FFmpeg: libavformat/hls.c Source File

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libavformat

hls.c

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1 /*

2 * Apple HTTP Live Streaming demuxer

5 *

6 * This file is part of FFmpeg.

7 *

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

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

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

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

12 *

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

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

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

16 * Lesser General Public License for more details.

17 *

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

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

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

21 */

23 /**

24 * @file

25 * Apple HTTP Live Streaming demuxer

26 * http://tools.ietf.org/html/draft-pantos-http-live-streaming

27 */

29 #include "libavutil/avstring.h"

30 #include "libavutil/avassert.h"

31 #include "libavutil/intreadwrite.h"

32 #include "libavutil/mathematics.h"

33 #include "libavutil/opt.h"

34 #include "libavutil/dict.h"

35 #include "libavutil/time.h"

36 #include "avformat.h"

37 #include "internal.h"

38 #include "avio_internal.h"

39 #include "url.h"

40 #include "id3v2.h"

42 #define INITIAL_BUFFER_SIZE 32768

44 #define MAX_FIELD_LEN 64

45 #define MAX_CHARACTERISTICS_LEN 512

47 #define MPEG_TIME_BASE 90000

48 #define MPEG_TIME_BASE_Q (AVRational){1, MPEG_TIME_BASE}

50 /*

51 * An apple http stream consists of a playlist with media segment files,

52 * played sequentially. There may be several playlists with the same

53 * video content, in different bandwidth variants, that are played in

54 * parallel (preferably only one bandwidth variant at a time). In this case,

55 * the user supplied the url to a main playlist that only lists the variant

56 * playlists.

57 *

58 * If the main playlist doesn't point at any variants, we still create

59 * one anonymous toplevel variant for this, to maintain the structure.

60 */

62 enum KeyType {

63 KEY_NONE,

64 KEY_AES_128,

65 };

67 struct segment {

68 int64_t duration;

69 int64_t url_offset;

70 int64_t size;

71 char *url;

72 char *key;

73 enum KeyType key_type;

74 uint8_t iv[16];

75 };

77 struct rendition;

79 enum PlaylistType {

80 PLS_TYPE_UNSPECIFIED,

81 PLS_TYPE_EVENT,

82 PLS_TYPE_VOD

83 };

85 /*

86 * Each playlist has its own demuxer. If it currently is active,

87 * it has an open AVIOContext too, and potentially an AVPacket

88 * containing the next packet from this stream.

89 */

90 struct playlist {

91 char url[MAX_URL_SIZE];

92 AVIOContext pb;

93 uint8_t* read_buffer;

94 URLContext *input;

95 AVFormatContext *parent;

96 int index;

97 AVFormatContext *ctx;

98 AVPacket pkt;

99 int stream_offset;

100

101 int finished;

102 enum PlaylistType type;

103 int64_t target_duration;

104 int start_seq_no;

105 int n_segments;

106 struct segment **segments;

107 int needed, cur_needed;

108 int cur_seq_no;

109 int64_t cur_seg_offset;

110 int64_t last_load_time;

111

112 char key_url[MAX_URL_SIZE];

113 uint8_t key[16];

114

115 /* ID3 timestamp handling (elementary audio streams have ID3 timestamps

116 * (and possibly other ID3 tags) in the beginning of each segment) */

117 int is_id3_timestamped; /* -1: not yet known */

118 int64_t id3_mpegts_timestamp; /* in mpegts tb */

119 int64_t id3_offset; /* in stream original tb */

120 uint8_t* id3_buf; /* temp buffer for id3 parsing */

121 unsigned int id3_buf_size;

122 AVDictionary *id3_initial; /* data from first id3 tag */

123 int id3_found; /* ID3 tag found at some point */

124 int id3_changed; /* ID3 tag data has changed at some point */

125 ID3v2ExtraMeta *id3_deferred_extra; /* stored here until subdemuxer is opened */

126

127 int64_t seek_timestamp;

128 int seek_flags;

129 int seek_stream_index; /* into subdemuxer stream array */

130

131 /* Renditions associated with this playlist, if any.

132 * Alternative rendition playlists have a single rendition associated

133 * with them, and variant main Media Playlists may have

134 * multiple (playlist-less) renditions associated with them. */

135 int n_renditions;

136 struct rendition **renditions;

137 };

138

139 /*

140 * Renditions are e.g. alternative subtitle or audio streams.

141 * The rendition may either be an external playlist or it may be

142 * contained in the main Media Playlist of the variant (in which case

143 * playlist is NULL).

144 */

145 struct rendition {

146 enum AVMediaType type;

147 struct playlist *playlist;

148 char group_id[MAX_FIELD_LEN];

149 char language[MAX_FIELD_LEN];

150 char name[MAX_FIELD_LEN];

151 int disposition;

152 };

153

154 struct variant {

155 int bandwidth;

156

157 /* every variant contains at least the main Media Playlist in index 0 */

158 int n_playlists;

159 struct playlist **playlists;

160

161 char audio_group[MAX_FIELD_LEN];

162 char video_group[MAX_FIELD_LEN];

163 char subtitles_group[MAX_FIELD_LEN];

164 };

165

166 typedef struct HLSContext {

167 int n_variants;

168 struct variant **variants;

169 int n_playlists;

170 struct playlist **playlists;

171 int n_renditions;

172 struct rendition **renditions;

173

174 int cur_seq_no;

175 int first_packet;

176 int64_t first_timestamp;

177 int64_t cur_timestamp;

178 AVIOInterruptCB *interrupt_callback;

179 char *user_agent; ///< holds HTTP user agent set as an AVOption to the HTTP protocol context

180 char *cookies; ///< holds HTTP cookie values set in either the initial response or as an AVOption to the HTTP protocol context

181 char *headers; ///< holds HTTP headers set as an AVOption to the HTTP protocol context

182 } HLSContext;

183

184 static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)

185 {

186 int len = ff_get_line(s, buf, maxlen);

187 while (len > 0 && av_isspace(buf[len - 1]))

188 buf[--len] = '0円';

189 return len;

190 }

191

192 static void free_segment_list(struct playlist *pls)

193 {

194 int i;

195 for (i = 0; i < pls->n_segments; i++) {

196 av_free(pls->segments[i]->key);

197 av_free(pls->segments[i]->url);

198 av_free(pls->segments[i]);

199 }

200 av_freep(&pls->segments);

201 pls->n_segments = 0;

202 }

203

204 static void free_playlist_list(HLSContext *c)

205 {

206 int i;

207 for (i = 0; i < c->n_playlists; i++) {

208 struct playlist *pls = c->playlists[i];

209 free_segment_list(pls);

210 av_freep(&pls->renditions);

211 av_freep(&pls->id3_buf);

212 av_dict_free(&pls->id3_initial);

213 ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);

214 av_free_packet(&pls->pkt);

215 av_free(pls->pb.buffer);

216 if (pls->input)

217 ffurl_close(pls->input);

218 if (pls->ctx) {

219 pls->ctx->pb = NULL;

220 avformat_close_input(&pls->ctx);

221 }

222 av_free(pls);

223 }

224 av_freep(&c->playlists);

225 av_freep(&c->cookies);

226 av_freep(&c->user_agent);

227 c->n_playlists = 0;

228 }

229

230 static void free_variant_list(HLSContext *c)

231 {

232 int i;

233 for (i = 0; i < c->n_variants; i++) {

234 struct variant *var = c->variants[i];

235 av_freep(&var->playlists);

236 av_free(var);

237 }

238 av_freep(&c->variants);

239 c->n_variants = 0;

240 }

241

242 static void free_rendition_list(HLSContext *c)

243 {

244 int i;

245 for (i = 0; i < c->n_renditions; i++)

246 av_free(c->renditions[i]);

247 av_freep(&c->renditions);

248 c->n_renditions = 0;

249 }

250

251 /*

252 * Used to reset a statically allocated AVPacket to a clean slate,

253 * containing no data.

