forked from FFmpeg/FFmpeg
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathmpegenc.c
1366 lines (1184 loc) · 47.6 KB
/
mpegenc.c
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
/*
* MPEG-1/2 muxer
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
*
* 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
*/
#include <stdint.h>
#include "libavutil/attributes.h"
#include "libavutil/fifo.h"
#include "libavutil/log.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavcodec/put_bits.h"
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "mpeg.h"
#define MAX_PAYLOAD_SIZE 4096
typedef struct PacketDesc {
int64_t pts;
int64_t dts;
int size;
int unwritten_size;
struct PacketDesc *next;
} PacketDesc;
typedef struct StreamInfo {
AVFifoBuffer *fifo;
uint8_t id;
int max_buffer_size; /* in bytes */
int buffer_index;
PacketDesc *predecode_packet; /* start of packet queue */
PacketDesc *last_packet; /* end of packet queue */
PacketDesc *premux_packet;
int packet_number;
uint8_t lpcm_header[3];
int lpcm_align;
int bytes_to_iframe;
int align_iframe;
int64_t vobu_start_pts;
} StreamInfo;
typedef struct MpegMuxContext {
const AVClass *class;
int packet_size; /* required packet size */
int packet_number;
int pack_header_freq; /* frequency (in packets^-1) at which we send pack headers */
int system_header_freq;
int system_header_size;
int user_mux_rate; /* bitrate in units of bits/s */
int mux_rate; /* bitrate in units of 50 bytes/s */
/* stream info */
int audio_bound;
int video_bound;
int is_mpeg2;
int is_vcd;
int is_svcd;
int is_dvd;
int64_t last_scr; /* current system clock */
int64_t vcd_padding_bitrate_num;
int64_t vcd_padding_bytes_written;
int preload;
} MpegMuxContext;
extern const AVOutputFormat ff_mpeg1vcd_muxer;
extern const AVOutputFormat ff_mpeg2dvd_muxer;
extern const AVOutputFormat ff_mpeg2svcd_muxer;
extern const AVOutputFormat ff_mpeg2vob_muxer;
static int put_pack_header(AVFormatContext *ctx, uint8_t *buf,
int64_t timestamp)
{
MpegMuxContext *s = ctx->priv_data;
PutBitContext pb;
init_put_bits(&pb, buf, 128);
put_bits32(&pb, PACK_START_CODE);
if (s->is_mpeg2)
put_bits(&pb, 2, 0x1);
else
put_bits(&pb, 4, 0x2);
put_bits(&pb, 3, (uint32_t)((timestamp >> 30) & 0x07));
put_bits(&pb, 1, 1);
put_bits(&pb, 15, (uint32_t)((timestamp >> 15) & 0x7fff));
put_bits(&pb, 1, 1);
put_bits(&pb, 15, (uint32_t)((timestamp) & 0x7fff));
put_bits(&pb, 1, 1);
if (s->is_mpeg2)
/* clock extension */
put_bits(&pb, 9, 0);
put_bits(&pb, 1, 1);
put_bits(&pb, 22, s->mux_rate);
put_bits(&pb, 1, 1);
if (s->is_mpeg2) {
put_bits(&pb, 1, 1);
put_bits(&pb, 5, 0x1f); /* reserved */
put_bits(&pb, 3, 0); /* stuffing length */
}
flush_put_bits(&pb);
return put_bits_ptr(&pb) - pb.buf;
}
static int put_system_header(AVFormatContext *ctx, uint8_t *buf,
int only_for_stream_id)
{
MpegMuxContext *s = ctx->priv_data;
int size, i, private_stream_coded, id;
PutBitContext pb;
init_put_bits(&pb, buf, 128);
put_bits32(&pb, SYSTEM_HEADER_START_CODE);
put_bits(&pb, 16, 0);
put_bits(&pb, 1, 1);
/* maximum bit rate of the multiplexed stream */
put_bits(&pb, 22, s->mux_rate);
put_bits(&pb, 1, 1); /* marker */
if (s->is_vcd && only_for_stream_id == VIDEO_ID) {
/* This header applies only to the video stream
* (see VCD standard p. IV-7) */
put_bits(&pb, 6, 0);
} else
put_bits(&pb, 6, s->audio_bound);
if (s->is_vcd) {
/* see VCD standard, p. IV-7 */
put_bits(&pb, 1, 0);
put_bits(&pb, 1, 1);
} else {
put_bits(&pb, 1, 0); /* variable bitrate */
