aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/mpeg12enc.c
blob: 2db1d93d0ead3004a950f5443e3fa6653c69af27 (plain) (blame)
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
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
/*
 * MPEG-1/2 encoder
 * Copyright (c) 2000,2001 Fabrice Bellard
 * Copyright (c) 2002-2004 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
 * MPEG-1/2 encoder
 */

#include <stdint.h>

#include "config.h"
#include "config_components.h"
#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/thread.h"
#include "libavutil/timecode.h"
#include "libavutil/stereo3d.h"

#include "avcodec.h"
#include "codec_internal.h"
#include "mathops.h"
#include "mpeg12.h"
#include "mpeg12data.h"
#include "mpeg12enc.h"
#include "mpeg12vlc.h"
#include "mpegutils.h"
#include "mpegvideo.h"
#include "mpegvideodata.h"
#include "mpegvideoenc.h"
#include "profiles.h"
#include "rl.h"

#if CONFIG_MPEG1VIDEO_ENCODER || CONFIG_MPEG2VIDEO_ENCODER
static const uint8_t svcd_scan_offset_placeholder[] = {
    0x10, 0x0E, 0x00, 0x80, 0x81, 0x00, 0x80,
    0x81, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};

static uint8_t mv_penalty[MAX_FCODE + 1][MAX_DMV * 2 + 1];
static uint8_t fcode_tab[MAX_MV * 2 + 1];

static uint8_t uni_mpeg1_ac_vlc_len[64 * 64 * 2];
static uint8_t uni_mpeg2_ac_vlc_len[64 * 64 * 2];

static uint8_t mpeg12_max_level[MAX_LEVEL + 1];
static uint8_t mpeg12_index_run[MAX_RUN   + 1];

/* simple include everything table for dc, first byte is bits
 * number next 3 are code */
static uint32_t mpeg1_lum_dc_uni[512];
static uint32_t mpeg1_chr_dc_uni[512];

typedef struct MPEG12EncContext {
    MpegEncContext mpeg;
    AVRational frame_rate_ext;
    unsigned frame_rate_index;

    int gop_picture_number;  ///< index of the first picture of a GOP based on fake_pic_num

    int64_t timecode_frame_start; ///< GOP timecode frame start number, in non drop frame format
    AVTimecode tc;           ///< timecode context
    char *tc_opt_str;        ///< timecode option string
    int drop_frame_timecode; ///< timecode is in drop frame format.
    int scan_offset;         ///< reserve space for SVCD scan offset user data.

    int a53_cc;
    int seq_disp_ext;
    int video_format;
#define VIDEO_FORMAT_COMPONENT   0
#define VIDEO_FORMAT_PAL         1
#define VIDEO_FORMAT_NTSC        2
#define VIDEO_FORMAT_SECAM       3
#define VIDEO_FORMAT_MAC         4
#define VIDEO_FORMAT_UNSPECIFIED 5
} MPEG12EncContext;

#define A53_MAX_CC_COUNT 0x1f
#endif /* CONFIG_MPEG1VIDEO_ENCODER || CONFIG_MPEG2VIDEO_ENCODER */

av_cold void ff_mpeg1_init_uni_ac_vlc(const int8_t max_level[],
                                      const uint8_t index_run[],
                                      const uint16_t table_vlc[][2],
                                      uint8_t uni_ac_vlc_len[])
{
    int i;

    for (i = 0; i < 128; i++) {
        int level = i - 64;
        int run;
        if (!level)
            continue;
        for (run = 0; run < 64; run++) {
            int len, code;
            int alevel = FFABS(level);

            if (alevel > max_level[run])
                code = 111;                         /* rl->n */
            else
                code = index_run[run] + alevel - 1;

            if (code < 111) {                       /* rl->n */
                /* length of VLC and sign */
                len = table_vlc[code][1] + 1;
            } else {
                len = table_vlc[MPEG12_RL_NB_ELEMS][1] + 6;

                if (alevel < 128)
                    len += 8;
                else
                    len += 16;
            }

            uni_ac_vlc_len[UNI_AC_ENC_INDEX(run, i)] = len;
        }
    }
}

#if CONFIG_MPEG1VIDEO_ENCODER || CONFIG_MPEG2VIDEO_ENCODER
static int find_frame_rate_index(MPEG12EncContext *mpeg12)
{
    MpegEncContext *const s = &mpeg12->mpeg;
    int i;
    AVRational bestq = (AVRational) {0, 0};
    AVRational ext;
    AVRational target = av_inv_q(s->avctx->time_base);

    for (i = 1; i < 14; i++) {
        if (s->avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL &&
            i >= 9)
            break;

        for (ext.num=1; ext.num <= 4; ext.num++) {
            for (ext.den=1; ext.den <= 32; ext.den++) {
                AVRational q = av_mul_q(ext, ff_mpeg12_frame_rate_tab[i]);

                if (s->codec_id != AV_CODEC_ID_MPEG2VIDEO && (ext.den!=1 || ext.num!=1))
                    continue;
                if (av_gcd(ext.den, ext.num) != 1)
                    continue;

                if (    bestq.num==0
                    || av_nearer_q(target, bestq, q) < 0
                    || ext.num==1 && ext.den==1 && av_nearer_q(target, bestq, q) == 0) {
                    bestq               = q;
                    mpeg12->frame_rate_index   = i;
                    mpeg12->frame_rate_ext.num = ext.num;
                    mpeg12->frame_rate_ext.den = ext.den;
                }
            }
        }
    }

    if (av_cmp_q(target, bestq))
        return -1;
    else
        return 0;
}

static av_cold int encode_init(AVCodecContext *avctx)
{
    MPEG12EncContext *const mpeg12 = avctx->priv_data;
    MpegEncContext *const s = &mpeg12->mpeg;
    int ret;
    int max_size = avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO ? 16383 : 4095;

    if (avctx->width > max_size || avctx->height > max_size) {
        av_log(avctx, AV_LOG_ERROR, "%s does not support resolutions above %dx%d\n",
               CONFIG_SMALL ? avctx->codec->name : avctx->codec->long_name,
               max_size, max_size);
        return AVERROR(EINVAL);
    }
    if ((avctx->width & 0xFFF) == 0 && (avctx->height & 0xFFF) == 1) {
        av_log(avctx, AV_LOG_ERROR, "Width / Height is invalid for MPEG2\n");
        return AVERROR(EINVAL);
    }

    if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
        if ((avctx->width & 0xFFF) == 0 || (avctx->height & 0xFFF) == 0) {
            av_log(avctx, AV_LOG_ERROR, "Width or Height are not allowed to be multiples of 4096\n"
                                        "add '-strict %d' if you want to use them anyway.\n", FF_COMPLIANCE_UNOFFICIAL);
            return AVERROR(EINVAL);
        }
    }