254 */

255 static void reset_packet(AVPacket *pkt)

256 {

257 av_init_packet(pkt);

258 pkt->data = NULL;

259 }

260

261 static struct playlist *new_playlist(HLSContext *c, const char *url,

262 const char *base)

263 {

264 struct playlist *pls = av_mallocz(sizeof(struct playlist));

265 if (!pls)

266 return NULL;

267 reset_packet(&pls->pkt);

268 ff_make_absolute_url(pls->url, sizeof(pls->url), base, url);

269 pls->seek_timestamp = AV_NOPTS_VALUE;

270

271 pls->is_id3_timestamped = -1;

272 pls->id3_mpegts_timestamp = AV_NOPTS_VALUE;

273

274 dynarray_add(&c->playlists, &c->n_playlists, pls);

275 return pls;

276 }

277

278 struct variant_info {

279 char bandwidth[20];

280 /* variant group ids: */

281 char audio[MAX_FIELD_LEN];

282 char video[MAX_FIELD_LEN];

283 char subtitles[MAX_FIELD_LEN];

284 };

285

286 static struct variant *new_variant(HLSContext *c, struct variant_info *info,

287 const char *url, const char *base)

288 {

289 struct variant *var;

290 struct playlist *pls;

291

292 pls = new_playlist(c, url, base);

293 if (!pls)

294 return NULL;

295

296 var = av_mallocz(sizeof(struct variant));

297 if (!var)

298 return NULL;

299

300 if (info) {

301 var->bandwidth = atoi(info->bandwidth);

302 strcpy(var->audio_group, info->audio);

303 strcpy(var->video_group, info->video);

304 strcpy(var->subtitles_group, info->subtitles);

305 }

306

307 dynarray_add(&c->variants, &c->n_variants, var);

308 dynarray_add(&var->playlists, &var->n_playlists, pls);

309 return var;

310 }

311

312 static void handle_variant_args(struct variant_info *info, const char *key,

313 int key_len, char **dest, int *dest_len)

314 {

315 if (!strncmp(key, "BANDWIDTH=", key_len)) {

316 *dest = info->bandwidth;

317 *dest_len = sizeof(info->bandwidth);

318 } else if (!strncmp(key, "AUDIO=", key_len)) {

319 *dest = info->audio;

320 *dest_len = sizeof(info->audio);

321 } else if (!strncmp(key, "VIDEO=", key_len)) {

322 *dest = info->video;

323 *dest_len = sizeof(info->video);

324 } else if (!strncmp(key, "SUBTITLES=", key_len)) {

325 *dest = info->subtitles;

326 *dest_len = sizeof(info->subtitles);

327 }

328 }

329

330 struct key_info {

331 char uri[MAX_URL_SIZE];

332 char method[10];

333 char iv[35];

334 };

335

336 static void handle_key_args(struct key_info *info, const char *key,

337 int key_len, char **dest, int *dest_len)

338 {

339 if (!strncmp(key, "METHOD=", key_len)) {

340 *dest = info->method;

341 *dest_len = sizeof(info->method);

342 } else if (!strncmp(key, "URI=", key_len)) {

343 *dest = info->uri;

344 *dest_len = sizeof(info->uri);

345 } else if (!strncmp(key, "IV=", key_len)) {

346 *dest = info->iv;

347 *dest_len = sizeof(info->iv);

348 }

349 }

350

351 struct rendition_info {

352 char type[16];

353 char uri[MAX_URL_SIZE];

354 char group_id[MAX_FIELD_LEN];

355 char language[MAX_FIELD_LEN];

356 char assoc_language[MAX_FIELD_LEN];

357 char name[MAX_FIELD_LEN];

358 char defaultr[4];

359 char forced[4];

360 char characteristics[MAX_CHARACTERISTICS_LEN];

361 };

362

363 static struct rendition *new_rendition(HLSContext *c, struct rendition_info *info,

364 const char *url_base)

365 {

366 struct rendition *rend;

367 enum AVMediaType type = AVMEDIA_TYPE_UNKNOWN;

368 char *characteristic;

369 char *chr_ptr;

370 char *saveptr;

371

372 if (!strcmp(info->type, "AUDIO"))

373 type = AVMEDIA_TYPE_AUDIO;

374 else if (!strcmp(info->type, "VIDEO"))

375 type = AVMEDIA_TYPE_VIDEO;

376 else if (!strcmp(info->type, "SUBTITLES"))

377 type = AVMEDIA_TYPE_SUBTITLE;

378 else if (!strcmp(info->type, "CLOSED-CAPTIONS"))

379 /* CLOSED-CAPTIONS is ignored since we do not support CEA-608 CC in

380 * AVC SEI RBSP anyway */

381 return NULL;

382

383 if (type == AVMEDIA_TYPE_UNKNOWN)

384 return NULL;

385

386 /* URI is mandatory for subtitles as per spec */

387 if (type == AVMEDIA_TYPE_SUBTITLE && !info->uri[0])

388 return NULL;

389

390 /* TODO: handle subtitles (each segment has to parsed separately) */

391 if (type == AVMEDIA_TYPE_SUBTITLE)

392 return NULL;

393

394 rend = av_mallocz(sizeof(struct rendition));

395 if (!rend)

396 return NULL;

397

398 dynarray_add(&c->renditions, &c->n_renditions, rend);

399

400 rend->type = type;

401 strcpy(rend->group_id, info->group_id);

402 strcpy(rend->language, info->language);

403 strcpy(rend->name, info->name);

404

405 /* add the playlist if this is an external rendition */

406 if (info->uri[0]) {

407 rend->playlist = new_playlist(c, info->uri, url_base);

408 if (rend->playlist)

409 dynarray_add(&rend->playlist->renditions,

410 &rend->playlist->n_renditions, rend);

411 }

412

413 if (info->assoc_language[0]) {

414 int langlen = strlen(rend->language);

415 if (langlen < sizeof(rend->language) - 3) {

416 rend->language[langlen] = ',';

