FFmpeg: libavformat/mpeg.c Source File

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libavformat

mpeg.c

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1 /*

2 * MPEG1/2 demuxer

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 #include "avformat.h"

23 #include "internal.h"

24 #include "mpeg.h"

26 #if CONFIG_VOBSUB_DEMUXER

27 # include "subtitles.h"

28 # include "libavutil/bprint.h"

29 #endif

31 #undef NDEBUG

32 #include <assert.h>

33 #include "libavutil/avassert.h"

35 /*********************************************/

36 /* demux code */

38 #define MAX_SYNC_SIZE 100000

40 static int check_pes(const uint8_t *p, const uint8_t *end){

41 int pes1;

42 int pes2= (p[3] & 0xC0) == 0x80

43 && (p[4] & 0xC0) != 0x40

44 &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));

46 for(p+=3; p<end && *p == 0xFF; p++);

47 if((*p&0xC0) == 0x40) p+=2;

48 if((*p&0xF0) == 0x20){

49 pes1= p[0]&p[2]&p[4]&1;

50 }else if((*p&0xF0) == 0x30){

51 pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;

52 }else

53 pes1 = *p == 0x0F;

55 return pes1||pes2;

56 }

58 static int check_pack_header(const uint8_t *buf) {

59 return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;

60 }

62 static int mpegps_probe(AVProbeData *p)

63 {

64 uint32_t code= -1;

65 int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0;

66 int i;

67 int score=0;

69 for(i=0; i<p->buf_size; i++){

70 code = (code<<8) + p->buf[i];

71 if ((code & 0xffffff00) == 0x100) {

72 int len= p->buf[i+1] << 8 | p->buf[i+2];

73 int pes= check_pes(p->buf+i, p->buf+p->buf_size);

74 int pack = check_pack_header(p->buf+i);

76 if(code == SYSTEM_HEADER_START_CODE) sys++;

77 else if(code == PACK_START_CODE && pack) pspack++;

78 else if((code & 0xf0) == VIDEO_ID && pes) vid++;

79 // skip pes payload to avoid start code emulation for private

80 // and audio streams

81 else if((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}

82 else if(code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}

83 else if(code == 0x1fd && pes) vid++; //VC1

85 else if((code & 0xf0) == VIDEO_ID && !pes) invalid++;

86 else if((code & 0xe0) == AUDIO_ID && !pes) invalid++;

87 else if(code == PRIVATE_STREAM_1 && !pes) invalid++;

88 }

89 }

91 if(vid+audio > invalid+1) /* invalid VDR files nd short PES streams */

92 score = AVPROBE_SCORE_EXTENSION / 2;

94 if(sys>invalid && sys*9 <= pspack*10)

95 return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2 : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg

96 if(pspack > invalid && (priv1+vid+audio)*10 >= pspack*9)

97 return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2 : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg

98 if((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys && !pspack && p->buf_size>2048 && vid + audio > invalid) /* PES stream */

99 return (audio > 12 || vid > 3 + 2*invalid) ? AVPROBE_SCORE_EXTENSION + 2 : AVPROBE_SCORE_EXTENSION / 2;

100

101 //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1

102 //mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6

103 //Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618

104 return score;

105 }

106

107

108 typedef struct MpegDemuxContext {

109 int32_t header_state;

110 unsigned char psm_es_type[256];

111 int sofdec;

112 int dvd;

113 int imkh_cctv;

114 #if CONFIG_VOBSUB_DEMUXER

115 AVFormatContext *sub_ctx;

116 FFDemuxSubtitlesQueue q;

117 #endif

118 } MpegDemuxContext;

119

120 static int mpegps_read_header(AVFormatContext *s)

121 {

122 MpegDemuxContext *m = s->priv_data;

123 char buffer[7];

124 int64_t last_pos = avio_tell(s->pb);

125

126 m->header_state = 0xff;

127 s->ctx_flags |= AVFMTCTX_NOHEADER;

128

129 avio_get_str(s->pb, 6, buffer, sizeof(buffer));