    if (avctx->profile == FF_PROFILE_UNKNOWN) {
        if (avctx->level != FF_LEVEL_UNKNOWN) {
            av_log(avctx, AV_LOG_ERROR, "Set profile and level\n");
            return AVERROR(EINVAL);
        }
        /* Main or 4:2:2 */
        avctx->profile = avctx->pix_fmt == AV_PIX_FMT_YUV420P ? FF_PROFILE_MPEG2_MAIN
                                                              : FF_PROFILE_MPEG2_422;
    }
    if (avctx->level == FF_LEVEL_UNKNOWN) {
        if (avctx->profile == FF_PROFILE_MPEG2_422) {   /* 4:2:2 */
            if (avctx->width <= 720 && avctx->height <= 608)
                avctx->level = 5;                   /* Main */
            else
                avctx->level = 2;                   /* High */
        } else {
            if (avctx->profile != FF_PROFILE_MPEG2_HIGH &&
                avctx->pix_fmt != AV_PIX_FMT_YUV420P) {
                av_log(avctx, AV_LOG_ERROR,
                       "Only High(1) and 4:2:2(0) profiles support 4:2:2 color sampling\n");
                return AVERROR(EINVAL);
            }
            if (avctx->width <= 720 && avctx->height <= 576)
                avctx->level = 8;                   /* Main */
            else if (avctx->width <= 1440)
                avctx->level = 6;                   /* High 1440 */
            else
                avctx->level = 4;                   /* High */
        }
    }

    if ((ret = ff_mpv_encode_init(avctx)) < 0)
        return ret;

    if (find_frame_rate_index(mpeg12) < 0) {
        if (avctx->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
            av_log(avctx, AV_LOG_ERROR, "MPEG-1/2 does not support %d/%d fps\n",
                   avctx->time_base.den, avctx->time_base.num);
            return AVERROR(EINVAL);
        } else {
            av_log(avctx, AV_LOG_INFO,
                   "MPEG-1/2 does not support %d/%d fps, there may be AV sync issues\n",
                   avctx->time_base.den, avctx->time_base.num);
        }
    }

    mpeg12->drop_frame_timecode = mpeg12->drop_frame_timecode || !!(avctx->flags2 & AV_CODEC_FLAG2_DROP_FRAME_TIMECODE);
    if (mpeg12->drop_frame_timecode)
        mpeg12->tc.flags |= AV_TIMECODE_FLAG_DROPFRAME;
    if (mpeg12->drop_frame_timecode && mpeg12->frame_rate_index != 4) {
        av_log(avctx, AV_LOG_ERROR,
               "Drop frame time code only allowed with 1001/30000 fps\n");
        return AVERROR(EINVAL);
    }

    if (mpeg12->tc_opt_str) {
        AVRational rate = ff_mpeg12_frame_rate_tab[mpeg12->frame_rate_index];
        int ret = av_timecode_init_from_string(&mpeg12->tc, rate, mpeg12->tc_opt_str, s);
        if (ret < 0)
            return ret;
        mpeg12->drop_frame_timecode  = !!(mpeg12->tc.flags & AV_TIMECODE_FLAG_DROPFRAME);
        mpeg12->timecode_frame_start = mpeg12->tc.start;
    } else {
        mpeg12->timecode_frame_start = 0; // default is -1
    }

    return 0;
}

static void put_header(MpegEncContext *s, int header)
{
    align_put_bits(&s->pb);
    put_bits(&s->pb, 16, header >> 16);
    put_sbits(&s->pb, 16, header);
}

/* put sequence header if needed */
static void mpeg1_encode_sequence_header(MpegEncContext *s)
{
    MPEG12EncContext *const mpeg12 = (MPEG12EncContext*)s;
    unsigned int vbv_buffer_size, fps, v;
    int constraint_parameter_flag;
    AVRational framerate = ff_mpeg12_frame_rate_tab[mpeg12->frame_rate_index];
    uint64_t time_code;
    int64_t best_aspect_error = INT64_MAX;
    AVRational aspect_ratio = s->avctx->sample_aspect_ratio;
    int aspect_ratio_info;

    if (!s->current_picture.f->key_frame)
        return;

    if (aspect_ratio.num == 0 || aspect_ratio.den == 0)
        aspect_ratio = (AVRational){1,1};             // pixel aspect 1.1 (VGA)

    /* MPEG-1 header repeated every GOP */
    put_header(s, SEQ_START_CODE);

    put_sbits(&s->pb, 12, s->width  & 0xFFF);
    put_sbits(&s->pb, 12, s->height & 0xFFF);

    for (int i = 1; i < 15; i++) {
        int64_t error = aspect_ratio.num * (1LL<<32) / aspect_ratio.den;
        if (s->codec_id == AV_CODEC_ID_MPEG1VIDEO || i <= 1)
            error -= (1LL<<32) / ff_mpeg1_aspect[i];
        else
            error -= (1LL<<32)*ff_mpeg2_aspect[i].num * s->height / s->width / ff_mpeg2_aspect[i].den;

        error = FFABS(error);

        if (error - 2 <= best_aspect_error) {
            best_aspect_error = error;
            aspect_ratio_info = i;
        }
    }

    put_bits(&s->pb, 4, aspect_ratio_info);
    put_bits(&s->pb, 4, mpeg12->frame_rate_index);

    if (s->avctx->rc_max_rate) {
        v = (s->avctx->rc_max_rate + 399) / 400;
        if (v > 0x3ffff && s->codec_id == AV_CODEC_ID_MPEG1VIDEO)
            v = 0x3ffff;
    } else {
        v = 0x3FFFF;
    }

    if (s->avctx->rc_buffer_size)
        vbv_buffer_size = s->avctx->rc_buffer_size;
    else
        /* VBV calculation: Scaled so that a VCD has the proper
         * VBV size of 40 kilobytes */
        vbv_buffer_size = ((20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;
    vbv_buffer_size = (vbv_buffer_size + 16383) / 16384;

    put_sbits(&s->pb, 18, v);
    put_bits(&s->pb, 1, 1);         // marker
    put_sbits(&s->pb, 10, vbv_buffer_size);

    constraint_parameter_flag =
        s->width  <= 768                                    &&
        s->height <= 576                                    &&
        s->mb_width * s->mb_height                 <= 396   &&
        s->mb_width * s->mb_height * framerate.num <= 396 * 25 * framerate.den &&
        framerate.num <= framerate.den * 30                 &&
        s->avctx->me_range                                  &&
        s->avctx->me_range < 128                            &&
        vbv_buffer_size <= 20                               &&
        v <= 1856000 / 400                                  &&
        s->codec_id == AV_CODEC_ID_MPEG1VIDEO;

