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