summaryrefslogtreecommitdiff
path: root/libavcodec/h264.h
blob: 430a6f9b9916e7a5e893ac599134f904b967befa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
/*
 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * H.264 / AVC / MPEG4 part10 codec.
 * @author Michael Niedermayer <michaelni@gmx.at>
 */

#ifndef AVCODEC_H264_H
#define AVCODEC_H264_H

#include "libavutil/intreadwrite.h"
#include "dsputil.h"
#include "cabac.h"
#include "mpegvideo.h"
#include "h264dsp.h"
#include "h264pred.h"
#include "rectangle.h"

#define interlaced_dct interlaced_dct_is_a_bad_name
#define mb_intra       mb_intra_is_not_initialized_see_mb_type

#define MAX_SPS_COUNT          32
#define MAX_PPS_COUNT         256

#define MAX_MMCO_COUNT         66

#define MAX_DELAYED_PIC_COUNT  16

#define MAX_MBPAIR_SIZE (256*1024) // a tighter bound could be calculated if someone cares about a few bytes

/* Compiling in interlaced support reduces the speed
 * of progressive decoding by about 2%. */
#define ALLOW_INTERLACE

#define FMO 0

/**
 * The maximum number of slices supported by the decoder.
 * must be a power of 2
 */
#define MAX_SLICES 16

#ifdef ALLOW_INTERLACE
#define MB_MBAFF    h->mb_mbaff
#define MB_FIELD    h->mb_field_decoding_flag
#define FRAME_MBAFF h->mb_aff_frame
#define FIELD_PICTURE (s->picture_structure != PICT_FRAME)
#define LEFT_MBS 2
#define LTOP     0
#define LBOT     1
#define LEFT(i)  (i)
#else
#define MB_MBAFF      0
#define MB_FIELD      0
#define FRAME_MBAFF   0
#define FIELD_PICTURE 0
#undef  IS_INTERLACED
#define IS_INTERLACED(mb_type) 0
#define LEFT_MBS 1
#define LTOP     0
#define LBOT     0
#define LEFT(i)  0
#endif
#define FIELD_OR_MBAFF_PICTURE (FRAME_MBAFF || FIELD_PICTURE)

#ifndef CABAC
#define CABAC h->pps.cabac
#endif

#define CHROMA    (h->sps.chroma_format_idc)
#define CHROMA422 (h->sps.chroma_format_idc == 2)
#define CHROMA444 (h->sps.chroma_format_idc == 3)

#define EXTENDED_SAR       255

#define MB_TYPE_REF0       MB_TYPE_ACPRED // dirty but it fits in 16 bit
#define MB_TYPE_8x8DCT     0x01000000
#define IS_REF0(a)         ((a) & MB_TYPE_REF0)
#define IS_8x8DCT(a)       ((a) & MB_TYPE_8x8DCT)

/**
 * Value of Picture.reference when Picture is not a reference picture, but
 * is held for delayed output.
 */
#define DELAYED_PIC_REF 4

#define QP_MAX_NUM (51 + 6*6)           // The maximum supported qp

/* NAL unit types */
enum {
    NAL_SLICE = 1,
    NAL_DPA,
    NAL_DPB,
    NAL_DPC,
    NAL_IDR_SLICE,
    NAL_SEI,
    NAL_SPS,
    NAL_PPS,
    NAL_AUD,
    NAL_END_SEQUENCE,
    NAL_END_STREAM,
    NAL_FILLER_DATA,
    NAL_SPS_EXT,
    NAL_SUBSET_SEQ_PARAM_SET = 0x0F,
    NAL_AUXILIARY_SLICE = 19
};

/**
 * SEI message types
 */
typedef enum {
    SEI_BUFFERING_PERIOD            = 0,   ///< buffering period (H.264, D.1.1)
    SEI_TYPE_PIC_TIMING             = 1,   ///< picture timing
    SEI_TYPE_USER_DATA_ITU_T_T35    = 4,   ///< user data registered by ITU-T Recommendation T.35
    SEI_TYPE_USER_DATA_UNREGISTERED = 5,   ///< unregistered user data
    SEI_TYPE_RECOVERY_POINT         = 6    ///< recovery point (frame # to decoder sync)
} SEI_Type;