    put_bits(&s->pb, 1, constraint_parameter_flag);

    ff_write_quant_matrix(&s->pb, s->avctx->intra_matrix);
    ff_write_quant_matrix(&s->pb, s->avctx->inter_matrix);

    if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
        const AVFrameSideData *side_data;
        int width = s->width;
        int height = s->height;
        int use_seq_disp_ext;

        put_header(s, EXT_START_CODE);
        put_bits(&s->pb, 4, 1);                 // seq ext

        put_bits(&s->pb, 1, s->avctx->profile == FF_PROFILE_MPEG2_422); // escx 1 for 4:2:2 profile

        put_bits(&s->pb, 3, s->avctx->profile); // profile
        put_bits(&s->pb, 4, s->avctx->level);   // level

        put_bits(&s->pb, 1, s->progressive_sequence);
        put_bits(&s->pb, 2, s->chroma_format);
        put_bits(&s->pb, 2, s->width  >> 12);
        put_bits(&s->pb, 2, s->height >> 12);
        put_bits(&s->pb, 12, v >> 18);          // bitrate ext
        put_bits(&s->pb, 1, 1);                 // marker
        put_bits(&s->pb, 8, vbv_buffer_size >> 10); // vbv buffer ext
        put_bits(&s->pb, 1, s->low_delay);
        put_bits(&s->pb, 2, mpeg12->frame_rate_ext.num-1); // frame_rate_ext_n
        put_bits(&s->pb, 5, mpeg12->frame_rate_ext.den-1); // frame_rate_ext_d

        side_data = av_frame_get_side_data(s->current_picture_ptr->f, AV_FRAME_DATA_PANSCAN);
        if (side_data) {
            const AVPanScan *pan_scan = (AVPanScan *)side_data->data;
            if (pan_scan->width && pan_scan->height) {
                width  = pan_scan->width  >> 4;
                height = pan_scan->height >> 4;
            }
        }

        use_seq_disp_ext = (width != s->width ||
                            height != s->height ||
                            s->avctx->color_primaries != AVCOL_PRI_UNSPECIFIED ||
                            s->avctx->color_trc != AVCOL_TRC_UNSPECIFIED ||
                            s->avctx->colorspace != AVCOL_SPC_UNSPECIFIED ||
                            mpeg12->video_format != VIDEO_FORMAT_UNSPECIFIED);

        if (mpeg12->seq_disp_ext == 1 ||
            (mpeg12->seq_disp_ext == -1 && use_seq_disp_ext)) {
            put_header(s, EXT_START_CODE);
            put_bits(&s->pb, 4, 2);                         // sequence display extension
            put_bits(&s->pb, 3, mpeg12->video_format);      // video_format
            put_bits(&s->pb, 1, 1);                         // colour_description
            put_bits(&s->pb, 8, s->avctx->color_primaries); // colour_primaries
            put_bits(&s->pb, 8, s->avctx->color_trc);       // transfer_characteristics
            put_bits(&s->pb, 8, s->avctx->colorspace);      // matrix_coefficients
            put_bits(&s->pb, 14, width);                    // display_horizontal_size
            put_bits(&s->pb, 1, 1);                         // marker_bit
            put_bits(&s->pb, 14, height);                   // display_vertical_size
            put_bits(&s->pb, 3, 0);                         // remaining 3 bits are zero padding
        }
    }

    put_header(s, GOP_START_CODE);
    put_bits(&s->pb, 1, mpeg12->drop_frame_timecode);    // drop frame flag
    /* time code: we must convert from the real frame rate to a
     * fake MPEG frame rate in case of low frame rate */
    fps       = (framerate.num + framerate.den / 2) / framerate.den;
    time_code = s->current_picture_ptr->f->coded_picture_number +
                mpeg12->timecode_frame_start;

    mpeg12->gop_picture_number = s->current_picture_ptr->f->coded_picture_number;

    av_assert0(mpeg12->drop_frame_timecode == !!(mpeg12->tc.flags & AV_TIMECODE_FLAG_DROPFRAME));
    if (mpeg12->drop_frame_timecode)
        time_code = av_timecode_adjust_ntsc_framenum2(time_code, fps);

    put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
    put_bits(&s->pb, 6, (uint32_t)((time_code / (fps *   60)) % 60));
    put_bits(&s->pb, 1, 1);
    put_bits(&s->pb, 6, (uint32_t)((time_code / fps) % 60));
    put_bits(&s->pb, 6, (uint32_t)((time_code % fps)));
    put_bits(&s->pb, 1, !!(s->avctx->flags & AV_CODEC_FLAG_CLOSED_GOP) ||
                        s->intra_only || !mpeg12->gop_picture_number);
    put_bits(&s->pb, 1, 0);                     // broken link
}

static inline void encode_mb_skip_run(MpegEncContext *s, int run)
{
    while (run >= 33) {
        put_bits(&s->pb, 11, 0x008);
        run -= 33;
    }
    put_bits(&s->pb, ff_mpeg12_mbAddrIncrTable[run][1],
             ff_mpeg12_mbAddrIncrTable[run][0]);
}

static av_always_inline void put_qscale(MpegEncContext *s)
{
    put_bits(&s->pb, 5, s->qscale);
}

void ff_mpeg1_encode_slice_header(MpegEncContext *s)
{
    if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->height > 2800) {
        put_header(s, SLICE_MIN_START_CODE + (s->mb_y & 127));
        /* slice_vertical_position_extension */
        put_bits(&s->pb, 3, s->mb_y >> 7);
    } else {
        put_header(s, SLICE_MIN_START_CODE + s->mb_y);
    }
    put_qscale(s);
    /* slice extra information */
    put_bits(&s->pb, 1, 0);
}

void ff_mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
{
    MPEG12EncContext *const mpeg12 = (MPEG12EncContext*)s;
    AVFrameSideData *side_data;
    mpeg1_encode_sequence_header(s);

    /* MPEG-1 picture header */
    put_header(s, PICTURE_START_CODE);
    /* temporal reference */

    // RAL: s->picture_number instead of s->fake_picture_number
    put_bits(&s->pb, 10,
             (s->picture_number - mpeg12->gop_picture_number) & 0x3ff);
    put_bits(&s->pb, 3, s->pict_type);

    s->vbv_delay_pos = put_bytes_count(&s->pb, 0);
    put_bits(&s->pb, 16, 0xFFFF);               /* vbv_delay */

