AOMedia AV1 Codec
rc_utils.h
1 /*
2  * Copyright (c) 2020, Alliance for Open Media. All rights reserved.
3  *
4  * This source code is subject to the terms of the BSD 2 Clause License and
5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6  * was not distributed with this source code in the LICENSE file, you can
7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8  * Media Patent License 1.0 was not distributed with this source code in the
9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10  */
11 
12 #ifndef AOM_AV1_ENCODER_RC_UTILS_H_
13 #define AOM_AV1_ENCODER_RC_UTILS_H_
14 
15 #include "av1/encoder/encoder.h"
16 #include "aom_dsp/psnr.h"
17 
18 #ifdef __cplusplus
19 extern "C" {
20 #endif
21 
22 static inline void check_reset_rc_flag(AV1_COMP *cpi) {
23  RATE_CONTROL *rc = &cpi->rc;
24  PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
25  if (cpi->common.current_frame.frame_number >
26  (unsigned int)cpi->svc.number_spatial_layers) {
27  if (cpi->ppi->use_svc) {
28  av1_svc_check_reset_layer_rc_flag(cpi);
29  } else {
30  if (rc->avg_frame_bandwidth > (3 * rc->prev_avg_frame_bandwidth >> 1) ||
31  rc->avg_frame_bandwidth < (rc->prev_avg_frame_bandwidth >> 1)) {
32  rc->rc_1_frame = 0;
33  rc->rc_2_frame = 0;
35  p_rc->buffer_level = p_rc->optimal_buffer_level;
36  }
37  }
38  }
39 }
40 
41 static inline void set_primary_rc_buffer_sizes(const AV1EncoderConfig *oxcf,
42  AV1_PRIMARY *ppi) {
43  PRIMARY_RATE_CONTROL *p_rc = &ppi->p_rc;
44  const RateControlCfg *const rc_cfg = &oxcf->rc_cfg;
45 
46  const int64_t bandwidth = rc_cfg->target_bandwidth;
47  const int64_t starting = rc_cfg->starting_buffer_level_ms;
48  const int64_t optimal = rc_cfg->optimal_buffer_level_ms;
49  const int64_t maximum = rc_cfg->maximum_buffer_size_ms;
50 
51  p_rc->starting_buffer_level = starting * bandwidth / 1000;
52  p_rc->optimal_buffer_level =
53  (optimal == 0) ? bandwidth / 8 : optimal * bandwidth / 1000;
54  p_rc->maximum_buffer_size =
55  (maximum == 0) ? bandwidth / 8 : maximum * bandwidth / 1000;
56 
57  // Under a configuration change, where maximum_buffer_size may change,
58  // keep buffer level clipped to the maximum allowed buffer size.
59  p_rc->bits_off_target =
60  AOMMIN(p_rc->bits_off_target, p_rc->maximum_buffer_size);
61  p_rc->buffer_level = AOMMIN(p_rc->buffer_level, p_rc->maximum_buffer_size);
62 }
63 
64 static inline void config_target_level(AV1_COMP *const cpi,
65  AV1_LEVEL target_level, int tier) {
66  AV1EncoderConfig *const oxcf = &cpi->oxcf;
67  SequenceHeader *const seq_params = cpi->common.seq_params;
68  TileConfig *const tile_cfg = &oxcf->tile_cfg;
69  RateControlCfg *const rc_cfg = &oxcf->rc_cfg;
70 
71  // Adjust target bitrate to be no larger than 70% of level limit.
72  const BITSTREAM_PROFILE profile = seq_params->profile;
73  const double level_bitrate_limit =
74  av1_get_max_bitrate_for_level(target_level, tier, profile);
75  const int64_t max_bitrate = (int64_t)(level_bitrate_limit * 0.70);
76  rc_cfg->target_bandwidth = AOMMIN(rc_cfg->target_bandwidth, max_bitrate);
77  // Also need to update cpi->ppi->twopass.bits_left.
