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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_FIRSTPASS_H_
13 #define AOM_AV1_ENCODER_FIRSTPASS_H_
14 
15 #include <stdbool.h>
16 
17 #include "av1/common/av1_common_int.h"
18 #include "av1/common/enums.h"
19 #include "av1/encoder/lookahead.h"
20 #include "av1/encoder/ratectrl.h"
21 
22 #ifdef __cplusplus
23 extern "C" {
24 #endif
25 
26 #define DOUBLE_DIVIDE_CHECK(x) ((x) < 0 ? (x)-0.000001 : (x) + 0.000001)
27 
28 #define MIN_ZERO_MOTION 0.95
29 #define MAX_SR_CODED_ERROR 40
30 #define MAX_RAW_ERR_VAR 2000
31 #define MIN_MV_IN_OUT 0.4
32 
33 #define VLOW_MOTION_THRESHOLD 950
34 struct ThreadData;
35 
36 /*!
37  * \brief The stucture of acummulated frame stats in the first pass.
38  *
39  * Errors (coded_error, intra_error, etc.) and counters (new_mv_count) are
40  * normalized to each MB. MV related stats (MVc, MVr, etc.) are normalized to
41  * the frame width and height. See function normalize_firstpass_stats.
42  */
43 typedef struct FIRSTPASS_STATS {
44   /*!
45    * Frame number in display order, if stats are for a single frame.
46    * No real meaning for a collection of frames.
47    */
48   double frame;
49   /*!
50    * Weight assigned to this frame (or total weight for the collection of
51    * frames) currently based on intra factor and brightness factor. This is used
52    * to distribute bits betweeen easier and harder frames.
53    */
54   double weight;
55   /*!
56    * Intra prediction error.
57    */
58   double intra_error;
59   /*!
60    * Average wavelet energy computed using Discrete Wavelet Transform (DWT).
61    */
62   double frame_avg_wavelet_energy;
63   /*!
64    * Best of intra pred error and inter pred error using last frame as ref.
65    */
66   double coded_error;
67   /*!
68    * Best of intra pred error and inter pred error using golden frame as ref.
69    */
70   double sr_coded_error;
71   /*!
72    * Percentage of blocks with inter pred error < intra pred error.
73    */
74   double pcnt_inter;
75   /*!
76    * Percentage of blocks using (inter prediction and) non-zero motion vectors.
77    */
78   double pcnt_motion;
79   /*!
80    * Percentage of blocks where golden frame was better than last or intra:
81    * inter pred error using golden frame < inter pred error using last frame and
82    * inter pred error using golden frame < intra pred error
83    */
84   double pcnt_second_ref;
85   /*!
86    * Percentage of blocks where intra and inter prediction errors were very
87    * close. Note that this is a 'weighted count', that is, the so blocks may be
88    * weighted by how close the two errors were.
89    */
90   double pcnt_neutral;
91   /*!
92    * Percentage of blocks that have almost no intra error residual
93    * (i.e. are in effect completely flat and untextured in the intra
94    * domain). In natural videos this is uncommon, but it is much more
95    * common in animations, graphics and screen content, so may be used
96    * as a signal to detect these types of content.
97    */
98   double intra_skip_pct;
99   /*!
100    * Image mask rows top and bottom.
101    */
102   double inactive_zone_rows;
103   /*!
104    * Image mask columns at left and right edges.
105    */
106   double inactive_zone_cols;
107   /*!
108    * Average of row motion vectors.
109    */
110   double MVr;
111   /*!
112    * Mean of absolute value of row motion vectors.
113    */
114   double mvr_abs;
115   /*!
116    * Mean of column motion vectors.
117    */
118   double MVc;
119   /*!
120    * Mean of absolute value of column motion vectors.
121    */
122   double mvc_abs;
123   /*!
124    * Variance of row motion vectors.
125    */
126   double MVrv;
127   /*!
128    * Variance of column motion vectors.