    // RAL: Forward f_code also needed for B-frames
    if (s->pict_type == AV_PICTURE_TYPE_P ||
        s->pict_type == AV_PICTURE_TYPE_B) {
        put_bits(&s->pb, 1, 0);                 /* half pel coordinates */
        if (s->codec_id == AV_CODEC_ID_MPEG1VIDEO)
            put_bits(&s->pb, 3, s->f_code);     /* forward_f_code */
        else
            put_bits(&s->pb, 3, 7);             /* forward_f_code */
    }

    // RAL: Backward f_code necessary for B-frames
    if (s->pict_type == AV_PICTURE_TYPE_B) {
        put_bits(&s->pb, 1, 0);                 /* half pel coordinates */
        if (s->codec_id == AV_CODEC_ID_MPEG1VIDEO)
            put_bits(&s->pb, 3, s->b_code);     /* backward_f_code */
        else
            put_bits(&s->pb, 3, 7);             /* backward_f_code */
    }

    put_bits(&s->pb, 1, 0);                     /* extra bit picture */

    s->frame_pred_frame_dct = 1;
    if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
        put_header(s, EXT_START_CODE);
        put_bits(&s->pb, 4, 8);                 /* pic ext */
        if (s->pict_type == AV_PICTURE_TYPE_P ||
            s->pict_type == AV_PICTURE_TYPE_B) {
            put_bits(&s->pb, 4, s->f_code);
            put_bits(&s->pb, 4, s->f_code);
        } else {
            put_bits(&s->pb, 8, 255);
        }
        if (s->pict_type == AV_PICTURE_TYPE_B) {
            put_bits(&s->pb, 4, s->b_code);
            put_bits(&s->pb, 4, s->b_code);
        } else {
            put_bits(&s->pb, 8, 255);
        }
        put_bits(&s->pb, 2, s->intra_dc_precision);

        av_assert0(s->picture_structure == PICT_FRAME);
        put_bits(&s->pb, 2, s->picture_structure);
        if (s->progressive_sequence)
            put_bits(&s->pb, 1, 0);             /* no repeat */
        else
            put_bits(&s->pb, 1, s->current_picture_ptr->f->top_field_first);
        /* XXX: optimize the generation of this flag with entropy measures */
        s->frame_pred_frame_dct = s->progressive_sequence;

        put_bits(&s->pb, 1, s->frame_pred_frame_dct);
        put_bits(&s->pb, 1, s->concealment_motion_vectors);
        put_bits(&s->pb, 1, s->q_scale_type);
        put_bits(&s->pb, 1, s->intra_vlc_format);
        put_bits(&s->pb, 1, s->alternate_scan);
        put_bits(&s->pb, 1, s->repeat_first_field);
        s->progressive_frame = s->progressive_sequence;
        /* chroma_420_type */
        put_bits(&s->pb, 1, s->chroma_format ==
                            CHROMA_420 ? s->progressive_frame : 0);
        put_bits(&s->pb, 1, s->progressive_frame);
        put_bits(&s->pb, 1, 0);                 /* composite_display_flag */
    }
    if (mpeg12->scan_offset) {
        int i;

        put_header(s, USER_START_CODE);
        for (i = 0; i < sizeof(svcd_scan_offset_placeholder); i++)
            put_bits(&s->pb, 8, svcd_scan_offset_placeholder[i]);
    }
    side_data = av_frame_get_side_data(s->current_picture_ptr->f,
                                       AV_FRAME_DATA_STEREO3D);
    if (side_data) {
        AVStereo3D *stereo = (AVStereo3D *)side_data->data;
        uint8_t fpa_type;

        switch (stereo->type) {
        case AV_STEREO3D_SIDEBYSIDE:
            fpa_type = 0x03;
            break;
        case AV_STEREO3D_TOPBOTTOM:
            fpa_type = 0x04;
            break;
        case AV_STEREO3D_2D:
            fpa_type = 0x08;
            break;
        case AV_STEREO3D_SIDEBYSIDE_QUINCUNX:
            fpa_type = 0x23;
            break;
        default:
            fpa_type = 0;
            break;
        }

        if (fpa_type != 0) {
            put_header(s, USER_START_CODE);
            put_bits(&s->pb, 8, 'J');   // S3D_video_format_signaling_identifier
            put_bits(&s->pb, 8, 'P');
            put_bits(&s->pb, 8, '3');
            put_bits(&s->pb, 8, 'D');
            put_bits(&s->pb, 8, 0x03);  // S3D_video_format_length

            put_bits(&s->pb, 1, 1);     // reserved_bit
            put_bits(&s->pb, 7, fpa_type); // S3D_video_format_type
            put_bits(&s->pb, 8, 0x04);  // reserved_data[0]
            put_bits(&s->pb, 8, 0xFF);  // reserved_data[1]
        }
    }

    if (CONFIG_MPEG2VIDEO_ENCODER && mpeg12->a53_cc) {
        side_data = av_frame_get_side_data(s->current_picture_ptr->f,
            AV_FRAME_DATA_A53_CC);
        if (side_data) {
            if (side_data->size <= A53_MAX_CC_COUNT * 3 && side_data->size % 3 == 0) {
                int i = 0;

                put_header (s, USER_START_CODE);

                put_bits(&s->pb, 8, 'G');                   // user_identifier
                put_bits(&s->pb, 8, 'A');
                put_bits(&s->pb, 8, '9');
                put_bits(&s->pb, 8, '4');
                put_bits(&s->pb, 8, 3);                     // user_data_type_code
                put_bits(&s->pb, 8,
                    (side_data->size / 3 & A53_MAX_CC_COUNT) | 0x40); // flags, cc_count
                put_bits(&s->pb, 8, 0xff);                  // em_data

                for (i = 0; i < side_data->size; i++)
                    put_bits(&s->pb, 8, side_data->data[i]);

                put_bits(&s->pb, 8, 0xff);                  // marker_bits
            } else {
                av_log(s->avctx, AV_LOG_WARNING,
                    "Closed Caption size (%"SIZE_SPECIFIER") can not exceed "
                    "93 bytes and must be a multiple of 3\n", side_data->size);
            }
        }
    }

    s->mb_y = 0;
    ff_mpeg1_encode_slice_header(s);
}

static inline void put_mb_modes(MpegEncContext *s, int n, int bits,
                                int has_mv, int field_motion)
{
    put_bits(&s->pb, n, bits);
    if (!s->frame_pred_frame_dct) {
        if (has_mv)
            /* motion_type: frame/field */
            put_bits(&s->pb, 2, 2 - field_motion);
        put_bits(&s->pb, 1, s->interlaced_dct);
    }
}