78  TWO_PASS *const twopass = &cpi->ppi->twopass;
79  FIRSTPASS_STATS *stats = twopass->stats_buf_ctx->total_stats;
80  if (stats != NULL)
81  cpi->ppi->twopass.bits_left =
82  (int64_t)(stats->duration * rc_cfg->target_bandwidth / 10000000.0);
83 
84  // Adjust max over-shoot percentage.
85  rc_cfg->over_shoot_pct = 0;
86 
87  // Adjust max quantizer.
88  rc_cfg->worst_allowed_q = 255;
89 
90  // Adjust number of tiles and tile columns to be under level limit.
91  int max_tiles, max_tile_cols;
92  av1_get_max_tiles_for_level(target_level, &max_tiles, &max_tile_cols);
93  while (tile_cfg->tile_columns > 0 &&
94  (1 << tile_cfg->tile_columns) > max_tile_cols) {
95  --tile_cfg->tile_columns;
96  }
97  const int tile_cols = (1 << tile_cfg->tile_columns);
98  while (tile_cfg->tile_rows > 0 &&
99  tile_cols * (1 << tile_cfg->tile_rows) > max_tiles) {
100  --tile_cfg->tile_rows;
101  }
102 
103  // Adjust min compression ratio.
104  const int still_picture = seq_params->still_picture;
105  const double min_cr =
106  av1_get_min_cr_for_level(target_level, tier, still_picture);
107  rc_cfg->min_cr = AOMMAX(rc_cfg->min_cr, (unsigned int)(min_cr * 100));
108 }
109 
110 #if !CONFIG_REALTIME_ONLY
111 
128 static inline int recode_loop_test(AV1_COMP *cpi, int high_limit, int low_limit,
129  int q, int maxq, int minq) {
130  const RATE_CONTROL *const rc = &cpi->rc;
131  const AV1EncoderConfig *const oxcf = &cpi->oxcf;
132  const int frame_is_kfgfarf = frame_is_kf_gf_arf(cpi);
133  int force_recode = 0;
134 
135  if ((rc->projected_frame_size >= rc->max_frame_bandwidth) ||
136  (cpi->sf.hl_sf.recode_loop == ALLOW_RECODE) ||
137  (frame_is_kfgfarf &&
138  (cpi->sf.hl_sf.recode_loop == ALLOW_RECODE_KFARFGF))) {
139  // TODO(agrange) high_limit could be greater than the scale-down threshold.
140  if ((rc->projected_frame_size > high_limit && q < maxq) ||
141  (rc->projected_frame_size < low_limit && q > minq)) {
142  force_recode = 1;
143  } else if (cpi->oxcf.rc_cfg.mode == AOM_CQ) {
144  // Deal with frame undershoot and whether or not we are
145  // below the automatically set cq level.
146  if (q > oxcf->rc_cfg.cq_level &&
147  rc->projected_frame_size < ((rc->this_frame_target * 7) >> 3)) {
148  force_recode = 1;
149  }
150  }
151  }
152  return force_recode;
153 }
154 
155 static inline double av1_get_gfu_boost_projection_factor(double min_factor,
156  double max_factor,
157  int frame_count) {
158  double factor = sqrt((double)frame_count);
159  factor = AOMMIN(factor, max_factor);
160  factor = AOMMAX(factor, min_factor);
161  factor = (200.0 + 10.0 * factor);
162  return factor;
163 }
164 
165 static inline int get_gfu_boost_from_r0_lap(double min_factor,
166  double max_factor, double r0,
167  int frames_to_key) {
168  double factor = av1_get_gfu_boost_projection_factor(min_factor, max_factor,
169  frames_to_key);
170  const int boost = (int)rint(factor / r0);
171  return boost;
172 }
173 
174 static inline double av1_get_kf_boost_projection_factor(int frame_count) {
175  double factor = sqrt((double)frame_count);
176  factor = AOMMIN(factor, 10.0);
177  factor = AOMMAX(factor, 4.0);
178  factor = (75.0 + 14.0 * factor);
179  return factor;
180 }
