xref: /aosp_15_r20/external/libaom/av1/encoder/ratectrl.h (revision 77c1e3ccc04c968bd2bc212e87364f250e820521)
1 /*
2  * Copyright (c) 2016, 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_RATECTRL_H_
13 #define AOM_AV1_ENCODER_RATECTRL_H_
14 
15 #include "aom/aom_codec.h"
16 #include "aom/aom_integer.h"
17 
18 #include "aom_ports/mem.h"
19 
20 #include "av1/common/av1_common_int.h"
21 #include "av1/common/blockd.h"
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 /*!\cond */
28 
29 // Bits Per MB at different Q (Multiplied by 512)
30 #define BPER_MB_NORMBITS 9
31 
32 // Use this macro to turn on/off use of alt-refs in one-pass mode.
33 #define USE_ALTREF_FOR_ONE_PASS 1
34 
35 // Threshold used to define if a KF group is static (e.g. a slide show).
36 // Essentially, this means that no frame in the group has more than 1% of MBs
37 // that are not marked as coded with 0,0 motion in the first pass.
38 #define STATIC_KF_GROUP_THRESH 99
39 #define STATIC_KF_GROUP_FLOAT_THRESH 0.99
40 
41 // The maximum duration of a GF group that is static (e.g. a slide show).
42 #define MAX_STATIC_GF_GROUP_LENGTH 250
43 
44 #define MIN_GF_INTERVAL 4
45 #define MAX_GF_INTERVAL 32
46 #define FIXED_GF_INTERVAL 16
47 #define MAX_GF_LENGTH_LAP 16
48 
49 #define FIXED_GF_INTERVAL_RT 80
50 #define MAX_GF_INTERVAL_RT 160
51 
52 #define MAX_NUM_GF_INTERVALS 15
53 
54 #define MAX_ARF_LAYERS 6
55 // #define STRICT_RC
56 
57 #define DEFAULT_KF_BOOST_RT 2300
58 #define DEFAULT_GF_BOOST_RT 2000
59 
60 // A passive rate control strategy for screen content type in real-time mode.
61 // When it is turned on, the compression performance is improved by
62 // 7.8% (overall_psnr), 5.0% (VMAF) on average. Some clips see gains
63 // over 20% on metric.
64 // The downside is that it does not guarantee frame size.
65 // Since RT mode has a tight restriction on buffer overflow control, we
66 // turn it off by default.
67 #define RT_PASSIVE_STRATEGY 0
68 #define MAX_Q_HISTORY 1000
69 
70 typedef struct {
71   int resize_width;
72   int resize_height;
73   uint8_t superres_denom;
74 } size_params_type;
75 
76 enum {
77   INTER_NORMAL,
78   GF_ARF_LOW,
79   GF_ARF_STD,
80   KF_STD,
81   RATE_FACTOR_LEVELS
82 } UENUM1BYTE(RATE_FACTOR_LEVEL);
83 
84 enum {
85   KF_UPDATE,
86   LF_UPDATE,
87   GF_UPDATE,
88   ARF_UPDATE,
89   OVERLAY_UPDATE,
90   INTNL_OVERLAY_UPDATE,  // Internal Overlay Frame
91   INTNL_ARF_UPDATE,      // Internal Altref Frame
92   FRAME_UPDATE_TYPES
93 } UENUM1BYTE(FRAME_UPDATE_TYPE);
94 
95 enum {
96   REFBUF_RESET,   // Clear reference frame buffer
97   REFBUF_UPDATE,  // Refresh reference frame buffer
98   REFBUF_STATES
99 } UENUM1BYTE(REFBUF_STATE);
