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 #ifdef CONFIG_ENCODERS
65 extern AVOutputFormat mpeg1system_mux;
66 extern AVOutputFormat mpeg1vcd_mux;
67 extern AVOutputFormat mpeg2vob_mux;
69 static int put_pack_header(AVFormatContext *ctx,
70 uint8_t *buf, int64_t timestamp)
72 MpegMuxContext *s = ctx->priv_data;
75 init_put_bits(&pb, buf, 128);
77 put_bits(&pb, 32, PACK_START_CODE);
79 put_bits(&pb, 2, 0x1);
81 put_bits(&pb, 4, 0x2);
83 put_bits(&pb, 3, (uint32_t)((timestamp >> 30) & 0x07));
85 put_bits(&pb, 15, (uint32_t)((timestamp >> 15) & 0x7fff));
87 put_bits(&pb, 15, (uint32_t)((timestamp) & 0x7fff));
95 put_bits(&pb, 22, s->mux_rate);
98 put_bits(&pb, 5, 0x1f); /* reserved */
99 put_bits(&pb, 3, 0); /* stuffing length */
102 return pbBufPtr(&pb) - pb.buf;
105 static int put_system_header(AVFormatContext *ctx, uint8_t *buf)
107 MpegMuxContext *s = ctx->priv_data;
108 int size, rate_bound, i, private_stream_coded, id;
111 init_put_bits(&pb, buf, 128);
113 put_bits(&pb, 32, SYSTEM_HEADER_START_CODE);
114 put_bits(&pb, 16, 0);
117 rate_bound = s->mux_rate; /* maximum bit rate of the multiplexed stream */
118 put_bits(&pb, 22, rate_bound);
119 put_bits(&pb, 1, 1); /* marker */
120 put_bits(&pb, 6, s->audio_bound);
122 put_bits(&pb, 1, 1); /* variable bitrate */
123 put_bits(&pb, 1, 1); /* non constrainted bit stream */
125 put_bits(&pb, 1, 0); /* audio locked */
126 put_bits(&pb, 1, 0); /* video locked */
127 put_bits(&pb, 1, 1); /* marker */
129 put_bits(&pb, 5, s->video_bound);
130 put_bits(&pb, 8, 0xff); /* reserved byte */
132 /* audio stream info */
133 private_stream_coded = 0;
134 for(i=0;i<ctx->nb_streams;i++) {
135 StreamInfo *stream = ctx->streams[i]->priv_data;
138 /* special case for private streams (AC3 use that) */
139 if (private_stream_coded)
141 private_stream_coded = 1;
144 put_bits(&pb, 8, id); /* stream ID */
149 put_bits(&pb, 13, stream->max_buffer_size / 128);
153 put_bits(&pb, 13, stream->max_buffer_size / 1024);
157 size = pbBufPtr(&pb) - pb.buf;
158 /* patch packet size */
159 buf[4] = (size - 6) >> 8;
160 buf[5] = (size - 6) & 0xff;
165 static int mpeg_mux_init(AVFormatContext *ctx)
167 MpegMuxContext *s = ctx->priv_data;
168 int bitrate, i, mpa_id, mpv_id, ac3_id;
172 s->packet_number = 0;
173 s->is_vcd = (ctx->oformat == &mpeg1vcd_mux);
174 s->is_mpeg2 = (ctx->oformat == &mpeg2vob_mux);
177 s->packet_size = 2324; /* VCD packet size */
179 s->packet_size = 2048;
181 /* startcode(4) + length(2) + flags(1) */
182 s->packet_data_max_size = s->packet_size - 7;
188 for(i=0;i<ctx->nb_streams;i++) {
189 st = ctx->streams[i];
190 stream = av_mallocz(sizeof(StreamInfo));
193 st->priv_data = stream;
195 switch(st->codec.codec_type) {
196 case CODEC_TYPE_AUDIO:
197 if (st->codec.codec_id == CODEC_ID_AC3)
198 stream->id = ac3_id++;
200 stream->id = mpa_id++;
201 stream->max_buffer_size = 4 * 1024;
204 case CODEC_TYPE_VIDEO:
205 stream->id = mpv_id++;
206 stream->max_buffer_size = 46 * 1024;
214 /* we increase slightly the bitrate to take into account the
215 headers. XXX: compute it exactly */
217 for(i=0;i<ctx->nb_streams;i++) {
218 st = ctx->streams[i];
219 bitrate += st->codec.bit_rate;
221 s->mux_rate = (bitrate + (8 * 50) - 1) / (8 * 50);