put_bits(&pb, 1, 0); /* nonconstrained bitstream */
}
if (s->is_vcd || s->is_dvd) {
/* see VCD standard p IV-7 */
put_bits(&pb, 1, 1); /* audio locked */
put_bits(&pb, 1, 1); /* video locked */
} else {
put_bits(&pb, 1, 0); /* audio locked */
put_bits(&pb, 1, 0); /* video locked */
}
put_bits(&pb, 1, 1); /* marker */
if (s->is_vcd && (only_for_stream_id & 0xe0) == AUDIO_ID) {
/* This header applies only to the audio stream
* (see VCD standard p. IV-7) */
put_bits(&pb, 5, 0);
} else
put_bits(&pb, 5, s->video_bound);
if (s->is_dvd) {
put_bits(&pb, 1, 0); /* packet_rate_restriction_flag */
put_bits(&pb, 7, 0x7f); /* reserved byte */
} else
put_bits(&pb, 8, 0xff); /* reserved byte */
/* DVD-Video Stream_bound entries
* id (0xB9) video, maximum P-STD for stream 0xE0. (P-STD_buffer_bound_scale = 1)
* id (0xB8) audio, maximum P-STD for any MPEG audio (0xC0 to 0xC7) streams. If there are none set to 4096 (32x128). (P-STD_buffer_bound_scale = 0)
* id (0xBD) private stream 1 (audio other than MPEG and subpictures). (P-STD_buffer_bound_scale = 1)
* id (0xBF) private stream 2, NAV packs, set to 2x1024. */
if (s->is_dvd) {
int P_STD_max_video = 0;
int P_STD_max_mpeg_audio = 0;
int P_STD_max_mpeg_PS1 = 0;
for (i = 0; i < ctx->nb_streams; i++) {
StreamInfo *stream = ctx->streams[i]->priv_data;
id = stream->id;
if (id == 0xbd && stream->max_buffer_size > P_STD_max_mpeg_PS1) {
P_STD_max_mpeg_PS1 = stream->max_buffer_size;
} else if (id >= 0xc0 && id <= 0xc7 &&
stream->max_buffer_size > P_STD_max_mpeg_audio) {
P_STD_max_mpeg_audio = stream->max_buffer_size;
} else if (id == 0xe0 &&
stream->max_buffer_size > P_STD_max_video) {
P_STD_max_video = stream->max_buffer_size;
}
}
/* video */
put_bits(&pb, 8, 0xb9); /* stream ID */
put_bits(&pb, 2, 3);
put_bits(&pb, 1, 1);
put_bits(&pb, 13, P_STD_max_video / 1024);
/* audio */
if (P_STD_max_mpeg_audio == 0)
P_STD_max_mpeg_audio = 4096;
put_bits(&pb, 8, 0xb8); /* stream ID */
put_bits(&pb, 2, 3);
put_bits(&pb, 1, 0);
put_bits(&pb, 13, P_STD_max_mpeg_audio / 128);
/* private stream 1 */
put_bits(&pb, 8, 0xbd); /* stream ID */
put_bits(&pb, 2, 3);
put_bits(&pb, 1, 0);
put_bits(&pb, 13, P_STD_max_mpeg_PS1 / 128);
/* private stream 2 */
put_bits(&pb, 8, 0xbf); /* stream ID */
put_bits(&pb, 2, 3);
put_bits(&pb, 1, 1);
put_bits(&pb, 13, 2);
} else {
/* audio stream info */
private_stream_coded = 0;
for (i = 0; i < ctx->nb_streams; i++) {
StreamInfo *stream = ctx->streams[i]->priv_data;
/* For VCDs, only include the stream info for the stream
* that the pack which contains this system belongs to.
* (see VCD standard p. IV-7) */
if (!s->is_vcd || stream->id == only_for_stream_id ||
only_for_stream_id == 0) {
id = stream->id;
if (id < 0xc0) {
/* special case for private streams (AC-3 uses that) */
if (private_stream_coded)
continue;
private_stream_coded = 1;
id = 0xbd;
}
put_bits(&pb, 8, id); /* stream ID */
put_bits(&pb, 2, 3);
if (id < 0xe0) {
/* audio */
put_bits(&pb, 1, 0);
put_bits(&pb, 13, stream->max_buffer_size / 128);
} else {
/* video */
put_bits(&pb, 1, 1);
put_bits(&pb, 13, stream->max_buffer_size / 1024);
}
}
}
}
flush_put_bits(&pb);
size = put_bits_ptr(&pb) - pb.buf;
/* patch packet size */
AV_WB16(buf + 4, size - 6);
return size;
}
static int get_system_header_size(AVFormatContext *ctx)
{
int buf_index, i, private_stream_coded;
StreamInfo *stream;
MpegMuxContext *s = ctx->priv_data;
if (s->is_dvd)
return 18; // DVD-Video system headers are 18 bytes fixed length.