417 strncpy(rend->language + langlen + 1, info->assoc_language,

418 sizeof(rend->language) - langlen - 2);

419 }

420 }

421

422 if (!strcmp(info->defaultr, "YES"))

423 rend->disposition |= AV_DISPOSITION_DEFAULT;

424 if (!strcmp(info->forced, "YES"))

425 rend->disposition |= AV_DISPOSITION_FORCED;

426

427 chr_ptr = info->characteristics;

428 while ((characteristic = av_strtok(chr_ptr, ",", &saveptr))) {

429 if (!strcmp(characteristic, "public.accessibility.describes-music-and-sound"))

430 rend->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;

431 else if (!strcmp(characteristic, "public.accessibility.describes-video"))

432 rend->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;

433

434 chr_ptr = NULL;

435 }

436

437 return rend;

438 }

439

440 static void handle_rendition_args(struct rendition_info *info, const char *key,

441 int key_len, char **dest, int *dest_len)

442 {

443 if (!strncmp(key, "TYPE=", key_len)) {

444 *dest = info->type;

445 *dest_len = sizeof(info->type);

446 } else if (!strncmp(key, "URI=", key_len)) {

447 *dest = info->uri;

448 *dest_len = sizeof(info->uri);

449 } else if (!strncmp(key, "GROUP-ID=", key_len)) {

450 *dest = info->group_id;

451 *dest_len = sizeof(info->group_id);

452 } else if (!strncmp(key, "LANGUAGE=", key_len)) {

453 *dest = info->language;

454 *dest_len = sizeof(info->language);

455 } else if (!strncmp(key, "ASSOC-LANGUAGE=", key_len)) {

456 *dest = info->assoc_language;

457 *dest_len = sizeof(info->assoc_language);

458 } else if (!strncmp(key, "NAME=", key_len)) {

459 *dest = info->name;

460 *dest_len = sizeof(info->name);

461 } else if (!strncmp(key, "DEFAULT=", key_len)) {

462 *dest = info->defaultr;

463 *dest_len = sizeof(info->defaultr);

464 } else if (!strncmp(key, "FORCED=", key_len)) {

465 *dest = info->forced;

466 *dest_len = sizeof(info->forced);

467 } else if (!strncmp(key, "CHARACTERISTICS=", key_len)) {

468 *dest = info->characteristics;

469 *dest_len = sizeof(info->characteristics);

470 }

471 /*

472 * ignored:

473 * - AUTOSELECT: client may autoselect based on e.g. system language

474 * - INSTREAM-ID: EIA-608 closed caption number ("CC1".."CC4")

475 */

476 }

477

478 /* used by parse_playlist to allocate a new variant+playlist when the

479 * playlist is detected to be a Media Playlist (not Master Playlist)

480 * and we have no parent Master Playlist (parsing of which would have

481 * allocated the variant and playlist already) */

482 static int ensure_playlist(HLSContext *c, struct playlist **pls, const char *url)

483 {

484 if (*pls)

485 return 0;

486 if (!new_variant(c, NULL, url, NULL))

487 return AVERROR(ENOMEM);

488 *pls = c->playlists[c->n_playlists - 1];

489 return 0;

490 }

491

492 /* pls = NULL => Master Playlist or parentless Media Playlist

493 * pls = !NULL => parented Media Playlist, playlist+variant allocated */

494 static int parse_playlist(HLSContext *c, const char *url,

495 struct playlist *pls, AVIOContext *in)

496 {

497 int ret = 0, is_segment = 0, is_variant = 0;

498 int64_t duration = 0;

499 enum KeyType key_type = KEY_NONE;

500 uint8_t iv[16] = "";

501 int has_iv = 0;

502 char key[MAX_URL_SIZE] = "";

503 char line[MAX_URL_SIZE];

504 const char *ptr;

505 int close_in = 0;

506 int64_t seg_offset = 0;

507 int64_t seg_size = -1;

508 uint8_t *new_url = NULL;

509 struct variant_info variant_info;

510 char tmp_str[MAX_URL_SIZE];

511

512 if (!in) {

513 AVDictionary *opts = NULL;

514 close_in = 1;

515 /* Some HLS servers don't like being sent the range header */

516 av_dict_set(&opts, "seekable", "0", 0);

517

518 // broker prior HTTP options that should be consistent across requests

519 av_dict_set(&opts, "user-agent", c->user_agent, 0);

520 av_dict_set(&opts, "cookies", c->cookies, 0);

521 av_dict_set(&opts, "headers", c->headers, 0);

522

523 ret = avio_open2(&in, url, AVIO_FLAG_READ,

524 c->interrupt_callback, &opts);

525 av_dict_free(&opts);

526 if (ret < 0)

527 return ret;

528 }

529

530 if (av_opt_get(in, "location", AV_OPT_SEARCH_CHILDREN, &new_url) >= 0)

531 url = new_url;

532

533 read_chomp_line(in, line, sizeof(line));

534 if (strcmp(line, "#EXTM3U")) {

535 ret = AVERROR_INVALIDDATA;

536 goto fail;

537 }

538

539 if (pls) {

540 free_segment_list(pls);

541 pls->finished = 0;

542 pls->type = PLS_TYPE_UNSPECIFIED;

543 }

544 while (!url_feof(in)) {

545 read_chomp_line(in, line, sizeof(line));

546 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {

547 is_variant = 1;

548 memset(&variant_info, 0, sizeof(variant_info));

549 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,

550 &variant_info);

551 } else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {

552 struct key_info info = {{0}};

553 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_key_args,

554 &info);

555 key_type = KEY_NONE;

556 has_iv = 0;

557 if (!strcmp(info.method, "AES-128"))

558 key_type = KEY_AES_128;

559 if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {

560 ff_hex_to_data(iv, info.iv + 2);

561 has_iv = 1;

562 }

563 av_strlcpy(key, info.uri, sizeof(key));

564 } else if (av_strstart(line, "#EXT-X-MEDIA:", &ptr)) {

565 struct rendition_info info = {{0}};

566 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_rendition_args,

567 &info);

568 new_rendition(c, &info, url);

569 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {

570 ret = ensure_playlist(c, &pls, url);

571 if (ret < 0)

572 goto fail;

573 pls->target_duration = atoi(ptr) * AV_TIME_BASE;

574 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {

575 ret = ensure_playlist(c, &pls, url);

576 if (ret < 0)

577 goto fail;

578 pls->start_seq_no = atoi(ptr);

579 } else if (av_strstart(line, "#EXT-X-PLAYLIST-TYPE:", &ptr)) {

580 ret = ensure_playlist(c, &pls, url);

581 if (ret < 0)

582 goto fail;

583 if (!strcmp(ptr, "EVENT"))

584 pls->type = PLS_TYPE_EVENT;

585 else if (!strcmp(ptr, "VOD"))

586 pls->type = PLS_TYPE_VOD;

587 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {

588 if (pls)