223 if (s->is_vcd || s->is_mpeg2)
225 s->pack_header_freq = 1;
227 /* every 2 seconds */
228 s->pack_header_freq = 2 * bitrate / s->packet_size / 8;
230 /* the above seems to make pack_header_freq zero sometimes */
231 if (s->pack_header_freq == 0)
232 s->pack_header_freq = 1;
235 /* every 200 packets. Need to look at the spec. */
236 s->system_header_freq = s->pack_header_freq * 40;
238 /* every 40 packets, this is my invention */
239 s->system_header_freq = s->pack_header_freq * 40;
241 s->system_header_freq = s->pack_header_freq * 5;
243 for(i=0;i<ctx->nb_streams;i++) {
244 stream = ctx->streams[i]->priv_data;
245 stream->buffer_ptr = 0;
246 stream->packet_number = 0;
247 stream->start_pts = -1;
251 for(i=0;i<ctx->nb_streams;i++) {
252 av_free(ctx->streams[i]->priv_data);
257 /* flush the packet on stream stream_index */
258 static void flush_packet(AVFormatContext *ctx, int stream_index)
260 MpegMuxContext *s = ctx->priv_data;
261 StreamInfo *stream = ctx->streams[stream_index]->priv_data;
263 int size, payload_size, startcode, id, len, stuffing_size, i, header_len;
268 timestamp = stream->start_pts;
271 printf("packet ID=%2x PTS=%0.3f\n",
272 id, timestamp / 90000.0);
276 if (((s->packet_number % s->pack_header_freq) == 0)) {
277 /* output pack and systems header if needed */
278 size = put_pack_header(ctx, buf_ptr, timestamp);
280 if ((s->packet_number % s->system_header_freq) == 0) {
281 size = put_system_header(ctx, buf_ptr);
285 size = buf_ptr - buffer;
286 put_buffer(&ctx->pb, buffer, size);
294 payload_size = s->packet_size - (size + 6 + header_len);
296 startcode = PRIVATE_STREAM_1;
299 startcode = 0x100 + id;
301 stuffing_size = payload_size - stream->buffer_ptr;
302 if (stuffing_size < 0)
305 put_be32(&ctx->pb, startcode);
307 put_be16(&ctx->pb, payload_size + header_len);
309 for(i=0;i<stuffing_size;i++)
310 put_byte(&ctx->pb, 0xff);
313 put_byte(&ctx->pb, 0x80); /* mpeg2 id */
314 put_byte(&ctx->pb, 0x80); /* flags */
315 put_byte(&ctx->pb, 0x05); /* header len (only pts is included) */
319 (((timestamp >> 30) & 0x07) << 1) |
321 put_be16(&ctx->pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
322 put_be16(&ctx->pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
324 if (startcode == PRIVATE_STREAM_1) {
325 put_byte(&ctx->pb, id);
326 if (id >= 0x80 && id <= 0xbf) {
327 /* XXX: need to check AC3 spec */
328 put_byte(&ctx->pb, 1);
329 put_byte(&ctx->pb, 0);
330 put_byte(&ctx->pb, 2);
335 put_buffer(&ctx->pb, stream->buffer, payload_size - stuffing_size);
336 put_flush_packet(&ctx->pb);
338 /* preserve remaining data */
339 len = stream->buffer_ptr - payload_size;
342 memmove(stream->buffer, stream->buffer + stream->buffer_ptr - len, len);
343 stream->buffer_ptr = len;
346 stream->packet_number++;
347 stream->start_pts = -1;
350 static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
351 const uint8_t *buf, int size, int64_t pts)
353 MpegMuxContext *s = ctx->priv_data;
354 AVStream *st = ctx->streams[stream_index];
355 StreamInfo *stream = st->priv_data;
360 if (stream->start_pts == -1) {
361 stream->start_pts = pts;
363 len = s->packet_data_max_size - stream->buffer_ptr;