130 if (!memcmp("IMKH", buffer, 4)) {

131 m->imkh_cctv = 1;

132 } else if (!memcmp("Sofdec", buffer, 6)) {

133 m->sofdec = 1;

134 } else

135 avio_seek(s->pb, last_pos, SEEK_SET);

136

137 /* no need to do more */

138 return 0;

139 }

140

141 static int64_t get_pts(AVIOContext *pb, int c)

142 {

143 uint8_t buf[5];

144

145 buf[0] = c<0 ? avio_r8(pb) : c;

146 avio_read(pb, buf+1, 4);

147

148 return ff_parse_pes_pts(buf);

149 }

150

151 static int find_next_start_code(AVIOContext *pb, int *size_ptr,

152 int32_t *header_state)

153 {

154 unsigned int state, v;

155 int val, n;

156

157 state = *header_state;

158 n = *size_ptr;

159 while (n > 0) {

160 if (url_feof(pb))

161 break;

162 v = avio_r8(pb);

163 n--;

164 if (state == 0x000001) {

165 state = ((state << 8) | v) & 0xffffff;

166 val = state;

167 goto found;

168 }

169 state = ((state << 8) | v) & 0xffffff;

170 }

171 val = -1;

172 found:

173 *header_state = state;

174 *size_ptr = n;

175 return val;

176 }

177

178 /**

179 * Extract stream types from a program stream map

180 * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35

181 *

182 * @return number of bytes occupied by PSM in the bitstream

183 */

184 static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)

185 {

186 int psm_length, ps_info_length, es_map_length;

187

188 psm_length = avio_rb16(pb);

189 avio_r8(pb);

190 avio_r8(pb);

191 ps_info_length = avio_rb16(pb);

192

193 /* skip program_stream_info */

194 avio_skip(pb, ps_info_length);

195 es_map_length = avio_rb16(pb);

196

197 /* at least one es available? */

198 while (es_map_length >= 4){

199 unsigned char type = avio_r8(pb);

200 unsigned char es_id = avio_r8(pb);

201 uint16_t es_info_length = avio_rb16(pb);

202 /* remember mapping from stream id to stream type */

203 m->psm_es_type[es_id] = type;

204 /* skip program_stream_info */

205 avio_skip(pb, es_info_length);

206 es_map_length -= 4 + es_info_length;

207 }

208 avio_rb32(pb); /* crc32 */

209 return 2 + psm_length;

210 }

211

212 /* read the next PES header. Return its position in ppos

213 (if not NULL), and its start code, pts and dts.

214 */

215 static int mpegps_read_pes_header(AVFormatContext *s,

216 int64_t *ppos, int *pstart_code,

217 int64_t *ppts, int64_t *pdts)

218 {

219 MpegDemuxContext *m = s->priv_data;

220 int len, size, startcode, c, flags, header_len;

221 int pes_ext, ext2_len, id_ext, skip;

222 int64_t pts, dts;

223 int64_t last_sync= avio_tell(s->pb);

224

225 error_redo:

226 avio_seek(s->pb, last_sync, SEEK_SET);

227 redo:

228 /* next start code (should be immediately after) */

229 m->header_state = 0xff;

230 size = MAX_SYNC_SIZE;

231 startcode = find_next_start_code(s->pb, &size, &m->header_state);

232 last_sync = avio_tell(s->pb);

233 if (startcode < 0){

234 if(url_feof(s->pb))

235 return AVERROR_EOF;

236 //FIXME we should remember header_state

237 return AVERROR(EAGAIN);

238 }

239

240 if (startcode == PACK_START_CODE)

241 goto redo;

242 if (startcode == SYSTEM_HEADER_START_CODE)

243 goto redo;

244 if (startcode == PADDING_STREAM) {

245 avio_skip(s->pb, avio_rb16(s->pb));

246 goto redo;

247 }

248 if (startcode == PRIVATE_STREAM_2) {

249 if (!m->sofdec) {

250 /* Need to detect whether this from a DVD or a 'Sofdec' stream */

251 int len = avio_rb16(s->pb);