589 pls->finished = 1;

590 } else if (av_strstart(line, "#EXTINF:", &ptr)) {

591 is_segment = 1;

592 duration = atof(ptr) * AV_TIME_BASE;

593 } else if (av_strstart(line, "#EXT-X-BYTERANGE:", &ptr)) {

594 seg_size = atoi(ptr);

595 ptr = strchr(ptr, '@');

596 if (ptr)

597 seg_offset = atoi(ptr+1);

598 } else if (av_strstart(line, "#", NULL)) {

599 continue;

600 } else if (line[0]) {

601 if (is_variant) {

602 if (!new_variant(c, &variant_info, line, url)) {

603 ret = AVERROR(ENOMEM);

604 goto fail;

605 }

606 is_variant = 0;

607 }

608 if (is_segment) {

609 struct segment *seg;

610 if (!pls) {

611 if (!new_variant(c, 0, url, NULL)) {

612 ret = AVERROR(ENOMEM);

613 goto fail;

614 }

615 pls = c->playlists[c->n_playlists - 1];

616 }

617 seg = av_malloc(sizeof(struct segment));

618 if (!seg) {

619 ret = AVERROR(ENOMEM);

620 goto fail;

621 }

622 seg->duration = duration;

623 seg->key_type = key_type;

624 if (has_iv) {

625 memcpy(seg->iv, iv, sizeof(iv));

626 } else {

627 int seq = pls->start_seq_no + pls->n_segments;

628 memset(seg->iv, 0, sizeof(seg->iv));

629 AV_WB32(seg->iv + 12, seq);

630 }

631

632 if (key_type != KEY_NONE) {

633 ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, key);

634 seg->key = av_strdup(tmp_str);

635 if (!seg->key) {

636 av_free(seg);

637 ret = AVERROR(ENOMEM);

638 goto fail;

639 }

640 } else {

641 seg->key = NULL;

642 }

643

644 ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, line);

645 seg->url = av_strdup(tmp_str);

646 if (!seg->url) {

647 av_free(seg->key);

648 av_free(seg);

649 ret = AVERROR(ENOMEM);

650 goto fail;

651 }

652

653 dynarray_add(&pls->segments, &pls->n_segments, seg);

654 is_segment = 0;

655

656 seg->size = seg_size;

657 if (seg_size >= 0) {

658 seg->url_offset = seg_offset;

659 seg_offset += seg_size;

660 seg_size = -1;

661 } else {

662 seg->url_offset = 0;

663 seg_offset = 0;

664 }

665 }

666 }

667 }

668 if (pls)

669 pls->last_load_time = av_gettime();

670

671 fail:

672 av_free(new_url);

673 if (close_in)

674 avio_close(in);

675 return ret;

676 }

677

678 enum ReadFromURLMode {

679 READ_NORMAL,

680 READ_COMPLETE,

681 };

682

683 /* read from URLContext, limiting read to current segment */

684 static int read_from_url(struct playlist *pls, uint8_t *buf, int buf_size,

685 enum ReadFromURLMode mode)

686 {

687 int ret;

688 struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];

689

690 /* limit read if the segment was only a part of a file */

691 if (seg->size >= 0)

692 buf_size = FFMIN(buf_size, seg->size - pls->cur_seg_offset);

693

694 if (mode == READ_COMPLETE)

695 ret = ffurl_read_complete(pls->input, buf, buf_size);

696 else

697 ret = ffurl_read(pls->input, buf, buf_size);

698

699 if (ret > 0)

700 pls->cur_seg_offset += ret;

701

702 return ret;

703 }

704

705 /* Parse the raw ID3 data and pass contents to caller */

706 static void parse_id3(AVFormatContext *s, AVIOContext *pb,

707 AVDictionary **metadata, int64_t *dts,

708 ID3v2ExtraMetaAPIC **apic, ID3v2ExtraMeta **extra_meta)

709 {

710 static const char id3_priv_owner_ts[] = "com.apple.streaming.transportStreamTimestamp";

711 ID3v2ExtraMeta *meta;

712

713 ff_id3v2_read_dict(pb, metadata, ID3v2_DEFAULT_MAGIC, extra_meta);

714 for (meta = *extra_meta; meta; meta = meta->next) {

715 if (!strcmp(meta->tag, "PRIV")) {

716 ID3v2ExtraMetaPRIV *priv = meta->data;

717 if (priv->datasize == 8 && !strcmp(priv->owner, id3_priv_owner_ts)) {

718 /* 33-bit MPEG timestamp */

719 int64_t ts = AV_RB64(priv->data);

720 av_log(s, AV_LOG_DEBUG, "HLS ID3 audio timestamp %"PRId64"\n", ts);

721 if ((ts & ~((1ULL << 33) - 1)) == 0)

722 *dts = ts;

723 else

724 av_log(s, AV_LOG_ERROR, "Invalid HLS ID3 audio timestamp %"PRId64"\n", ts);

725 }

726 } else if (!strcmp(meta->tag, "APIC") && apic)

727 *apic = meta->data;

728 }

729 }

730

731 /* Check if the ID3 metadata contents have changed */

732 static int id3_has_changed_values(struct playlist *pls, AVDictionary *metadata,

733 ID3v2ExtraMetaAPIC *apic)

734 {

735 AVDictionaryEntry *entry = NULL;

736 AVDictionaryEntry *oldentry;

737 /* check that no keys have changed values */

738 while ((entry = av_dict_get(metadata, "", entry, AV_DICT_IGNORE_SUFFIX))) {

739 oldentry = av_dict_get(pls->id3_initial, entry->key, NULL, AV_DICT_MATCH_CASE);

740 if (!oldentry || strcmp(oldentry->value, entry->value) != 0)

741 return 1;

742 }

743

744 /* check if apic appeared */

745 if (apic && (pls->ctx->nb_streams != 2 || !pls->ctx->streams[1]->attached_pic.data))

746 return 1;

747

748 if (apic) {

749 int size = pls->ctx->streams[1]->attached_pic.size;

750 if (size != apic->buf->size - FF_INPUT_BUFFER_PADDING_SIZE)

751 return 1;

752

753 if (memcmp(apic->buf->data, pls->ctx->streams[1]->attached_pic.data, size) != 0)

754 return 1;

755 }

756

757 return 0;

758 }

759

760 /* Parse ID3 data and handle the found data */

761 static void handle_id3(AVIOContext *pb, struct playlist *pls)

762 {

763 AVDictionary *metadata = NULL;

764 ID3v2ExtraMetaAPIC *apic = NULL;

765 ID3v2ExtraMeta *extra_meta = NULL;

766 int64_t timestamp = AV_NOPTS_VALUE;

767

768 parse_id3(pls->ctx, pb, &metadata, &timestamp, &apic, &extra_meta);

769

770 if (timestamp != AV_NOPTS_VALUE) {

771 pls->id3_mpegts_timestamp = timestamp;

772 pls->id3_offset = 0;