buf_index = 12;
private_stream_coded = 0;
for (i = 0; i < ctx->nb_streams; i++) {
stream = ctx->streams[i]->priv_data;
if (stream->id < 0xc0) {
if (private_stream_coded)
continue;
private_stream_coded = 1;
}
buf_index += 3;
}
return buf_index;
}
static av_cold int mpeg_mux_init(AVFormatContext *ctx)
{
MpegMuxContext *s = ctx->priv_data;
int bitrate, i, mpa_id, mpv_id, h264_id, mps_id, ac3_id, dts_id, lpcm_id, j;
AVStream *st;
StreamInfo *stream;
int audio_bitrate;
int video_bitrate;
s->packet_number = 0;
s->is_vcd = (CONFIG_MPEG1VCD_MUXER && ctx->oformat == &ff_mpeg1vcd_muxer);
s->is_svcd = (CONFIG_MPEG2SVCD_MUXER && ctx->oformat == &ff_mpeg2svcd_muxer);
s->is_mpeg2 = ((CONFIG_MPEG2VOB_MUXER && ctx->oformat == &ff_mpeg2vob_muxer) ||
(CONFIG_MPEG2DVD_MUXER && ctx->oformat == &ff_mpeg2dvd_muxer) ||
(CONFIG_MPEG2SVCD_MUXER && ctx->oformat == &ff_mpeg2svcd_muxer));
s->is_dvd = (CONFIG_MPEG2DVD_MUXER && ctx->oformat == &ff_mpeg2dvd_muxer);
if (ctx->packet_size) {
if (ctx->packet_size < 20 || ctx->packet_size > (1 << 23) + 10) {
av_log(ctx, AV_LOG_ERROR, "Invalid packet size %d\n",
ctx->packet_size);
return AVERROR(EINVAL);
}
s->packet_size = ctx->packet_size;
} else
s->packet_size = 2048;
if (ctx->max_delay < 0) /* Not set by the caller */
ctx->max_delay = AV_TIME_BASE*7/10;
s->vcd_padding_bytes_written = 0;
s->vcd_padding_bitrate_num = 0;
s->audio_bound = 0;
s->video_bound = 0;
mpa_id = AUDIO_ID;
ac3_id = AC3_ID;
dts_id = DTS_ID;
mpv_id = VIDEO_ID;
h264_id = H264_ID;
mps_id = SUB_ID;
lpcm_id = LPCM_ID;
for (i = 0; i < ctx->nb_streams; i++) {
AVCPBProperties *props;
st = ctx->streams[i];
stream = av_mallocz(sizeof(StreamInfo));
if (!stream)
return AVERROR(ENOMEM);
st->priv_data = stream;
avpriv_set_pts_info(st, 64, 1, 90000);
switch (st->codecpar->codec_type) {
case AVMEDIA_TYPE_AUDIO:
if (!s->is_mpeg2 &&
(st->codecpar->codec_id == AV_CODEC_ID_AC3 ||
st->codecpar->codec_id == AV_CODEC_ID_DTS ||
st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE ||
st->codecpar->codec_id == AV_CODEC_ID_PCM_DVD))
av_log(ctx, AV_LOG_WARNING,
"%s in MPEG-1 system streams is not widely supported, "
"consider using the vob or the dvd muxer "
"to force a MPEG-2 program stream.\n",
avcodec_get_name(st->codecpar->codec_id));
if (st->codecpar->codec_id == AV_CODEC_ID_AC3) {
stream->id = ac3_id++;
} else if (st->codecpar->codec_id == AV_CODEC_ID_DTS) {
stream->id = dts_id++;
} else if (st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE) {
stream->id = lpcm_id++;
for (j = 0; j < 4; j++) {
if (lpcm_freq_tab[j] == st->codecpar->sample_rate)
break;
}
if (j == 4) {
int sr;
av_log(ctx, AV_LOG_ERROR, "Invalid sampling rate for PCM stream.\n");
av_log(ctx, AV_LOG_INFO, "Allowed sampling rates:");
for (sr = 0; sr < 4; sr++)
av_log(ctx, AV_LOG_INFO, " %d", lpcm_freq_tab[sr]);
av_log(ctx, AV_LOG_INFO, "\n");
return AVERROR(EINVAL);
}
if (st->codecpar->channels > 8) {
av_log(ctx, AV_LOG_ERROR, "At most 8 channels allowed for LPCM streams.\n");
return AVERROR(EINVAL);
}
stream->lpcm_header[0] = 0x0c;
stream->lpcm_header[1] = (st->codecpar->channels - 1) | (j << 4);
stream->lpcm_header[2] = 0x80;
stream->lpcm_align = st->codecpar->channels * 2;
} else if (st->codecpar->codec_id == AV_CODEC_ID_PCM_DVD) {
int freq;
switch (st->codecpar->sample_rate) {
case 48000: freq = 0; break;
case 96000: freq = 1; break;
case 44100: freq = 2; break;
case 32000: freq = 3; break;
default:
av_log(ctx, AV_LOG_ERROR, "Unsupported sample rate.\n");
