FFmpeg: libavformat/dv.c Source File

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libavformat

dv.c

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1 /*

2 * General DV muxer/demuxer

4 *

5 * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth

6 * of DV technical info.

7 *

8 * Raw DV format

10 *

11 * 50 Mbps (DVCPRO50) and 100 Mbps (DVCPRO HD) support

13 * Funded by BBC Research & Development

14 *

15 * This file is part of FFmpeg.

16 *

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

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

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

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

21 *

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

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

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

25 * Lesser General Public License for more details.

26 *

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

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

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

30 */

31 #include <time.h>

32 #include "avformat.h"

33 #include "internal.h"

34 #include "libavcodec/dv_profile.h"

35 #include "libavcodec/dv.h"

36 #include "libavutil/channel_layout.h"

37 #include "libavutil/intreadwrite.h"

38 #include "libavutil/mathematics.h"

39 #include "libavutil/timecode.h"

40 #include "dv.h"

41 #include "libavutil/avassert.h"

43 struct DVDemuxContext {

44 const DVprofile* sys; /* Current DV profile. E.g.: 525/60, 625/50 */

45 AVFormatContext* fctx;

46 AVStream* vst;

47 AVStream* ast[4];

48 AVPacket audio_pkt[4];

49 uint8_t audio_buf[4][8192];

50 int ach;

51 int frames;

52 uint64_t abytes;

53 };

55 static inline uint16_t dv_audio_12to16(uint16_t sample)

56 {

57 uint16_t shift, result;

59 sample = (sample < 0x800) ? sample : sample | 0xf000;

60 shift = (sample & 0xf00) >> 8;

62 if (shift < 0x2 || shift > 0xd) {

63 result = sample;

64 } else if (shift < 0x8) {

65 shift--;

66 result = (sample - (256 * shift)) << shift;

67 } else {

68 shift = 0xe - shift;

69 result = ((sample + ((256 * shift) + 1)) << shift) - 1;

70 }

72 return result;

73 }

75 /*

76 * This is the dumbest implementation of all -- it simply looks at

77 * a fixed offset and if pack isn't there -- fails. We might want

78 * to have a fallback mechanism for complete search of missing packs.

79 */

80 static const uint8_t *dv_extract_pack(uint8_t *frame, enum dv_pack_type t)

81 {

82 int offs;

84 switch (t) {

85 case dv_audio_source:

86 offs = (80 * 6 + 80 * 16 * 3 + 3);

87 break;

88 case dv_audio_control:

89 offs = (80 * 6 + 80 * 16 * 4 + 3);

90 break;

91 case dv_video_control:

92 offs = (80 * 5 + 48 + 5);

93 break;

94 case dv_timecode:

95 offs = (80*1 + 3 + 3);

96 break;

97 default:

98 return NULL;

99 }

100

101 return frame[offs] == t ? &frame[offs] : NULL;

102 }

103

104 static const int dv_audio_frequency[3] = {

105 48000, 44100, 32000,

106 };

107

108 /*

109 * There's a couple of assumptions being made here:

110 * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.

111 * We can pass them upwards when libavcodec will be ready to deal with them.

112 * 2. We don't do software emphasis.

113 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples

114 * are converted into 16bit linear ones.

115 */

116 static int dv_extract_audio(uint8_t *frame, uint8_t **ppcm,

117 const DVprofile *sys)

118 {

119 int size, chan, i, j, d, of, smpls, freq, quant, half_ch;

120 uint16_t lc, rc;

121 const uint8_t *as_pack;

122 uint8_t *pcm, ipcm;

123

124 as_pack = dv_extract_pack(frame, dv_audio_source);

125 if (!as_pack) /* No audio ? */

126 return 0;

127

128 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */

129 freq = as_pack[4] >> 3 & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */

130 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */

131

132 if (quant > 1)

133 return -1; /* unsupported quantization */

134

135 if (freq >= FF_ARRAY_ELEMS(dv_audio_frequency))

136 return AVERROR_INVALIDDATA;

137

138 size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */

139 half_ch = sys->difseg_size / 2;

140

141 /* We work with 720p frames split in half, thus even frames have

142 * channels 0,1 and odd 2,3. */

143 ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 2 : 0;

144

145 if (ipcm + sys->n_difchan > (quant == 1 ? 2 : 4)) {

146 av_log(NULL, AV_LOG_ERROR, "too many dv pcm frames\n");