252 int bytesread = 0;

253 uint8_t *ps2buf = av_malloc(len);

254

255 if (ps2buf) {

256 bytesread = avio_read(s->pb, ps2buf, len);

257

258 if (bytesread != len) {

259 avio_skip(s->pb, len - bytesread);

260 } else {

261 uint8_t *p = 0;

262 if (len >= 6)

263 p = memchr(ps2buf, 'S', len - 5);

264

265 if (p)

266 m->sofdec = !memcmp(p+1, "ofdec", 5);

267

268 m->sofdec -= !m->sofdec;

269

270 if (m->sofdec < 0) {

271 if (len == 980 && ps2buf[0] == 0) {

272 /* PCI structure? */

273 uint32_t startpts = AV_RB32(ps2buf + 0x0d);

274 uint32_t endpts = AV_RB32(ps2buf + 0x11);

275 uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);

276 uint8_t mins = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);

277 uint8_t secs = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);

278

279 m->dvd = (hours <= 23 &&

280 mins <= 59 &&

281 secs <= 59 &&

282 (ps2buf[0x19] & 0x0f) < 10 &&

283 (ps2buf[0x1a] & 0x0f) < 10 &&

284 (ps2buf[0x1b] & 0x0f) < 10 &&

285 endpts >= startpts);

286 } else if (len == 1018 && ps2buf[0] == 1) {

287 /* DSI structure? */

288 uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);

289 uint8_t mins = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);

290 uint8_t secs = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);

291

292 m->dvd = (hours <= 23 &&

293 mins <= 59 &&

294 secs <= 59 &&

295 (ps2buf[0x1d] & 0x0f) < 10 &&

296 (ps2buf[0x1e] & 0x0f) < 10 &&

297 (ps2buf[0x1f] & 0x0f) < 10);

298 }

299 }

300 }

301

302 av_free(ps2buf);

303

304 /* If this isn't a DVD packet or no memory

305 * could be allocated, just ignore it.

306 * If we did, move back to the start of the

307 * packet (plus 'length' field) */

308 if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {

309 /* Skip back failed.

310 * This packet will be lost but that can't be helped

311 * if we can't skip back

312 */

313 goto redo;

314 }

315 } else {

316 /* No memory */

317 avio_skip(s->pb, len);

318 goto redo;

319 }

320 } else if (!m->dvd) {

321 int len = avio_rb16(s->pb);

322 avio_skip(s->pb, len);

323 goto redo;

324 }

325 }

326 if (startcode == PROGRAM_STREAM_MAP) {

327 mpegps_psm_parse(m, s->pb);

328 goto redo;

329 }

330

331 /* find matching stream */

332 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||

333 (startcode >= 0x1e0 && startcode <= 0x1ef) ||

334 (startcode == 0x1bd) ||

335 (startcode == PRIVATE_STREAM_2) ||

336 (startcode == 0x1fd)))

337 goto redo;

338 if (ppos) {

339 *ppos = avio_tell(s->pb) - 4;

340 }

341 len = avio_rb16(s->pb);

342 pts =

343 dts = AV_NOPTS_VALUE;

344 if (startcode != PRIVATE_STREAM_2)

345 {

346 /* stuffing */

347 for(;;) {

348 if (len < 1)

349 goto error_redo;

350 c = avio_r8(s->pb);

351 len--;

352 /* XXX: for mpeg1, should test only bit 7 */

353 if (c != 0xff)

354 break;

355 }

356 if ((c & 0xc0) == 0x40) {

357 /* buffer scale & size */

358 avio_r8(s->pb);

359 c = avio_r8(s->pb);

360 len -= 2;

361 }

362 if ((c & 0xe0) == 0x20) {

363 dts = pts = get_pts(s->pb, c);

364 len -= 4;

365 if (c & 0x10){

366 dts = get_pts(s->pb, -1);

367 len -= 5;