return AVERROR(EINVAL);
}
stream->lpcm_header[0] = 0x0c;
stream->lpcm_header[1] = (freq << 4) |
(((st->codecpar->bits_per_coded_sample - 16) / 4) << 6) |
st->codecpar->channels - 1;
stream->lpcm_header[2] = 0x80;
stream->id = lpcm_id++;
stream->lpcm_align = st->codecpar->channels * st->codecpar->bits_per_coded_sample / 8;
} else if (st->codecpar->codec_id == AV_CODEC_ID_MLP ||
st->codecpar->codec_id == AV_CODEC_ID_TRUEHD) {
av_log(ctx, AV_LOG_ERROR, "Support for muxing audio codec %s not implemented.\n",
avcodec_get_name(st->codecpar->codec_id));
return AVERROR_PATCHWELCOME;
} else if (st->codecpar->codec_id != AV_CODEC_ID_MP1 &&
st->codecpar->codec_id != AV_CODEC_ID_MP2 &&
st->codecpar->codec_id != AV_CODEC_ID_MP3) {
av_log(ctx, AV_LOG_ERROR, "Unsupported audio codec. Must be one of mp1, mp2, mp3, 16-bit pcm_dvd, pcm_s16be, ac3 or dts.\n");
return AVERROR(EINVAL);
} else {
stream->id = mpa_id++;
}
/* This value HAS to be used for VCD (see VCD standard, p. IV-7).
* Right now it is also used for everything else. */
stream->max_buffer_size = 4 * 1024;
s->audio_bound++;
break;
case AVMEDIA_TYPE_VIDEO:
if (st->codecpar->codec_id == AV_CODEC_ID_H264)
stream->id = h264_id++;
else
stream->id = mpv_id++;
props = (AVCPBProperties*)av_stream_get_side_data(st, AV_PKT_DATA_CPB_PROPERTIES, NULL);
if (props && props->buffer_size)
stream->max_buffer_size = 6 * 1024 + props->buffer_size / 8;
else {
av_log(ctx, AV_LOG_WARNING,
"VBV buffer size not set, using default size of 230KB\n"
"If you want the mpeg file to be compliant to some specification\n"
"Like DVD, VCD or others, make sure you set the correct buffer size\n");
// FIXME: this is probably too small as default
stream->max_buffer_size = 230 * 1024;
}
if (stream->max_buffer_size > 1024 * 8191) {
av_log(ctx, AV_LOG_WARNING, "buffer size %d, too large\n", stream->max_buffer_size);
stream->max_buffer_size = 1024 * 8191;
}
s->video_bound++;
break;
case AVMEDIA_TYPE_SUBTITLE:
stream->id = mps_id++;
stream->max_buffer_size = 16 * 1024;
break;
default:
av_log(ctx, AV_LOG_ERROR, "Invalid media type %s for output stream #%d\n",
av_get_media_type_string(st->codecpar->codec_type), i);
return AVERROR(EINVAL);
}
stream->fifo = av_fifo_alloc(16);
if (!stream->fifo)
return AVERROR(ENOMEM);
}
bitrate = 0;
audio_bitrate = 0;
video_bitrate = 0;
for (i = 0; i < ctx->nb_streams; i++) {
AVCPBProperties *props;
int codec_rate;
st = ctx->streams[i];
stream = (StreamInfo *)st->priv_data;
props = (AVCPBProperties*)av_stream_get_side_data(st, AV_PKT_DATA_CPB_PROPERTIES, NULL);
if (props)
codec_rate = props->max_bitrate;
else
codec_rate = st->codecpar->bit_rate;
if (!codec_rate)
codec_rate = (1 << 21) * 8 * 50 / ctx->nb_streams;
bitrate += codec_rate;
if ((stream->id & 0xe0) == AUDIO_ID)
audio_bitrate += codec_rate;
else if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
video_bitrate += codec_rate;
}
if (s->user_mux_rate) {
s->mux_rate = (s->user_mux_rate + (8 * 50) - 1) / (8 * 50);
} else {
/* we increase slightly the bitrate to take into account the
* headers. XXX: compute it exactly */
bitrate += bitrate / 20;
bitrate += 10000;
s->mux_rate = (bitrate + (8 * 50) - 1) / (8 * 50);
if (s->mux_rate >= (1<<22)) {
av_log(ctx, AV_LOG_WARNING, "mux rate %d is too large\n", s->mux_rate);
s->mux_rate = (1<<22) - 1;
}
}
if (s->is_vcd) {
int64_t overhead_rate;
/* The VCD standard mandates that the mux_rate field is 3528
* (see standard p. IV-6).