147 return AVERROR_INVALIDDATA;

148 }

149

150 /* for each DIF channel */

151 for (chan = 0; chan < sys->n_difchan; chan++) {

152 av_assert0(ipcm<4);

153 pcm = ppcm[ipcm++];

154 if (!pcm)

155 break;

156

157 /* for each DIF segment */

158 for (i = 0; i < sys->difseg_size; i++) {

159 frame += 6 * 80; /* skip DIF segment header */

160 if (quant == 1 && i == half_ch) {

161 /* next stereo channel (12bit mode only) */

162 av_assert0(ipcm<4);

163 pcm = ppcm[ipcm++];

164 if (!pcm)

165 break;

166 }

167

168 /* for each AV sequence */

169 for (j = 0; j < 9; j++) {

170 for (d = 8; d < 80; d += 2) {

171 if (quant == 0) { /* 16bit quantization */

172 of = sys->audio_shuffle[i][j] +

173 (d - 8) / 2 * sys->audio_stride;

174 if (of * 2 >= size)

175 continue;

176

177 /* FIXME: maybe we have to admit that DV is a

178 * big-endian PCM */

179 pcm[of * 2] = frame[d + 1];

180 pcm[of * 2 + 1] = frame[d];

181

182 if (pcm[of * 2 + 1] == 0x80 && pcm[of * 2] == 0x00)

183 pcm[of * 2 + 1] = 0;

184 } else { /* 12bit quantization */

185 lc = ((uint16_t)frame[d] << 4) |

186 ((uint16_t)frame[d + 2] >> 4);

187 rc = ((uint16_t)frame[d + 1] << 4) |

188 ((uint16_t)frame[d + 2] & 0x0f);

189 lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));

190 rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));

191

192 of = sys->audio_shuffle[i % half_ch][j] +

193 (d - 8) / 3 * sys->audio_stride;

194 if (of * 2 >= size)

195 continue;

196

197 /* FIXME: maybe we have to admit that DV is a

198 * big-endian PCM */

199 pcm[of * 2] = lc & 0xff;

200 pcm[of * 2 + 1] = lc >> 8;

201 of = sys->audio_shuffle[i % half_ch + half_ch][j] +

202 (d - 8) / 3 * sys->audio_stride;

203 /* FIXME: maybe we have to admit that DV is a

204 * big-endian PCM */

205 pcm[of * 2] = rc & 0xff;

206 pcm[of * 2 + 1] = rc >> 8;

207 ++d;

208 }

209 }

210

211 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */

212 }

213 }

214 }

215

216 return size;

217 }

218

219 static int dv_extract_audio_info(DVDemuxContext *c, uint8_t *frame)

220 {

221 const uint8_t *as_pack;

222 int freq, stype, smpls, quant, i, ach;

223

224 as_pack = dv_extract_pack(frame, dv_audio_source);

225 if (!as_pack || !c->sys) { /* No audio ? */

226 c->ach = 0;

227 return 0;

228 }

229

230 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */

231 freq = as_pack[4] >> 3 & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */

232 stype = as_pack[3] & 0x1f; /* 0 - 2CH, 2 - 4CH, 3 - 8CH */

233 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */

234

235 if (freq >= FF_ARRAY_ELEMS(dv_audio_frequency)) {

236 av_log(c->fctx, AV_LOG_ERROR,

237 "Unrecognized audio sample rate index (%d)\n", freq);

238 return 0;

239 }

240

241 if (stype > 3) {

242 av_log(c->fctx, AV_LOG_ERROR, "stype %d is invalid\n", stype);

243 c->ach = 0;

244 return 0;

245 }

246

247 /* note: ach counts PAIRS of channels (i.e. stereo channels) */

248 ach = ((int[4]) { 1, 0, 2, 4 })[stype];

249 if (ach == 1 && quant && freq == 2)

250 ach = 2;

251

252 /* Dynamic handling of the audio streams in DV */

253 for (i = 0; i < ach; i++) {

254 if (!c->ast[i]) {

255 c->ast[i] = avformat_new_stream(c->fctx, NULL);

256 if (!c->ast[i])

257 break;

258 avpriv_set_pts_info(c->ast[i], 64, 1, 30000);

259 c->ast[i]->codec->codec_type = AVMEDIA_TYPE_AUDIO;

260 c->ast[i]->codec->codec_id = AV_CODEC_ID_PCM_S16LE;