129    */
130   double MVcv;
131   /*!
132    * Value in range [-1,1] indicating fraction of row and column motion vectors
133    * that point inwards (negative MV value) or outwards (positive MV value).
134    * For example, value of 1 indicates, all row/column MVs are inwards.
135    */
136   double mv_in_out_count;
137   /*!
138    * Count of unique non-zero motion vectors.
139    */
140   double new_mv_count;
141   /*!
142    * Duration of the frame / collection of frames.
143    */
144   double duration;
145   /*!
146    * 1.0 if stats are for a single frame, OR
147    * Number of frames in this collection for which the stats are accumulated.
148    */
149   double count;
150   /*!
151    * standard deviation for (0, 0) motion prediction error
152    */
153   double raw_error_stdev;
154   /*!
155    * Whether the frame contains a flash
156    */
157   int64_t is_flash;
158   /*!
159    * Estimated noise variance
160    */
161   double noise_var;
162   /*!
163    * Correlation coefficient with the previous frame
164    */
165   double cor_coeff;
166   /*!
167    * log of intra_error
168    */
169   double log_intra_error;
170   /*!
171    * log of coded_error
172    */
173   double log_coded_error;
174 } FIRSTPASS_STATS;
175 
176 // We want to keep one past stats for key frame detection
177 // in test_candidate_kf()
178 #define FIRSTPASS_INFO_STATS_PAST_MIN 1
179 
180 // The size of static buffer used in FIRSTPASS_INFO.
181 #define FIRSTPASS_INFO_STATIC_BUF_SIZE \
182   (MAX_LAP_BUFFERS + FIRSTPASS_INFO_STATS_PAST_MIN)
183 
184 /*!
185  * \brief  Data structure used for managing first pass stats
186  */
187 typedef struct {
188   /*!
189    * A static buffer that will be used when no ext_stats_buf is assigned. The
190    * ext_stats_buf is assigned through av1_firstpass_info_init() when the user
191    * already has a pre-existing firstpass stats that is stored in an external
192    * buffer. The ext_stats_buf is usually used in two pass mode. When using one
193    * pass mode, we generate "firstpass" stats and encode the video in the same
194    * pass. In this scenario, the stats will be pushed and popped from
195    * static_stats_buf.
196    */
197   FIRSTPASS_STATS static_stats_buf[FIRSTPASS_INFO_STATIC_BUF_SIZE];
198   /*!
199    * A pointer to first pass stats.
200    * Note that this buffer will be used as ring buffer.
201    */
202   FIRSTPASS_STATS *stats_buf;
203   /*!
204    * size of stats_buf
205    */
206   int stats_buf_size;
207   /*!
208    * start index of the available frame stats
209    * Note that start_index doesn't always point to
210    * current frame's stats because we need to
211    * keep past stats as well. To access current
212    * frame's stats, please use cur_index.
213    */
214   int start_index;
215 
216   /*!
217    * count available stats stored in stats_buf
218    * the following condition should stay true
219    * stats_count = future_stats_count + past_stats_count
220    */
221   int stats_count;
222 
223   /*!
224    *  index of the current frame's stats
225    */
226   int cur_index;
227 
228   /*!
229    * count available future stats including current stats
230    */
231   int future_stats_count;
232 
233   /*!
234    * count available past stats EXCLUDING current stats
235    */
236   int past_stats_count;
237 
238   /*!
239    * Accumulation of the stats being pushed into firstpass_info
240    */
241   FIRSTPASS_STATS total_stats;
242 } FIRSTPASS_INFO;
243 
244 /*!\brief Init firstpass_info
245  *
246  * If using ext_stats_buf, the buffer needs to stay available during encoding
247  * process.
248  *
249  * \ingroup rate_control
250  * \param[out]   firstpass_info      struct of firstpass_info.
251  * \param[in]    ext_stats_buf       external stats buffer. Pass in NULL if
252  *                                   choose to use internal static_stats_buf.