100 
101 typedef enum {
102   NO_RESIZE = 0,
103   DOWN_THREEFOUR = 1,  // From orig to 3/4.
104   DOWN_ONEHALF = 2,    // From orig or 3/4 to 1/2.
105   UP_THREEFOUR = -1,   // From 1/2 to 3/4.
106   UP_ORIG = -2,        // From 1/2 or 3/4 to orig.
107 } RESIZE_ACTION;
108 
109 typedef enum { ORIG = 0, THREE_QUARTER = 1, ONE_HALF = 2 } RESIZE_STATE;
110 
111 #define MAX_FIRSTPASS_ANALYSIS_FRAMES 150
112 typedef enum region_types {
113   STABLE_REGION = 0,
114   HIGH_VAR_REGION = 1,
115   SCENECUT_REGION = 2,
116   BLENDING_REGION = 3,
117 } REGION_TYPES;
118 
119 typedef struct regions {
120   int start;
121   int last;
122   double avg_noise_var;
123   double avg_cor_coeff;
124   double avg_sr_fr_ratio;
125   double avg_intra_err;
126   double avg_coded_err;
127   REGION_TYPES type;
128 } REGIONS;
129 
130 /*!\endcond */
131 /*!
132  * \brief  Rate Control parameters and status
133  */
134 typedef struct {
135   // Rate targetting variables
136 
137   /*!
138    * Baseline target rate for frame before adjustment for previous under or
139    * over shoot.
140    */
141   int base_frame_target;
142   /*!
143    * Target rate for frame after adjustment for previous under or over shoot.
144    */
145   int this_frame_target;  // Actual frame target after rc adjustment.
146 
147   /*!
148    * Projected size for current frame
149    */
150   int projected_frame_size;
151 
152   /*!
153    * Bit size of transform coefficient for current frame.
154    */
155   int coefficient_size;
156 
157   /*!
158    * Super block rate target used with some adaptive quantization strategies.
159    */
160   int sb64_target_rate;
161 
162   /*!
163    * Number of frames since the last ARF / GF.
164    */
165   int frames_since_golden;
166 
167   /*!
168    * Number of frames till the next ARF / GF is due.
169    */
170   int frames_till_gf_update_due;
171 
172   /*!
173    * Number of determined gf groups left
174    */
175   int intervals_till_gf_calculate_due;
176 
177   /*!\cond */
178   int min_gf_interval;
179   int max_gf_interval;
180   int static_scene_max_gf_interval;
181   /*!\endcond */
182   /*!
183    * Frames before the next key frame
184    */
185   int frames_to_key;
186   /*!\cond */
187   int frames_since_key;
188   int frames_to_fwd_kf;
189   int is_src_frame_alt_ref;
190   int sframe_due;
191 
192   int high_source_sad;
193   int high_motion_content_screen_rtc;
194   uint64_t avg_source_sad;
195   uint64_t prev_avg_source_sad;
196   uint64_t frame_source_sad;
197   uint64_t frame_spatial_variance;
198   int static_since_last_scene_change;
199   int last_encoded_size_keyframe;
200   int last_target_size_keyframe;
201   int frames_since_scene_change;
202   int perc_flat_blocks_keyframe;
203 
204   int avg_frame_bandwidth;  // Average frame size target for clip
205   int min_frame_bandwidth;  // Minimum allocation used for any frame
206   int max_frame_bandwidth;  // Maximum burst rate allowed for a frame.
207   int prev_avg_frame_bandwidth;
208 
209   int ni_av_qi;
210   int ni_tot_qi;
211 
212   int decimation_factor;
213   int decimation_count;
214   int prev_frame_is_dropped;
215   int drop_count_consec;
216   int max_consec_drop;
217   int force_max_q;
218   int postencode_drop;
219 
220   /*!
221    * Frame number for encoded frames (non-dropped).
222    * Use for setting the rtc reference structure.
223    */
224   unsigned int frame_number_encoded;
225 
226   /*!\endcond */
227   /*!
228    * User specified maximum Q allowed for current frame
229    */
230   int worst_quality;
231   /*!
232    * User specified minimum Q allowed for current frame
233    */
234   int best_quality;
235 
236   /*!\cond */
237 
238   // rate control history for last frame(1) and the frame before(2).
239   // -1: overshoot
240   //  1: undershoot
241   //  0: not initialized.
242   int rc_1_frame;
243   int rc_2_frame;
244   int q_1_frame;
245   int q_2_frame;
246 
247   /*!\endcond */
248   /*!