261

262 av_init_packet(&c->audio_pkt[i]);

263 c->audio_pkt[i].size = 0;

264 c->audio_pkt[i].data = c->audio_buf[i];

265 c->audio_pkt[i].stream_index = c->ast[i]->index;

266 c->audio_pkt[i].flags |= AV_PKT_FLAG_KEY;

267 }

268 c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];

269 c->ast[i]->codec->channels = 2;

270 c->ast[i]->codec->channel_layout = AV_CH_LAYOUT_STEREO;

271 c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16;

272 c->ast[i]->start_time = 0;

273 }

274 c->ach = i;

275

276 return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */

277 }

278

279 static int dv_extract_video_info(DVDemuxContext *c, uint8_t *frame)

280 {

281 const uint8_t *vsc_pack;

282 AVCodecContext *avctx;

283 int apt, is16_9;

284 int size = 0;

285

286 if (c->sys) {

287 avctx = c->vst->codec;

288

289 avpriv_set_pts_info(c->vst, 64, c->sys->time_base.num,

290 c->sys->time_base.den);

291 avctx->time_base = c->sys->time_base;

292

293 /* finding out SAR is a little bit messy */

294 vsc_pack = dv_extract_pack(frame, dv_video_control);

295 apt = frame[4] & 0x07;

296 is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||

297 (!apt && (vsc_pack[2] & 0x07) == 0x07)));

298 c->vst->sample_aspect_ratio = c->sys->sar[is16_9];

299 avctx->bit_rate = av_rescale_q(c->sys->frame_size,

300 (AVRational) { 8, 1 },

301 c->sys->time_base);

302 size = c->sys->frame_size;

303 }

304 return size;

305 }

306

307 static int dv_extract_timecode(DVDemuxContext* c, uint8_t* frame, char *tc)

308 {

309 const uint8_t *tc_pack;

310

311 // For PAL systems, drop frame bit is replaced by an arbitrary

312 // bit so its value should not be considered. Drop frame timecode

313 // is only relevant for NTSC systems.

314 int prevent_df = c->sys->ltc_divisor == 25 || c->sys->ltc_divisor == 50;

315

316 tc_pack = dv_extract_pack(frame, dv_timecode);

317 if (!tc_pack)

318 return 0;

319 av_timecode_make_smpte_tc_string(tc, AV_RB32(tc_pack + 1), prevent_df);

320 return 1;

321 }

322

323 /* The following 3 functions constitute our interface to the world */

324

325 DVDemuxContext *avpriv_dv_init_demux(AVFormatContext *s)

326 {

327 DVDemuxContext *c;

328

329 c = av_mallocz(sizeof(DVDemuxContext));

330 if (!c)

331 return NULL;

332

333 c->vst = avformat_new_stream(s, NULL);

334 if (!c->vst) {

335 av_free(c);

336 return NULL;

337 }

338

339 c->fctx = s;

340 c->vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

341 c->vst->codec->codec_id = AV_CODEC_ID_DVVIDEO;

342 c->vst->codec->bit_rate = 25000000;

343 c->vst->start_time = 0;

344

345 return c;

346 }

347

348 int avpriv_dv_get_packet(DVDemuxContext *c, AVPacket *pkt)

349 {

350 int size = -1;

351 int i;

352

353 for (i = 0; i < c->ach; i++) {

354 if (c->ast[i] && c->audio_pkt[i].size) {

355 *pkt = c->audio_pkt[i];

356 c->audio_pkt[i].size = 0;

357 size = pkt->size;

358 break;

359 }

360 }

361

362 return size;

363 }

364

365 int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,

366 uint8_t *buf, int buf_size, int64_t pos)

367 {

368 int size, i;

369 uint8_t *ppcm[5] = { 0 };

370

371 if (buf_size < DV_PROFILE_BYTES ||

372 !(c->sys = avpriv_dv_frame_profile(c->sys, buf, buf_size)) ||

373 buf_size < c->sys->frame_size) {

374 return -1; /* Broken frame, or not enough data */

375 }

376

377 /* Queueing audio packet */

378 /* FIXME: in case of no audio/bad audio we have to do something */

379 size = dv_extract_audio_info(c, buf);

380 for (i = 0; i < c->ach; i++) {

381 c->audio_pkt[i].pos = pos;

382 c->audio_pkt[i].size = size;