773 }

774

775 if (!pls->id3_found) {

776 /* initial ID3 tags */

777 av_assert0(!pls->id3_deferred_extra);

778 pls->id3_found = 1;

779

780 /* get picture attachment and set text metadata */

781 if (pls->ctx->nb_streams)

782 ff_id3v2_parse_apic(pls->ctx, &extra_meta);

783 else

784 /* demuxer not yet opened, defer picture attachment */

785 pls->id3_deferred_extra = extra_meta;

786

787 av_dict_copy(&pls->ctx->metadata, metadata, 0);

788 pls->id3_initial = metadata;

789

790 } else {

791 if (!pls->id3_changed && id3_has_changed_values(pls, metadata, apic)) {

792 avpriv_report_missing_feature(pls->ctx, "Changing ID3 metadata in HLS audio elementary stream");

793 pls->id3_changed = 1;

794 }

795 av_dict_free(&metadata);

796 }

797

798 if (!pls->id3_deferred_extra)

799 ff_id3v2_free_extra_meta(&extra_meta);

800 }

801

802 /* Intercept and handle ID3 tags between URLContext and AVIOContext */

803 static void intercept_id3(struct playlist *pls, uint8_t *buf,

804 int buf_size, int *len)

805 {

806 /* intercept id3 tags, we do not want to pass them to the raw

807 * demuxer on all segment switches */

808 int bytes;

809 int id3_buf_pos = 0;

810 int fill_buf = 0;

811

812 /* gather all the id3 tags */

813 while (1) {

814 /* see if we can retrieve enough data for ID3 header */

815 if (*len < ID3v2_HEADER_SIZE && buf_size >= ID3v2_HEADER_SIZE) {

816 bytes = read_from_url(pls, buf + *len, ID3v2_HEADER_SIZE - *len, READ_COMPLETE);

817 if (bytes > 0) {

818

819 if (bytes == ID3v2_HEADER_SIZE - *len)

820 /* no EOF yet, so fill the caller buffer again after

821 * we have stripped the ID3 tags */

822 fill_buf = 1;

823

824 *len += bytes;

825

826 } else if (*len <= 0) {

827 /* error/EOF */

828 *len = bytes;

829 fill_buf = 0;

830 }

831 }

832

833 if (*len < ID3v2_HEADER_SIZE)

834 break;

835

836 if (ff_id3v2_match(buf, ID3v2_DEFAULT_MAGIC)) {

837 struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];

838 int64_t maxsize = seg->size >= 0 ? seg->size : 1024*1024;

839 int taglen = ff_id3v2_tag_len(buf);

840 int tag_got_bytes = FFMIN(taglen, *len);

841 int remaining = taglen - tag_got_bytes;

842

843 if (taglen > maxsize) {

844 av_log(pls->ctx, AV_LOG_ERROR, "Too large HLS ID3 tag (%d > %"PRId64" bytes)\n",

845 taglen, maxsize);

846 break;

847 }

848

849 /*

850 * Copy the id3 tag to our temporary id3 buffer.

851 * We could read a small id3 tag directly without memcpy, but

852 * we would still need to copy the large tags, and handling

853 * both of those cases together with the possibility for multiple

854 * tags would make the handling a bit complex.

855 */

856 pls->id3_buf = av_fast_realloc(pls->id3_buf, &pls->id3_buf_size, id3_buf_pos + taglen);

857 if (!pls->id3_buf)

858 break;

859 memcpy(pls->id3_buf + id3_buf_pos, buf, tag_got_bytes);

860 id3_buf_pos += tag_got_bytes;

861

862 /* strip the intercepted bytes */

863 *len -= tag_got_bytes;

864 memmove(buf, buf + tag_got_bytes, *len);

865 av_log(pls->ctx, AV_LOG_DEBUG, "Stripped %d HLS ID3 bytes\n", tag_got_bytes);

866

867 if (remaining > 0) {

868 /* read the rest of the tag in */

869 if (read_from_url(pls, pls->id3_buf + id3_buf_pos, remaining, READ_COMPLETE) != remaining)

870 break;

871 id3_buf_pos += remaining;

872 av_log(pls->ctx, AV_LOG_DEBUG, "Stripped additional %d HLS ID3 bytes\n", remaining);

873 }

874

875 } else {

876 /* no more ID3 tags */

877 break;

878 }

879 }

880

881 /* re-fill buffer for the caller unless EOF */

882 if (*len >= 0 && (fill_buf || *len == 0)) {

883 bytes = read_from_url(pls, buf + *len, buf_size - *len, READ_NORMAL);

884

885 /* ignore error if we already had some data */

886 if (bytes >= 0)

887 *len += bytes;

888 else if (*len == 0)

889 *len = bytes;

890 }

891

892 if (pls->id3_buf) {

893 /* Now parse all the ID3 tags */

894 AVIOContext id3ioctx;

895 ffio_init_context(&id3ioctx, pls->id3_buf, id3_buf_pos, 0, NULL, NULL, NULL, NULL);

896 handle_id3(&id3ioctx, pls);

897 }

898

899 if (pls->is_id3_timestamped == -1)

900 pls->is_id3_timestamped = (pls->id3_mpegts_timestamp != AV_NOPTS_VALUE);

901 }

902

903 static int open_input(HLSContext *c, struct playlist *pls)

904 {

905 AVDictionary *opts = NULL;

906 AVDictionary *opts2 = NULL;

907 int ret;

908 struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];

909

910 // broker prior HTTP options that should be consistent across requests

911 av_dict_set(&opts, "user-agent", c->user_agent, 0);

912 av_dict_set(&opts, "cookies", c->cookies, 0);

913 av_dict_set(&opts, "headers", c->headers, 0);

914 av_dict_set(&opts, "seekable", "0", 0);

915

916 // Same opts for key request (ffurl_open mutilates the opts so it cannot be used twice)

917 av_dict_copy(&opts2, opts, 0);

918

919 if (seg->size >= 0) {

920 /* try to restrict the HTTP request to the part we want

921 * (if this is in fact a HTTP request) */

922 char offset[24] = { 0 };

923 char end_offset[24] = { 0 };

924 snprintf(offset, sizeof(offset) - 1, "%"PRId64,

925 seg->url_offset);

926 snprintf(end_offset, sizeof(end_offset) - 1, "%"PRId64,

927 seg->url_offset + seg->size);

928 av_dict_set(&opts, "offset", offset, 0);

929 av_dict_set(&opts, "end_offset", end_offset, 0);

930 }

931

932 av_log(pls->parent, AV_LOG_VERBOSE, "HLS request for url '%s', offset %"PRId64", playlist %d\n",

933 seg->url, seg->url_offset, pls->index);

934

935 if (seg->key_type == KEY_NONE) {

936 ret = ffurl_open(&pls->input, seg->url, AVIO_FLAG_READ,

937 &pls->parent->interrupt_callback, &opts);

938

939 } else if (seg->key_type == KEY_AES_128) {

940 char iv[33], key[33], url[MAX_URL_SIZE];