/**
 * pic_struct in picture timing SEI message
 */
typedef enum {
    SEI_PIC_STRUCT_FRAME             = 0, ///<  0: %frame
    SEI_PIC_STRUCT_TOP_FIELD         = 1, ///<  1: top field
    SEI_PIC_STRUCT_BOTTOM_FIELD      = 2, ///<  2: bottom field
    SEI_PIC_STRUCT_TOP_BOTTOM        = 3, ///<  3: top field, bottom field, in that order
    SEI_PIC_STRUCT_BOTTOM_TOP        = 4, ///<  4: bottom field, top field, in that order
    SEI_PIC_STRUCT_TOP_BOTTOM_TOP    = 5, ///<  5: top field, bottom field, top field repeated, in that order
    SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM = 6, ///<  6: bottom field, top field, bottom field repeated, in that order
    SEI_PIC_STRUCT_FRAME_DOUBLING    = 7, ///<  7: %frame doubling
    SEI_PIC_STRUCT_FRAME_TRIPLING    = 8  ///<  8: %frame tripling
} SEI_PicStructType;

/**
 * Sequence parameter set
 */
typedef struct SPS {
    int profile_idc;
    int level_idc;
    int chroma_format_idc;
    int transform_bypass;              ///< qpprime_y_zero_transform_bypass_flag
    int log2_max_frame_num;            ///< log2_max_frame_num_minus4 + 4
    int poc_type;                      ///< pic_order_cnt_type
    int log2_max_poc_lsb;              ///< log2_max_pic_order_cnt_lsb_minus4
    int delta_pic_order_always_zero_flag;
    int offset_for_non_ref_pic;
    int offset_for_top_to_bottom_field;
    int poc_cycle_length;              ///< num_ref_frames_in_pic_order_cnt_cycle
    int ref_frame_count;               ///< num_ref_frames
    int gaps_in_frame_num_allowed_flag;
    int mb_width;                      ///< pic_width_in_mbs_minus1 + 1
    int mb_height;                     ///< pic_height_in_map_units_minus1 + 1
    int frame_mbs_only_flag;
    int mb_aff;                        ///< mb_adaptive_frame_field_flag
    int direct_8x8_inference_flag;
    int crop;                          ///< frame_cropping_flag
    unsigned int crop_left;            ///< frame_cropping_rect_left_offset
    unsigned int crop_right;           ///< frame_cropping_rect_right_offset
    unsigned int crop_top;             ///< frame_cropping_rect_top_offset
    unsigned int crop_bottom;          ///< frame_cropping_rect_bottom_offset
    int vui_parameters_present_flag;
    AVRational sar;
    int video_signal_type_present_flag;
    int full_range;
    int colour_description_present_flag;
    enum AVColorPrimaries color_primaries;
    enum AVColorTransferCharacteristic color_trc;
    enum AVColorSpace colorspace;
    int timing_info_present_flag;
    uint32_t num_units_in_tick;
    uint32_t time_scale;
    int fixed_frame_rate_flag;
    short offset_for_ref_frame[256]; // FIXME dyn aloc?
    int bitstream_restriction_flag;
    int num_reorder_frames;
    int scaling_matrix_present;
    uint8_t scaling_matrix4[6][16];
    uint8_t scaling_matrix8[6][64];
    int nal_hrd_parameters_present_flag;
    int vcl_hrd_parameters_present_flag;
    int pic_struct_present_flag;
    int time_offset_length;
    int cpb_cnt;                          ///< See H.264 E.1.2
    int initial_cpb_removal_delay_length; ///< initial_cpb_removal_delay_length_minus1 + 1
    int cpb_removal_delay_length;         ///< cpb_removal_delay_length_minus1 + 1
    int dpb_output_delay_length;          ///< dpb_output_delay_length_minus1 + 1
    int bit_depth_luma;                   ///< bit_depth_luma_minus8 + 8
    int bit_depth_chroma;                 ///< bit_depth_chroma_minus8 + 8
    int residual_color_transform_flag;    ///< residual_colour_transform_flag
    int constraint_set_flags;             ///< constraint_set[0-3]_flag
} SPS;