// RAL: Parameter added: f_or_b_code
static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
{
    if (val == 0) {
        /* zero vector, corresponds to ff_mpeg12_mbMotionVectorTable[0] */
        put_bits(&s->pb, 1, 0x01);
    } else {
        int code, sign, bits;
        int bit_size = f_or_b_code - 1;
        int range    = 1 << bit_size;
        /* modulo encoding */
        val = sign_extend(val, 5 + bit_size);

        if (val >= 0) {
            val--;
            code = (val >> bit_size) + 1;
            bits = val & (range - 1);
            sign = 0;
        } else {
            val = -val;
            val--;
            code = (val >> bit_size) + 1;
            bits = val & (range - 1);
            sign = 1;
        }

        av_assert2(code > 0 && code <= 16);

        put_bits(&s->pb,
                 ff_mpeg12_mbMotionVectorTable[code][1],
                 ff_mpeg12_mbMotionVectorTable[code][0]);

        put_bits(&s->pb, 1, sign);
        if (bit_size > 0)
            put_bits(&s->pb, bit_size, bits);
    }
}

static inline void encode_dc(MpegEncContext *s, int diff, int component)
{
    unsigned int diff_u = diff + 255;
    if (diff_u >= 511) {
        int index;

        if (diff < 0) {
            index = av_log2_16bit(-2 * diff);
            diff--;
        } else {
            index = av_log2_16bit(2 * diff);
        }
        if (component == 0)
            put_bits(&s->pb,
                     ff_mpeg12_vlc_dc_lum_bits[index] + index,
                     (ff_mpeg12_vlc_dc_lum_code[index] << index) +
                     av_mod_uintp2(diff, index));
        else
            put_bits(&s->pb,
                     ff_mpeg12_vlc_dc_chroma_bits[index] + index,
                     (ff_mpeg12_vlc_dc_chroma_code[index] << index) +
                     av_mod_uintp2(diff, index));
    } else {
        if (component == 0)
            put_bits(&s->pb,
                     mpeg1_lum_dc_uni[diff + 255] & 0xFF,
                     mpeg1_lum_dc_uni[diff + 255] >> 8);
        else
            put_bits(&s->pb,
                     mpeg1_chr_dc_uni[diff + 255] & 0xFF,
                     mpeg1_chr_dc_uni[diff + 255] >> 8);
    }
}

static void mpeg1_encode_block(MpegEncContext *s, int16_t *block, int n)
{
    int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
    int code, component;
    const uint16_t (*table_vlc)[2] = ff_mpeg1_vlc_table;

    last_index = s->block_last_index[n];

    /* DC coef */
    if (s->mb_intra) {
        component = (n <= 3 ? 0 : (n & 1) + 1);
        dc        = block[0];                   /* overflow is impossible */
        diff      = dc - s->last_dc[component];
        encode_dc(s, diff, component);
        s->last_dc[component] = dc;
        i = 1;
        if (s->intra_vlc_format)
            table_vlc = ff_mpeg2_vlc_table;
    } else {
        /* encode the first coefficient: needs to be done here because
         * it is handled slightly differently */
        level = block[0];
        if (abs(level) == 1) {
            code = ((uint32_t)level >> 31);     /* the sign bit */
            put_bits(&s->pb, 2, code | 0x02);
            i = 1;
        } else {
            i             = 0;
            last_non_zero = -1;
            goto next_coef;
        }
    }

    /* now quantify & encode AC coefs */
    last_non_zero = i - 1;

    for (; i <= last_index; i++) {
        j     = s->intra_scantable.permutated[i];
        level = block[j];

next_coef:
        /* encode using VLC */
        if (level != 0) {
            run = i - last_non_zero - 1;

            alevel = level;
            MASK_ABS(sign, alevel);
            sign &= 1;

            if (alevel <= mpeg12_max_level[run]) {
                code = mpeg12_index_run[run] + alevel - 1;
                /* store the VLC & sign at once */
                put_bits(&s->pb, table_vlc[code][1] + 1,
                         (table_vlc[code][0] << 1) + sign);
            } else {
                /* Escape seems to be pretty rare <5% so I do not optimize it;
                 * the following value is the common escape value for both
                 * possible tables (i.e. table_vlc[111]). */
                put_bits(&s->pb, 6, 0x01);
                /* escape: only clip in this case */
                put_bits(&s->pb, 6, run);
                if (s->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
                    if (alevel < 128) {
                        put_sbits(&s->pb, 8, level);
                    } else {
                        if (level < 0)
                            put_bits(&s->pb, 16, 0x8001 + level + 255);
                        else
                            put_sbits(&s->pb, 16, level);
                    }
                } else {
                    put_sbits(&s->pb, 12, level);
                }
            }
            last_non_zero = i;
        }
    }
    /* end of block */
    put_bits(&s->pb, table_vlc[112][1], table_vlc[112][0]);
}

static av_always_inline void mpeg1_encode_mb_internal(MpegEncContext *s,
                                                      int16_t block[8][64],
                                                      int motion_x, int motion_y,
                                                      int mb_block_count,
                                                      int chroma_y_shift)
{
/* MPEG-1 is always 420. */
#define IS_MPEG1(s) (chroma_y_shift == 1 && (s)->codec_id == AV_CODEC_ID_MPEG1VIDEO)
    int i, cbp;
    const int mb_x     = s->mb_x;
    const int mb_y     = s->mb_y;
    const int first_mb = mb_x == s->resync_mb_x && mb_y == s->resync_mb_y;

    /* compute cbp */
    cbp = 0;
    for (i = 0; i < mb_block_count; i++)
        if (s->block_last_index[i] >= 0)
            cbp |= 1 << (mb_block_count - 1 - i);

    if (cbp == 0 && !first_mb && s->mv_type == MV_TYPE_16X16 &&
        (mb_x != s->mb_width - 1 ||
         (mb_y != s->end_mb_y - 1 && IS_MPEG1(s))) &&
        ((s->pict_type == AV_PICTURE_TYPE_P && (motion_x | motion_y) == 0) ||
         (s->pict_type == AV_PICTURE_TYPE_B && s->mv_dir == s->last_mv_dir &&
          (((s->mv_dir & MV_DIR_FORWARD)
            ? ((s->mv[0][0][0] - s->last_mv[0][0][0]) |
               (s->mv[0][0][1] - s->last_mv[0][0][1])) : 0) |
           ((s->mv_dir & MV_DIR_BACKWARD)
            ? ((s->mv[1][0][0] - s->last_mv[1][0][0]) |
               (s->mv[1][0][1] - s->last_mv[1][0][1])) : 0)) == 0))) {
        s->mb_skip_run++;
        s->qscale -= s->dquant;
        s->skip_count++;
        s->misc_bits++;
        s->last_bits++;
        if (s->pict_type == AV_PICTURE_TYPE_P) {
            s->last_mv[0][0][0] =
            s->last_mv[0][0][1] =
            s->last_mv[0][1][0] =
            s->last_mv[0][1][1] = 0;
        }
    } else {
        if (first_mb) {
            av_assert0(s->mb_skip_run == 0);
            encode_mb_skip_run(s, s->mb_x);
        } else {
            encode_mb_skip_run(s, s->mb_skip_run);
        }

