3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #define MAX_PAYLOAD_SIZE 4096
25 uint8_t buffer[MAX_PAYLOAD_SIZE];
28 int max_buffer_size; /* in bytes */
34 int packet_size; /* required packet size */
35 int packet_data_max_size; /* maximum data size inside a packet */
37 int pack_header_freq; /* frequency (in packets^-1) at which we send pack headers */
38 int system_header_freq;
39 int mux_rate; /* bitrate in units of 50 bytes/s */
47 #define PACK_START_CODE ((unsigned int)0x000001ba)
48 #define SYSTEM_HEADER_START_CODE ((unsigned int)0x000001bb)
49 #define SEQUENCE_END_CODE ((unsigned int)0x000001b7)
50 #define PACKET_START_CODE_MASK ((unsigned int)0xffffff00)
51 #define PACKET_START_CODE_PREFIX ((unsigned int)0x00000100)
52 #define ISO_11172_END_CODE ((unsigned int)0x000001b9)
55 #define PROGRAM_STREAM_MAP 0x1bc
56 #define PRIVATE_STREAM_1 0x1bd
57 #define PADDING_STREAM 0x1be
58 #define PRIVATE_STREAM_2 0x1bf
64 extern AVOutputFormat mpeg1system_mux;
65 extern AVOutputFormat mpeg1vcd_mux;
66 extern AVOutputFormat mpeg2vob_mux;
68 static int put_pack_header(AVFormatContext *ctx,
69 uint8_t *buf, int64_t timestamp)
71 MpegMuxContext *s = ctx->priv_data;
74 init_put_bits(&pb, buf, 128, NULL, NULL);
76 put_bits(&pb, 32, PACK_START_CODE);
78 put_bits(&pb, 2, 0x1);
80 put_bits(&pb, 4, 0x2);
82 put_bits(&pb, 3, (uint32_t)((timestamp >> 30) & 0x07));
84 put_bits(&pb, 15, (uint32_t)((timestamp >> 15) & 0x7fff));
86 put_bits(&pb, 15, (uint32_t)((timestamp) & 0x7fff));
94 put_bits(&pb, 22, s->mux_rate);
97 put_bits(&pb, 5, 0x1f); /* reserved */
98 put_bits(&pb, 3, 0); /* stuffing length */
101 return pbBufPtr(&pb) - pb.buf;
104 static int put_system_header(AVFormatContext *ctx, uint8_t *buf)
106 MpegMuxContext *s = ctx->priv_data;
107 int size, rate_bound, i, private_stream_coded, id;
110 init_put_bits(&pb, buf, 128, NULL, NULL);
112 put_bits(&pb, 32, SYSTEM_HEADER_START_CODE);
113 put_bits(&pb, 16, 0);
116 rate_bound = s->mux_rate; /* maximum bit rate of the multiplexed stream */
117 put_bits(&pb, 22, rate_bound);
118 put_bits(&pb, 1, 1); /* marker */
119 put_bits(&pb, 6, s->audio_bound);
121 put_bits(&pb, 1, 1); /* variable bitrate */
122 put_bits(&pb, 1, 1); /* non constrainted bit stream */
124 put_bits(&pb, 1, 0); /* audio locked */
125 put_bits(&pb, 1, 0); /* video locked */
126 put_bits(&pb, 1, 1); /* marker */
128 put_bits(&pb, 5, s->video_bound);
129 put_bits(&pb, 8, 0xff); /* reserved byte */
131 /* audio stream info */
132 private_stream_coded = 0;
133 for(i=0;i<ctx->nb_streams;i++) {
134 StreamInfo *stream = ctx->streams[i]->priv_data;
137 /* special case for private streams (AC3 use that) */
138 if (private_stream_coded)
140 private_stream_coded = 1;
143 put_bits(&pb, 8, id); /* stream ID */
148 put_bits(&pb, 13, stream->max_buffer_size / 128);
152 put_bits(&pb, 13, stream->max_buffer_size / 1024);
156 size = pbBufPtr(&pb) - pb.buf;
157 /* patch packet size */
158 buf[4] = (size - 6) >> 8;
159 buf[5] = (size - 6) & 0xff;
164 static int mpeg_mux_init(AVFormatContext *ctx)
166 MpegMuxContext *s = ctx->priv_data;
167 int bitrate, i, mpa_id, mpv_id, ac3_id;
171 s->packet_number = 0;
172 s->is_vcd = (ctx->oformat == &mpeg1vcd_mux);
173 s->is_mpeg2 = (ctx->oformat == &mpeg2vob_mux);
176 s->packet_size = 2324; /* VCD packet size */
178 s->packet_size = 2048;
180 /* startcode(4) + length(2) + flags(1) */