249    * Proposed maximum allowed Q for current frame
250    */
251   int active_worst_quality;
252 
253   /*!\cond */
254   // Track amount of low motion in scene
255   int avg_frame_low_motion;
256   int cnt_zeromv;
257 
258   // signals if number of blocks with motion is high
259   int percent_blocks_with_motion;
260 
261   // signals percentage of 16x16 blocks that are inactive, via active_maps
262   int percent_blocks_inactive;
263 
264   // Maximum value of source sad across all blocks of frame.
265   uint64_t max_block_source_sad;
266 
267   // For dynamic resize, 1 pass cbr.
268   RESIZE_STATE resize_state;
269   int resize_avg_qp;
270   int resize_buffer_underflow;
271   int resize_count;
272 
273   // Flag to disable content related qp adjustment.
274   int rtc_external_ratectrl;
275 
276   // Stores fast_extra_bits of the current frame.
277   int frame_level_fast_extra_bits;
278 
279   double frame_level_rate_correction_factors[RATE_FACTOR_LEVELS];
280 
281   int frame_num_last_gf_refresh;
282 
283   int prev_coded_width;
284   int prev_coded_height;
285 
286   // The ratio used for inter frames in bit estimation.
287   // TODO(yunqing): if golden frame is treated differently (e.g. gf_cbr_boost_
288   // pct > THR), consider to add bit_est_ratio_g for golden frames.
289   int bit_est_ratio;
290 
291   // Whether to use a fixed qp for the frame, bypassing internal rate control.
292   // This flag will reset to 0 after every frame.
293   int use_external_qp_one_pass;
294   /*!\endcond */
295 } RATE_CONTROL;
296 
297 /*!
298  * \brief  Primary Rate Control parameters and status
299  */
300 typedef struct {
301   // Sub-gop level Rate targetting variables
302 
303   /*!
304    * Target bit budget for the current GF / ARF group of frame.
305    */
306   int64_t gf_group_bits;
307 
308   /*!
309    * Boost factor used to calculate the extra bits allocated to the key frame
310    */
311   int kf_boost;
312 
313   /*!
314    * Boost factor used to calculate the extra bits allocated to ARFs and GFs
315    */
316   int gfu_boost;
317 
318   /*!
319    * Stores the determined gf group lengths for a set of gf groups
320    */
321   int gf_intervals[MAX_NUM_GF_INTERVALS];
322 
323   /*!
324    * The current group's index into gf_intervals[]
325    */
326   int cur_gf_index;
327 
328   /*!\cond */
329   int num_regions;
330 
331   REGIONS regions[MAX_FIRSTPASS_ANALYSIS_FRAMES];
332   int regions_offset;  // offset of regions from the last keyframe
333   int frames_till_regions_update;
334 
335   int baseline_gf_interval;
336 
337   int constrained_gf_group;
338 
339   int this_key_frame_forced;
340 
341   int next_key_frame_forced;
342   /*!\endcond */
343 
344   /*!
345    * Initial buffuer level in ms for CBR / low delay encoding
346    */
347   int64_t starting_buffer_level;
348 
349   /*!
350    * Optimum / target buffuer level in ms for CBR / low delay encoding
351    */
352   int64_t optimal_buffer_level;
353 
354   /*!
355    * Maximum target buffuer level in ms for CBR / low delay encoding
356    */
357   int64_t maximum_buffer_size;
358 
359   /*!
360    * Q index used for ALT frame
361    */
362   int arf_q;
363 
364   /*!\cond */
365   float_t arf_boost_factor;
366 
367   int base_layer_qp;
368 
369   // Total number of stats used only for kf_boost calculation.
370   int num_stats_used_for_kf_boost;
371 
372   // Total number of stats used only for gfu_boost calculation.
373   int num_stats_used_for_gfu_boost;
374 
375   // Total number of stats required by gfu_boost calculation.
376   int num_stats_required_for_gfu_boost;
377 
378   int enable_scenecut_detection;
379 
380   int use_arf_in_this_kf_group;
381 
382   int ni_frames;
383 
384   double tot_q;
385   /*!\endcond */
386 
387   /*!
388    * Q used for last boosted (non leaf) frame
389    */
390   int last_kf_qindex;
391 
392   /*!
393    * Average of q index of previous encoded frames in a sequence.