181 
182 static inline int get_regulated_q_overshoot(AV1_COMP *const cpi,
183  int is_encode_stage, int q_low,
184  int q_high, int top_index,
185  int bottom_index) {
186  const AV1_COMMON *const cm = &cpi->common;
187  const RATE_CONTROL *const rc = &cpi->rc;
188 
189  av1_rc_update_rate_correction_factors(cpi, is_encode_stage, cm->width,
190  cm->height);
191 
192  int q_regulated =
193  av1_rc_regulate_q(cpi, rc->this_frame_target, bottom_index,
194  AOMMAX(q_high, top_index), cm->width, cm->height);
195 
196  int retries = 0;
197  while (q_regulated < q_low && retries < 10) {
198  av1_rc_update_rate_correction_factors(cpi, is_encode_stage, cm->width,
199  cm->height);
200  q_regulated =
201  av1_rc_regulate_q(cpi, rc->this_frame_target, bottom_index,
202  AOMMAX(q_high, top_index), cm->width, cm->height);
203  retries++;
204  }
205  return q_regulated;
206 }
207 
208 static inline int get_regulated_q_undershoot(AV1_COMP *const cpi,
209  int is_encode_stage, int q_high,
210  int top_index, int bottom_index) {
211  const AV1_COMMON *const cm = &cpi->common;
212  const RATE_CONTROL *const rc = &cpi->rc;
213 
214  av1_rc_update_rate_correction_factors(cpi, is_encode_stage, cm->width,
215  cm->height);
216  int q_regulated = av1_rc_regulate_q(cpi, rc->this_frame_target, bottom_index,
217  top_index, cm->width, cm->height);
218 
219  int retries = 0;
220  while (q_regulated > q_high && retries < 10) {
221  av1_rc_update_rate_correction_factors(cpi, is_encode_stage, cm->width,
222  cm->height);
223  q_regulated = av1_rc_regulate_q(cpi, rc->this_frame_target, bottom_index,
224  top_index, cm->width, cm->height);
225  retries++;
226  }
227  return q_regulated;
228 }
229 
252 static inline void recode_loop_update_q(
253  AV1_COMP *const cpi, int *const loop, int *const q, int *const q_low,
254  int *const q_high, const int top_index, const int bottom_index,
255  int *const undershoot_seen, int *const overshoot_seen,
256  int *const low_cr_seen, const int loop_count) {
257  AV1_COMMON *const cm = &cpi->common;
258  RATE_CONTROL *const rc = &cpi->rc;
259  PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
260  const RateControlCfg *const rc_cfg = &cpi->oxcf.rc_cfg;
261  *loop = 0;
262 
263  // Special case for overlay frame.
264  if (rc->is_src_frame_alt_ref &&
265  rc->projected_frame_size < rc->max_frame_bandwidth)
266  return;
267 
268  const int min_cr = rc_cfg->min_cr;
269  if (min_cr > 0) {
270  const double compression_ratio =
271  av1_get_compression_ratio(cm, rc->projected_frame_size >> 3);
272  const double target_cr = min_cr / 100.0;
273  if (compression_ratio < target_cr) {
274  *low_cr_seen = 1;
275  if (*q < rc->worst_quality) {
276  const double cr_ratio = target_cr / compression_ratio;
277  const int projected_q = AOMMAX(*q + 1, (int)(*q * cr_ratio * cr_ratio));
278  *q = AOMMIN(AOMMIN(projected_q, *q + 32), rc->worst_quality);
279  *q_low = AOMMAX(*q, *q_low);
280  *q_high = AOMMAX(*q, *q_high);
281  *loop = 1;
282  }
283  }
284  if (*low_cr_seen) return;
285  }
286 
287  if (cpi->ppi->level_params.keep_level_stats &&
288  !is_stat_generation_stage(cpi)) {
289  // Initialize level info. at the beginning of each sequence.