941 if (strcmp(seg->key, pls->key_url)) {

942 URLContext *uc;

943 if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,

944 &pls->parent->interrupt_callback, &opts2) == 0) {

945 if (ffurl_read_complete(uc, pls->key, sizeof(pls->key))

946 != sizeof(pls->key)) {

947 av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",

948 seg->key);

949 }

950 ffurl_close(uc);

951 } else {

952 av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",

953 seg->key);

954 }

955 av_strlcpy(pls->key_url, seg->key, sizeof(pls->key_url));

956 }

957 ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);

958 ff_data_to_hex(key, pls->key, sizeof(pls->key), 0);

959 iv[32] = key[32] = '0円';

960 if (strstr(seg->url, "://"))

961 snprintf(url, sizeof(url), "crypto+%s", seg->url);

962 else

963 snprintf(url, sizeof(url), "crypto:%s", seg->url);

964 if ((ret = ffurl_alloc(&pls->input, url, AVIO_FLAG_READ,

965 &pls->parent->interrupt_callback)) < 0)

966 goto cleanup;

967 av_opt_set(pls->input->priv_data, "key", key, 0);

968 av_opt_set(pls->input->priv_data, "iv", iv, 0);

969

970 if ((ret = ffurl_connect(pls->input, &opts)) < 0) {

971 ffurl_close(pls->input);

972 pls->input = NULL;

973 goto cleanup;

974 }

975 ret = 0;

976 }

977 else

978 ret = AVERROR(ENOSYS);

979

980 /* Seek to the requested position. If this was a HTTP request, the offset

981 * should already be where want it to, but this allows e.g. local testing

982 * without a HTTP server. */

983 if (ret == 0 && seg->key_type == KEY_NONE) {

984 int seekret = ffurl_seek(pls->input, seg->url_offset, SEEK_SET);

985 if (seekret < 0) {

986 av_log(pls->parent, AV_LOG_ERROR, "Unable to seek to offset %"PRId64" of HLS segment '%s'\n", seg->url_offset, seg->url);

987 ret = seekret;

988 ffurl_close(pls->input);

989 pls->input = NULL;

990 }

991 }

992

993 cleanup:

994 av_dict_free(&opts);

995 av_dict_free(&opts2);

996 pls->cur_seg_offset = 0;

997 return ret;

998 }

999

1000 static int64_t default_reload_interval(struct playlist *pls)

1001 {

1002 return pls->n_segments > 0 ?

1003 pls->segments[pls->n_segments - 1]->duration :

1004 pls->target_duration;

1005 }

1006

1007 static int read_data(void *opaque, uint8_t *buf, int buf_size)

1008 {

1009 struct playlist *v = opaque;

1010 HLSContext *c = v->parent->priv_data;

1011 int ret, i;

1012 int just_opened = 0;

1013

1014 restart:

1015 if (!v->needed)

1016 return AVERROR_EOF;

1017

1018 if (!v->input) {

1019 int64_t reload_interval;

1020

1021 /* Check that the playlist is still needed before opening a new

1022 * segment. */

1023 if (v->ctx && v->ctx->nb_streams &&

1024 v->parent->nb_streams >= v->stream_offset + v->ctx->nb_streams) {

1025 v->needed = 0;

1026 for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;

1027 i++) {

1028 if (v->parent->streams[i]->discard < AVDISCARD_ALL)

1029 v->needed = 1;

1030 }

1031 }

1032 if (!v->needed) {

1033 av_log(v->parent, AV_LOG_INFO, "No longer receiving playlist %d\n",

1034 v->index);

1035 return AVERROR_EOF;

1036 }

1037

1038 /* If this is a live stream and the reload interval has elapsed since

1039 * the last playlist reload, reload the playlists now. */

1040 reload_interval = default_reload_interval(v);

1041

1042 reload:

1043 if (!v->finished &&

1044 av_gettime() - v->last_load_time >= reload_interval) {

1045 if ((ret = parse_playlist(c, v->url, v, NULL)) < 0) {

1046 av_log(v->parent, AV_LOG_WARNING, "Failed to reload playlist %d\n",

1047 v->index);

1048 return ret;

1049 }

1050 /* If we need to reload the playlist again below (if

1051 * there's still no more segments), switch to a reload

1052 * interval of half the target duration. */

1053 reload_interval = v->target_duration / 2;

1054 }

1055 if (v->cur_seq_no < v->start_seq_no) {

1056 av_log(NULL, AV_LOG_WARNING,

1057 "skipping %d segments ahead, expired from playlists\n",

1058 v->start_seq_no - v->cur_seq_no);

1059 v->cur_seq_no = v->start_seq_no;

1060 }

1061 if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {

1062 if (v->finished)

1063 return AVERROR_EOF;

1064 while (av_gettime() - v->last_load_time < reload_interval) {

1065 if (ff_check_interrupt(c->interrupt_callback))

1066 return AVERROR_EXIT;

1067 av_usleep(100*1000);

1068 }

1069 /* Enough time has elapsed since the last reload */

1070 goto reload;

1071 }

1072

1073 ret = open_input(c, v);

1074 if (ret < 0) {

1075 av_log(v->parent, AV_LOG_WARNING, "Failed to open segment of playlist %d\n",

1076 v->index);

1077 return ret;

1078 }

1079 just_opened = 1;

1080 }

1081

1082 ret = read_from_url(v, buf, buf_size, READ_NORMAL);

1083 if (ret > 0) {

1084 if (just_opened && v->is_id3_timestamped != 0) {

1085 /* Intercept ID3 tags here, elementary audio streams are required

1086 * to convey timestamps using them in the beginning of each segment. */

1087 intercept_id3(v, buf, buf_size, &ret);

1088 }

1089

1090 return ret;

1091 }

1092 ffurl_close(v->input);

1093 v->input = NULL;

1094 v->cur_seq_no++;

1095

1096 c->cur_seq_no = v->cur_seq_no;

1097

1098 goto restart;

1099 }

1100

1101 static int playlist_in_multiple_variants(HLSContext *c, struct playlist *pls)

1102 {

1103 int variant_count = 0;

1104 int i, j;

1105

1106 for (i = 0; i < c->n_variants && variant_count < 2; i++) {

1107 struct variant *v = c->variants[i];

1108

1109 for (j = 0; j < v->n_playlists; j++) {

1110 if (v->playlists[j] == pls) {

1111 variant_count++;

1112 break;

1113 }

1114 }

1115 }

1116

1117 return variant_count >= 2;

1118 }

1119

1120 static void add_renditions_to_variant(HLSContext *c, struct variant *var,

1121 enum AVMediaType type, const char *group_id)

1122 {

1123 int i;

1124

1125 for (i = 0; i < c->n_renditions; i++) {

1126 struct rendition *rend = c->renditions[i];

1127

1128 if (rend->type == type && !strcmp(rend->group_id, group_id)) {

1129

1130 if (rend->playlist)