383 c->audio_pkt[i].pts = c->abytes * 30000 * 8 /

384 c->ast[i]->codec->bit_rate;

385 ppcm[i] = c->audio_buf[i];

386 }

387 if (c->ach)

388 dv_extract_audio(buf, ppcm, c->sys);

389

390 /* We work with 720p frames split in half, thus even frames have

391 * channels 0,1 and odd 2,3. */

392 if (c->sys->height == 720) {

393 if (buf[1] & 0x0C) {

394 c->audio_pkt[2].size = c->audio_pkt[3].size = 0;

395 } else {

396 c->audio_pkt[0].size = c->audio_pkt[1].size = 0;

397 c->abytes += size;

398 }

399 } else {

400 c->abytes += size;

401 }

402

403 /* Now it's time to return video packet */

404 size = dv_extract_video_info(c, buf);

405 av_init_packet(pkt);

406 pkt->data = buf;

407 pkt->pos = pos;

408 pkt->size = size;

409 pkt->flags |= AV_PKT_FLAG_KEY;

410 pkt->stream_index = c->vst->index;

411 pkt->pts = c->frames;

412

413 c->frames++;

414

415 return size;

416 }

417

418 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,

419 int64_t timestamp, int flags)

420 {

421 // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)

422 const DVprofile *sys = avpriv_dv_codec_profile(c->vst->codec);

423 int64_t offset;

424 int64_t size = avio_size(s->pb) - s->data_offset;

425 int64_t max_offset = ((size - 1) / sys->frame_size) * sys->frame_size;

426

427 offset = sys->frame_size * timestamp;

428

429 if (size >= 0 && offset > max_offset)

430 offset = max_offset;

431 else if (offset < 0)

432 offset = 0;

433

434 return offset + s->data_offset;

435 }

436

437 void ff_dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)

438 {

439 c->frames = frame_offset;

440 if (c->ach) {

441 if (c->sys) {

442 c->abytes = av_rescale_q(c->frames, c->sys->time_base,

443 (AVRational) { 8, c->ast[0]->codec->bit_rate });

444 } else

445 av_log(c->fctx, AV_LOG_ERROR, "cannot adjust audio bytes\n");

446 }

447 c->audio_pkt[0].size = c->audio_pkt[1].size = 0;

448 c->audio_pkt[2].size = c->audio_pkt[3].size = 0;

449 }

450

451 /************************************************************

452 * Implementation of the easiest DV storage of all -- raw DV.

453 ************************************************************/

454

455 typedef struct RawDVContext {

456 DVDemuxContext *dv_demux;

457 uint8_t buf[DV_MAX_FRAME_SIZE];

458 } RawDVContext;

459

460 static int dv_read_timecode(AVFormatContext *s) {

461 int ret;

462 char timecode[AV_TIMECODE_STR_SIZE];

463 int64_t pos = avio_tell(s->pb);

464

465 // Read 3 DIF blocks: Header block and 2 Subcode blocks.

466 int partial_frame_size = 3 * 80;

467 uint8_t *partial_frame = av_mallocz(sizeof(*partial_frame) *

468 partial_frame_size);

469

470 RawDVContext *c = s->priv_data;

471 ret = avio_read(s->pb, partial_frame, partial_frame_size);

472 if (ret < 0)

473 goto finish;

474

475 if (ret < partial_frame_size) {

476 ret = -1;

477 goto finish;

478 }

479

480 ret = dv_extract_timecode(c->dv_demux, partial_frame, timecode);

481 if (ret)

482 av_dict_set(&s->metadata, "timecode", timecode, 0);

483 else

484 av_log(s, AV_LOG_ERROR, "Detected timecode is invalid\n");

485

486 finish:

487 av_free(partial_frame);

488 avio_seek(s->pb, pos, SEEK_SET);

489 return ret;

490 }

491

492 static int dv_read_header(AVFormatContext *s)

493 {

494 unsigned state, marker_pos = 0;

495 RawDVContext *c = s->priv_data;

496

497 c->dv_demux = avpriv_dv_init_demux(s);

498 if (!c->dv_demux)

499 return -1;

500

501 state = avio_rb32(s->pb);

502 while ((state & 0xffffff7f) != 0x1f07003f) {

503 if (url_feof(s->pb)) {

504 av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n");

505 return -1;

506 }

507 if (state == 0x003f0700 || state == 0xff3f0700)