253  * \param[in]    ext_stats_buf_size  external stats buffer size. Pass in 0 if
254  * choose to use internal static_stats_buf. \return status
255  */
256 aom_codec_err_t av1_firstpass_info_init(FIRSTPASS_INFO *firstpass_info,
257                                         FIRSTPASS_STATS *ext_stats_buf,
258                                         int ext_stats_buf_size);
259 
260 /*!\brief Move cur_index by 1
261  *
262  * \ingroup rate_control
263  * \param[out]   firstpass_info      struct of firstpass_info.
264  * \return status
265  */
266 aom_codec_err_t av1_firstpass_info_move_cur_index(
267     FIRSTPASS_INFO *firstpass_info);
268 
269 /*!\brief Pop a stats from firstpass_info
270  *
271  * \ingroup rate_control
272  * \param[out]   firstpass_info      struct of firstpass_info.
273  * \return status
274  */
275 aom_codec_err_t av1_firstpass_info_pop(FIRSTPASS_INFO *firstpass_info);
276 
277 /*!\brief Move cur_index by 1 and pop a stats from firstpass_info
278  *
279  * \ingroup rate_control
280  * \param[out]   firstpass_info      struct of firstpass_info.
281  * \return status
282  */
283 aom_codec_err_t av1_firstpass_info_move_cur_index_and_pop(
284     FIRSTPASS_INFO *firstpass_info);
285 
286 /*!\brief Push a stats into firstpass_info
287  *
288  * Note that the input stats will be copied into firstpass_info.
289  * \ingroup rate_control
290  * \param[out]  firstpass_info      struct of firstpass_info.
291  * \param[in]   input_stats         input stats
292  * \return status
293  */
294 aom_codec_err_t av1_firstpass_info_push(FIRSTPASS_INFO *firstpass_info,
295                                         const FIRSTPASS_STATS *input_stats);
296 
297 /*!\brief Peek at a stats from firstpass_info
298  *
299  * The target index is as follows.
300  * (cur_index + offset_from_cur) % firstpass_info->stats_buf_size
301  *
302  * \ingroup rate_control
303  * \param[in]  firstpass_info      struct of firstpass_info.
304  * \param[in]  offset_from_cur  index offset from cur_index.
305  * \return pointer to the stats. The pointer will be NULL if
306  *         stats_index_offset is invalid.
307  */
308 const FIRSTPASS_STATS *av1_firstpass_info_peek(
309     const FIRSTPASS_INFO *firstpass_info, int offset_from_cur);
310 
311 /*!\brief Count the future stats from the target in firstpass_info
312  * Note that the target stats will be counted as well.
313  * The target index is as follows.
314  * (cur_index + offset_from_cur) % firstpass_info->stats_buf_size
315  *
316  * \ingroup rate_control
317  * \param[in]  firstpass_info    struct of firstpass_info.
318  * \param[in]  offset_from_cur  target stats's inffset
319  *                               from cur_index.
320  * \return Number of stats in the future after the target stats
321  *         including itself.
322  */
323 int av1_firstpass_info_future_count(const FIRSTPASS_INFO *firstpass_info,
324                                     int offset_from_cur);
325 
326 /*!\brief Count the past stats before the target in firstpass_info
327  * Note that the target stats will NOT be counted.
328  * The target index is as follows.
329  * (cur_index + offset_from_cur) % firstpass_info->stats_buf_size
330  *
331  * \ingroup rate_control
332  * \param[in]  firstpass_info    struct of firstpass_info.
333  * \param[in]  offset_from_cur  target stats's index offset
334  *                               from cur_index.
335  * \return Number of stats in the past before the target stats
336  *         excluding itself.