/**
 * Picture parameter set
 */
typedef struct PPS {
    unsigned int sps_id;
    int cabac;                  ///< entropy_coding_mode_flag
    int pic_order_present;      ///< pic_order_present_flag
    int slice_group_count;      ///< num_slice_groups_minus1 + 1
    int mb_slice_group_map_type;
    unsigned int ref_count[2];  ///< num_ref_idx_l0/1_active_minus1 + 1
    int weighted_pred;          ///< weighted_pred_flag
    int weighted_bipred_idc;
    int init_qp;                ///< pic_init_qp_minus26 + 26
    int init_qs;                ///< pic_init_qs_minus26 + 26
    int chroma_qp_index_offset[2];
    int deblocking_filter_parameters_present; ///< deblocking_filter_parameters_present_flag
    int constrained_intra_pred;     ///< constrained_intra_pred_flag
    int redundant_pic_cnt_present;  ///< redundant_pic_cnt_present_flag
    int transform_8x8_mode;         ///< transform_8x8_mode_flag
    uint8_t scaling_matrix4[6][16];
    uint8_t scaling_matrix8[6][64];
    uint8_t chroma_qp_table[2][QP_MAX_NUM+1];  ///< pre-scaled (with chroma_qp_index_offset) version of qp_table
    int chroma_qp_diff;
} PPS;

/**
 * Memory management control operation opcode.
 */
typedef enum MMCOOpcode {
    MMCO_END = 0,
    MMCO_SHORT2UNUSED,
    MMCO_LONG2UNUSED,
    MMCO_SHORT2LONG,
    MMCO_SET_MAX_LONG,
    MMCO_RESET,
    MMCO_LONG,
} MMCOOpcode;

/**
 * Memory management control operation.
 */
typedef struct MMCO {
    MMCOOpcode opcode;
    int short_pic_num;  ///< pic_num without wrapping (pic_num & max_pic_num)
    int long_arg;       ///< index, pic_num, or num long refs depending on opcode
} MMCO;

/**
 * H264Context
 */
typedef struct H264Context {
    MpegEncContext s;
    H264DSPContext h264dsp;
    int pixel_shift;    ///< 0 for 8-bit H264, 1 for high-bit-depth H264
    int chroma_qp[2];   // QPc

    int qp_thresh;      ///< QP threshold to skip loopfilter

    int prev_mb_skipped;
    int next_mb_skipped;

    // prediction stuff
    int chroma_pred_mode;
    int intra16x16_pred_mode;

    int topleft_mb_xy;
    int top_mb_xy;
    int topright_mb_xy;
    int left_mb_xy[LEFT_MBS];

    int topleft_type;
    int top_type;
    int topright_type;
    int left_type[LEFT_MBS];

    const uint8_t *left_block;
    int topleft_partition;

    int8_t intra4x4_pred_mode_cache[5 * 8];
    int8_t(*intra4x4_pred_mode);
    H264PredContext hpc;
    unsigned int topleft_samples_available;
    unsigned int top_samples_available;
    unsigned int topright_samples_available;
    unsigned int left_samples_available;
    uint8_t (*top_borders[2])[(16 * 3) * 2];

    /**
     * non zero coeff count cache.
     * is 64 if not available.
     */
    DECLARE_ALIGNED(8, uint8_t, non_zero_count_cache)[15 * 8];

    uint8_t (*non_zero_count)[48];

    /**
     * Motion vector cache.
     */
    DECLARE_ALIGNED(16, int16_t, mv_cache)[2][5 * 8][2];
    DECLARE_ALIGNED(8, int8_t, ref_cache)[2][5 * 8];
#define LIST_NOT_USED -1 // FIXME rename?
#define PART_NOT_AVAILABLE -2

    /**
     * number of neighbors (top and/or left) that used 8x8 dct
     */
    int neighbor_transform_size;

    /**
     * block_offset[ 0..23] for frame macroblocks
     * block_offset[24..47] for field macroblocks
     */
    int block_offset[2 * (16 * 3)];

    uint32_t *mb2b_xy;  // FIXME are these 4 a good idea?
    uint32_t *mb2br_xy;
    int b_stride;       // FIXME use s->b4_stride

    int mb_linesize;    ///< may be equal to s->linesize or s->linesize * 2, for mbaff
    int mb_uvlinesize;

    int emu_edge_width;
    int emu_edge_height;

    SPS sps; ///< current sps

    /**
     * current pps
     */
    PPS pps; // FIXME move to Picture perhaps? (->no) do we need that?

    uint32_t dequant4_buffer[6][QP_MAX_NUM + 1][16]; // FIXME should these be moved down?
    uint32_t dequant8_buffer[6][QP_MAX_NUM + 1][64];
    uint32_t(*dequant4_coeff[6])[16];
    uint32_t(*dequant8_coeff[6])[64];

    int slice_num;
    uint16_t *slice_table;      ///< slice_table_base + 2*mb_stride + 1
    int slice_type;
    int slice_type_nos;         ///< S free slice type (SI/SP are remapped to I/P)
    int slice_type_fixed;