1131 /* rendition is an external playlist

1132 * => add the playlist to the variant */

1133 dynarray_add(&var->playlists, &var->n_playlists, rend->playlist);

1134 else

1135 /* rendition is part of the variant main Media Playlist

1136 * => add the rendition to the main Media Playlist */

1137 dynarray_add(&var->playlists[0]->renditions,

1138 &var->playlists[0]->n_renditions,

1139 rend);

1140 }

1141 }

1142 }

1143

1144 static void add_metadata_from_renditions(AVFormatContext *s, struct playlist *pls,

1145 enum AVMediaType type)

1146 {

1147 int rend_idx = 0;

1148 int i;

1149

1150 for (i = 0; i < pls->ctx->nb_streams; i++) {

1151 AVStream *st = s->streams[pls->stream_offset + i];

1152

1153 if (st->codec->codec_type != type)

1154 continue;

1155

1156 for (; rend_idx < pls->n_renditions; rend_idx++) {

1157 struct rendition *rend = pls->renditions[rend_idx];

1158

1159 if (rend->type != type)

1160 continue;

1161

1162 if (rend->language[0])

1163 av_dict_set(&st->metadata, "language", rend->language, 0);

1164 if (rend->name[0])

1165 av_dict_set(&st->metadata, "comment", rend->name, 0);

1166

1167 st->disposition |= rend->disposition;

1168 }

1169 if (rend_idx >=pls->n_renditions)

1170 break;

1171 }

1172 }

1173

1174 /* if timestamp was in valid range: returns 1 and sets seq_no

1175 * if not: returns 0 and sets seq_no to closest segment */

1176 static int find_timestamp_in_playlist(HLSContext *c, struct playlist *pls,

1177 int64_t timestamp, int *seq_no)

1178 {

1179 int i;

1180 int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?

1181 0 : c->first_timestamp;

1182

1183 if (timestamp < pos) {

1184 *seq_no = pls->start_seq_no;

1185 return 0;

1186 }

1187

1188 for (i = 0; i < pls->n_segments; i++) {

1189 int64_t diff = pos + pls->segments[i]->duration - timestamp;

1190 if (diff > 0) {

1191 *seq_no = pls->start_seq_no + i;

1192 return 1;

1193 }

1194 pos += pls->segments[i]->duration;

1195 }

1196

1197 *seq_no = pls->start_seq_no + pls->n_segments - 1;

1198

1199 return 0;

1200 }

1201

1202 static int select_cur_seq_no(HLSContext *c, struct playlist *pls)

1203 {

1204 int seq_no;

1205

1206 if (!pls->finished && !c->first_packet &&

1207 av_gettime() - pls->last_load_time >= default_reload_interval(pls))

1208 /* reload the playlist since it was suspended */

1209 parse_playlist(c, pls->url, pls, NULL);

1210

1211 /* If playback is already in progress (we are just selecting a new

1212 * playlist) and this is a complete file, find the matching segment

1213 * by counting durations. */

1214 if (pls->finished && c->cur_timestamp != AV_NOPTS_VALUE) {

1215 find_timestamp_in_playlist(c, pls, c->cur_timestamp, &seq_no);

1216 return seq_no;

1217 }

1218

1219 if (!pls->finished) {

1220 if (!c->first_packet && /* we are doing a segment selection during playback */

1221 c->cur_seq_no >= pls->start_seq_no &&

1222 c->cur_seq_no < pls->start_seq_no + pls->n_segments)

1223 /* While spec 3.4.3 says that we cannot assume anything about the

1224 * content at the same sequence number on different playlists,

1225 * in practice this seems to work and doing it otherwise would

1226 * require us to download a segment to inspect its timestamps. */

1227 return c->cur_seq_no;

1228

1229 /* If this is a live stream with more than 3 segments, start at the

1230 * third last segment. */

1231 if (pls->n_segments > 3)

1232 return pls->start_seq_no + pls->n_segments - 3;

1233 }

1234

1235 /* Otherwise just start on the first segment. */

1236 return pls->start_seq_no;

1237 }

1238

1239 static int hls_read_header(AVFormatContext *s)

1240 {

1241 URLContext *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb->opaque;

1242 HLSContext *c = s->priv_data;

1243 int ret = 0, i, j, stream_offset = 0;

1244

1245 c->interrupt_callback = &s->interrupt_callback;

1246

1247 c->first_packet = 1;

1248 c->first_timestamp = AV_NOPTS_VALUE;

1249 c->cur_timestamp = AV_NOPTS_VALUE;

1250

1251 // if the URL context is good, read important options we must broker later

1252 if (u && u->prot->priv_data_class) {

1253 // get the previous user agent & set back to null if string size is zero

1254 av_freep(&c->user_agent);

1255 av_opt_get(u->priv_data, "user-agent", 0, (uint8_t**)&(c->user_agent));

1256 if (c->user_agent && !strlen(c->user_agent))

1257 av_freep(&c->user_agent);

1258

1259 // get the previous cookies & set back to null if string size is zero

1260 av_freep(&c->cookies);

1261 av_opt_get(u->priv_data, "cookies", 0, (uint8_t**)&(c->cookies));

1262 if (c->cookies && !strlen(c->cookies))

1263 av_freep(&c->cookies);

1264

1265 // get the previous headers & set back to null if string size is zero

1266 av_freep(&c->headers);

1267 av_opt_get(u->priv_data, "headers", 0, (uint8_t**)&(c->headers));

1268 if (c->headers && !strlen(c->headers))

1269 av_freep(&c->headers);

1270 }

1271

1272 if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)

1273 goto fail;

1274

1275 if (c->n_variants == 0) {

1276 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");

1277 ret = AVERROR_EOF;

1278 goto fail;

1279 }

1280 /* If the playlist only contained playlists (Master Playlist),

1281 * parse each individual playlist. */

1282 if (c->n_playlists > 1 || c->playlists[0]->n_segments == 0) {

1283 for (i = 0; i < c->n_playlists; i++) {

1284 struct playlist *pls = c->playlists[i];

1285 if ((ret = parse_playlist(c, pls->url, pls, NULL)) < 0)

1286 goto fail;

1287 }

1288 }

1289

1290 if (c->variants[0]->playlists[0]->n_segments == 0) {

1291 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");

1292 ret = AVERROR_EOF;

1293 goto fail;

1294 }

1295

1296 /* If this isn't a live stream, calculate the total duration of the

1297 * stream. */

1298 if (c->variants[0]->playlists[0]->finished) {

1299 int64_t duration = 0;

1300 for (i = 0; i < c->variants[0]->playlists[0]->n_segments; i++)

1301 duration += c->variants[0]->playlists[0]->segments[i]->duration;

1302 s->duration = duration;

1303 }

1304

1305 /* Associate renditions with variants */

1306 for (i = 0; i < c->n_variants; i++) {

1307 struct variant *var = c->variants[i];

1308

1309 if (var->audio_group[0])