337  */
338 int av1_firstpass_info_past_count(const FIRSTPASS_INFO *firstpass_info,
339                                   int offset_from_cur);
340 
341 /*!\cond */
342 #define FC_ANIMATION_THRESH 0.15
343 enum {
344   FC_NORMAL = 0,
345   FC_GRAPHICS_ANIMATION = 1,
346   FRAME_CONTENT_TYPES = 2
347 } UENUM1BYTE(FRAME_CONTENT_TYPE);
348 /*!\endcond */
349 
350 /*!
351  * \brief  Data related to the current GF/ARF group and the
352  * individual frames within the group
353  */
354 typedef struct GF_GROUP {
355   /*!\cond */
356   // Frame update type, e.g. ARF/GF/LF/Overlay
357   FRAME_UPDATE_TYPE update_type[MAX_STATIC_GF_GROUP_LENGTH];
358   unsigned char arf_src_offset[MAX_STATIC_GF_GROUP_LENGTH];
359   // The number of frames displayed so far within the GOP at a given coding
360   // frame.
361   unsigned char cur_frame_idx[MAX_STATIC_GF_GROUP_LENGTH];
362   int layer_depth[MAX_STATIC_GF_GROUP_LENGTH];
363   int arf_boost[MAX_STATIC_GF_GROUP_LENGTH];
364   int max_layer_depth;
365   int max_layer_depth_allowed;
366   // This is currently only populated for AOM_Q mode
367   int q_val[MAX_STATIC_GF_GROUP_LENGTH];
368   int rdmult_val[MAX_STATIC_GF_GROUP_LENGTH];
369   int bit_allocation[MAX_STATIC_GF_GROUP_LENGTH];
370   // The frame coding type - inter/intra frame
371   FRAME_TYPE frame_type[MAX_STATIC_GF_GROUP_LENGTH];
372   // The reference frame buffer control - update or reset
373   REFBUF_STATE refbuf_state[MAX_STATIC_GF_GROUP_LENGTH];
374   int arf_index;  // the index in the gf group of ARF, if no arf, then -1
375   int size;       // The total length of a GOP
376 
377   // The offset into lookahead_ctx for choosing
378   // source of frame parallel encodes.
379   int src_offset[MAX_STATIC_GF_GROUP_LENGTH];
380   // Stores the display order hint of each frame in the current GF_GROUP.
381   int display_idx[MAX_STATIC_GF_GROUP_LENGTH];
382 
383   // The reference frame list maps the reference frame indexes to its
384   // buffer index in the decoded buffer. A value of -1 means the
385   // corresponding reference frame index doesn't point towards any
386   // previously decoded frame.
387   int8_t ref_frame_list[MAX_STATIC_GF_GROUP_LENGTH][REF_FRAMES];
388   // Update frame index
389   int update_ref_idx[MAX_STATIC_GF_GROUP_LENGTH];
390   // The map_idx of primary reference
391   int primary_ref_idx[MAX_STATIC_GF_GROUP_LENGTH];
392 
393   // Indicates the level of parallelism in frame parallel encodes.
394   // 0 : frame is independently encoded (not part of parallel encodes).
395   // 1 : frame is the first in encode order in a given parallel encode set.
396   // 2 : frame occurs later in encode order in a given parallel encode set.
397   int frame_parallel_level[MAX_STATIC_GF_GROUP_LENGTH];
398   // Indicates whether a frame should act as non-reference frame.
399   bool is_frame_non_ref[MAX_STATIC_GF_GROUP_LENGTH];
400   // Indicates whether a frame is dropped.
401   bool is_frame_dropped[MAX_STATIC_GF_GROUP_LENGTH];
402 
403   // Stores the display order hint of the frames not to be
404   // refreshed by the current frame.
405   int skip_frame_refresh[MAX_STATIC_GF_GROUP_LENGTH][REF_FRAMES];
406   // Stores the display order hint of the frame to be excluded during reference
407   // assignment.
408   int skip_frame_as_ref[MAX_STATIC_GF_GROUP_LENGTH];
409   /*!\endcond */
410 } GF_GROUP;
411 /*!\cond */
412 
413 typedef struct {
414   // Track if the last frame in a GOP has higher quality.