181 s->packet_data_max_size = s->packet_size - 7;
187 for(i=0;i<ctx->nb_streams;i++) {
188 st = ctx->streams[i];
189 stream = av_mallocz(sizeof(StreamInfo));
192 st->priv_data = stream;
194 switch(st->codec.codec_type) {
195 case CODEC_TYPE_AUDIO:
196 if (st->codec.codec_id == CODEC_ID_AC3)
197 stream->id = ac3_id++;
199 stream->id = mpa_id++;
200 stream->max_buffer_size = 4 * 1024;
203 case CODEC_TYPE_VIDEO:
204 stream->id = mpv_id++;
205 stream->max_buffer_size = 46 * 1024;
213 /* we increase slightly the bitrate to take into account the
214 headers. XXX: compute it exactly */
216 for(i=0;i<ctx->nb_streams;i++) {
217 st = ctx->streams[i];
218 bitrate += st->codec.bit_rate;
220 s->mux_rate = (bitrate + (8 * 50) - 1) / (8 * 50);
222 if (s->is_vcd || s->is_mpeg2)
224 s->pack_header_freq = 1;
226 /* every 2 seconds */
227 s->pack_header_freq = 2 * bitrate / s->packet_size / 8;
230 /* every 200 packets. Need to look at the spec. */
231 s->system_header_freq = s->pack_header_freq * 40;
233 /* every 40 packets, this is my invention */
234 s->system_header_freq = s->pack_header_freq * 40;
236 s->system_header_freq = s->pack_header_freq * 5;
238 for(i=0;i<ctx->nb_streams;i++) {
239 stream = ctx->streams[i]->priv_data;
240 stream->buffer_ptr = 0;
241 stream->packet_number = 0;
242 stream->start_pts = -1;
246 for(i=0;i<ctx->nb_streams;i++) {
247 av_free(ctx->streams[i]->priv_data);
252 /* flush the packet on stream stream_index */
253 static void flush_packet(AVFormatContext *ctx, int stream_index)
255 MpegMuxContext *s = ctx->priv_data;
256 StreamInfo *stream = ctx->streams[stream_index]->priv_data;
258 int size, payload_size, startcode, id, len, stuffing_size, i, header_len;
263 timestamp = stream->start_pts;
266 printf("packet ID=%2x PTS=%0.3f\n",
267 id, timestamp / 90000.0);
271 if (((s->packet_number % s->pack_header_freq) == 0)) {
272 /* output pack and systems header if needed */
273 size = put_pack_header(ctx, buf_ptr, timestamp);
275 if ((s->packet_number % s->system_header_freq) == 0) {
276 size = put_system_header(ctx, buf_ptr);
280 size = buf_ptr - buffer;
281 put_buffer(&ctx->pb, buffer, size);
289 payload_size = s->packet_size - (size + 6 + header_len);
291 startcode = PRIVATE_STREAM_1;
294 startcode = 0x100 + id;
296 stuffing_size = payload_size - stream->buffer_ptr;
297 if (stuffing_size < 0)
300 put_be32(&ctx->pb, startcode);
302 put_be16(&ctx->pb, payload_size + header_len);
304 for(i=0;i<stuffing_size;i++)
305 put_byte(&ctx->pb, 0xff);
308 put_byte(&ctx->pb, 0x80); /* mpeg2 id */
309 put_byte(&ctx->pb, 0x80); /* flags */
310 put_byte(&ctx->pb, 0x05); /* header len (only pts is included) */
314 (((timestamp >> 30) & 0x07) << 1) |
316 put_be16(&ctx->pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
317 put_be16(&ctx->pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
319 if (startcode == PRIVATE_STREAM_1) {
320 put_byte(&ctx->pb, id);
321 if (id >= 0x80 && id <= 0xbf) {
322 /* XXX: need to check AC3 spec */
323 put_byte(&ctx->pb, 1);
324 put_byte(&ctx->pb, 0);
325 put_byte(&ctx->pb, 2);
330 put_buffer(&ctx->pb, stream->buffer, payload_size - stuffing_size);
331 put_flush_packet(&ctx->pb);
333 /* preserve remaining data */
334 len = stream->buffer_ptr - payload_size;
337 memmove(stream->buffer, stream->buffer + stream->buffer_ptr - len, len);
338 stream->buffer_ptr = len;