368 }

369 } else if ((c & 0xc0) == 0x80) {

370 /* mpeg 2 PES */

371 flags = avio_r8(s->pb);

372 header_len = avio_r8(s->pb);

373 len -= 2;

374 if (header_len > len)

375 goto error_redo;

376 len -= header_len;

377 if (flags & 0x80) {

378 dts = pts = get_pts(s->pb, -1);

379 header_len -= 5;

380 if (flags & 0x40) {

381 dts = get_pts(s->pb, -1);

382 header_len -= 5;

383 }

384 }

385 if (flags & 0x3f && header_len == 0){

386 flags &= 0xC0;

387 av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");

388 }

389 if (flags & 0x01) { /* PES extension */

390 pes_ext = avio_r8(s->pb);

391 header_len--;

392 /* Skip PES private data, program packet sequence counter and P-STD buffer */

393 skip = (pes_ext >> 4) & 0xb;

394 skip += skip & 0x9;

395 if (pes_ext & 0x40 || skip > header_len){

396 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);

397 pes_ext=skip=0;

398 }

399 avio_skip(s->pb, skip);

400 header_len -= skip;

401

402 if (pes_ext & 0x01) { /* PES extension 2 */

403 ext2_len = avio_r8(s->pb);

404 header_len--;

405 if ((ext2_len & 0x7f) > 0) {

406 id_ext = avio_r8(s->pb);

407 if ((id_ext & 0x80) == 0)

408 startcode = ((startcode & 0xff) << 8) | id_ext;

409 header_len--;

410 }

411 }

412 }

413 if(header_len < 0)

414 goto error_redo;

415 avio_skip(s->pb, header_len);

416 }

417 else if( c!= 0xf )

418 goto redo;

419 }

420

421 if (startcode == PRIVATE_STREAM_1) {

422 startcode = avio_r8(s->pb);

423 len--;

424 }

425 if(len<0)

426 goto error_redo;

427 if(dts != AV_NOPTS_VALUE && ppos){

428 int i;

429 for(i=0; i<s->nb_streams; i++){

430 if(startcode == s->streams[i]->id &&

431 s->pb->seekable /* index useless on streams anyway */) {

432 ff_reduce_index(s, i);

433 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);

434 }

435 }

436 }

437

438 *pstart_code = startcode;

439 *ppts = pts;

440 *pdts = dts;

441 return len;

442 }

443

444 static int mpegps_read_packet(AVFormatContext *s,

445 AVPacket *pkt)

446 {

447 MpegDemuxContext *m = s->priv_data;

448 AVStream *st;

449 int len, startcode, i, es_type, ret;

450 int lpcm_header_len = -1; //Init to supress warning

451 int request_probe= 0;

452 enum AVCodecID codec_id = AV_CODEC_ID_NONE;

453 enum AVMediaType type;

454 int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work

455

456 redo:

457 len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);

458 if (len < 0)

459 return len;

460

461 if (startcode >= 0x80 && startcode <= 0xcf) {

462 if(len < 4)

463 goto skip;

464

465 /* audio: skip header */

466 avio_r8(s->pb);

467 lpcm_header_len = avio_rb16(s->pb);

468 len -= 3;

469 if (startcode >= 0xb0 && startcode <= 0xbf) {

470 /* MLP/TrueHD audio has a 4-byte header */

471 avio_r8(s->pb);

472 len--;

473 }

474 }

475

476 /* now find stream */

477 for(i=0;i<s->nb_streams;i++) {

478 st = s->streams[i];

479 if (st->id == startcode)

480 goto found;

481 }

482

483 es_type = m->psm_es_type[startcode & 0xff];

484 if(es_type == STREAM_TYPE_VIDEO_MPEG1){

485 codec_id = AV_CODEC_ID_MPEG2VIDEO;

486 type = AVMEDIA_TYPE_VIDEO;

487 } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){

488 codec_id = AV_CODEC_ID_MPEG2VIDEO;

489 type = AVMEDIA_TYPE_VIDEO;