290  if (cm->current_frame.frame_type == KEY_FRAME &&
291  cpi->ppi->gf_group.refbuf_state[cpi->gf_frame_index] == REFBUF_RESET) {
292  av1_init_level_info(cpi);
293  }
294  const AV1LevelParams *const level_params = &cpi->ppi->level_params;
295  // TODO(any): currently only checking operating point 0
296  const AV1LevelInfo *const level_info = level_params->level_info[0];
297  const DECODER_MODEL *const decoder_models = level_info->decoder_models;
298  const AV1_LEVEL target_level = level_params->target_seq_level_idx[0];
299 
300  if (target_level < SEQ_LEVELS &&
301  decoder_models[target_level].status == DECODER_MODEL_OK) {
302  DECODER_MODEL_STATUS status = av1_decoder_model_try_smooth_buf(
303  cpi, rc->projected_frame_size, &decoder_models[target_level]);
304 
305  if ((status == SMOOTHING_BUFFER_UNDERFLOW ||
306  status == SMOOTHING_BUFFER_OVERFLOW) &&
307  *q < rc->worst_quality) {
308  *q = AOMMIN(*q + 10, rc->worst_quality);
309  *q_low = AOMMAX(*q, *q_low);
310  *q_high = AOMMAX(*q, *q_high);
311  *loop = 1;
312  return;
313  }
314  }
315  }
316 
317  if (rc_cfg->mode == AOM_Q) return;
318 
319  const int last_q = *q;
320  int frame_over_shoot_limit = 0, frame_under_shoot_limit = 0;
321  av1_rc_compute_frame_size_bounds(cpi, rc->this_frame_target,
322  &frame_under_shoot_limit,
323  &frame_over_shoot_limit);
324  if (frame_over_shoot_limit == 0) frame_over_shoot_limit = 1;
325 
326  if (cm->current_frame.frame_type == KEY_FRAME &&
327  p_rc->this_key_frame_forced &&
328  rc->projected_frame_size < rc->max_frame_bandwidth) {
329  int64_t kf_err;
330  const int64_t high_err_target = cpi->ambient_err;
331  const int64_t low_err_target = cpi->ambient_err >> 1;
332 
333 #if CONFIG_AV1_HIGHBITDEPTH
334  if (cm->seq_params->use_highbitdepth) {
335  kf_err = aom_highbd_get_y_sse(cpi->source, &cm->cur_frame->buf);
336  } else {
337  kf_err = aom_get_y_sse(cpi->source, &cm->cur_frame->buf);
338  }
339 #else
340  kf_err = aom_get_y_sse(cpi->source, &cm->cur_frame->buf);
341 #endif
342  // Prevent possible divide by zero error below for perfect KF
343  kf_err += !kf_err;
344 
345  // The key frame is not good enough or we can afford
346  // to make it better without undue risk of popping.
347  if ((kf_err > high_err_target &&
348  rc->projected_frame_size <= frame_over_shoot_limit) ||
349  (kf_err > low_err_target &&
350  rc->projected_frame_size <= frame_under_shoot_limit)) {
351  // Lower q_high
352  *q_high = AOMMAX(*q - 1, *q_low);
353 
354  // Adjust Q
355  *q = (int)((*q * high_err_target) / kf_err);
356  *q = AOMMIN(*q, (*q_high + *q_low) >> 1);
357  } else if (kf_err < low_err_target &&
358  rc->projected_frame_size >= frame_under_shoot_limit) {
359  // The key frame is much better than the previous frame
360  // Raise q_low
361  *q_low = AOMMIN(*q + 1, *q_high);
362 
363  // Adjust Q
364  *q = (int)((*q * low_err_target) / kf_err);
365  *q = AOMMIN(*q, (*q_high + *q_low + 1) >> 1);
366  }
367 
368  // Clamp Q to upper and lower limits:
369  *q = clamp(*q, *q_low, *q_high);
370  *loop = (*q != last_q);
371  return;
372  }
373 
374  if (recode_loop_test(cpi, frame_over_shoot_limit, frame_under_shoot_limit, *q,
375  AOMMAX(*q_high, top_index), bottom_index)) {
376  // Is the projected frame size out of range and are we allowed
377  // to attempt to recode.
378 
379  // Frame size out of permitted range:
380  // Update correction factor & compute new Q to try...
