if (refresh_this_block == 0 && bsize <= BLOCK_16X16 &&
167      cpi->use_skin_detection) {
168    is_skin =
169        vp9_compute_skin_block(p[0].src.buf, p[1].src.buf, p[2].src.buf,
170                               p[0].src.stride, p[1].src.stride, bsize, 0, 0);
171    if (is_skin) refresh_this_block = 1;
172  }
173
174  if (cpi->oxcf.rc_mode == VPX_VBR && mi->ref_frame[0] == GOLDEN_FRAME)
175    refresh_this_block = 0;
176
177  // If this block is labeled for refresh, check if we should reset the
178  // segment_id.
179  if (cyclic_refresh_segment_id_boosted(mi->segment_id)) {
180    mi->segment_id = refresh_this_block;
181    // Reset segment_id if it will be skipped.
182    if (skip) mi->segment_id = CR_SEGMENT_ID_BASE;
183  }
184
185  // Update the cyclic refresh map, to be used for setting segmentation map
186  // for the next frame. If the block  will be refreshed this frame, mark it
187  // as clean. The magnitude of the -ve influences how long before we consider
188  // it for refresh again.
189  if (cyclic_refresh_segment_id_boosted(mi->segment_id)) {
190    new_map_value = -cr->time_for_refresh;
191  } else if (refresh_this_block) {
192    // Else if it is accepted as candidate for refresh, and has not already
193    // been refreshed (marked as 1) then mark it as a candidate for cleanup
194    // for future time (marked as 0), otherwise don't update it.
195    if (cr->map[block_index] == 1) new_map_value = 0;
196  } else {
197    // Leave it marked as block that is not candidate for refresh.
198    new_map_value = 1;
199  }
200
201  // Update entries in the cyclic refresh map with new_map_value, and
202  // copy mbmi->segment_id into global segmentation map.
203  for (y = 0; y < ymis; y++)
204    for (x = 0; x < xmis; x++) {
205      int map_offset = block_index + y * cm->mi_cols + x;
206      cr->map[map_offset] = new_map_value;
207      cpi->segmentation_map[map_offset] = mi->segment_id;
208    }
209}
210
211void vp9_cyclic_refresh_update_sb_postencode(VP9_COMP *const cpi,
212                                             const MODE_INFO *const mi,
213                                             int mi_row, int mi_col,
214                                             BLOCK_SIZE bsize) {
215  const VP9_COMMON *const cm = &cpi->common;
216  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
217  const int bw = num_8x8_blocks_wide_lookup[bsize];
218  const int bh = num_8x8_blocks_high_lookup[bsize];
219  const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
220  const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
221  const int block_index = mi_row * cm->mi_cols + mi_col;
222  int x, y;
223  for (y = 0; y < ymis; y++)
224    for (x = 0; x < xmis; x++) {
225      int map_offset = block_index + y * cm->mi_cols + x;
226      // Inter skip blocks were clearly not coded at the current qindex, so
227      // don't update the map for them. For cases where motion is non-zero or
228      // the reference frame isn't the previous frame, the previous value in
229      // the map for this spatial location is not entirely correct.
230      if ((!is_inter_block(mi) || !mi->skip) &&
231          mi->segment_id <= CR_SEGMENT_ID_BOOST2) {
232        cr->last_coded_q_map[map_offset] =
233            clamp(cm->base_qindex + cr->qindex_delta[mi->segment_id], 0, MAXQ);
234      } else if (is_inter_block(mi) && mi->skip &&
235                 mi->segment_id <= CR_SEGMENT_ID_BOOST2) {
236        cr->last_coded_q_map[map_offset] = VPXMIN(
237            clamp(cm->base_qindex + cr->qindex_delta[mi->segment_id], 0, MAXQ),
238            cr->last_coded_q_map[map_offset]);
239      }
240    }
241}
242
243// From the just encoded frame: update the actual number of blocks that were
244// applied the segment delta q, and the amount of low motion in the frame.
245// Also check conditions for forcing golden update, or preventing golden
246// update if the period is up.