490 } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 ||

491 es_type == STREAM_TYPE_AUDIO_MPEG2){

492 codec_id = AV_CODEC_ID_MP3;

493 type = AVMEDIA_TYPE_AUDIO;

494 } else if(es_type == STREAM_TYPE_AUDIO_AAC){

495 codec_id = AV_CODEC_ID_AAC;

496 type = AVMEDIA_TYPE_AUDIO;

497 } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){

498 codec_id = AV_CODEC_ID_MPEG4;

499 type = AVMEDIA_TYPE_VIDEO;

500 } else if(es_type == STREAM_TYPE_VIDEO_H264){

501 codec_id = AV_CODEC_ID_H264;

502 type = AVMEDIA_TYPE_VIDEO;

503 } else if(es_type == STREAM_TYPE_AUDIO_AC3){

504 codec_id = AV_CODEC_ID_AC3;

505 type = AVMEDIA_TYPE_AUDIO;

506 } else if(m->imkh_cctv && es_type == 0x91){

507 codec_id = AV_CODEC_ID_PCM_MULAW;

508 type = AVMEDIA_TYPE_AUDIO;

509 } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {

510 static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };

511 unsigned char buf[8];

512 avio_read(s->pb, buf, 8);

513 avio_seek(s->pb, -8, SEEK_CUR);

514 if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))

515 codec_id = AV_CODEC_ID_CAVS;

516 else

517 request_probe= 1;

518 type = AVMEDIA_TYPE_VIDEO;

519 } else if (startcode == PRIVATE_STREAM_2) {

520 type = AVMEDIA_TYPE_DATA;

521 codec_id = AV_CODEC_ID_DVD_NAV;

522 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {

523 type = AVMEDIA_TYPE_AUDIO;

524 codec_id = m->sofdec > 0 ? AV_CODEC_ID_ADPCM_ADX : AV_CODEC_ID_MP2;

525 } else if (startcode >= 0x80 && startcode <= 0x87) {

526 type = AVMEDIA_TYPE_AUDIO;

527 codec_id = AV_CODEC_ID_AC3;

528 } else if ( ( startcode >= 0x88 && startcode <= 0x8f)

529 ||( startcode >= 0x98 && startcode <= 0x9f)) {

530 /* 0x90 - 0x97 is reserved for SDDS in DVD specs */

531 type = AVMEDIA_TYPE_AUDIO;

532 codec_id = AV_CODEC_ID_DTS;

533 } else if (startcode >= 0xa0 && startcode <= 0xaf) {

534 type = AVMEDIA_TYPE_AUDIO;

535 if(lpcm_header_len == 6) {

536 codec_id = AV_CODEC_ID_MLP;

537 } else {

538 /* 16 bit form will be handled as AV_CODEC_ID_PCM_S16BE */

539 codec_id = AV_CODEC_ID_PCM_DVD;

540 }

541 } else if (startcode >= 0xb0 && startcode <= 0xbf) {

542 type = AVMEDIA_TYPE_AUDIO;

543 codec_id = AV_CODEC_ID_TRUEHD;

544 } else if (startcode >= 0xc0 && startcode <= 0xcf) {

545 /* Used for both AC-3 and E-AC-3 in EVOB files */

546 type = AVMEDIA_TYPE_AUDIO;

547 codec_id = AV_CODEC_ID_AC3;

548 } else if (startcode >= 0x20 && startcode <= 0x3f) {

549 type = AVMEDIA_TYPE_SUBTITLE;

550 codec_id = AV_CODEC_ID_DVD_SUBTITLE;

551 } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {

552 type = AVMEDIA_TYPE_VIDEO;

553 codec_id = AV_CODEC_ID_VC1;

554 } else {

555 skip:

556 /* skip packet */

557 avio_skip(s->pb, len);

558 goto redo;

559 }

560 /* no stream found: add a new stream */

561 st = avformat_new_stream(s, NULL);

562 if (!st)

563 goto skip;

564 st->id = startcode;