* The value is actually "wrong", i.e. if you calculate
* it using the normal formula and the 75 sectors per second transfer
* rate you get a different value because the real pack size is 2324,
* not 2352. But the standard explicitly specifies that the mux_rate
* field in the header must have this value. */
// s->mux_rate = 2352 * 75 / 50; /* = 3528 */
/* The VCD standard states that the muxed stream must be
* exactly 75 packs / second (the data rate of a single speed cdrom).
* Since the video bitrate (probably 1150000 bits/sec) will be below
* the theoretical maximum we have to add some padding packets
* to make up for the lower data rate.
* (cf. VCD standard p. IV-6 ) */
/* Add the header overhead to the data rate.
* 2279 data bytes per audio pack, 2294 data bytes per video pack */
overhead_rate = audio_bitrate * 2294LL * (2324 - 2279);
overhead_rate += video_bitrate * 2279LL * (2324 - 2294);
/* Add padding so that the full bitrate is 2324*75 bytes/sec */
s->vcd_padding_bitrate_num = (2324LL * 75 * 8 - bitrate) * 2279 * 2294 - overhead_rate;
#define VCD_PADDING_BITRATE_DEN (2279 * 2294)
}
if (s->is_vcd || s->is_mpeg2)
/* every packet */
s->pack_header_freq = 1;
else
/* every 2 seconds */
s->pack_header_freq = 2 * bitrate / s->packet_size / 8;
/* the above seems to make pack_header_freq zero sometimes */
if (s->pack_header_freq == 0)
s->pack_header_freq = 1;
if (s->is_mpeg2)
/* every 200 packets. Need to look at the spec. */
s->system_header_freq = s->pack_header_freq * 40;
else if (s->is_vcd)
/* the standard mandates that there are only two system headers
* in the whole file: one in the first packet of each stream.
* (see standard p. IV-7 and IV-8) */
s->system_header_freq = 0x7fffffff;
else
s->system_header_freq = s->pack_header_freq * 5;
for (i = 0; i < ctx->nb_streams; i++) {
stream = ctx->streams[i]->priv_data;
stream->packet_number = 0;
}
s->system_header_size = get_system_header_size(ctx);
s->last_scr = AV_NOPTS_VALUE;
return 0;
}
static inline void put_timestamp(AVIOContext *pb, int id, int64_t timestamp)
{
avio_w8(pb, (id << 4) | (((timestamp >> 30) & 0x07) << 1) | 1);
avio_wb16(pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
avio_wb16(pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
}
/* return the number of padding bytes that should be inserted into
* the multiplexed stream. */
static int get_vcd_padding_size(AVFormatContext *ctx, int64_t pts)
{
MpegMuxContext *s = ctx->priv_data;
int pad_bytes = 0;
if (s->vcd_padding_bitrate_num > 0 && pts != AV_NOPTS_VALUE) {
int64_t full_pad_bytes;
// FIXME: this is wrong
full_pad_bytes =
av_rescale(s->vcd_padding_bitrate_num, pts, 90000LL * 8 * VCD_PADDING_BITRATE_DEN);
pad_bytes = (int)(full_pad_bytes - s->vcd_padding_bytes_written);
if (pad_bytes < 0)
/* might happen if we have already padded to a later timestamp. This
* can occur if another stream has already advanced further. */
pad_bytes = 0;
}
return pad_bytes;
}
/* Write an MPEG padding packet header. */
static void put_padding_packet(AVFormatContext *ctx, AVIOContext *pb,
int packet_bytes)
{
MpegMuxContext *s = ctx->priv_data;
avio_wb32(pb, PADDING_STREAM);
avio_wb16(pb, packet_bytes - 6);
if (!s->is_mpeg2) {
avio_w8(pb, 0x0f);
packet_bytes -= 7;
} else
packet_bytes -= 6;