    // interlacing specific flags
    int mb_aff_frame;
    int mb_field_decoding_flag;
    int mb_mbaff;               ///< mb_aff_frame && mb_field_decoding_flag

    DECLARE_ALIGNED(8, uint16_t, sub_mb_type)[4];

    // Weighted pred stuff
    int use_weight;
    int use_weight_chroma;
    int luma_log2_weight_denom;
    int chroma_log2_weight_denom;
    // The following 2 can be changed to int8_t but that causes 10cpu cycles speedloss
    int luma_weight[48][2][2];
    int chroma_weight[48][2][2][2];
    int implicit_weight[48][48][2];

    int direct_spatial_mv_pred;
    int col_parity;
    int col_fieldoff;
    int dist_scale_factor[16];
    int dist_scale_factor_field[2][32];
    int map_col_to_list0[2][16 + 32];
    int map_col_to_list0_field[2][2][16 + 32];

    /**
     * num_ref_idx_l0/1_active_minus1 + 1
     */
    unsigned int ref_count[2];          ///< counts frames or fields, depending on current mb mode
    unsigned int list_count;
    uint8_t *list_counts;               ///< Array of list_count per MB specifying the slice type
    Picture ref_list[2][48];            /**< 0..15: frame refs, 16..47: mbaff field refs.
                                         *   Reordered version of default_ref_list
                                         *   according to picture reordering in slice header */
    int ref2frm[MAX_SLICES][2][64];     ///< reference to frame number lists, used in the loop filter, the first 2 are for -2,-1

    // data partitioning
    GetBitContext intra_gb;
    GetBitContext inter_gb;
    GetBitContext *intra_gb_ptr;
    GetBitContext *inter_gb_ptr;

    DECLARE_ALIGNED(16, DCTELEM, mb)[16 * 48 * 2]; ///< as a dct coeffecient is int32_t in high depth, we need to reserve twice the space.
    DECLARE_ALIGNED(16, DCTELEM, mb_luma_dc)[3][16 * 2];
    DCTELEM mb_padding[256 * 2];        ///< as mb is addressed by scantable[i] and scantable is uint8_t we can either check that i is not too large or ensure that there is some unused stuff after mb

    /**
     * Cabac
     */
    CABACContext cabac;
    uint8_t cabac_state[1024];

    /* 0x100 -> non null luma_dc, 0x80/0x40 -> non null chroma_dc (cb/cr), 0x?0 -> chroma_cbp(0, 1, 2), 0x0? luma_cbp */
    uint16_t *cbp_table;
    int cbp;
    int top_cbp;
    int left_cbp;
    /* chroma_pred_mode for i4x4 or i16x16, else 0 */
    uint8_t *chroma_pred_mode_table;
    int last_qscale_diff;
    uint8_t (*mvd_table[2])[2];
    DECLARE_ALIGNED(16, uint8_t, mvd_cache)[2][5 * 8][2];
    uint8_t *direct_table;
    uint8_t direct_cache[5 * 8];

    uint8_t zigzag_scan[16];
    uint8_t zigzag_scan8x8[64];
    uint8_t zigzag_scan8x8_cavlc[64];
    uint8_t field_scan[16];
    uint8_t field_scan8x8[64];
    uint8_t field_scan8x8_cavlc[64];
    uint8_t zigzag_scan_q0[16];
    uint8_t zigzag_scan8x8_q0[64];
    uint8_t zigzag_scan8x8_cavlc_q0[64];
    uint8_t field_scan_q0[16];
    uint8_t field_scan8x8_q0[64];
    uint8_t field_scan8x8_cavlc_q0[64];

    int x264_build;

    int mb_xy;

    int is_complex;

    // deblock
    int deblocking_filter;          ///< disable_deblocking_filter_idc with 1 <-> 0
    int slice_alpha_c0_offset;
    int slice_beta_offset;

    // =============================================================
    // Things below are not used in the MB or more inner code

    int nal_ref_idc;
    int nal_unit_type;
    uint8_t *rbsp_buffer[2];
    unsigned int rbsp_buffer_size[2];

    /**
     * Used to parse AVC variant of h264
     */
    int is_avc;           ///< this flag is != 0 if codec is avc1
    int nal_length_size;  ///< Number of bytes used for nal length (1, 2 or 4)
    int got_first;        ///< this flag is != 0 if we've parsed a frame

    SPS *sps_buffers[MAX_SPS_COUNT];
    PPS *pps_buffers[MAX_PPS_COUNT];

    int dequant_coeff_pps;      ///< reinit tables when pps changes

    uint16_t *slice_table_base;