394    */
395   int avg_frame_qindex[FRAME_TYPES];
396 
397 #if CONFIG_FPMT_TEST
398   /*!
399    * Temporary variable used in simulating the delayed update of
400    * active_best_quality.
401    */
402   int temp_active_best_quality[MAX_ARF_LAYERS + 1];
403 
404   /*!
405    * Temporary variable used in simulating the delayed update of
406    * last_boosted_qindex.
407    */
408   int temp_last_boosted_qindex;
409 
410   /*!
411    * Temporary variable used in simulating the delayed update of
412    * avg_q.
413    */
414   double temp_avg_q;
415 
416   /*!
417    * Temporary variable used in simulating the delayed update of
418    * last_q.
419    */
420   int temp_last_q[FRAME_TYPES];
421 
422   /*!
423    * Temporary variable used in simulating the delayed update of
424    * projected_frame_size.
425    */
426   int temp_projected_frame_size;
427 
428   /*!
429    * Temporary variable used in simulating the delayed update of
430    * total_actual_bits.
431    */
432   int64_t temp_total_actual_bits;
433 
434   /*!
435    * Temporary variable used in simulating the delayed update of
436    * buffer_level.
437    */
438   int64_t temp_buffer_level;
439 
440   /*!
441    * Temporary variable used in simulating the delayed update of
442    * vbr_bits_off_target.
443    */
444   int64_t temp_vbr_bits_off_target;
445 
446   /*!
447    * Temporary variable used in simulating the delayed update of
448    * vbr_bits_off_target_fast.
449    */
450   int64_t temp_vbr_bits_off_target_fast;
451 
452   /*!
453    * Temporary variable used in simulating the delayed update of
454    * rate_correction_factors.
455    */
456   double temp_rate_correction_factors[RATE_FACTOR_LEVELS];
457 
458   /*!
459    * Temporary variable used in simulating the delayed update of
460    * rate_error_estimate.
461    */
462   int temp_rate_error_estimate;
463 
464   /*!
465    * Temporary variable used in simulating the delayed update of
466    * rolling_arf_group_target_bits.
467    */
468   int temp_rolling_arf_group_target_bits;
469 
470   /*!
471    * Temporary variable used in simulating the delayed update of
472    * rolling_arf_group_actual_bits;.
473    */
474   int temp_rolling_arf_group_actual_bits;
475 
476   /*!
477    * Temporary variable used in simulating the delayed update of
478    * bits_left;.
479    */
480   int64_t temp_bits_left;
481 
482   /*!
483    * Temporary variable used in simulating the delayed update of
484    * extend_minq.
485    */
486   int temp_extend_minq;
487 
488   /*!
489    * Temporary variable used in simulating the delayed update of
490    * extend_maxq.
491    */
492   int temp_extend_maxq;
493 
494 #endif
495   /*!
496    * Proposed minimum allowed Q different layers in a coding pyramid
497    */
498   int active_best_quality[MAX_ARF_LAYERS + 1];
499 
500   /*!
501    * Q used for last boosted (non leaf) frame (GF/KF/ARF)
502    */
503   int last_boosted_qindex;
504 
505   /*!
506    * Average Q value of previous inter frames
507    */
508   double avg_q;
509 
510   /*!
511    * Q used on last encoded frame of the given type.
512    */
513   int last_q[FRAME_TYPES];
514 
515   /*!
516    * Correction factors used to adjust the q estimate for a given target rate
517    * in the encode loop.
518    */
519   double rate_correction_factors[RATE_FACTOR_LEVELS];
520 
521   /*!
522    * Current total consumed bits.
523    */
524   int64_t total_actual_bits;
525 
526   /*!
527    * Current total target bits.
528    */
529   int64_t total_target_bits;
530 
531   /*!
532    * Current buffer level.
533    */
534   int64_t buffer_level;
535 
536   /*!
537    * PCT rc error.
538    */
539   int rate_error_estimate;
540 
541   /*!
542    * Error bits available from previously encoded frames.
543    */
544   int64_t vbr_bits_off_target;
545 
546   /*!
547    * Error bits available from previously encoded frames undershoot.