366 memcpy(stream->buffer + stream->buffer_ptr, buf, len);
367 stream->buffer_ptr += len;
370 while (stream->buffer_ptr >= s->packet_data_max_size) {
371 /* output the packet */
372 if (stream->start_pts == -1)
373 stream->start_pts = pts;
374 flush_packet(ctx, stream_index);
380 static int mpeg_mux_end(AVFormatContext *ctx)
385 /* flush each packet */
386 for(i=0;i<ctx->nb_streams;i++) {
387 stream = ctx->streams[i]->priv_data;
388 if (stream->buffer_ptr > 0) {
389 flush_packet(ctx, i);
393 /* End header according to MPEG1 systems standard. We do not write
394 it as it is usually not needed by decoders and because it
395 complicates MPEG stream concatenation. */
396 //put_be32(&ctx->pb, ISO_11172_END_CODE);
397 //put_flush_packet(&ctx->pb);
399 for(i=0;i<ctx->nb_streams;i++)
400 av_freep(&ctx->streams[i]->priv_data);
404 #endif //CONFIG_ENCODERS
406 /*********************************************/
409 #define MAX_SYNC_SIZE 100000
411 static int mpegps_probe(AVProbeData *p)
416 /* we search the first start code. If it is a packet start code,
417 then we decide it is mpeg ps. We do not send highest value to
418 give a chance to mpegts */
419 /* NOTE: the search range was restricted to avoid too many false
425 for (i = 0; i < 20; i++) {
427 code = (code << 8) | c;
428 if ((code & 0xffffff00) == 0x100) {
429 if (code == PACK_START_CODE ||
430 code == SYSTEM_HEADER_START_CODE ||
431 (code >= 0x1e0 && code <= 0x1ef) ||
432 (code >= 0x1c0 && code <= 0x1df) ||
433 code == PRIVATE_STREAM_2 ||
434 code == PROGRAM_STREAM_MAP ||
435 code == PRIVATE_STREAM_1 ||
436 code == PADDING_STREAM)
437 return AVPROBE_SCORE_MAX - 2;
446 typedef struct MpegDemuxContext {
450 static int find_start_code(ByteIOContext *pb, int *size_ptr,
451 uint32_t *header_state)
453 unsigned int state, v;
456 state = *header_state;
463 if (state == 0x000001) {
464 state = ((state << 8) | v) & 0xffffff;
468 state = ((state << 8) | v) & 0xffffff;
472 *header_state = state;
477 static int mpegps_read_header(AVFormatContext *s,
478 AVFormatParameters *ap)
480 MpegDemuxContext *m = s->priv_data;
481 m->header_state = 0xff;
482 s->ctx_flags |= AVFMTCTX_NOHEADER;
484 /* no need to do more */
488 static int64_t get_pts(ByteIOContext *pb, int c)
495 pts = (int64_t)((c >> 1) & 0x07) << 30;
497 pts |= (int64_t)(val >> 1) << 15;
499 pts |= (int64_t)(val >> 1);
503 static int mpegps_read_packet(AVFormatContext *s,
506 MpegDemuxContext *m = s->priv_data;
508 int len, size, startcode, i, c, flags, header_len, type, codec_id;
511 /* next start code (should be immediately after) */
513 m->header_state = 0xff;
514 size = MAX_SYNC_SIZE;
515 startcode = find_start_code(&s->pb, &size, &m->header_state);
516 //printf("startcode=%x pos=0x%Lx\n", startcode, url_ftell(&s->pb));
519 if (startcode == PACK_START_CODE)
521 if (startcode == SYSTEM_HEADER_START_CODE)
523 if (startcode == PADDING_STREAM ||
524 startcode == PRIVATE_STREAM_2) {
526 len = get_be16(&s->pb);
527 url_fskip(&s->pb, len);
530 /* find matching stream */
531 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
532 (startcode >= 0x1e0 && startcode <= 0x1ef) ||
533 (startcode == 0x1bd)))
536 len = get_be16(&s->pb);
537 pts = AV_NOPTS_VALUE;
538 dts = AV_NOPTS_VALUE;