    // POC stuff
    int poc_lsb;
    int poc_msb;
    int delta_poc_bottom;
    int delta_poc[2];
    int frame_num;
    int prev_poc_msb;           ///< poc_msb of the last reference pic for POC type 0
    int prev_poc_lsb;           ///< poc_lsb of the last reference pic for POC type 0
    int frame_num_offset;       ///< for POC type 2
    int prev_frame_num_offset;  ///< for POC type 2
    int prev_frame_num;         ///< frame_num of the last pic for POC type 1/2

    /**
     * frame_num for frames or 2 * frame_num + 1 for field pics.
     */
    int curr_pic_num;

    /**
     * max_frame_num or 2 * max_frame_num for field pics.
     */
    int max_pic_num;

    int redundant_pic_count;

    Picture *short_ref[32];
    Picture *long_ref[32];
    Picture default_ref_list[2][32]; ///< base reference list for all slices of a coded picture
    Picture *delayed_pic[MAX_DELAYED_PIC_COUNT + 2]; // FIXME size?
    int last_pocs[MAX_DELAYED_PIC_COUNT];
    Picture *next_output_pic;
    int outputed_poc;
    int next_outputed_poc;

    /**
     * memory management control operations buffer.
     */
    MMCO mmco[MAX_MMCO_COUNT];
    int mmco_index;
    int mmco_reset;

    int long_ref_count;     ///< number of actual long term references
    int short_ref_count;    ///< number of actual short term references

    int cabac_init_idc;

    /**
     * @name Members for slice based multithreading
     * @{
     */
    struct H264Context *thread_context[MAX_THREADS];

    /**
     * current slice number, used to initialize slice_num of each thread/context
     */
    int current_slice;

    /**
     * Max number of threads / contexts.
     * This is equal to AVCodecContext.thread_count unless
     * multithreaded decoding is impossible, in which case it is
     * reduced to 1.
     */
    int max_contexts;

    /**
     *  1 if the single thread fallback warning has already been
     *  displayed, 0 otherwise.
     */
    int single_decode_warning;

    int last_slice_type;
    /** @} */

    /**
     * pic_struct in picture timing SEI message
     */
    SEI_PicStructType sei_pic_struct;

    /**
     * Complement sei_pic_struct
     * SEI_PIC_STRUCT_TOP_BOTTOM and SEI_PIC_STRUCT_BOTTOM_TOP indicate interlaced frames.
     * However, soft telecined frames may have these values.
     * This is used in an attempt to flag soft telecine progressive.
     */
    int prev_interlaced_frame;

    /**
     * Bit set of clock types for fields/frames in picture timing SEI message.
     * For each found ct_type, appropriate bit is set (e.g., bit 1 for
     * interlaced).
     */
    int sei_ct_type;

    /**
     * dpb_output_delay in picture timing SEI message, see H.264 C.2.2
     */
    int sei_dpb_output_delay;

    /**
     * cpb_removal_delay in picture timing SEI message, see H.264 C.1.2
     */
    int sei_cpb_removal_delay;

    /**
     * recovery_frame_cnt from SEI message
     *
     * Set to -1 if no recovery point SEI message found or to number of frames
     * before playback synchronizes. Frames having recovery point are key
     * frames.
     */
    int sei_recovery_frame_cnt;
    /**
     * recovery_frame is the frame_num at which the next frame should
     * be fully constructed.
     *
     * Set to -1 when not expecting a recovery point.
     */
    int recovery_frame;

    /**
     * Are the SEI recovery points looking valid.
     */
    int valid_recovery_point;

    int luma_weight_flag[2];    ///< 7.4.3.2 luma_weight_lX_flag
    int chroma_weight_flag[2];  ///< 7.4.3.2 chroma_weight_lX_flag

    // Timestamp stuff
    int sei_buffering_period_present;   ///< Buffering period SEI flag
    int initial_cpb_removal_delay[32];  ///< Initial timestamps for CPBs

    int cur_chroma_format_idc;

    int16_t slice_row[MAX_SLICES]; ///< to detect when MAX_SLICES is too low

    int sync;                      ///< did we had a keyframe or recovery point

    uint8_t parse_history[4];
    int parse_history_count;
    int parse_last_mb;
} H264Context;

extern const uint8_t ff_h264_chroma_qp[7][QP_MAX_NUM + 1]; ///< One chroma qp table for each possible bit depth (8-14).
extern const uint16_t ff_h264_mb_sizes[4];