ffio_fill(pb, 0xff, packet_bytes);
}
static int get_nb_frames(AVFormatContext *ctx, StreamInfo *stream, int len)
{
int nb_frames = 0;
PacketDesc *pkt_desc = stream->premux_packet;
while (len > 0) {
if (pkt_desc->size == pkt_desc->unwritten_size)
nb_frames++;
len -= pkt_desc->unwritten_size;
pkt_desc = pkt_desc->next;
}
return nb_frames;
}
/* flush the packet on stream stream_index */
static int flush_packet(AVFormatContext *ctx, int stream_index,
int64_t pts, int64_t dts, int64_t scr, int trailer_size)
{
MpegMuxContext *s = ctx->priv_data;
StreamInfo *stream = ctx->streams[stream_index]->priv_data;
uint8_t *buf_ptr;
int size, payload_size, startcode, id, stuffing_size, header_len;
int packet_size;
uint8_t buffer[128];
int zero_trail_bytes = 0;
int pad_packet_bytes = 0;
int pes_flags;
/* "general" pack without data specific to one stream? */
int general_pack = 0;
int nb_frames;
id = stream->id;
av_log(ctx, AV_LOG_TRACE, "packet ID=%2x PTS=%0.3f\n", id, pts / 90000.0);
buf_ptr = buffer;
if ((s->packet_number % s->pack_header_freq) == 0 || s->last_scr != scr) {
/* output pack and systems header if needed */
size = put_pack_header(ctx, buf_ptr, scr);
buf_ptr += size;
s->last_scr = scr;
if (s->is_vcd) {
/* there is exactly one system header for each stream in a VCD MPEG,
* One in the very first video packet and one in the very first
* audio packet (see VCD standard p. IV-7 and IV-8). */
if (stream->packet_number == 0) {
size = put_system_header(ctx, buf_ptr, id);
buf_ptr += size;
}
} else if (s->is_dvd) {
if (stream->align_iframe || s->packet_number == 0) {
int PES_bytes_to_fill = s->packet_size - size - 10;
if (pts != AV_NOPTS_VALUE) {
if (dts != pts)
PES_bytes_to_fill -= 5 + 5;
else
PES_bytes_to_fill -= 5;
}
if (stream->bytes_to_iframe == 0 || s->packet_number == 0) {
size = put_system_header(ctx, buf_ptr, 0);
buf_ptr += size;
size = buf_ptr - buffer;
avio_write(ctx->pb, buffer, size);
avio_wb32(ctx->pb, PRIVATE_STREAM_2);
avio_wb16(ctx->pb, 0x03d4); // length
avio_w8(ctx->pb, 0x00); // substream ID, 00=PCI
ffio_fill(ctx->pb, 0x00, 979);
avio_wb32(ctx->pb, PRIVATE_STREAM_2);
avio_wb16(ctx->pb, 0x03fa); // length
avio_w8(ctx->pb, 0x01); // substream ID, 01=DSI
ffio_fill(ctx->pb, 0x00, 1017);
memset(buffer, 0, 128);
buf_ptr = buffer;
s->packet_number++;
stream->align_iframe = 0;
// FIXME: rounding and first few bytes of each packet
scr += s->packet_size * 90000LL /
(s->mux_rate * 50LL);
size = put_pack_header(ctx, buf_ptr, scr);
s->last_scr = scr;
buf_ptr += size;
/* GOP Start */
} else if (stream->bytes_to_iframe < PES_bytes_to_fill) {
pad_packet_bytes = PES_bytes_to_fill -
stream->bytes_to_iframe;
}
}
} else {
if ((s->packet_number % s->system_header_freq) == 0) {
size = put_system_header(ctx, buf_ptr, 0);
buf_ptr += size;
}
}
}
size = buf_ptr - buffer;
avio_write(ctx->pb, buffer, size);
packet_size = s->packet_size - size;
if (s->is_vcd && (id & 0xe0) == AUDIO_ID)
/* The VCD standard demands that 20 zero bytes follow
* each audio pack (see standard p. IV-8). */
zero_trail_bytes += 20;
if ((s->is_vcd && stream->packet_number == 0) ||
(s->is_svcd && s->packet_number == 0)) {
/* for VCD the first pack of each stream contains only the pack header,
* the system header and lots of padding (see VCD standard p. IV-6).