565 st->codec->codec_type = type;

566 st->codec->codec_id = codec_id;

567 if (st->codec->codec_id == AV_CODEC_ID_PCM_MULAW) {

568 st->codec->channels = 1;

569 st->codec->channel_layout = AV_CH_LAYOUT_MONO;

570 st->codec->sample_rate = 8000;

571 }

572 st->request_probe = request_probe;

573 if (codec_id != AV_CODEC_ID_PCM_S16BE)

574 st->need_parsing = AVSTREAM_PARSE_FULL;

575 found:

576 if(st->discard >= AVDISCARD_ALL)

577 goto skip;

578 if (startcode >= 0xa0 && startcode <= 0xaf) {

579 if (lpcm_header_len == 6 && st->codec->codec_id == AV_CODEC_ID_MLP) {

580 if (len < 6)

581 goto skip;

582 avio_skip(s->pb, 6);

583 len -=6;

584 } else {

585 int b1, freq;

586

587 /* for LPCM, we just skip the header and consider it is raw

588 audio data */

589 if (len <= 3)

590 goto skip;

591 avio_r8(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */

592 b1 = avio_r8(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */

593 avio_r8(s->pb); /* dynamic range control (0x80 = off) */

594 len -= 3;

595 freq = (b1 >> 4) & 3;

596 st->codec->sample_rate = lpcm_freq_tab[freq];

597 st->codec->channels = 1 + (b1 & 7);

598 st->codec->bits_per_coded_sample = 16 + ((b1 >> 6) & 3) * 4;

599 st->codec->bit_rate = st->codec->channels *

600 st->codec->sample_rate *

601 st->codec->bits_per_coded_sample;

602 if (st->codec->bits_per_coded_sample == 16)

603 st->codec->codec_id = AV_CODEC_ID_PCM_S16BE;

604 else if (st->codec->bits_per_coded_sample == 28)

605 return AVERROR(EINVAL);

606 }

607 }

608 ret = av_get_packet(s->pb, pkt, len);

609 pkt->pts = pts;

610 pkt->dts = dts;

611 pkt->pos = dummy_pos;

612 pkt->stream_index = st->index;

613 av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n",

614 pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,

615 pkt->size);

616

617 return (ret < 0) ? ret : 0;

618 }

619

620 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,

621 int64_t *ppos, int64_t pos_limit)

622 {

623 int len, startcode;

624 int64_t pos, pts, dts;

625

626 pos = *ppos;

627 if (avio_seek(s->pb, pos, SEEK_SET) < 0)

628 return AV_NOPTS_VALUE;

629

630 for(;;) {

631 len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);

632 if (len < 0) {

633 av_dlog(s, "none (ret=%d)\n", len);

634 return AV_NOPTS_VALUE;

635 }

636 if (startcode == s->streams[stream_index]->id &&

637 dts != AV_NOPTS_VALUE) {

638 break;

639 }

640 avio_skip(s->pb, len);

641 }

642 av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",

643 pos, dts, dts / 90000.0);

644 *ppos = pos;

645 return dts;

646 }

647

648 AVInputFormat ff_mpegps_demuxer = {

649 .name = "mpeg",

650 .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),

651 .priv_data_size = sizeof(MpegDemuxContext),

652 .read_probe = mpegps_probe,

653 .read_header = mpegps_read_header,

654 .read_packet = mpegps_read_packet,

655 .read_timestamp = mpegps_read_dts,

656 .flags = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,

657 };

658

659 #if CONFIG_VOBSUB_DEMUXER

660

661 #define REF_STRING "# VobSub index file,"

662

663 static int vobsub_probe(AVProbeData *p)

664 {

665 if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))

666 return AVPROBE_SCORE_MAX;

667 return 0;

668 }

669

670 static int vobsub_read_header(AVFormatContext *s)

671 {

672 int i, ret = 0, header_parsed = 0, langidx = 0;

673 MpegDemuxContext *vobsub = s->priv_data;

674 char *sub_name = NULL;