/**
 * Decode SEI
 */
int ff_h264_decode_sei(H264Context *h);

/**
 * Decode SPS
 */
int ff_h264_decode_seq_parameter_set(H264Context *h);

/**
 * compute profile from sps
 */
int ff_h264_get_profile(SPS *sps);

/**
 * Decode PPS
 */
int ff_h264_decode_picture_parameter_set(H264Context *h, int bit_length);

/**
 * Decode a network abstraction layer unit.
 * @param consumed is the number of bytes used as input
 * @param length is the length of the array
 * @param dst_length is the number of decoded bytes FIXME here
 *                   or a decode rbsp tailing?
 * @return decoded bytes, might be src+1 if no escapes
 */
const uint8_t *ff_h264_decode_nal(H264Context *h, const uint8_t *src,
                                  int *dst_length, int *consumed, int length);

/**
 * Free any data that may have been allocated in the H264 context
 * like SPS, PPS etc.
 */
av_cold void ff_h264_free_context(H264Context *h);

/**
 * Reconstruct bitstream slice_type.
 */
int ff_h264_get_slice_type(const H264Context *h);

/**
 * Allocate tables.
 * needs width/height
 */
int ff_h264_alloc_tables(H264Context *h);

/**
 * Fill the default_ref_list.
 */
int ff_h264_fill_default_ref_list(H264Context *h);

int ff_h264_decode_ref_pic_list_reordering(H264Context *h);
void ff_h264_fill_mbaff_ref_list(H264Context *h);
void ff_h264_remove_all_refs(H264Context *h);

/**
 * Execute the reference picture marking (memory management control operations).
 */
int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count);

int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb);

void ff_generate_sliding_window_mmcos(H264Context *h);

/**
 * Check if the top & left blocks are available if needed & change the
 * dc mode so it only uses the available blocks.
 */
int ff_h264_check_intra4x4_pred_mode(H264Context *h);

/**
 * Check if the top & left blocks are available if needed & change the
 * dc mode so it only uses the available blocks.
 */
int ff_h264_check_intra_pred_mode(H264Context *h, int mode, int is_chroma);

void ff_h264_hl_decode_mb(H264Context *h);
int ff_h264_frame_start(H264Context *h);
int ff_h264_decode_extradata(H264Context *h, const uint8_t *buf, int size);
av_cold int ff_h264_decode_init(AVCodecContext *avctx);
av_cold void ff_h264_decode_init_vlc(void);

/**
 * Decode a macroblock
 * @return 0 if OK, ER_AC_ERROR / ER_DC_ERROR / ER_MV_ERROR on error
 */
int ff_h264_decode_mb_cavlc(H264Context *h);

/**
 * Decode a CABAC coded macroblock
 * @return 0 if OK, ER_AC_ERROR / ER_DC_ERROR / ER_MV_ERROR on error
 */
int ff_h264_decode_mb_cabac(H264Context *h);

void ff_h264_init_cabac_states(H264Context *h);

void ff_h264_direct_dist_scale_factor(H264Context *const h);
void ff_h264_direct_ref_list_init(H264Context *const h);
void ff_h264_pred_direct_motion(H264Context *const h, int *mb_type);

void ff_h264_filter_mb_fast(H264Context *h, int mb_x, int mb_y,
                            uint8_t *img_y, uint8_t *img_cb, uint8_t *img_cr,
                            unsigned int linesize, unsigned int uvlinesize);
void ff_h264_filter_mb(H264Context *h, int mb_x, int mb_y,
                       uint8_t *img_y, uint8_t *img_cb, uint8_t *img_cr,
                       unsigned int linesize, unsigned int uvlinesize);

/**
 * Reset SEI values at the beginning of the frame.
 *
 * @param h H.264 context.
 */
void ff_h264_reset_sei(H264Context *h);

/*
 * o-o o-o
 *  / / /
 * o-o o-o
 *  ,---'
 * o-o o-o
 *  / / /
 * o-o o-o
 */

/* Scan8 organization:
 *    0 1 2 3 4 5 6 7
 * 0  DY    y y y y y
 * 1        y Y Y Y Y
 * 2        y Y Y Y Y
 * 3        y Y Y Y Y
 * 4        y Y Y Y Y
 * 5  DU    u u u u u
 * 6        u U U U U
 * 7        u U U U U
 * 8        u U U U U
 * 9        u U U U U
 * 10 DV    v v v v v
 * 11       v V V V V
 * 12       v V V V V
 * 13       v V V V V
 * 14       v V V V V
 * DY/DU/DV are for luma/chroma DC.
 */