* In the case of an audio pack, 20 zero bytes are also added at
* the end. */
/* For SVCD we fill the very first pack to increase compatibility with
* some DVD players. Not mandated by the standard. */
if (s->is_svcd)
/* the system header refers to both streams and no stream data */
general_pack = 1;
pad_packet_bytes = packet_size - zero_trail_bytes;
}
packet_size -= pad_packet_bytes + zero_trail_bytes;
if (packet_size > 0) {
/* packet header size */
packet_size -= 6;
/* packet header */
if (s->is_mpeg2) {
header_len = 3;
if (stream->packet_number == 0)
header_len += 3; /* PES extension */
header_len += 1; /* obligatory stuffing byte */
} else {
header_len = 0;
}
if (pts != AV_NOPTS_VALUE) {
if (dts != pts)
header_len += 5 + 5;
else
header_len += 5;
} else {
if (!s->is_mpeg2)
header_len++;
}
payload_size = packet_size - header_len;
if (id < 0xc0) {
startcode = PRIVATE_STREAM_1;
payload_size -= 1;
if (id >= 0x40) {
payload_size -= 3;
if (id >= 0xa0)
payload_size -= 3;
}
} else {
startcode = 0x100 + id;
}
stuffing_size = payload_size - av_fifo_size(stream->fifo);
// first byte does not fit -> reset pts/dts + stuffing
if (payload_size <= trailer_size && pts != AV_NOPTS_VALUE) {
int timestamp_len = 0;
if (dts != pts)
timestamp_len += 5;
if (pts != AV_NOPTS_VALUE)
timestamp_len += s->is_mpeg2 ? 5 : 4;
pts =
dts = AV_NOPTS_VALUE;
header_len -= timestamp_len;
if (s->is_dvd && stream->align_iframe) {
pad_packet_bytes += timestamp_len;
packet_size -= timestamp_len;
} else {
payload_size += timestamp_len;
}
stuffing_size += timestamp_len;
if (payload_size > trailer_size)
stuffing_size += payload_size - trailer_size;
}
// can't use padding, so use stuffing
if (pad_packet_bytes > 0 && pad_packet_bytes <= 7) {
packet_size += pad_packet_bytes;
payload_size += pad_packet_bytes; // undo the previous adjustment
if (stuffing_size < 0)
stuffing_size = pad_packet_bytes;
else
stuffing_size += pad_packet_bytes;
pad_packet_bytes = 0;
}
if (stuffing_size < 0)
stuffing_size = 0;
if (startcode == PRIVATE_STREAM_1 && id >= 0xa0) {
if (payload_size < av_fifo_size(stream->fifo))
stuffing_size += payload_size % stream->lpcm_align;
}
if (stuffing_size > 16) { /* <=16 for MPEG-1, <=32 for MPEG-2 */
pad_packet_bytes += stuffing_size;
packet_size -= stuffing_size;
payload_size -= stuffing_size;
stuffing_size = 0;
}
nb_frames = get_nb_frames(ctx, stream, payload_size - stuffing_size);
avio_wb32(ctx->pb, startcode);
avio_wb16(ctx->pb, packet_size);
if (!s->is_mpeg2)
ffio_fill(ctx->pb, 0xff, stuffing_size);
if (s->is_mpeg2) {
avio_w8(ctx->pb, 0x80); /* mpeg2 id */
pes_flags = 0;
if (pts != AV_NOPTS_VALUE) {
pes_flags |= 0x80;
if (dts != pts)
pes_flags |= 0x40;
}
/* Both the MPEG-2 and the SVCD standards demand that the
* P-STD_buffer_size field be included in the first packet of
* every stream. (see SVCD standard p. 26 V.2.3.1 and V.2.3.2
* and MPEG-2 standard 2.7.7) */
if (stream->packet_number == 0)
pes_flags |= 0x01;
avio_w8(ctx->pb, pes_flags); /* flags */
avio_w8(ctx->pb, header_len - 3 + stuffing_size);
if (pes_flags & 0x80) /* write pts */
put_timestamp(ctx->pb, (pes_flags & 0x40) ? 0x03 : 0x02, pts);
if (pes_flags & 0x40) /* write dts */
put_timestamp(ctx->pb, 0x01, dts);
if (pes_flags & 0x01) { /* write pes extension */
avio_w8(ctx->pb, 0x10); /* flags */
/* P-STD buffer info */
if ((id & 0xe0) == AUDIO_ID)
avio_wb16(ctx->pb, 0x4000 | stream->max_buffer_size / 128);
else