        if (s->pict_type == AV_PICTURE_TYPE_I) {
            if (s->dquant && cbp) {
                /* macroblock_type: macroblock_quant = 1 */
                put_mb_modes(s, 2, 1, 0, 0);
                put_qscale(s);
            } else {
                /* macroblock_type: macroblock_quant = 0 */
                put_mb_modes(s, 1, 1, 0, 0);
                s->qscale -= s->dquant;
            }
            s->misc_bits += get_bits_diff(s);
            s->i_count++;
        } else if (s->mb_intra) {
            if (s->dquant && cbp) {
                put_mb_modes(s, 6, 0x01, 0, 0);
                put_qscale(s);
            } else {
                put_mb_modes(s, 5, 0x03, 0, 0);
                s->qscale -= s->dquant;
            }
            s->misc_bits += get_bits_diff(s);
            s->i_count++;
            memset(s->last_mv, 0, sizeof(s->last_mv));
        } else if (s->pict_type == AV_PICTURE_TYPE_P) {
            if (s->mv_type == MV_TYPE_16X16) {
                if (cbp != 0) {
                    if ((motion_x | motion_y) == 0) {
                        if (s->dquant) {
                            /* macroblock_pattern & quant */
                            put_mb_modes(s, 5, 1, 0, 0);
                            put_qscale(s);
                        } else {
                            /* macroblock_pattern only */
                            put_mb_modes(s, 2, 1, 0, 0);
                        }
                        s->misc_bits += get_bits_diff(s);
                    } else {
                        if (s->dquant) {
                            put_mb_modes(s, 5, 2, 1, 0);    /* motion + cbp */
                            put_qscale(s);
                        } else {
                            put_mb_modes(s, 1, 1, 1, 0);    /* motion + cbp */
                        }
                        s->misc_bits += get_bits_diff(s);
                        // RAL: f_code parameter added
                        mpeg1_encode_motion(s,
                                            motion_x - s->last_mv[0][0][0],
                                            s->f_code);
                        // RAL: f_code parameter added
                        mpeg1_encode_motion(s,
                                            motion_y - s->last_mv[0][0][1],
                                            s->f_code);
                        s->mv_bits += get_bits_diff(s);
                    }
                } else {
                    put_bits(&s->pb, 3, 1);         /* motion only */
                    if (!s->frame_pred_frame_dct)
                        put_bits(&s->pb, 2, 2);     /* motion_type: frame */
                    s->misc_bits += get_bits_diff(s);
                    // RAL: f_code parameter added
                    mpeg1_encode_motion(s,
                                        motion_x - s->last_mv[0][0][0],
                                        s->f_code);
                    // RAL: f_code parameter added
                    mpeg1_encode_motion(s,
                                        motion_y - s->last_mv[0][0][1],
                                        s->f_code);
                    s->qscale  -= s->dquant;
                    s->mv_bits += get_bits_diff(s);
                }
                s->last_mv[0][1][0] = s->last_mv[0][0][0] = motion_x;
                s->last_mv[0][1][1] = s->last_mv[0][0][1] = motion_y;
            } else {
                av_assert2(!s->frame_pred_frame_dct && s->mv_type == MV_TYPE_FIELD);