#define LUMA_DC_BLOCK_INDEX   48
#define CHROMA_DC_BLOCK_INDEX 49

// This table must be here because scan8[constant] must be known at compiletime
static const uint8_t scan8[16 * 3 + 3] = {
    4 +  1 * 8, 5 +  1 * 8, 4 +  2 * 8, 5 +  2 * 8,
    6 +  1 * 8, 7 +  1 * 8, 6 +  2 * 8, 7 +  2 * 8,
    4 +  3 * 8, 5 +  3 * 8, 4 +  4 * 8, 5 +  4 * 8,
    6 +  3 * 8, 7 +  3 * 8, 6 +  4 * 8, 7 +  4 * 8,
    4 +  6 * 8, 5 +  6 * 8, 4 +  7 * 8, 5 +  7 * 8,
    6 +  6 * 8, 7 +  6 * 8, 6 +  7 * 8, 7 +  7 * 8,
    4 +  8 * 8, 5 +  8 * 8, 4 +  9 * 8, 5 +  9 * 8,
    6 +  8 * 8, 7 +  8 * 8, 6 +  9 * 8, 7 +  9 * 8,
    4 + 11 * 8, 5 + 11 * 8, 4 + 12 * 8, 5 + 12 * 8,
    6 + 11 * 8, 7 + 11 * 8, 6 + 12 * 8, 7 + 12 * 8,
    4 + 13 * 8, 5 + 13 * 8, 4 + 14 * 8, 5 + 14 * 8,
    6 + 13 * 8, 7 + 13 * 8, 6 + 14 * 8, 7 + 14 * 8,
    0 +  0 * 8, 0 +  5 * 8, 0 + 10 * 8
};

static av_always_inline uint32_t pack16to32(int a, int b)
{
#if HAVE_BIGENDIAN
    return (b & 0xFFFF) + (a << 16);
#else
    return (a & 0xFFFF) + (b << 16);
#endif
}

static av_always_inline uint16_t pack8to16(int a, int b)
{
#if HAVE_BIGENDIAN
    return (b & 0xFF) + (a << 8);
#else
    return (a & 0xFF) + (b << 8);
#endif
}

/**
 * Get the chroma qp.
 */
static av_always_inline int get_chroma_qp(H264Context *h, int t, int qscale)
{
    return h->pps.chroma_qp_table[t][qscale];
}

/**
 * Get the predicted intra4x4 prediction mode.
 */
static av_always_inline int pred_intra_mode(H264Context *h, int n)
{
    const int index8 = scan8[n];
    const int left   = h->intra4x4_pred_mode_cache[index8 - 1];
    const int top    = h->intra4x4_pred_mode_cache[index8 - 8];
    const int min    = FFMIN(left, top);

    tprintf(h->s.avctx, "mode:%d %d min:%d\n", left, top, min);

    if (min < 0)
        return DC_PRED;
    else
        return min;
}

static av_always_inline void write_back_intra_pred_mode(H264Context *h)
{
    int8_t *i4x4       = h->intra4x4_pred_mode + h->mb2br_xy[h->mb_xy];
    int8_t *i4x4_cache = h->intra4x4_pred_mode_cache;

    AV_COPY32(i4x4, i4x4_cache + 4 + 8 * 4);
    i4x4[4] = i4x4_cache[7 + 8 * 3];
    i4x4[5] = i4x4_cache[7 + 8 * 2];
    i4x4[6] = i4x4_cache[7 + 8 * 1];
}

static av_always_inline void write_back_non_zero_count(H264Context *h)
{
    const int mb_xy    = h->mb_xy;
    uint8_t *nnz       = h->non_zero_count[mb_xy];
    uint8_t *nnz_cache = h->non_zero_count_cache;