avio_wb16(ctx->pb, 0x6000 | stream->max_buffer_size / 1024);
}
} else {
if (pts != AV_NOPTS_VALUE) {
if (dts != pts) {
put_timestamp(ctx->pb, 0x03, pts);
put_timestamp(ctx->pb, 0x01, dts);
} else {
put_timestamp(ctx->pb, 0x02, pts);
}
} else {
avio_w8(ctx->pb, 0x0f);
}
}
if (s->is_mpeg2) {
/* special stuffing byte that is always written
* to prevent accidental generation of start codes. */
avio_w8(ctx->pb, 0xff);
ffio_fill(ctx->pb, 0xff, stuffing_size);
}
if (startcode == PRIVATE_STREAM_1) {
avio_w8(ctx->pb, id);
if (id >= 0xa0) {
/* LPCM (XXX: check nb_frames) */
avio_w8(ctx->pb, 7);
avio_wb16(ctx->pb, 4); /* skip 3 header bytes */
avio_w8(ctx->pb, stream->lpcm_header[0]);
avio_w8(ctx->pb, stream->lpcm_header[1]);
avio_w8(ctx->pb, stream->lpcm_header[2]);
} else if (id >= 0x40) {
/* AC-3 */
avio_w8(ctx->pb, nb_frames);
avio_wb16(ctx->pb, trailer_size + 1);
}
}
/* output data */
av_assert0(payload_size - stuffing_size <= av_fifo_size(stream->fifo));
av_fifo_generic_read(stream->fifo, ctx->pb,
payload_size - stuffing_size,
(void (*)(void*, void*, int))avio_write);
stream->bytes_to_iframe -= payload_size - stuffing_size;
} else {
payload_size =
stuffing_size = 0;
}
if (pad_packet_bytes > 0)
put_padding_packet(ctx, ctx->pb, pad_packet_bytes);
ffio_fill(ctx->pb, 0x00, zero_trail_bytes);
avio_write_marker(ctx->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_FLUSH_POINT);
s->packet_number++;
/* only increase the stream packet number if this pack actually contains
* something that is specific to this stream! I.e. a dedicated header
* or some data. */
if (!general_pack)
stream->packet_number++;
return payload_size - stuffing_size;
}
static void put_vcd_padding_sector(AVFormatContext *ctx)
{
/* There are two ways to do this padding: writing a sector/pack
* of 0 values, or writing an MPEG padding pack. Both seem to
* work with most decoders, BUT the VCD standard only allows a 0-sector
* (see standard p. IV-4, IV-5).
* So a 0-sector it is... */
MpegMuxContext *s = ctx->priv_data;
ffio_fill(ctx->pb, 0, s->packet_size);
s->vcd_padding_bytes_written += s->packet_size;
avio_write_marker(ctx->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_FLUSH_POINT);
/* increasing the packet number is correct. The SCR of the following packs
* is calculated from the packet_number and it has to include the padding
* sector (it represents the sector index, not the MPEG pack index)
* (see VCD standard p. IV-6) */
s->packet_number++;
}
static int remove_decoded_packets(AVFormatContext *ctx, int64_t scr)
{
int i;
for (i = 0; i < ctx->nb_streams; i++) {
AVStream *st = ctx->streams[i];
StreamInfo *stream = st->priv_data;
PacketDesc *pkt_desc;
while ((pkt_desc = stream->predecode_packet) &&
scr > pkt_desc->dts) { // FIXME: > vs >=
if (stream->buffer_index < pkt_desc->size ||
stream->predecode_packet == stream->premux_packet) {
av_log(ctx, AV_LOG_ERROR,
"buffer underflow st=%d bufi=%d size=%d\n",
i, stream->buffer_index, pkt_desc->size);
break;
}
stream->buffer_index -= pkt_desc->size;
stream->predecode_packet = pkt_desc->next;
if (!stream->predecode_packet)
stream->last_packet = NULL;
av_freep(&pkt_desc);
}
}
return 0;
}
static int output_packet(AVFormatContext *ctx, int flush)
{
MpegMuxContext *s = ctx->priv_data;
AVStream *st;
StreamInfo *stream;
int i, avail_space = 0, es_size, trailer_size;
int best_i = -1;
int best_score = INT_MIN;
int ignore_constraints = 0;
int ignore_delay = 0;
int64_t scr = s->last_scr;