548    */
549   int64_t vbr_bits_off_target_fast;
550 
551   /*!
552    * Total bits deviated from the average frame target, from previously
553    * encoded frames.
554    */
555   int64_t bits_off_target;
556 
557   /*!
558    * Rolling monitor target bits updated based on current frame target size.
559    */
560   int rolling_target_bits;
561 
562   /*!
563    * Rolling monitor actual bits updated based on current frame final projected
564    * size.
565    */
566   int rolling_actual_bits;
567 
568   /*!
569    * The history of qindex for each frame.
570    * Only used when RT_PASSIVE_STRATEGY = 1.
571    */
572   int q_history[MAX_Q_HISTORY];
573 } PRIMARY_RATE_CONTROL;
574 
575 /*!\cond */
576 
577 struct AV1_COMP;
578 struct AV1EncoderConfig;
579 struct GF_GROUP;
580 
581 void av1_primary_rc_init(const struct AV1EncoderConfig *oxcf,
582                          PRIMARY_RATE_CONTROL *p_rc);
583 
584 void av1_rc_init(const struct AV1EncoderConfig *oxcf, RATE_CONTROL *rc);
585 
586 int av1_estimate_bits_at_q(const struct AV1_COMP *cpi, int q,
587                            double correction_factor);
588 
589 double av1_convert_qindex_to_q(int qindex, aom_bit_depth_t bit_depth);
590 
591 void av1_rc_init_minq_luts(void);
592 
593 int av1_rc_get_default_min_gf_interval(int width, int height, double framerate);
594 
595 // Generally at the high level, the following flow is expected
596 // to be enforced for rate control:
597 // First call per frame, one of:
598 //   av1_get_one_pass_rt_params()
599 //   av1_get_second_pass_params()
600 // depending on the usage to set the rate control encode parameters desired.
601 //
602 // Then, call encode_frame_to_data_rate() to perform the
603 // actual encode. This function will in turn call encode_frame()
604 // one or more times, followed by:
605 //   av1_rc_postencode_update_drop_frame()
606 //
607 // The majority of rate control parameters are only expected
608 // to be set in the av1_get_..._params() functions and
609 // updated during the av1_rc_postencode_update...() functions.
610 // The only exceptions are av1_rc_drop_frame() and
611 // av1_rc_update_rate_correction_factors() functions.
612 
613 // Functions to set parameters for encoding before the actual
614 // encode_frame_to_data_rate() function.
615 struct EncodeFrameInput;
616 
617 // Post encode update of the rate control parameters based
618 // on bytes used
619 void av1_rc_postencode_update(struct AV1_COMP *cpi, uint64_t bytes_used);
620 // Post encode update of the rate control parameters for dropped frames
621 void av1_rc_postencode_update_drop_frame(struct AV1_COMP *cpi);
622 
623 /*!\endcond */
624 /*!\brief Updates the rate correction factor linking Q to output bits
625  *
626  * This function updates the Q rate correction factor after an encode
627  * cycle depending on whether we overshot or undershot the target rate.
628  *
629  * \ingroup rate_control
630  * \param[in]   cpi                   Top level encoder instance structure
631  * \param[in]   is_encode_stage       Indicates if recode loop or post-encode
632  * \param[in]   width                 Frame width
633  * \param[in]   height                Frame height
634  *
635  * \remark Updates the relevant rate correction factor in cpi->rc
636  */
637 void av1_rc_update_rate_correction_factors(struct AV1_COMP *cpi,
638                                            int is_encode_stage, int width,
639                                            int height);
640 /*!\cond */
641 
642 // Decide if we should drop this frame: For 1-pass CBR.
643 // Changes only the decimation count in the rate control structure
644 int av1_rc_drop_frame(struct AV1_COMP *cpi);
645 
646 // Computes frame size bounds.
647 void av1_rc_compute_frame_size_bounds(const struct AV1_COMP *cpi,
648                                       int this_frame_target,
649                                       int *frame_under_shoot_limit,
650                                       int *frame_over_shoot_limit);
651 
652 /*!\endcond */
653 
654 /*!\brief Picks q and q bounds given the rate control parameters in \c cpi->rc.