247void vp9_cyclic_refresh_postencode(VP9_COMP *const cpi) {
248  VP9_COMMON *const cm = &cpi->common;
249  MODE_INFO **mi = cm->mi_grid_visible;
250  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
251  RATE_CONTROL *const rc = &cpi->rc;
252  unsigned char *const seg_map = cpi->segmentation_map;
253  double fraction_low = 0.0;
254  int force_gf_refresh = 0;
255  int low_content_frame = 0;
256  int mi_row, mi_col;
257  cr->actual_num_seg1_blocks = 0;
258  cr->actual_num_seg2_blocks = 0;
259  for (mi_row = 0; mi_row < cm->mi_rows; mi_row++) {
260    for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) {
261      MV mv = mi[0]->mv[0].as_mv;
262      int map_index = mi_row * cm->mi_cols + mi_col;
263      if (cyclic_refresh_segment_id(seg_map[map_index]) == CR_SEGMENT_ID_BOOST1)
264        cr->actual_num_seg1_blocks++;
265      else if (cyclic_refresh_segment_id(seg_map[map_index]) ==
266               CR_SEGMENT_ID_BOOST2)
267        cr->actual_num_seg2_blocks++;
268      // Accumulate low_content_frame.
269      if (is_inter_block(mi[0]) && abs(mv.row) < 16 && abs(mv.col) < 16)
270        low_content_frame++;
271      mi++;
272    }
273    mi += 8;
274  }
275  // Check for golden frame update: only for non-SVC and non-golden boost.
276  if (!cpi->use_svc && cpi->ext_refresh_frame_flags_pending == 0 &&
277      !cpi->oxcf.gf_cbr_boost_pct) {
278    // Force this frame as a golden update frame if this frame changes the
279    // resolution (resize_pending != 0).
280    if (cpi->resize_pending != 0) {
281      vp9_cyclic_refresh_set_golden_update(cpi);
282      rc->frames_till_gf_update_due = rc->baseline_gf_interval;
283      if (rc->frames_till_gf_update_due > rc->frames_to_key)
284        rc->frames_till_gf_update_due = rc->frames_to_key;
285      cpi->refresh_golden_frame = 1;
286      force_gf_refresh = 1;
287    }
288    // Update average of low content/motion in the frame.
289    fraction_low = (double)low_content_frame / (cm->mi_rows * cm->mi_cols);
290    cr->low_content_avg = (fraction_low + 3 * cr->low_content_avg) / 4;
291    if (!force_gf_refresh && cpi->refresh_golden_frame == 1 &&
292        rc->frames_since_key > rc->frames_since_golden + 1) {
293      // Don't update golden reference if the amount of low_content for the
294      // current encoded frame is small, or if the recursive average of the
295      // low_content over the update interval window falls below threshold.
296      if (fraction_low < 0.65 || cr->low_content_avg < 0.6) {
297        cpi->refresh_golden_frame = 0;
298      }
299      // Reset for next internal.
300      cr->low_content_avg = fraction_low;
301    }
302  }
303}
304
305// Set golden frame update interval, for non-svc 1 pass CBR mode.
306void vp9_cyclic_refresh_set_golden_update(VP9_COMP *const cpi) {
307  RATE_CONTROL *const rc = &cpi->rc;
308  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
309  // Set minimum gf_interval for GF update to a multiple of the refresh period,
310  // with some max limit. Depending on past encoding stats, GF flag may be
311  // reset and update may not occur until next baseline_gf_interval.
312  if (cr->percent_refresh > 0)
313    rc->baseline_gf_interval = VPXMIN(4 * (100 / cr->percent_refresh), 40);
314  else
315    rc->baseline_gf_interval = 40;
316  if (cpi->oxcf.rc_mode == VPX_VBR) rc->baseline_gf_interval = 20;
317  if (rc->avg_frame_low_motion < 50 && rc->frames_since_key > 40)
318    rc->baseline_gf_interval = 10;
319}
320
321// Update the segmentation map, and related quantities: cyclic refresh map,
322// refresh sb_index, and target number of blocks to be refreshed.
323// The map is set to either 0/CR_SEGMENT_ID_BASE (no refresh) or to
324// 1/CR_SEGMENT_ID_BOOST1 (refresh) for each superblock.
325// Blocks labeled as BOOST1 may later get set to BOOST2 (during the
326// encoding of the superblock).
327static void cyclic_refresh_update_map(VP9_COMP *const cpi) {
328  VP9_COMMON *const cm = &cpi->common;
329  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
330  unsigned char *const seg_map = cpi->segmentation_map;
331  int i, block_count, bl_index, sb_rows, sb_cols, sbs_in_frame;
332  int xmis, ymis, x, y;
333  int consec_zero_mv_thresh = 0;
334  int qindex_thresh = 0;
335  int count_sel = 0;
336  int count_tot = 0;
337  memset(seg_map, CR_SEGMENT_ID_BASE, cm->mi_rows * cm->mi_cols);
338  sb_cols = (cm->mi_cols + MI_BLOCK_SIZE - 1) / MI_BLOCK_SIZE;
339  sb_rows = (cm->mi_rows + MI_BLOCK_SIZE - 1) / MI_BLOCK_SIZE;
340  sbs_in_frame = sb_cols * sb_rows;
341  // Number of target blocks to get the q delta (segment 1).