508 marker_pos = avio_tell(s->pb);

509 if (state == 0xff3f0701 && avio_tell(s->pb) - marker_pos == 80) {

510 avio_seek(s->pb, -163, SEEK_CUR);

511 state = avio_rb32(s->pb);

512 break;

513 }

514 state = (state << 8) | avio_r8(s->pb);

515 }

516 AV_WB32(c->buf, state);

517

518 if (avio_read(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) != DV_PROFILE_BYTES - 4 ||

519 avio_seek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)

520 return AVERROR(EIO);

521

522 c->dv_demux->sys = avpriv_dv_frame_profile(c->dv_demux->sys,

523 c->buf,

524 DV_PROFILE_BYTES);

525 if (!c->dv_demux->sys) {

526 av_log(s, AV_LOG_ERROR,

527 "Can't determine profile of DV input stream.\n");

528 return -1;

529 }

530

531 s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size,

532 (AVRational) { 8, 1 },

533 c->dv_demux->sys->time_base);

534

535 if (s->pb->seekable)

536 dv_read_timecode(s);

537

538 return 0;

539 }

540

541 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)

542 {

543 int size;

544 RawDVContext *c = s->priv_data;

545

546 size = avpriv_dv_get_packet(c->dv_demux, pkt);

547

548 if (size < 0) {

549 int64_t pos = avio_tell(s->pb);

550 if (!c->dv_demux->sys)

551 return AVERROR(EIO);

552 size = c->dv_demux->sys->frame_size;

553 if (avio_read(s->pb, c->buf, size) <= 0)

554 return AVERROR(EIO);

555

556 size = avpriv_dv_produce_packet(c->dv_demux, pkt, c->buf, size, pos);

557 }

558

559 return size;

560 }

561

562 static int dv_read_seek(AVFormatContext *s, int stream_index,

563 int64_t timestamp, int flags)

564 {

565 RawDVContext *r = s->priv_data;

566 DVDemuxContext *c = r->dv_demux;

567 int64_t offset = dv_frame_offset(s, c, timestamp, flags);

568

569 if (avio_seek(s->pb, offset, SEEK_SET) < 0)

570 return -1;

571

572 ff_dv_offset_reset(c, offset / c->sys->frame_size);

573 return 0;

574 }

575

576 static int dv_read_close(AVFormatContext *s)

577 {

578 RawDVContext *c = s->priv_data;

579 av_free(c->dv_demux);

580 return 0;

581 }

582

583 static int dv_probe(AVProbeData *p)

584 {

585 unsigned marker_pos = 0;

586 int i;

587 int matches = 0;

588 int firstmatch = 0;

589 int secondary_matches = 0;

590

591 if (p->buf_size < 5)

592 return 0;

593

594 for (i = 0; i < p->buf_size-4; i++) {

595 unsigned state = AV_RB32(p->buf+i);

596 if ((state & 0x0007f840) == 0x00070000) {

597 // any section header, also with seq/chan num != 0,

598 // should appear around every 12000 bytes, at least 10 per frame

599 if ((state & 0xff07ff7f) == 0x1f07003f) {

600 secondary_matches++;

601 if ((state & 0xffffff7f) == 0x1f07003f) {

602 matches++;

603 if (!i)

604 firstmatch = 1;

605 }

606 }

607 if (state == 0x003f0700 || state == 0xff3f0700)

608 marker_pos = i;

609 if (state == 0xff3f0701 && i - marker_pos == 80)

610 matches++;

611 }

612 }

613

614 if (matches && p->buf_size / matches < 1024 * 1024) {

615 if (matches > 4 || firstmatch ||

616 (secondary_matches >= 10 &&

617 p->buf_size / secondary_matches < 24000))

618 // not max to avoid dv in mov to match

619 return AVPROBE_SCORE_MAX * 3 / 4;

620 return AVPROBE_SCORE_MAX / 4;

621 }

622 return 0;

623 }

624

625 #if CONFIG_DV_DEMUXER

626 AVInputFormat ff_dv_demuxer = {

627 .name = "dv",

628 .long_name = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),

629 .priv_data_size = sizeof(RawDVContext),

630 .read_probe = dv_probe,

631 .read_header = dv_read_header,

632 .read_packet = dv_read_packet,

633 .read_close = dv_read_close,

634 .read_seek = dv_read_seek,

635 .extensions = "dv,dif",

636 };

637 #endif

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