655  *
656  * \ingroup rate_control
657  * \param[in]       cpi          Top level encoder structure
658  * \param[in]       width        Coded frame width
659  * \param[in]       height       Coded frame height
660  * \param[in]       gf_index     Index of this frame in the golden frame group
661  * \param[out]      bottom_index Bottom bound for q index (best quality)
662  * \param[out]      top_index    Top bound for q index (worst quality)
663  * \return Returns selected q index to be used for encoding this frame.
664  * Also, updates \c rc->arf_q.
665  */
666 int av1_rc_pick_q_and_bounds(struct AV1_COMP *cpi, int width, int height,
667                              int gf_index, int *bottom_index, int *top_index);
668 
669 /*!\brief Estimates q to achieve a target bits per frame
670  *
671  * \ingroup rate_control
672  * \param[in]   cpi                   Top level encoder instance structure
673  * \param[in]   target_bits_per_frame Frame rate target
674  * \param[in]   active_worst_quality  Max Q allowed
675  * \param[in]   active_best_quality   Min Q allowed
676  * \param[in]   width                 Frame width
677  * \param[in]   height                Frame height
678  *
679  * \return Returns a q index value
680  */
681 int av1_rc_regulate_q(const struct AV1_COMP *cpi, int target_bits_per_frame,
682                       int active_best_quality, int active_worst_quality,
683                       int width, int height);
684 
685 /*!\cond */
686 // Estimates bits per mb for a given qindex and correction factor.
687 int av1_rc_bits_per_mb(const struct AV1_COMP *cpi, FRAME_TYPE frame_type,
688                        int qindex, double correction_factor,
689                        int accurate_estimate);
690 
691 // Find q_index corresponding to desired_q, within [best_qindex, worst_qindex].
692 // To be precise, 'q_index' is the smallest integer, for which the corresponding
693 // q >= desired_q.
694 // If no such q index is found, returns 'worst_qindex'.
695 int av1_find_qindex(double desired_q, aom_bit_depth_t bit_depth,
696                     int best_qindex, int worst_qindex);
697 
698 // Computes a q delta (in "q index" terms) to get from a starting q value
699 // to a target q value
700 int av1_compute_qdelta(const RATE_CONTROL *rc, double qstart, double qtarget,
701                        aom_bit_depth_t bit_depth);
702 
703 // Computes a q delta (in "q index" terms) to get from a starting q value
704 // to a value that should equate to the given rate ratio.
705 int av1_compute_qdelta_by_rate(const struct AV1_COMP *cpi,
706                                FRAME_TYPE frame_type, int qindex,
707                                double rate_target_ratio);
708 
709 void av1_rc_update_framerate(struct AV1_COMP *cpi, int width, int height);
710 
711 void av1_set_target_rate(struct AV1_COMP *cpi, int width, int height);
712 
713 int av1_resize_one_pass_cbr(struct AV1_COMP *cpi);
714 
715 void av1_rc_set_frame_target(struct AV1_COMP *cpi, int target, int width,
716                              int height);
717 
718 void av1_adjust_gf_refresh_qp_one_pass_rt(struct AV1_COMP *cpi);
719 
720 void av1_set_rtc_reference_structure_one_layer(struct AV1_COMP *cpi,
721                                                int gf_update);
722 
723 /*!\endcond */
724 /*!\brief Calculates how many bits to use for a P frame in one pass vbr
725  *
726  * \ingroup rate_control
727  * \callgraph
728  * \callergraph
729  *
730  * \param[in]       cpi                 Top level encoder structure
731  * \param[in]       frame_update_type   Type of frame
732  *
733  * \return	Returns the target number of bits for this frame.
734  */
735 int av1_calc_pframe_target_size_one_pass_vbr(
736     const struct AV1_COMP *const cpi, FRAME_UPDATE_TYPE frame_update_type);
737 
738 /*!\brief Calculates how many bits to use for an i frame in one pass vbr
739  *
740  * \ingroup rate_control
741  * \callgraph
742  * \callergraph
743  *
744  * \param[in]       cpi  Top level encoder structure
745  *
746  * \return	Returns the target number of bits for this frame.