342  block_count = cr->percent_refresh * cm->mi_rows * cm->mi_cols / 100;
343  // Set the segmentation map: cycle through the superblocks, starting at
344  // cr->mb_index, and stopping when either block_count blocks have been found
345  // to be refreshed, or we have passed through whole frame.
346  assert(cr->sb_index < sbs_in_frame);
347  i = cr->sb_index;
348  cr->target_num_seg_blocks = 0;
349  if (cpi->oxcf.content != VP9E_CONTENT_SCREEN) {
350    consec_zero_mv_thresh = 100;
351  }
352  qindex_thresh =
353      cpi->oxcf.content == VP9E_CONTENT_SCREEN
354          ? vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST2, cm->base_qindex)
355          : vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST1, cm->base_qindex);
356  // More aggressive settings for noisy content.
357  if (cpi->noise_estimate.enabled && cpi->noise_estimate.level >= kMedium) {
358    consec_zero_mv_thresh = 60;
359    qindex_thresh =
360        VPXMAX(vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST1, cm->base_qindex),
361               cm->base_qindex);
362  }
363  do {
364    int sum_map = 0;
365    int consec_zero_mv_thresh_block = consec_zero_mv_thresh;
366    // Get the mi_row/mi_col corresponding to superblock index i.
367    int sb_row_index = (i / sb_cols);
368    int sb_col_index = i - sb_row_index * sb_cols;
369    int mi_row = sb_row_index * MI_BLOCK_SIZE;
370    int mi_col = sb_col_index * MI_BLOCK_SIZE;
371    assert(mi_row >= 0 && mi_row < cm->mi_rows);
372    assert(mi_col >= 0 && mi_col < cm->mi_cols);
373    bl_index = mi_row * cm->mi_cols + mi_col;
374    // Loop through all 8x8 blocks in superblock and update map.
375    xmis =
376        VPXMIN(cm->mi_cols - mi_col, num_8x8_blocks_wide_lookup[BLOCK_64X64]);
377    ymis =
378        VPXMIN(cm->mi_rows - mi_row, num_8x8_blocks_high_lookup[BLOCK_64X64]);
379    if (cpi->noise_estimate.enabled && cpi->noise_estimate.level >= kMedium &&
380        (xmis <= 2 || ymis <= 2))
381      consec_zero_mv_thresh_block = 4;
382    for (y = 0; y < ymis; y++) {
383      for (x = 0; x < xmis; x++) {
384        const int bl_index2 = bl_index + y * cm->mi_cols + x;
385        // If the block is as a candidate for clean up then mark it
386        // for possible boost/refresh (segment 1). The segment id may get
387        // reset to 0 later depending on the coding mode.
388        if (cr->map[bl_index2] == 0) {
389          count_tot++;
390          if (cr->last_coded_q_map[bl_index2] > qindex_thresh ||
391              cpi->consec_zero_mv[bl_index2] < consec_zero_mv_thresh_block) {
392            sum_map++;
393            count_sel++;
394          }
395        } else if (cr->map[bl_index2] < 0) {
396          cr->map[bl_index2]++;
397        }
398      }
399    }
400    // Enforce constant segment over superblock.
401    // If segment is at least half of superblock, set to 1.
402    if (sum_map >= xmis * ymis / 2) {
403      for (y = 0; y < ymis; y++)
404        for (x = 0; x < xmis; x++) {
405          seg_map[bl_index + y * cm->mi_cols + x] = CR_SEGMENT_ID_BOOST1;
406        }
407      cr->target_num_seg_blocks += xmis * ymis;
408    }
409    i++;
410    if (i == sbs_in_frame) {
411      i = 0;
412    }
413  } while (cr->target_num_seg_blocks < block_count && i != cr->sb_index);
414  cr->sb_index = i;
415  cr->reduce_refresh = 0;
416  if (count_sel<(3 * count_tot)>> 2) cr->reduce_refresh = 1;
417}
418
419// Set cyclic refresh parameters.