541 c = get_byte(&s->pb);
543 /* XXX: for mpeg1, should test only bit 7 */
547 if ((c & 0xc0) == 0x40) {
548 /* buffer scale & size */
550 c = get_byte(&s->pb);
553 if ((c & 0xf0) == 0x20) {
554 pts = get_pts(&s->pb, c);
556 } else if ((c & 0xf0) == 0x30) {
557 pts = get_pts(&s->pb, c);
558 dts = get_pts(&s->pb, -1);
560 } else if ((c & 0xc0) == 0x80) {
562 if ((c & 0x30) != 0) {
563 fprintf(stderr, "Encrypted multiplex not handled\n");
566 flags = get_byte(&s->pb);
567 header_len = get_byte(&s->pb);
569 if (header_len > len)
571 if ((flags & 0xc0) == 0x80) {
572 pts = get_pts(&s->pb, -1);
575 } if ((flags & 0xc0) == 0xc0) {
576 pts = get_pts(&s->pb, -1);
577 dts = get_pts(&s->pb, -1);
582 while (header_len > 0) {
587 if (startcode == 0x1bd) {
588 startcode = get_byte(&s->pb);
590 if (startcode >= 0x80 && startcode <= 0xbf) {
591 /* audio: skip header */
599 /* now find stream */
600 for(i=0;i<s->nb_streams;i++) {
602 if (st->id == startcode)
605 if (startcode >= 0x1e0 && startcode <= 0x1ef) {
606 type = CODEC_TYPE_VIDEO;
607 codec_id = CODEC_ID_MPEG1VIDEO;
608 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
609 type = CODEC_TYPE_AUDIO;
610 codec_id = CODEC_ID_MP2;
611 } else if (startcode >= 0x80 && startcode <= 0x9f) {
612 type = CODEC_TYPE_AUDIO;
613 codec_id = CODEC_ID_AC3;
614 } else if (startcode >= 0xa0 && startcode <= 0xbf) {
615 type = CODEC_TYPE_AUDIO;
616 codec_id = CODEC_ID_PCM_S16BE;
620 url_fskip(&s->pb, len);
623 /* no stream found: add a new stream */
624 st = av_new_stream(s, startcode);
627 st->codec.codec_type = type;
628 st->codec.codec_id = codec_id;
630 if (startcode >= 0xa0 && startcode <= 0xbf) {
632 static const int lpcm_freq_tab[4] = { 48000, 96000, 44100, 32000 };
634 /* for LPCM, we just skip the header and consider it is raw
638 get_byte(&s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
639 b1 = get_byte(&s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
640 get_byte(&s->pb); /* dynamic range control (0x80 = off) */
642 freq = (b1 >> 4) & 3;
643 st->codec.sample_rate = lpcm_freq_tab[freq];
644 st->codec.channels = 1 + (b1 & 7);
645 st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2;
647 av_new_packet(pkt, len);
648 //printf("\nRead Packet ID: %x PTS: %f Size: %d", startcode,
649 // (float)pts/90000, len);
650 get_buffer(&s->pb, pkt->data, pkt->size);
652 pkt->stream_index = st->index;
656 static int mpegps_read_close(AVFormatContext *s)
661 #ifdef CONFIG_ENCODERS
662 static AVOutputFormat mpeg1system_mux = {
664 "MPEG1 System format",
667 sizeof(MpegMuxContext),
671 mpeg_mux_write_packet,
675 static AVOutputFormat mpeg1vcd_mux = {
677 "MPEG1 System format (VCD)",
680 sizeof(MpegMuxContext),
684 mpeg_mux_write_packet,
688 static AVOutputFormat mpeg2vob_mux = {
690 "MPEG2 PS format (VOB)",
693 sizeof(MpegMuxContext),
697 mpeg_mux_write_packet,
700 #endif //CONFIG_ENCODERS
702 AVInputFormat mpegps_demux = {
705 sizeof(MpegDemuxContext),
712 int mpegps_init(void)
714 #ifdef CONFIG_ENCODERS
715 av_register_output_format(&mpeg1system_mux);
716 av_register_output_format(&mpeg1vcd_mux);
717 av_register_output_format(&mpeg2vob_mux);
718 #endif //CONFIG_ENCODERS
719 av_register_input_format(&mpegps_demux);