                if (cbp) {
                    if (s->dquant) {
                        put_mb_modes(s, 5, 2, 1, 1);    /* motion + cbp */
                        put_qscale(s);
                    } else {
                        put_mb_modes(s, 1, 1, 1, 1);    /* motion + cbp */
                    }
                } else {
                    put_bits(&s->pb, 3, 1);             /* motion only */
                    put_bits(&s->pb, 2, 1);             /* motion_type: field */
                    s->qscale -= s->dquant;
                }
                s->misc_bits += get_bits_diff(s);
                for (i = 0; i < 2; i++) {
                    put_bits(&s->pb, 1, s->field_select[0][i]);
                    mpeg1_encode_motion(s,
                                        s->mv[0][i][0] - s->last_mv[0][i][0],
                                        s->f_code);
                    mpeg1_encode_motion(s,
                                        s->mv[0][i][1] - (s->last_mv[0][i][1] >> 1),
                                        s->f_code);
                    s->last_mv[0][i][0] = s->mv[0][i][0];
                    s->last_mv[0][i][1] = 2 * s->mv[0][i][1];
                }
                s->mv_bits += get_bits_diff(s);
            }
            if (cbp) {
                if (chroma_y_shift) {
                    put_bits(&s->pb,
                             ff_mpeg12_mbPatTable[cbp][1],
                             ff_mpeg12_mbPatTable[cbp][0]);
                } else {
                    put_bits(&s->pb,
                             ff_mpeg12_mbPatTable[cbp >> 2][1],
                             ff_mpeg12_mbPatTable[cbp >> 2][0]);
                    put_sbits(&s->pb, 2, cbp);
                }
            }
        } else {
            if (s->mv_type == MV_TYPE_16X16) {
                if (cbp) {                      // With coded bloc pattern
                    if (s->dquant) {
                        if (s->mv_dir == MV_DIR_FORWARD)
                            put_mb_modes(s, 6, 3, 1, 0);
                        else
                            put_mb_modes(s, 8 - s->mv_dir, 2, 1, 0);
                        put_qscale(s);
                    } else {
                        put_mb_modes(s, 5 - s->mv_dir, 3, 1, 0);
                    }
                } else {                        // No coded bloc pattern
                    put_bits(&s->pb, 5 - s->mv_dir, 2);
                    if (!s->frame_pred_frame_dct)
                        put_bits(&s->pb, 2, 2); /* motion_type: frame */
                    s->qscale -= s->dquant;
                }
                s->misc_bits += get_bits_diff(s);
                if (s->mv_dir & MV_DIR_FORWARD) {
                    mpeg1_encode_motion(s,
                                        s->mv[0][0][0] - s->last_mv[0][0][0],
                                        s->f_code);
                    mpeg1_encode_motion(s,
                                        s->mv[0][0][1] - s->last_mv[0][0][1],
                                        s->f_code);
                    s->last_mv[0][0][0] =
                    s->last_mv[0][1][0] = s->mv[0][0][0];
                    s->last_mv[0][0][1] =
                    s->last_mv[0][1][1] = s->mv[0][0][1];
                }
                if (s->mv_dir & MV_DIR_BACKWARD) {
                    mpeg1_encode_motion(s,
                                        s->mv[1][0][0] - s->last_mv[1][0][0],
                                        s->b_code);
                    mpeg1_encode_motion(s,
                                        s->mv[1][0][1] - s->last_mv[1][0][1],
                                        s->b_code);
                    s->last_mv[1][0][0] =
                    s->last_mv[1][1][0] = s->mv[1][0][0];
                    s->last_mv[1][0][1] =
                    s->last_mv[1][1][1] = s->mv[1][0][1];
                }
            } else {
                av_assert2(s->mv_type == MV_TYPE_FIELD);
                av_assert2(!s->frame_pred_frame_dct);
                if (cbp) {                      // With coded bloc pattern
                    if (s->dquant) {
                        if (s->mv_dir == MV_DIR_FORWARD)
                            put_mb_modes(s, 6, 3, 1, 1);
                        else
                            put_mb_modes(s, 8 - s->mv_dir, 2, 1, 1);
                        put_qscale(s);
                    } else {
                        put_mb_modes(s, 5 - s->mv_dir, 3, 1, 1);
                    }
                } else {                        // No coded bloc pattern
                    put_bits(&s->pb, 5 - s->mv_dir, 2);
                    put_bits(&s->pb, 2, 1);     /* motion_type: field */
                    s->qscale -= s->dquant;
                }
                s->misc_bits += get_bits_diff(s);
                if (s->mv_dir & MV_DIR_FORWARD) {
                    for (i = 0; i < 2; i++) {
                        put_bits(&s->pb, 1, s->field_select[0][i]);
                        mpeg1_encode_motion(s,
                                            s->mv[0][i][0] - s->last_mv[0][i][0],
                                            s->f_code);
                        mpeg1_encode_motion(s,
                                            s->mv[0][i][1] - (s->last_mv[0][i][1] >> 1),
                                            s->f_code);
                        s->last_mv[0][i][0] = s->mv[0][i][0];
                        s->last_mv[0][i][1] = s->mv[0][i][1] * 2;
                    }
                }
                if (s->mv_dir & MV_DIR_BACKWARD) {
                    for (i = 0; i < 2; i++) {
                        put_bits(&s->pb, 1, s->field_select[1][i]);
                        mpeg1_encode_motion(s,
                                            s->mv[1][i][0] - s->last_mv[1][i][0],
                                            s->b_code);
                        mpeg1_encode_motion(s,
                                            s->mv[1][i][1] - (s->last_mv[1][i][1] >> 1),
                                            s->b_code);
                        s->last_mv[1][i][0] = s->mv[1][i][0];
                        s->last_mv[1][i][1] = s->mv[1][i][1] * 2;
                    }
                }
            }
            s->mv_bits += get_bits_diff(s);
            if (cbp) {
                if (chroma_y_shift) {
                    put_bits(&s->pb,
                             ff_mpeg12_mbPatTable[cbp][1],
                             ff_mpeg12_mbPatTable[cbp][0]);
                } else {
                    put_bits(&s->pb,
                             ff_mpeg12_mbPatTable[cbp >> 2][1],
                             ff_mpeg12_mbPatTable[cbp >> 2][0]);
                    put_sbits(&s->pb, 2, cbp);
                }
            }
        }
        for (i = 0; i < mb_block_count; i++)
            if (cbp & (1 << (mb_block_count - 1 - i)))
                mpeg1_encode_block(s, block[i], i);
        s->mb_skip_run = 0;
        if (s->mb_intra)
            s->i_tex_bits += get_bits_diff(s);
        else
            s->p_tex_bits += get_bits_diff(s);
    }
}

void ff_mpeg1_encode_mb(MpegEncContext *s, int16_t block[8][64],
                        int motion_x, int motion_y)
{
    if (s->chroma_format == CHROMA_420)
        mpeg1_encode_mb_internal(s, block, motion_x, motion_y, 6, 1);
    else
        mpeg1_encode_mb_internal(s, block, motion_x, motion_y, 8, 0);
}

static av_cold void mpeg12_encode_init_static(void)
{
    ff_rl_init_level_run(mpeg12_max_level, mpeg12_index_run,
                         ff_mpeg12_run, ff_mpeg12_level, MPEG12_RL_NB_ELEMS);

    ff_mpeg1_init_uni_ac_vlc(mpeg12_max_level, mpeg12_index_run,
                             ff_mpeg1_vlc_table, uni_mpeg1_ac_vlc_len);
    ff_mpeg1_init_uni_ac_vlc(mpeg12_max_level, mpeg12_index_run,
                             ff_mpeg2_vlc_table, uni_mpeg2_ac_vlc_len);

    /* build unified dc encoding tables */
    for (int i = -255; i < 256; i++) {
        int adiff, index;
        int bits, code;
        int diff = i;

        adiff = FFABS(diff);
        if (diff < 0)
            diff--;
        index = av_log2(2 * adiff);

        bits = ff_mpeg12_vlc_dc_lum_bits[index] + index;
        code = (ff_mpeg12_vlc_dc_lum_code[index] << index) +
               av_mod_uintp2(diff, index);
        mpeg1_lum_dc_uni[i + 255] = bits + (code << 8);

        bits = ff_mpeg12_vlc_dc_chroma_bits[index] + index;
        code = (ff_mpeg12_vlc_dc_chroma_code[index] << index) +
               av_mod_uintp2(diff, index);
        mpeg1_chr_dc_uni[i + 255] = bits + (code << 8);
    }

    for (int f_code = 1; f_code <= MAX_FCODE; f_code++)
        for (int mv = -MAX_DMV; mv <= MAX_DMV; mv++) {
            int len;

            if (mv == 0) {
                len = 1; /* ff_mpeg12_mbMotionVectorTable[0][1] */
            } else {
                int val, bit_size, code;

                bit_size = f_code - 1;

                val = mv;
                if (val < 0)
                    val = -val;
                val--;
                code = (val >> bit_size) + 1;
                if (code < 17)
                    len = ff_mpeg12_mbMotionVectorTable[code][1] +
                          1 + bit_size;
                else
                    len = 10 /* ff_mpeg12_mbMotionVectorTable[16][1] */ +
                          2 + bit_size;
            }

            mv_penalty[f_code][mv + MAX_DMV] = len;
        }


    for (int f_code = MAX_FCODE; f_code > 0; f_code--)
        for (int mv = -(8 << f_code); mv < (8 << f_code); mv++)
            fcode_tab[mv + MAX_MV] = f_code;
}

av_cold void ff_mpeg1_encode_init(MpegEncContext *s)
{
    static AVOnce init_static_once = AV_ONCE_INIT;