420void vp9_cyclic_refresh_update_parameters(VP9_COMP *const cpi) {
421  const RATE_CONTROL *const rc = &cpi->rc;
422  const VP9_COMMON *const cm = &cpi->common;
423  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
424  int num8x8bl = cm->MBs << 2;
425  int target_refresh = 0;
426  double weight_segment_target = 0;
427  double weight_segment = 0;
428  cr->apply_cyclic_refresh = 1;
429  if (cm->frame_type == KEY_FRAME || cpi->svc.temporal_layer_id > 0 ||
430      (!cpi->use_svc && rc->avg_frame_low_motion < 55 &&
431       rc->frames_since_key > 40)) {
432    cr->apply_cyclic_refresh = 0;
433    return;
434  }
435  cr->percent_refresh = 10;
436  if (cr->reduce_refresh) cr->percent_refresh = 5;
437  cr->max_qdelta_perc = 60;
438  cr->time_for_refresh = 0;
439  cr->motion_thresh = 32;
440  cr->rate_boost_fac = 15;
441  // Use larger delta-qp (increase rate_ratio_qdelta) for first few (~4)
442  // periods of the refresh cycle, after a key frame.
443  // Account for larger interval on base layer for temporal layers.
444  if (cr->percent_refresh > 0 &&
445      rc->frames_since_key <
446          (4 * cpi->svc.number_temporal_layers) * (100 / cr->percent_refresh)) {
447    cr->rate_ratio_qdelta = 3.0;
448  } else {
449    cr->rate_ratio_qdelta = 2.0;
450    if (cpi->noise_estimate.enabled && cpi->noise_estimate.level >= kMedium) {
451      // Reduce the delta-qp if the estimated source noise is above threshold.
452      cr->rate_ratio_qdelta = 1.7;
453      cr->rate_boost_fac = 13;
454    }
455  }
456  // Adjust some parameters for low resolutions.
457  if (cm->width <= 352 && cm->height <= 288) {
458    if (rc->avg_frame_bandwidth < 3000) {
459      cr->motion_thresh = 16;
460      cr->rate_boost_fac = 13;
461    } else {
462      cr->max_qdelta_perc = 70;
463      cr->rate_ratio_qdelta = VPXMAX(cr->rate_ratio_qdelta, 2.5);
464    }
465  }
466  if (cpi->svc.spatial_layer_id > 0) {
467    cr->motion_thresh = 4;
468    cr->rate_boost_fac = 12;
469  }
470  if (cpi->oxcf.rc_mode == VPX_VBR) {
471    // To be adjusted for VBR mode, e.g., based on gf period and boost.
472    // For now use smaller qp-delta (than CBR), no second boosted seg, and
473    // turn-off (no refresh) on golden refresh (since it's already boosted).
474    cr->percent_refresh = 10;
475    cr->rate_ratio_qdelta = 1.5;
476    cr->rate_boost_fac = 10;
477    if (cpi->refresh_golden_frame == 1) {
478      cr->percent_refresh = 0;
479      cr->rate_ratio_qdelta = 1.0;
480    }
481  }
482  // Weight for segment prior to encoding: take the average of the target
483  // number for the frame to be encoded and the actual from the previous frame.
484  // Use the target if its less. To be used for setting the base qp for the
485  // frame in vp9_rc_regulate_q.
486  target_refresh = cr->percent_refresh * cm->mi_rows * cm->mi_cols / 100;
487  weight_segment_target = (double)(target_refresh) / num8x8bl;
488  weight_segment = (double)((target_refresh + cr->actual_num_seg1_blocks +
489                             cr->actual_num_seg2_blocks) >>
490                            1) /
491                   num8x8bl;
492  if (weight_segment_target < 7 * weight_segment / 8)
493    weight_segment = weight_segment_target;
494  cr->weight_segment = weight_segment;
495}
496
497// Setup cyclic background refresh: set delta q and segmentation map.
498void vp9_cyclic_refresh_setup(VP9_COMP *const cpi) {
499  VP9_COMMON *const cm = &cpi->common;
500  const RATE_CONTROL *const rc = &cpi->rc;
501  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
502  struct segmentation *const seg = &cm->seg;
503  if (cm->current_video_frame == 0) cr->low_content_avg = 0.0;
504  if (!cr->apply_cyclic_refresh || (cpi->force_update_segmentation)) {
505    // Set segmentation map to 0 and disable.