381  // Frame is too large
382  if (rc->projected_frame_size > rc->this_frame_target) {
383  // Special case if the projected size is > the max allowed.
384  if (*q == *q_high &&
385  rc->projected_frame_size >= rc->max_frame_bandwidth) {
386  const double q_val_high_current =
387  av1_convert_qindex_to_q(*q_high, cm->seq_params->bit_depth);
388  const double q_val_high_new =
389  q_val_high_current *
390  ((double)rc->projected_frame_size / rc->max_frame_bandwidth);
391  *q_high = av1_find_qindex(q_val_high_new, cm->seq_params->bit_depth,
392  rc->best_quality, rc->worst_quality);
393  }
394 
395  // Raise Qlow as to at least the current value
396  *q_low = AOMMIN(*q + 1, *q_high);
397 
398  if (*undershoot_seen || loop_count > 2 ||
399  (loop_count == 2 && !frame_is_intra_only(cm))) {
401 
402  *q = (*q_high + *q_low + 1) / 2;
403  } else if (loop_count == 2 && frame_is_intra_only(cm)) {
404  const int q_mid = (*q_high + *q_low + 1) / 2;
405  const int q_regulated = get_regulated_q_overshoot(
406  cpi, 1, *q_low, *q_high, top_index, bottom_index);
407  // Get 'q' in-between 'q_mid' and 'q_regulated' for a smooth
408  // transition between loop_count < 2 and loop_count > 2.
409  *q = (q_mid + q_regulated + 1) / 2;
410  } else {
411  *q = get_regulated_q_overshoot(cpi, 1, *q_low, *q_high, top_index,
412  bottom_index);
413  }
414 
415  *overshoot_seen = 1;
416  } else {
417  // Frame is too small
418  *q_high = AOMMAX(*q - 1, *q_low);
419 
420  if (*overshoot_seen || loop_count > 2 ||
421  (loop_count == 2 && !frame_is_intra_only(cm))) {
423  *q = (*q_high + *q_low) / 2;
424  } else if (loop_count == 2 && frame_is_intra_only(cm)) {
425  const int q_mid = (*q_high + *q_low) / 2;
426  const int q_regulated = get_regulated_q_undershoot(
427  cpi, 1, *q_high, top_index, bottom_index);
428  // Get 'q' in-between 'q_mid' and 'q_regulated' for a smooth
429  // transition between loop_count < 2 and loop_count > 2.
430  *q = (q_mid + q_regulated) / 2;
431 
432  // Special case reset for qlow for constrained quality.
433  // This should only trigger where there is very substantial
434  // undershoot on a frame and the auto cq level is above
435  // the user passsed in value.
436  if (rc_cfg->mode == AOM_CQ && q_regulated < *q_low) {
437  *q_low = *q;
438  }
439  } else {
440  *q = get_regulated_q_undershoot(cpi, 1, *q_high, top_index,
441  bottom_index);
442 
443  // Special case reset for qlow for constrained quality.
444  // This should only trigger where there is very substantial
445  // undershoot on a frame and the auto cq level is above
446  // the user passsed in value.
447  if (rc_cfg->mode == AOM_CQ && *q < *q_low) {
448  *q_low = *q;
449  }
450  }
451 
452  *undershoot_seen = 1;
453  }
454 
455  // Clamp Q to upper and lower limits:
456  *q = clamp(*q, *q_low, *q_high);
457  }
458 
459  *loop = (*q != last_q);
460 }
461 #endif
462 
463 #ifdef __cplusplus
464 } // extern "C"
465 #endif
466 
467 #endif // AOM_AV1_ENCODER_RC_UTILS_H_
Declares top-level encoder structures and functions.
@ AOM_CQ
Definition: aom_encoder.h:186
@ AOM_Q
Definition: aom_encoder.h:187
void av1_rc_update_rate_correction_factors(AV1_COMP *cpi, int is_encode_stage, int width, int height)
Updates the rate correction factor linking Q to output bits.