    AV_COPY32(&nnz[ 0], &nnz_cache[4 + 8 * 1]);
    AV_COPY32(&nnz[ 4], &nnz_cache[4 + 8 * 2]);
    AV_COPY32(&nnz[ 8], &nnz_cache[4 + 8 * 3]);
    AV_COPY32(&nnz[12], &nnz_cache[4 + 8 * 4]);
    AV_COPY32(&nnz[16], &nnz_cache[4 + 8 * 6]);
    AV_COPY32(&nnz[20], &nnz_cache[4 + 8 * 7]);
    AV_COPY32(&nnz[32], &nnz_cache[4 + 8 * 11]);
    AV_COPY32(&nnz[36], &nnz_cache[4 + 8 * 12]);

    if (!h->s.chroma_y_shift) {
        AV_COPY32(&nnz[24], &nnz_cache[4 + 8 * 8]);
        AV_COPY32(&nnz[28], &nnz_cache[4 + 8 * 9]);
        AV_COPY32(&nnz[40], &nnz_cache[4 + 8 * 13]);
        AV_COPY32(&nnz[44], &nnz_cache[4 + 8 * 14]);
    }
}

static av_always_inline void write_back_motion_list(H264Context *h,
                                                    MpegEncContext *const s,
                                                    int b_stride,
                                                    int b_xy, int b8_xy,
                                                    int mb_type, int list)
{
    int16_t(*mv_dst)[2] = &s->current_picture.f.motion_val[list][b_xy];
    int16_t(*mv_src)[2] = &h->mv_cache[list][scan8[0]];
    AV_COPY128(mv_dst + 0 * b_stride, mv_src + 8 * 0);
    AV_COPY128(mv_dst + 1 * b_stride, mv_src + 8 * 1);
    AV_COPY128(mv_dst + 2 * b_stride, mv_src + 8 * 2);
    AV_COPY128(mv_dst + 3 * b_stride, mv_src + 8 * 3);
    if (CABAC) {
        uint8_t (*mvd_dst)[2] = &h->mvd_table[list][FMO ? 8 * h->mb_xy
                                                        : h->mb2br_xy[h->mb_xy]];
        uint8_t(*mvd_src)[2]  = &h->mvd_cache[list][scan8[0]];
        if (IS_SKIP(mb_type)) {
            AV_ZERO128(mvd_dst);
        } else {
            AV_COPY64(mvd_dst, mvd_src + 8 * 3);
            AV_COPY16(mvd_dst + 3 + 3, mvd_src + 3 + 8 * 0);
            AV_COPY16(mvd_dst + 3 + 2, mvd_src + 3 + 8 * 1);
            AV_COPY16(mvd_dst + 3 + 1, mvd_src + 3 + 8 * 2);
        }
    }

    {
        int8_t *ref_index = &s->current_picture.f.ref_index[list][b8_xy];
        int8_t *ref_cache = h->ref_cache[list];
        ref_index[0 + 0 * 2] = ref_cache[scan8[0]];
        ref_index[1 + 0 * 2] = ref_cache[scan8[4]];
        ref_index[0 + 1 * 2] = ref_cache[scan8[8]];
        ref_index[1 + 1 * 2] = ref_cache[scan8[12]];
    }
}

static av_always_inline void write_back_motion(H264Context *h, int mb_type)
{
    MpegEncContext *const s = &h->s;
    const int b_stride      = h->b_stride;
    const int b_xy  = 4 * s->mb_x + 4 * s->mb_y * h->b_stride; // try mb2b(8)_xy
    const int b8_xy = 4 * h->mb_xy;

    if (USES_LIST(mb_type, 0)) {
        write_back_motion_list(h, s, b_stride, b_xy, b8_xy, mb_type, 0);
    } else {
        fill_rectangle(&s->current_picture.f.ref_index[0][b8_xy],
                       2, 2, 2, (uint8_t)LIST_NOT_USED, 1);
    }
    if (USES_LIST(mb_type, 1))
        write_back_motion_list(h, s, b_stride, b_xy, b8_xy, mb_type, 1);

    if (h->slice_type_nos == AV_PICTURE_TYPE_B && CABAC) {
        if (IS_8X8(mb_type)) {
            uint8_t *direct_table = &h->direct_table[4 * h->mb_xy];
            direct_table[1] = h->sub_mb_type[1] >> 1;
            direct_table[2] = h->sub_mb_type[2] >> 1;
            direct_table[3] = h->sub_mb_type[3] >> 1;
        }
    }
}

static av_always_inline int get_dct8x8_allowed(H264Context *h)
{
    if (h->sps.direct_8x8_inference_flag)
        return !(AV_RN64A(h->sub_mb_type) &
                 ((MB_TYPE_16x8 | MB_TYPE_8x16 | MB_TYPE_8x8) *
                  0x0001000100010001ULL));
    else
        return !(AV_RN64A(h->sub_mb_type) &
                 ((MB_TYPE_16x8 | MB_TYPE_8x16 | MB_TYPE_8x8 | MB_TYPE_DIRECT2) *
                  0x0001000100010001ULL));
}

#endif /* AVCODEC_H264_H */