415   int arf_gf_boost_lst;
416 } GF_STATE;
417 
418 typedef struct {
419   FIRSTPASS_STATS *stats_in_start;
420   FIRSTPASS_STATS *stats_in_end;
421   FIRSTPASS_STATS *stats_in_buf_end;
422   FIRSTPASS_STATS *total_stats;
423   FIRSTPASS_STATS *total_left_stats;
424 } STATS_BUFFER_CTX;
425 
426 /*!\endcond */
427 
428 /*!
429  * \brief Two pass status and control data.
430  */
431 typedef struct {
432   /*!\cond */
433   unsigned int section_intra_rating;
434   // Circular queue of first pass stats stored for most recent frames.
435   // cpi->output_pkt_list[i].data.twopass_stats.buf points to actual data stored
436   // here.
437   FIRSTPASS_STATS *frame_stats_arr[MAX_LAP_BUFFERS + 1];
438   int frame_stats_next_idx;  // Index to next unused element in frame_stats_arr.
439   STATS_BUFFER_CTX *stats_buf_ctx;
440   FIRSTPASS_INFO firstpass_info;  // This is the first pass data structure
441                                   // intended to replace stats_in
442   int first_pass_done;
443   int64_t bits_left;
444   double modified_error_min;
445   double modified_error_max;
446   double modified_error_left;
447 
448   // Projected total bits available for a key frame group of frames
449   int64_t kf_group_bits;
450 
451   // Error score of frames still to be coded in kf group
452   double kf_group_error_left;
453 
454   // Over time correction for bits per macro block estimation
455   double bpm_factor;
456 
457   // Record of target and actual bits spent in current ARF group
458   int rolling_arf_group_target_bits;
459   int rolling_arf_group_actual_bits;
460 
461   int sr_update_lag;
462 
463   int kf_zeromotion_pct;
464   int last_kfgroup_zeromotion_pct;
465   int extend_minq;
466   int extend_maxq;
467   /*!\endcond */
468 } TWO_PASS;
469 
470 /*!
471  * \brief Frame level Two pass status and control data.
472  */
473 typedef struct {
474   /*!\cond */
475   const FIRSTPASS_STATS *stats_in;
476   // Pointer to the stats of the current frame.
477   const FIRSTPASS_STATS *this_frame;
478   double mb_av_energy;
479   // An indication of the content type of the current frame
480   FRAME_CONTENT_TYPE fr_content_type;
481   double frame_avg_haar_energy;
482   /*!\endcond */
483 } TWO_PASS_FRAME;
484 
485 /*!\cond */
486 
487 // This structure contains several key parameters to be accumulated for this
488 // frame.
489 typedef struct {
490   // Intra prediction error.
491   int64_t intra_error;
492   // Average wavelet energy computed using Discrete Wavelet Transform (DWT).
493   int64_t frame_avg_wavelet_energy;
494   // Best of intra pred error and inter pred error using last frame as ref.
495   int64_t coded_error;
496   // Best of intra pred error and inter pred error using golden frame as ref.
497   int64_t sr_coded_error;
498   // Count of motion vector.
499   int mv_count;
500   // Count of blocks that pick inter prediction (inter pred error is smaller
501   // than intra pred error).
502   int inter_count;
503   // Count of blocks that pick second ref (golden frame).
504   int second_ref_count;
505   // Count of blocks where the inter and intra are very close and very low.
506   double neutral_count;
507   // Count of blocks where intra error is very small.
508   int intra_skip_count;
509   // Start row.
510   int image_data_start_row;
511   // Count of unique non-zero motion vectors.
512   int new_mv_count;
513   // Sum of inward motion vectors.
514   int sum_in_vectors;
515   // Sum of motion vector row.
516   int sum_mvr;
517   // Sum of motion vector column.
518   int sum_mvc;
519   // Sum of absolute value of motion vector row.