675 size_t fname_len;

676 char *ext, *header_str;

677 AVBPrint header;

678 int64_t delay = 0;

679 AVStream *st = NULL;

680

681 sub_name = av_strdup(s->filename);

682 fname_len = strlen(sub_name);

683 ext = sub_name - 3 + fname_len;

684 if (fname_len < 4 || *(ext - 1) != '.') {

685 av_log(s, AV_LOG_ERROR, "The input index filename is too short "

686 "to guess the associated .SUB file\n");

687 ret = AVERROR_INVALIDDATA;

688 goto end;

689 }

690 memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);

691 av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->filename, sub_name);

692 ret = avformat_open_input(&vobsub->sub_ctx, sub_name, &ff_mpegps_demuxer, NULL);

693 if (ret < 0) {

694 av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", sub_name);

695 goto end;

696 }

697

698 av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);

699 while (!url_feof(s->pb)) {

700 char line[2048];

701 int len = ff_get_line(s->pb, line, sizeof(line));

702

703 if (!len)

704 break;

705

706 line[strcspn(line, "\r\n")] = 0;

707

708 if (!strncmp(line, "id:", 3)) {

709 int n, stream_id = 0;

710 char id[64] = {0};

711

712 n = sscanf(line, "id: %63[^,], index: %u", id, &stream_id);

713 if (n != 2) {

714 av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "

715 "assuming 'id: und, index: 0'\n", line);

716 strcpy(id, "und");

717 stream_id = 0;

718 }

719

720 st = avformat_new_stream(s, NULL);

721 if (!st) {

722 ret = AVERROR(ENOMEM);

723 goto end;

724 }

725 st->id = stream_id;

726 st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

727 st->codec->codec_id = AV_CODEC_ID_DVD_SUBTITLE;

728 av_dict_set(&st->metadata, "language", id, 0);

729 av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);

730 header_parsed = 1;

731

732 } else if (st && !strncmp(line, "timestamp:", 10)) {

733 AVPacket *sub;

734 int hh, mm, ss, ms;

735 int64_t pos, timestamp;

736 const char *p = line + 10;

737

738 if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,

739 &hh, &mm, &ss, &ms, &pos) != 5) {

740 av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "

741 "abort parsing\n", line);

742 break;

743 }

744 timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;

745 timestamp = av_rescale_q(timestamp, (AVRational){1,1000}, st->time_base);

746

747 sub = ff_subtitles_queue_insert(&vobsub->q, "", 0, 0);

748 if (!sub) {

749 ret = AVERROR(ENOMEM);

750 goto end;

751 }

752 sub->pos = pos;

753 sub->pts = timestamp;

754 sub->stream_index = s->nb_streams - 1;

755

756 } else if (st && !strncmp(line, "alt:", 4)) {

757 const char *p = line + 4;

758

759 while (*p == ' ')

760 p++;

761 av_dict_set(&st->metadata, "title", p, 0);

762 av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", st->id, p);

763 header_parsed = 1;

764

765 } else if (!strncmp(line, "delay:", 6)) {

766 int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;

767 const char *p = line + 6;

768

769 while (*p == ' ')

770 p++;

771 if (*p == '-' || *p == '+') {

772 sign = *p == '-' ? -1 : 1;

773 p++;

774 }

775 sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);

776 delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;

777

778 } else if (!strncmp(line, "langidx:", 8)) {

779 const char *p = line + 8;

780

781 if (sscanf(p, "%d", &langidx) != 1)

782 av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");

783

784 } else if (!header_parsed) {

785 if (line[0] && line[0] != '#')

786 av_bprintf(&header, "%s\n", line);

787 }

788 }

789

790 if (langidx < s->nb_streams)

791 s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;

792

793 ff_subtitles_queue_finalize(&vobsub->q);

794

795 if (!av_bprint_is_complete(&header)) {

796 av_bprint_finalize(&header, NULL);

797 ret = AVERROR(ENOMEM);

798 goto end;