341 stream->packet_number++;
342 stream->start_pts = -1;
345 static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
346 const uint8_t *buf, int size, int64_t pts)
348 MpegMuxContext *s = ctx->priv_data;
349 AVStream *st = ctx->streams[stream_index];
350 StreamInfo *stream = st->priv_data;
355 if (stream->start_pts == -1) {
356 stream->start_pts = pts;
358 len = s->packet_data_max_size - stream->buffer_ptr;
361 memcpy(stream->buffer + stream->buffer_ptr, buf, len);
362 stream->buffer_ptr += len;
365 while (stream->buffer_ptr >= s->packet_data_max_size) {
366 /* output the packet */
367 if (stream->start_pts == -1)
368 stream->start_pts = pts;
369 flush_packet(ctx, stream_index);
375 static int mpeg_mux_end(AVFormatContext *ctx)
380 /* flush each packet */
381 for(i=0;i<ctx->nb_streams;i++) {
382 stream = ctx->streams[i]->priv_data;
383 if (stream->buffer_ptr > 0) {
384 flush_packet(ctx, i);
388 /* End header according to MPEG1 systems standard. We do not write
389 it as it is usually not needed by decoders and because it
390 complicates MPEG stream concatenation. */
391 //put_be32(&ctx->pb, ISO_11172_END_CODE);
392 //put_flush_packet(&ctx->pb);
394 for(i=0;i<ctx->nb_streams;i++)
395 av_freep(&ctx->streams[i]->priv_data);
400 /*********************************************/
403 #define MAX_SYNC_SIZE 100000
405 static int mpegps_probe(AVProbeData *p)
410 /* we search the first start code. If it is a packet start code,
411 then we decide it is mpeg ps. We do not send highest value to
412 give a chance to mpegts */
413 /* NOTE: the search range was restricted to avoid too many false
419 for (i = 0; i < 20; i++) {
421 code = (code << 8) | c;
422 if ((code & 0xffffff00) == 0x100) {
423 if (code == PACK_START_CODE ||
424 code == SYSTEM_HEADER_START_CODE ||
425 (code >= 0x1e0 && code <= 0x1ef) ||
426 (code >= 0x1c0 && code <= 0x1df) ||
427 code == PRIVATE_STREAM_2 ||
428 code == PROGRAM_STREAM_MAP ||
429 code == PRIVATE_STREAM_1 ||
430 code == PADDING_STREAM)
431 return AVPROBE_SCORE_MAX - 2;
440 typedef struct MpegDemuxContext {
444 static int find_start_code(ByteIOContext *pb, int *size_ptr,
445 uint32_t *header_state)
447 unsigned int state, v;
450 state = *header_state;
457 if (state == 0x000001) {
458 state = ((state << 8) | v) & 0xffffff;
462 state = ((state << 8) | v) & 0xffffff;
466 *header_state = state;
471 static int mpegps_read_header(AVFormatContext *s,
472 AVFormatParameters *ap)
474 MpegDemuxContext *m = s->priv_data;
475 m->header_state = 0xff;
476 /* no need to do more */
480 static int64_t get_pts(ByteIOContext *pb, int c)
487 pts = (int64_t)((c >> 1) & 0x07) << 30;
489 pts |= (int64_t)(val >> 1) << 15;
491 pts |= (int64_t)(val >> 1);
495 static int mpegps_read_packet(AVFormatContext *s,
498 MpegDemuxContext *m = s->priv_data;
500 int len, size, startcode, i, c, flags, header_len, type, codec_id;
503 /* next start code (should be immediately after) */
505 m->header_state = 0xff;
506 size = MAX_SYNC_SIZE;
507 startcode = find_start_code(&s->pb, &size, &m->header_state);
508 //printf("startcode=%x pos=0x%Lx\n", startcode, url_ftell(&s->pb));
511 if (startcode == PACK_START_CODE)
513 if (startcode == SYSTEM_HEADER_START_CODE)
515 if (startcode == PADDING_STREAM ||
516 startcode == PRIVATE_STREAM_2) {
518 len = get_be16(&s->pb);
519 url_fskip(&s->pb, len);