    s->y_dc_scale_table =
    s->c_dc_scale_table = ff_mpeg2_dc_scale_table[s->intra_dc_precision];

    s->me.mv_penalty = mv_penalty;
    s->fcode_tab     = fcode_tab;
    if (s->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
        s->min_qcoeff = -255;
        s->max_qcoeff = 255;
    } else {
        s->min_qcoeff = -2047;
        s->max_qcoeff = 2047;
        s->mpeg_quant = 1;
    }
    if (s->intra_vlc_format) {
        s->intra_ac_vlc_length      =
        s->intra_ac_vlc_last_length = uni_mpeg2_ac_vlc_len;
    } else {
        s->intra_ac_vlc_length      =
        s->intra_ac_vlc_last_length = uni_mpeg1_ac_vlc_len;
    }
    s->inter_ac_vlc_length      =
    s->inter_ac_vlc_last_length = uni_mpeg1_ac_vlc_len;

    ff_thread_once(&init_static_once, mpeg12_encode_init_static);
}

#define OFFSET(x) offsetof(MPEG12EncContext, x)
#define VE AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM
#define COMMON_OPTS                                                           \
    { "gop_timecode",        "MPEG GOP Timecode in hh:mm:ss[:;.]ff format. Overrides timecode_frame_start.",   \
      OFFSET(tc_opt_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, VE },\
    { "drop_frame_timecode", "Timecode is in drop frame format.",             \
      OFFSET(drop_frame_timecode), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE }, \
    { "scan_offset",         "Reserve space for SVCD scan offset user data.", \
      OFFSET(scan_offset),         AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE }, \
    { "timecode_frame_start", "GOP timecode frame start number, in non-drop-frame format", \
      OFFSET(timecode_frame_start), AV_OPT_TYPE_INT64, {.i64 = -1 }, -1, INT64_MAX, VE}, \
    FF_MPV_COMMON_BFRAME_OPTS

static const AVOption mpeg1_options[] = {
    COMMON_OPTS
    FF_MPV_COMMON_OPTS
    FF_MPV_COMMON_MOTION_EST_OPTS
    { NULL },
};

static const AVOption mpeg2_options[] = {
    COMMON_OPTS
    { "intra_vlc",        "Use MPEG-2 intra VLC table.",
      FF_MPV_OFFSET(intra_vlc_format),    AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE },
    { "non_linear_quant", "Use nonlinear quantizer.",    FF_MPV_OFFSET(q_scale_type),   AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE },
    { "alternate_scan",   "Enable alternate scantable.", FF_MPV_OFFSET(alternate_scan), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE },
    { "a53cc", "Use A53 Closed Captions (if available)", OFFSET(a53_cc),         AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE },
    { "seq_disp_ext",     "Write sequence_display_extension blocks.", OFFSET(seq_disp_ext), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, VE, "seq_disp_ext" },
    {     "auto",   NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = -1},  0, 0, VE, "seq_disp_ext" },
    {     "never",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = 0 },  0, 0, VE, "seq_disp_ext" },
    {     "always", NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = 1 },  0, 0, VE, "seq_disp_ext" },
    { "video_format",     "Video_format in the sequence_display_extension indicating the source of the video.", OFFSET(video_format), AV_OPT_TYPE_INT, { .i64 = VIDEO_FORMAT_UNSPECIFIED }, 0, 7, VE, "video_format" },
    {     "component",    NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_COMPONENT  },  0, 0, VE, "video_format" },
    {     "pal",          NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_PAL        },  0, 0, VE, "video_format" },
    {     "ntsc",         NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_NTSC       },  0, 0, VE, "video_format" },
    {     "secam",        NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_SECAM      },  0, 0, VE, "video_format" },
    {     "mac",          NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_MAC        },  0, 0, VE, "video_format" },
    {     "unspecified",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_UNSPECIFIED},  0, 0, VE, "video_format" },
#define LEVEL(name, value) name, NULL, 0, AV_OPT_TYPE_CONST, { .i64 = value }, 0, 0, VE, "avctx.level"
    { LEVEL("high",     4) },
    { LEVEL("high1440", 6) },
    { LEVEL("main",     8) },
    { LEVEL("low",     10) },
#undef LEVEL
    FF_MPV_COMMON_OPTS
    FF_MPV_COMMON_MOTION_EST_OPTS
    FF_MPEG2_PROFILE_OPTS
    { NULL },
};

#define mpeg12_class(x)                                 \
static const AVClass mpeg ## x ## _class = {            \
    .class_name = "mpeg" # x "video encoder",           \
    .item_name  = av_default_item_name,                 \
    .option     = mpeg ## x ## _options,                \
    .version    = LIBAVUTIL_VERSION_INT,                \
};

mpeg12_class(1)
mpeg12_class(2)

const FFCodec ff_mpeg1video_encoder = {
    .p.name               = "mpeg1video",
    CODEC_LONG_NAME("MPEG-1 video"),
    .p.type               = AVMEDIA_TYPE_VIDEO,
    .p.id                 = AV_CODEC_ID_MPEG1VIDEO,
    .priv_data_size       = sizeof(MPEG12EncContext),
    .init                 = encode_init,
    FF_CODEC_ENCODE_CB(ff_mpv_encode_picture),
    .close                = ff_mpv_encode_end,
    .p.supported_framerates = ff_mpeg12_frame_rate_tab + 1,
    .p.pix_fmts           = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                           AV_PIX_FMT_NONE },
    .p.capabilities       = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
    .caps_internal        = FF_CODEC_CAP_INIT_CLEANUP,
    .p.priv_class         = &mpeg1_class,
};

const FFCodec ff_mpeg2video_encoder = {
    .p.name               = "mpeg2video",
    CODEC_LONG_NAME("MPEG-2 video"),
    .p.type               = AVMEDIA_TYPE_VIDEO,
    .p.id                 = AV_CODEC_ID_MPEG2VIDEO,
    .priv_data_size       = sizeof(MPEG12EncContext),
    .init                 = encode_init,
    FF_CODEC_ENCODE_CB(ff_mpv_encode_picture),
    .close                = ff_mpv_encode_end,
    .p.supported_framerates = ff_mpeg2_frame_rate_tab,
    .p.pix_fmts           = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                           AV_PIX_FMT_YUV422P,
                                                           AV_PIX_FMT_NONE },
    .p.capabilities       = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
    .caps_internal        = FF_CODEC_CAP_INIT_CLEANUP,
    .p.priv_class         = &mpeg2_class,
};
#endif /* CONFIG_MPEG1VIDEO_ENCODER || CONFIG_MPEG2VIDEO_ENCODER */