520   int sum_mvr_abs;
521   // Sum of absolute value of motion vector column.
522   int sum_mvc_abs;
523   // Sum of the square of motion vector row.
524   int64_t sum_mvrs;
525   // Sum of the square of motion vector column.
526   int64_t sum_mvcs;
527   // A factor calculated using intra pred error.
528   double intra_factor;
529   // A factor that measures brightness.
530   double brightness_factor;
531 } FRAME_STATS;
532 
533 // This structure contains first pass data.
534 typedef struct {
535   // Buffer holding frame stats for all MACROBLOCKs.
536   // mb_stats[i] stores the FRAME_STATS of the ith
537   // MB in raster scan order.
538   FRAME_STATS *mb_stats;
539   // Buffer to store the prediction error of the (0,0) motion
540   // vector using the last source frame as the reference.
541   // raw_motion_err_list[i] stores the raw_motion_err of
542   // the ith MB in raster scan order.
543   int *raw_motion_err_list;
544 } FirstPassData;
545 
546 struct AV1_COMP;
547 struct EncodeFrameParams;
548 struct AV1EncoderConfig;
549 struct TileDataEnc;
550 
is_fp_wavelet_energy_invalid(const FIRSTPASS_STATS * fp_stats)551 static INLINE int is_fp_wavelet_energy_invalid(
552     const FIRSTPASS_STATS *fp_stats) {
553   assert(fp_stats != NULL);
554   return (fp_stats->frame_avg_wavelet_energy < 0);
555 }
556 
get_fp_block_size(int is_screen_content_type)557 static INLINE BLOCK_SIZE get_fp_block_size(int is_screen_content_type) {
558   return (is_screen_content_type ? BLOCK_8X8 : BLOCK_16X16);
559 }
560 
561 int av1_get_unit_rows_in_tile(const TileInfo *tile,
562                               const BLOCK_SIZE fp_block_size);
563 int av1_get_unit_cols_in_tile(const TileInfo *tile,
564                               const BLOCK_SIZE fp_block_size);
565 
566 void av1_first_pass_row(struct AV1_COMP *cpi, struct ThreadData *td,
567                         struct TileDataEnc *tile_data, const int mb_row,
568                         const BLOCK_SIZE fp_block_size);
569 void av1_end_first_pass(struct AV1_COMP *cpi);
570 
571 void av1_free_firstpass_data(FirstPassData *firstpass_data);
572 
573 void av1_twopass_zero_stats(FIRSTPASS_STATS *section);
574 void av1_accumulate_stats(FIRSTPASS_STATS *section,
575                           const FIRSTPASS_STATS *frame);
576 /*!\endcond */
577 
578 /*!\brief AV1 first pass encoding.
579  *
580  * \ingroup rate_control
581  * This function is the first encoding pass for the two pass encoding mode.
582  * It encodes the whole video and collect essential information.
583  * Two pass encoding is an encoding mode in the reference software (libaom)
584  * of AV1 for high performance encoding. The first pass is a fast encoding
585  * process to collect essential information to help the second pass make
586  * encoding decisions and improve coding quality. The collected stats is used
587  * in rate control, for example, to determine frame cut, the position of
588  * alternative reference frame (ARF), etc.
589  *
590  * \param[in]    cpi            Top-level encoder structure
591  * \param[in]    ts_duration    Duration of the frame / collection of frames
592  *
593  * \remark Nothing is returned. Instead, the "TWO_PASS" structure inside "cpi"
594  * is modified to store information computed in this function.
595  */
596 void av1_first_pass(struct AV1_COMP *cpi, const int64_t ts_duration);
597 
598 void av1_noop_first_pass_frame(struct AV1_COMP *cpi, const int64_t ts_duration);
599 #ifdef __cplusplus
600 }  // extern "C"
601 #endif
602 
603 #endif  // AOM_AV1_ENCODER_FIRSTPASS_H_
604