522 /* find matching stream */
523 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
524 (startcode >= 0x1e0 && startcode <= 0x1ef) ||
525 (startcode == 0x1bd)))
528 len = get_be16(&s->pb);
529 pts = AV_NOPTS_VALUE;
530 dts = AV_NOPTS_VALUE;
533 c = get_byte(&s->pb);
535 /* XXX: for mpeg1, should test only bit 7 */
539 if ((c & 0xc0) == 0x40) {
540 /* buffer scale & size */
542 c = get_byte(&s->pb);
545 if ((c & 0xf0) == 0x20) {
546 pts = get_pts(&s->pb, c);
548 } else if ((c & 0xf0) == 0x30) {
549 pts = get_pts(&s->pb, c);
550 dts = get_pts(&s->pb, -1);
552 } else if ((c & 0xc0) == 0x80) {
554 if ((c & 0x30) != 0) {
555 fprintf(stderr, "Encrypted multiplex not handled\n");
558 flags = get_byte(&s->pb);
559 header_len = get_byte(&s->pb);
561 if (header_len > len)
563 if ((flags & 0xc0) == 0x80) {
564 pts = get_pts(&s->pb, -1);
567 } if ((flags & 0xc0) == 0xc0) {
568 pts = get_pts(&s->pb, -1);
569 dts = get_pts(&s->pb, -1);
574 while (header_len > 0) {
579 if (startcode == 0x1bd) {
580 startcode = get_byte(&s->pb);
582 if (startcode >= 0x80 && startcode <= 0xbf) {
583 /* audio: skip header */
591 /* now find stream */
592 for(i=0;i<s->nb_streams;i++) {
594 if (st->id == startcode)
597 if (startcode >= 0x1e0 && startcode <= 0x1ef) {
598 type = CODEC_TYPE_VIDEO;
599 codec_id = CODEC_ID_MPEG1VIDEO;
600 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
601 type = CODEC_TYPE_AUDIO;
602 codec_id = CODEC_ID_MP2;
603 } else if (startcode >= 0x80 && startcode <= 0x9f) {
604 type = CODEC_TYPE_AUDIO;
605 codec_id = CODEC_ID_AC3;
606 } else if (startcode >= 0xa0 && startcode <= 0xbf) {
607 type = CODEC_TYPE_AUDIO;
608 codec_id = CODEC_ID_PCM_S16BE;
612 url_fskip(&s->pb, len);
615 /* no stream found: add a new stream */
616 st = av_new_stream(s, startcode);
619 st->codec.codec_type = type;
620 st->codec.codec_id = codec_id;
622 if (startcode >= 0xa0 && startcode <= 0xbf) {
624 static const int lpcm_freq_tab[4] = { 48000, 96000, 44100, 32000 };
626 /* for LPCM, we just skip the header and consider it is raw
630 get_byte(&s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
631 b1 = get_byte(&s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
632 get_byte(&s->pb); /* dynamic range control (0x80 = off) */
634 freq = (b1 >> 4) & 3;
635 st->codec.sample_rate = lpcm_freq_tab[freq];
636 st->codec.channels = 1 + (b1 & 7);
637 st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2;
639 av_new_packet(pkt, len);
640 //printf("\nRead Packet ID: %x PTS: %f Size: %d", startcode,
641 // (float)pts/90000, len);
642 get_buffer(&s->pb, pkt->data, pkt->size);
644 pkt->stream_index = st->index;
648 static int mpegps_read_close(AVFormatContext *s)
653 static AVOutputFormat mpeg1system_mux = {
655 "MPEG1 System format",
658 sizeof(MpegMuxContext),
662 mpeg_mux_write_packet,
666 static AVOutputFormat mpeg1vcd_mux = {
668 "MPEG1 System format (VCD)",
671 sizeof(MpegMuxContext),
675 mpeg_mux_write_packet,
679 static AVOutputFormat mpeg2vob_mux = {
681 "MPEG2 PS format (VOB)",
684 sizeof(MpegMuxContext),
688 mpeg_mux_write_packet,
692 AVInputFormat mpegps_demux = {
695 sizeof(MpegDemuxContext),
700 .flags = AVFMT_NOHEADER,
703 int mpegps_init(void)
705 av_register_output_format(&mpeg1system_mux);
706 av_register_output_format(&mpeg1vcd_mux);
707 av_register_output_format(&mpeg2vob_mux);
708 av_register_input_format(&mpegps_demux);