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, 0x2);
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, int last_pkt)
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;
261 int last = last_pkt ? 4 : 0;
264 timestamp = stream->start_pts;
267 printf("packet ID=%2x PTS=%0.3f\n",
268 id, timestamp / 90000.0);
272 if (((s->packet_number % s->pack_header_freq) == 0)) {
273 /* output pack and systems header if needed */
274 size = put_pack_header(ctx, buf_ptr, timestamp);
276 if ((s->packet_number % s->system_header_freq) == 0) {
277 size = put_system_header(ctx, buf_ptr);
281 size = buf_ptr - buffer;
282 put_buffer(&ctx->pb, buffer, size);
290 payload_size = s->packet_size - (size + 6 + header_len + last);
292 startcode = PRIVATE_STREAM_1;
295 startcode = 0x100 + id;
297 stuffing_size = payload_size - stream->buffer_ptr;
298 if (stuffing_size < 0)
301 put_be32(&ctx->pb, startcode);
303 put_be16(&ctx->pb, payload_size + header_len);
305 for(i=0;i<stuffing_size;i++)
306 put_byte(&ctx->pb, 0xff);
309 put_byte(&ctx->pb, 0x80); /* mpeg2 id */
310 put_byte(&ctx->pb, 0x80); /* flags */
311 put_byte(&ctx->pb, 0x05); /* header len (only pts is included) */
315 (((timestamp >> 30) & 0x07) << 1) |
317 put_be16(&ctx->pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
318 put_be16(&ctx->pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
320 if (startcode == PRIVATE_STREAM_1) {
321 put_byte(&ctx->pb, id);
322 if (id >= 0x80 && id <= 0xbf) {
323 /* XXX: need to check AC3 spec */
324 put_byte(&ctx->pb, 1);
325 put_byte(&ctx->pb, 0);
326 put_byte(&ctx->pb, 2);
331 put_be32(&ctx->pb, ISO_11172_END_CODE);
334 put_buffer(&ctx->pb, stream->buffer, payload_size - stuffing_size);
335 put_flush_packet(&ctx->pb);
337 /* preserve remaining data */
338 len = stream->buffer_ptr - payload_size;
341 memmove(stream->buffer, stream->buffer + stream->buffer_ptr - len, len);
342 stream->buffer_ptr = len;
345 stream->packet_number++;
346 stream->start_pts = -1;
349 static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
350 uint8_t *buf, int size, int pts)
352 MpegMuxContext *s = ctx->priv_data;
353 AVStream *st = ctx->streams[stream_index];
354 StreamInfo *stream = st->priv_data;
359 if (stream->start_pts == -1) {
360 stream->start_pts = pts;
362 len = s->packet_data_max_size - stream->buffer_ptr;
365 memcpy(stream->buffer + stream->buffer_ptr, buf, len);
366 stream->buffer_ptr += len;
369 while (stream->buffer_ptr >= s->packet_data_max_size) {
370 /* output the packet */
371 if (stream->start_pts == -1)
372 stream->start_pts = pts;
373 flush_packet(ctx, stream_index, 0);
379 static int mpeg_mux_end(AVFormatContext *ctx)
384 /* flush each packet */
385 for(i=0;i<ctx->nb_streams;i++) {
386 stream = ctx->streams[i]->priv_data;
387 if (stream->buffer_ptr > 0) {
388 if (i == (ctx->nb_streams - 1))
389 flush_packet(ctx, i, 1);
391 flush_packet(ctx, i, 0);
395 /* write the end header */
396 //put_be32(&ctx->pb, ISO_11172_END_CODE);
397 //put_flush_packet(&ctx->pb);
401 /*********************************************/
404 #define MAX_SYNC_SIZE 100000
406 static int mpegps_probe(AVProbeData *p)
411 /* we search the first start code. If it is a packet start code,
412 then we decide it is mpeg ps. We do not send highest value to
413 give a chance to mpegts */
414 /* NOTE: the search range was restricted to avoid too many false
420 code = (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | (d[3]);
421 if ((code & 0xffffff00) == 0x100) {
422 if (code == PACK_START_CODE ||
423 code == SYSTEM_HEADER_START_CODE ||
424 (code >= 0x1e0 && code <= 0x1ef) ||
425 (code >= 0x1c0 && code <= 0x1df) ||
426 code == PRIVATE_STREAM_2 ||
427 code == PROGRAM_STREAM_MAP ||
428 code == PRIVATE_STREAM_1 ||
429 code == PADDING_STREAM)
430 return AVPROBE_SCORE_MAX - 1;
438 typedef struct MpegDemuxContext {
442 static int find_start_code(ByteIOContext *pb, int *size_ptr,
443 uint32_t *header_state)
445 unsigned int state, v;
448 state = *header_state;
455 if (state == 0x000001) {
456 state = ((state << 8) | v) & 0xffffff;
460 state = ((state << 8) | v) & 0xffffff;
464 *header_state = state;
469 static int mpegps_read_header(AVFormatContext *s,
470 AVFormatParameters *ap)
472 MpegDemuxContext *m = s->priv_data;