506    unsigned char *const seg_map = cpi->segmentation_map;
507    memset(seg_map, 0, cm->mi_rows * cm->mi_cols);
508    vp9_disable_segmentation(&cm->seg);
509    if (cm->frame_type == KEY_FRAME) {
510      memset(cr->last_coded_q_map, MAXQ,
511             cm->mi_rows * cm->mi_cols * sizeof(*cr->last_coded_q_map));
512      cr->sb_index = 0;
513      cr->reduce_refresh = 0;
514    }
515    return;
516  } else {
517    int qindex_delta = 0;
518    int qindex2;
519    const double q = vp9_convert_qindex_to_q(cm->base_qindex, cm->bit_depth);
520    vpx_clear_system_state();
521    // Set rate threshold to some multiple (set to 2 for now) of the target
522    // rate (target is given by sb64_target_rate and scaled by 256).
523    cr->thresh_rate_sb = ((int64_t)(rc->sb64_target_rate) << 8) << 2;
524    // Distortion threshold, quadratic in Q, scale factor to be adjusted.
525    // q will not exceed 457, so (q * q) is within 32bit; see:
526    // vp9_convert_qindex_to_q(), vp9_ac_quant(), ac_qlookup*[].
527    cr->thresh_dist_sb = ((int64_t)(q * q)) << 2;
528
529    // Set up segmentation.
530    // Clear down the segment map.
531    vp9_enable_segmentation(&cm->seg);
532    vp9_clearall_segfeatures(seg);
533    // Select delta coding method.
534    seg->abs_delta = SEGMENT_DELTADATA;
535
536    // Note: setting temporal_update has no effect, as the seg-map coding method
537    // (temporal or spatial) is determined in vp9_choose_segmap_coding_method(),
538    // based on the coding cost of each method. For error_resilient mode on the
539    // last_frame_seg_map is set to 0, so if temporal coding is used, it is
540    // relative to 0 previous map.
541    // seg->temporal_update = 0;
542
543    // Segment BASE "Q" feature is disabled so it defaults to the baseline Q.
544    vp9_disable_segfeature(seg, CR_SEGMENT_ID_BASE, SEG_LVL_ALT_Q);
545    // Use segment BOOST1 for in-frame Q adjustment.
546    vp9_enable_segfeature(seg, CR_SEGMENT_ID_BOOST1, SEG_LVL_ALT_Q);
547    // Use segment BOOST2 for more aggressive in-frame Q adjustment.
548    vp9_enable_segfeature(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q);
549
550    // Set the q delta for segment BOOST1.
551    qindex_delta = compute_deltaq(cpi, cm->base_qindex, cr->rate_ratio_qdelta);
552    cr->qindex_delta[1] = qindex_delta;
553
554    // Compute rd-mult for segment BOOST1.
555    qindex2 = clamp(cm->base_qindex + cm->y_dc_delta_q + qindex_delta, 0, MAXQ);
556
557    cr->rdmult = vp9_compute_rd_mult(cpi, qindex2);
558
559    vp9_set_segdata(seg, CR_SEGMENT_ID_BOOST1, SEG_LVL_ALT_Q, qindex_delta);
560
561    // Set a more aggressive (higher) q delta for segment BOOST2.
562    qindex_delta = compute_deltaq(
563        cpi, cm->base_qindex,
564        VPXMIN(CR_MAX_RATE_TARGET_RATIO,
565               0.1 * cr->rate_boost_fac * cr->rate_ratio_qdelta));
566    cr->qindex_delta[2] = qindex_delta;
567    vp9_set_segdata(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q, qindex_delta);
568
569    // Reset if resoluton change has occurred.
570    if (cpi->resize_pending != 0) vp9_cyclic_refresh_reset_resize(cpi);
571
572    // Update the segmentation and refresh map.
573    cyclic_refresh_update_map(cpi);
574  }
575}
576
577int vp9_cyclic_refresh_get_rdmult(const CYCLIC_REFRESH *cr) {
578  return cr->rdmult;
579}
580
581void vp9_cyclic_refresh_reset_resize(VP9_COMP *const cpi) {
582  const VP9_COMMON *const cm = &cpi->common;
583  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
584  memset(cr->map, 0, cm->mi_rows * cm->mi_cols);
585  memset(cr->last_coded_q_map, MAXQ, cm->mi_rows * cm->mi_cols);
586  cr->sb_index = 0;
587  cpi->refresh_golden_frame = 1;
588  cpi->refresh_alt_ref_frame = 1;
589}
590