799 }

800 av_bprint_finalize(&header, &header_str);

801 for (i = 0; i < s->nb_streams; i++) {

802 AVStream *sub_st = s->streams[i];

803 sub_st->codec->extradata = av_strdup(header_str);

804 sub_st->codec->extradata_size = header.len;

805 }

806 av_free(header_str);

807

808 end:

809 av_free(sub_name);

810 return ret;

811 }

812

813 #define FAIL(r) do { ret = r; goto fail; } while (0)

814

815 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)

816 {

817 MpegDemuxContext *vobsub = s->priv_data;

818 FFDemuxSubtitlesQueue *q = &vobsub->q;

819 AVIOContext *pb = vobsub->sub_ctx->pb;

820 int ret, psize, len16 = -1;

821 AVPacket idx_pkt;

822

823 ret = ff_subtitles_queue_read_packet(q, &idx_pkt);

824 if (ret < 0)

825 return ret;

826

827 /* compute maximum packet size using the next packet position. This is

828 * useful when the len in the header is non-sense */

829 if (q->current_sub_idx < q->nb_subs) {

830 psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos;

831 } else {

832 int64_t fsize = avio_size(pb);

833 psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos;

834 }

835

836 avio_seek(pb, idx_pkt.pos, SEEK_SET);

837

838 av_init_packet(pkt);

839 pkt->size = 0;

840 pkt->data = NULL;

841

842 do {

843 int n, to_read, startcode;

844 int64_t pts, dts;

845

846 ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);

847 if (ret < 0)

848 FAIL(ret);

849 to_read = ret & 0xffff;

850

851 /* this prevents reads above the current packet */

852 if (pkt->size + to_read > psize)

853 break;

854

855 /* if the len is computed, we check for overread */

856 if (len16 != -1 && pkt->size + to_read > len16)

857 break;

858

859 /* the current chunk doesn't match the stream index (unlikely) */

860 if ((startcode & 0x1f) != idx_pkt.stream_index)

861 break;

862

863 ret = av_grow_packet(pkt, to_read);

864 if (ret < 0)

865 FAIL(ret);

866

867 n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);

868 if (n < to_read)

869 pkt->size -= to_read - n;

870

871 /* first chunk contains the total len of the packet to raise */

872 if (len16 == -1 && n > 2)

873 len16 = AV_RB16(pkt->data);

874 } while (len16 != -1 && pkt->size != len16);

875

876 pkt->pts = pkt->dts = idx_pkt.pts;

877 pkt->pos = idx_pkt.pos;

878 pkt->stream_index = idx_pkt.stream_index;

879

880 av_free_packet(&idx_pkt);

881 return 0;

882

883 fail:

884 av_free_packet(&idx_pkt);

885 return ret;

886 }

887

888 static int vobsub_read_seek(AVFormatContext *s, int stream_index,

889 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)

890 {

891 MpegDemuxContext *vobsub = s->priv_data;

892 return ff_subtitles_queue_seek(&vobsub->q, s, stream_index,

893 min_ts, ts, max_ts, flags);

894 }

895

896 static int vobsub_read_close(AVFormatContext *s)

897 {

898 MpegDemuxContext *vobsub = s->priv_data;

899 ff_subtitles_queue_clean(&vobsub->q);

900 if (vobsub->sub_ctx)

901 avformat_close_input(&vobsub->sub_ctx);

902 return 0;

903 }

904

905 AVInputFormat ff_vobsub_demuxer = {

906 .name = "vobsub",

907 .long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),

908 .priv_data_size = sizeof(MpegDemuxContext),

909 .read_probe = vobsub_probe,

910 .read_header = vobsub_read_header,

911 .read_packet = vobsub_read_packet,

912 .read_seek2 = vobsub_read_seek,

913 .read_close = vobsub_read_close,

914 .flags = AVFMT_SHOW_IDS,

915 .extensions = "idx",

916 };

917 #endif

Generated on Wed Jul 10 2013 23:48:13 for FFmpeg by doxygen 1.8.2