473 m->header_state = 0xff;
474 /* no need to do more */
478 static int64_t get_pts(ByteIOContext *pb, int c)
485 pts = (int64_t)((c >> 1) & 0x07) << 30;
487 pts |= (int64_t)(val >> 1) << 15;
489 pts |= (int64_t)(val >> 1);
493 static int mpegps_read_packet(AVFormatContext *s,
496 MpegDemuxContext *m = s->priv_data;
498 int len, size, startcode, i, c, flags, header_len, type, codec_id;
501 /* next start code (should be immediately after) */
503 m->header_state = 0xff;
504 size = MAX_SYNC_SIZE;
505 startcode = find_start_code(&s->pb, &size, &m->header_state);
506 //printf("startcode=%x pos=0x%Lx\n", startcode, url_ftell(&s->pb));
509 if (startcode == PACK_START_CODE)
511 if (startcode == SYSTEM_HEADER_START_CODE)
513 if (startcode == PADDING_STREAM ||
514 startcode == PRIVATE_STREAM_2) {
516 len = get_be16(&s->pb);
517 url_fskip(&s->pb, len);
520 /* find matching stream */
521 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
522 (startcode >= 0x1e0 && startcode <= 0x1ef) ||
523 (startcode == 0x1bd)))
526 len = get_be16(&s->pb);
527 pts = AV_NOPTS_VALUE;
528 dts = AV_NOPTS_VALUE;
531 c = get_byte(&s->pb);
533 /* XXX: for mpeg1, should test only bit 7 */
537 if ((c & 0xc0) == 0x40) {
538 /* buffer scale & size */
540 c = get_byte(&s->pb);
543 if ((c & 0xf0) == 0x20) {
544 pts = get_pts(&s->pb, c);
546 } else if ((c & 0xf0) == 0x30) {
547 pts = get_pts(&s->pb, c);
548 dts = get_pts(&s->pb, -1);
550 } else if ((c & 0xc0) == 0x80) {
552 if ((c & 0x30) != 0) {
553 fprintf(stderr, "Encrypted multiplex not handled\n");
556 flags = get_byte(&s->pb);
557 header_len = get_byte(&s->pb);
559 if (header_len > len)
561 if ((flags & 0xc0) == 0x80) {
562 pts = get_pts(&s->pb, -1);
565 } if ((flags & 0xc0) == 0xc0) {
566 pts = get_pts(&s->pb, -1);
567 dts = get_pts(&s->pb, -1);
572 while (header_len > 0) {
577 if (startcode == 0x1bd) {
578 startcode = get_byte(&s->pb);
580 if (startcode >= 0x80 && startcode <= 0xbf) {
581 /* audio: skip header */
589 /* now find stream */
590 for(i=0;i<s->nb_streams;i++) {
592 if (st->id == startcode)
595 if (startcode >= 0x1e0 && startcode <= 0x1ef) {
596 type = CODEC_TYPE_VIDEO;
597 codec_id = CODEC_ID_MPEG1VIDEO;
598 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
599 type = CODEC_TYPE_AUDIO;
600 codec_id = CODEC_ID_MP2;
601 } else if (startcode >= 0x80 && startcode <= 0x9f) {
602 type = CODEC_TYPE_AUDIO;
603 codec_id = CODEC_ID_AC3;
604 } else if (startcode >= 0xa0 && startcode <= 0xbf) {
605 type = CODEC_TYPE_AUDIO;
606 codec_id = CODEC_ID_PCM_S16BE;
610 url_fskip(&s->pb, len);
613 /* no stream found: add a new stream */
614 st = av_new_stream(s, startcode);
617 st->codec.codec_type = type;
618 st->codec.codec_id = codec_id;
620 if (startcode >= 0xa0 && startcode <= 0xbf) {
622 static const int lpcm_freq_tab[4] = { 48000, 96000, 44100, 32000 };
624 /* for LPCM, we just skip the header and consider it is raw
628 get_byte(&s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
629 b1 = get_byte(&s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
630 get_byte(&s->pb); /* dynamic range control (0x80 = off) */
632 freq = (b1 >> 4) & 3;
633 st->codec.sample_rate = lpcm_freq_tab[freq];
634 st->codec.channels = 1 + (b1 & 7);
635 st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2;
637 av_new_packet(pkt, len);
638 //printf("\nRead Packet ID: %x PTS: %f Size: %d", startcode,
639 // (float)pts/90000, len);
640 get_buffer(&s->pb, pkt->data, pkt->size);
642 pkt->stream_index = st->index;
646 static int mpegps_read_close(AVFormatContext *s)
651 static AVOutputFormat mpeg1system_mux = {
653 "MPEG1 System format",
656 sizeof(MpegMuxContext),
660 mpeg_mux_write_packet,
664 static AVOutputFormat mpeg1vcd_mux = {
666 "MPEG1 System format (VCD)",
669 sizeof(MpegMuxContext),
673 mpeg_mux_write_packet,
677 static AVOutputFormat mpeg2vob_mux = {
679 "MPEG2 PS format (VOB)",
682 sizeof(MpegMuxContext),
686 mpeg_mux_write_packet,
690 static AVInputFormat mpegps_demux = {
693 sizeof(MpegDemuxContext),
698 .flags = AVFMT_NOHEADER,
701 int mpegps_init(void)
703 av_register_output_format(&mpeg1system_mux);
704 av_register_output_format(&mpeg1vcd_mux);
705 av_register_output_format(&mpeg2vob_mux);
706 av_register_input_format(&mpegps_demux);