Definition: ratectrl.c:858
static int recode_loop_test(AV1_COMP *cpi, int high_limit, int low_limit, int q, int maxq, int minq)
Function to test for conditions that indicate we should loop back and recode a frame.
Definition: rc_utils.h:128
static void recode_loop_update_q(AV1_COMP *const cpi, int *const loop, int *const q, int *const q_low, int *const q_high, const int top_index, const int bottom_index, int *const undershoot_seen, int *const overshoot_seen, int *const low_cr_seen, const int loop_count)
Called after encode_with_recode_loop() has just encoded a frame. This function works out whether we u...
Definition: rc_utils.h:252
int av1_rc_regulate_q(const struct AV1_COMP *cpi, int target_bits_per_frame, int active_best_quality, int active_worst_quality, int width, int height)
Estimates q to achieve a target bits per frame.
Top level common structure used by both encoder and decoder.
Definition: av1_common_int.h:757
SequenceHeader * seq_params
Definition: av1_common_int.h:983
int width
Definition: av1_common_int.h:782
RefCntBuffer * cur_frame
Definition: av1_common_int.h:839
CurrentFrame current_frame
Definition: av1_common_int.h:761
int height
Definition: av1_common_int.h:783
Main encoder configuration data structure.
Definition: encoder.h:923
RateControlCfg rc_cfg
Definition: encoder.h:945
Top level encoder structure.
Definition: encoder.h:2873
RATE_CONTROL rc
Definition: encoder.h:3080
int64_t ambient_err
Definition: encoder.h:3049
SPEED_FEATURES sf
Definition: encoder.h:3100
unsigned char gf_frame_index
Definition: encoder.h:3131
AV1EncoderConfig oxcf
Definition: encoder.h:2921
AV1_COMMON common
Definition: encoder.h:2916
AV1_PRIMARY * ppi
Definition: encoder.h:2877
YV12_BUFFER_CONFIG * source
Definition: encoder.h:2934
SVC svc
Definition: encoder.h:3414
Top level primary encoder structure.
Definition: encoder.h:2577
AV1LevelParams level_params
Definition: encoder.h:2708
TWO_PASS twopass
Definition: encoder.h:2723
PRIMARY_RATE_CONTROL p_rc
Definition: encoder.h:2728
int use_svc
Definition: encoder.h:2743
GF_GROUP gf_group
Definition: encoder.h:2693
The stucture of acummulated frame stats in the first pass.
Definition: firstpass.h:43
double duration
Definition: firstpass.h:144
RECODE_LOOP_TYPE recode_loop
Definition: speed_features.h:414
Primary Rate Control parameters and status.
Definition: ratectrl.h:299
int64_t bits_off_target
Definition: ratectrl.h:554
int64_t maximum_buffer_size
Definition: ratectrl.h:356
int64_t starting_buffer_level
Definition: ratectrl.h:346
int64_t buffer_level
Definition: ratectrl.h:533
int64_t optimal_buffer_level
Definition: ratectrl.h:351
Rate Control parameters and status.
Definition: ratectrl.h:134
int best_quality
Definition: ratectrl.h:233
int this_frame_target
Definition: ratectrl.h:145
int projected_frame_size
Definition: ratectrl.h:150
int worst_quality
Definition: ratectrl.h:229
Encoder rate control configuration parameters.
Definition: encoder.h:521
int worst_allowed_q
Definition: encoder.h:591
int over_shoot_pct
Definition: encoder.h:586
int64_t maximum_buffer_size_ms
Definition: encoder.h:540
unsigned int min_cr
Definition: encoder.h:570
enum aom_rc_mode mode
Definition: encoder.h:605
int64_t starting_buffer_level_ms
Definition: encoder.h:530
int64_t target_bandwidth
Definition: encoder.h:545
int64_t optimal_buffer_level_ms
Definition: encoder.h:535
int cq_level
Definition: encoder.h:600
HIGH_LEVEL_SPEED_FEATURES hl_sf
Definition: speed_features.h:1936
Two pass status and control data.
Definition: firstpass.h:416