747  */
748 int av1_calc_iframe_target_size_one_pass_vbr(const struct AV1_COMP *const cpi);
749 
750 /*!\brief Calculates how many bits to use for a P frame in one pass cbr
751  *
752  * \ingroup rate_control
753  * \callgraph
754  * \callergraph
755  *
756  * \param[in]       cpi                 Top level encoder structure
757  * \param[in]       frame_update_type   Type of frame
758  *
759  * \return  Returns the target number of bits for this frame.
760  */
761 int av1_calc_pframe_target_size_one_pass_cbr(
762     const struct AV1_COMP *cpi, FRAME_UPDATE_TYPE frame_update_type);
763 
764 /*!\brief Calculates how many bits to use for an i frame in one pass cbr
765  *
766  * \ingroup rate_control
767  * \callgraph
768  * \callergraph
769  *
770  * \param[in]       cpi  Top level encoder structure
771  *
772  * \return  Returns the target number of bits for this frame.
773  */
774 int av1_calc_iframe_target_size_one_pass_cbr(const struct AV1_COMP *cpi);
775 
776 /*!\brief Setup the rate control parameters for 1 pass real-time mode.
777  *
778  * - Sets the frame type and target frame size.
779  * - Sets the GF update.
780  * - Checks for scene change.
781  * - Sets the reference prediction structure for 1 layers (non-SVC).
782  * - Resets and updates are done for SVC.
783  *
784  * \ingroup rate_control
785  * \param[in]       cpi          Top level encoder structure
786  * \param[in]       frame_type   Encoder frame type
787  * \param[in]       frame_input  Current and last input source frames
788  * \param[in]       frame_flags  Encoder frame flags
789  *
790  * \remark Nothing is returned. Instead the settings computed in this
791  * function are set in: \c frame_params, \c cpi->common, \c cpi->rc,
792  * \c cpi->svc.
793  */
794 void av1_get_one_pass_rt_params(struct AV1_COMP *cpi,
795                                 FRAME_TYPE *const frame_type,
796                                 const struct EncodeFrameInput *frame_input,
797                                 unsigned int frame_flags);
798 
799 /*!\brief Increase q on expected encoder overshoot, for CBR mode.
800  *
801  *  Handles the case when encoder is expected to create a large frame:
802  *  - q is increased to value closer to \c cpi->rc.worst_quality
803  *  - avg_frame_qindex is reset
804  *  - buffer levels are reset
805  *  - rate correction factor is adjusted
806  *
807  * \ingroup rate_control
808  * \param[in]       cpi          Top level encoder structure
809  * \param[in]        q           Current q index
810  *
811  * \return q is returned, and updates are done to \c cpi->rc.
812  */
813 int av1_encodedframe_overshoot_cbr(struct AV1_COMP *cpi, int *q);
814 
815 /*!\brief Check if frame should be dropped, for RTC mode.
816  *
817  * \ingroup rate_control
818  * \param[in]       cpi          Top level encoder structure
819  * \param[in,out]       size         Size of encoded frame
820  *
821  * \return 1 if frame is to be dropped, 0 otherwise (no drop).
822  * Set cpi->rc.force_max_q if frame is to be dropped, and updates are
823  * made to rate control parameters. *size is set to 0 when this
824  * function returns 1 (frame is dropped).
825  */
826 int av1_postencode_drop_cbr(struct AV1_COMP *cpi, size_t *size);
827 
828 /*!\brief Compute the q_indices for a single frame.
829  *
830  * Intended to be used with AOM_Q mode.
831  *
832  * \param[in]       base_q_index      Base q index
833  * \param[in]       gf_update_type    GOP update type
834  * \param[in]       gf_pyramid_level  GOP level of the current frame
835  * \param[in]       arf_q             ARF q_index
836  *
837  * \return Returns the q_index for the current frame.
838  */
839 int av1_q_mode_get_q_index(int base_q_index, int gf_update_type,
840                            int gf_pyramid_level, int arf_q);
841 
842 #ifdef __cplusplus
843 }  // extern "C"
844 #endif
845 
846 #endif  // AOM_AV1_ENCODER_RATECTRL_H_
847