1310 add_renditions_to_variant(c, var, AVMEDIA_TYPE_AUDIO, var->audio_group);

1311 if (var->video_group[0])

1312 add_renditions_to_variant(c, var, AVMEDIA_TYPE_VIDEO, var->video_group);

1313 if (var->subtitles_group[0])

1314 add_renditions_to_variant(c, var, AVMEDIA_TYPE_SUBTITLE, var->subtitles_group);

1315 }

1316

1317 /* Open the demuxer for each playlist */

1318 for (i = 0; i < c->n_playlists; i++) {

1319 struct playlist *pls = c->playlists[i];

1320 AVInputFormat *in_fmt = NULL;

1321

1322 if (pls->n_segments == 0)

1323 continue;

1324

1325 if (!(pls->ctx = avformat_alloc_context())) {

1326 ret = AVERROR(ENOMEM);

1327 goto fail;

1328 }

1329

1330 pls->index = i;

1331 pls->needed = 1;

1332 pls->parent = s;

1333 pls->cur_seq_no = select_cur_seq_no(c, pls);

1334

1335 pls->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);

1336 ffio_init_context(&pls->pb, pls->read_buffer, INITIAL_BUFFER_SIZE, 0, pls,

1337 read_data, NULL, NULL);

1338 pls->pb.seekable = 0;

1339 ret = av_probe_input_buffer(&pls->pb, &in_fmt, pls->segments[0]->url,

1340 NULL, 0, 0);

1341 if (ret < 0) {

1342 /* Free the ctx - it isn't initialized properly at this point,

1343 * so avformat_close_input shouldn't be called. If

1344 * avformat_open_input fails below, it frees and zeros the

1345 * context, so it doesn't need any special treatment like this. */

1346 av_log(s, AV_LOG_ERROR, "Error when loading first segment '%s'\n", pls->segments[0]->url);

1347 avformat_free_context(pls->ctx);

1348 pls->ctx = NULL;

1349 goto fail;

1350 }

1351 pls->ctx->pb = &pls->pb;

1352 pls->stream_offset = stream_offset;

1353 ret = avformat_open_input(&pls->ctx, pls->segments[0]->url, in_fmt, NULL);

1354 if (ret < 0)

1355 goto fail;

1356

1357 if (pls->id3_deferred_extra && pls->ctx->nb_streams == 1) {

1358 ff_id3v2_parse_apic(pls->ctx, &pls->id3_deferred_extra);

1359 avformat_queue_attached_pictures(pls->ctx);

1360 ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);

1361 pls->id3_deferred_extra = NULL;

1362 }

1363

1364 pls->ctx->ctx_flags &= ~AVFMTCTX_NOHEADER;

1365 ret = avformat_find_stream_info(pls->ctx, NULL);

1366 if (ret < 0)

1367 goto fail;

1368

1369 if (pls->is_id3_timestamped == -1)

1370 av_log(s, AV_LOG_WARNING, "No expected HTTP requests have been made\n");

1371

1372 /* Create new AVStreams for each stream in this playlist */

1373 for (j = 0; j < pls->ctx->nb_streams; j++) {

1374 AVStream *st = avformat_new_stream(s, NULL);

1375 AVStream *ist = pls->ctx->streams[j];

1376 if (!st) {

1377 ret = AVERROR(ENOMEM);

1378 goto fail;

1379 }

1380 st->id = i;

1381

1382 avcodec_copy_context(st->codec, pls->ctx->streams[j]->codec);

1383

1384 if (pls->is_id3_timestamped) /* custom timestamps via id3 */

1385 avpriv_set_pts_info(st, 33, 1, MPEG_TIME_BASE);

1386 else

1387 avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);

1388 }

1389

1390 add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_AUDIO);

1391 add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_VIDEO);

1392 add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_SUBTITLE);

1393

1394 stream_offset += pls->ctx->nb_streams;

1395 }

1396

1397 /* Create a program for each variant */

1398 for (i = 0; i < c->n_variants; i++) {

1399 struct variant *v = c->variants[i];

1400 char bitrate_str[20];

1401 AVProgram *program;

1402

1403 snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);

1404

1405 program = av_new_program(s, i);

1406 if (!program)

1407 goto fail;

1408 av_dict_set(&program->metadata, "variant_bitrate", bitrate_str, 0);

1409

1410 for (j = 0; j < v->n_playlists; j++) {

1411 struct playlist *pls = v->playlists[j];

1412 int is_shared = playlist_in_multiple_variants(c, pls);

1413 int k;

1414

1415 for (k = 0; k < pls->ctx->nb_streams; k++) {

1416 struct AVStream *st = s->streams[pls->stream_offset + k];

1417

1418 ff_program_add_stream_index(s, i, pls->stream_offset + k);

1419

1420 /* Set variant_bitrate for streams unique to this variant */

1421 if (!is_shared && v->bandwidth)

1422 av_dict_set(&st->metadata, "variant_bitrate", bitrate_str, 0);

1423 }

1424 }

1425 }

1426

1427 return 0;

1428 fail:

1429 free_playlist_list(c);

1430 free_variant_list(c);

1431 free_rendition_list(c);

1432 return ret;

1433 }

1434

1435 static int recheck_discard_flags(AVFormatContext *s, int first)

1436 {

1437 HLSContext *c = s->priv_data;

1438 int i, changed = 0;

1439

1440 /* Check if any new streams are needed */

1441 for (i = 0; i < c->n_playlists; i++)

1442 c->playlists[i]->cur_needed = 0;

1443

1444 for (i = 0; i < s->nb_streams; i++) {

1445 AVStream *st = s->streams[i];

1446 struct playlist *pls = c->playlists[s->streams[i]->id];

1447 if (st->discard < AVDISCARD_ALL)

1448 pls->cur_needed = 1;

1449 }

1450 for (i = 0; i < c->n_playlists; i++) {

1451 struct playlist *pls = c->playlists[i];

1452 if (pls->cur_needed && !pls->needed) {

1453 pls->needed = 1;

1454 changed = 1;

1455 pls->cur_seq_no = select_cur_seq_no(c, pls);

1456 pls->pb.eof_reached = 0;

1457 if (c->cur_timestamp != AV_NOPTS_VALUE) {

1458 /* catch up */

1459 pls->seek_timestamp = c->cur_timestamp;

1460 pls->seek_flags = AVSEEK_FLAG_ANY;

1461 pls->seek_stream_index = -1;

1462 }

1463 av_log(s, AV_LOG_INFO, "Now receiving playlist %d, segment %d\n", i, pls->cur_seq_no);

1464 } else if (first && !pls->cur_needed && pls->needed) {

1465 if (pls->input)

1466 ffurl_close(pls->input);

1467 pls->input = NULL;

1468 pls->needed = 0;

1469 changed = 1;

1470 av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i);

1471 }

1472 }

1473 return changed;

1474 }

1475

1476 static void fill_timing_for_id3_timestamped_stream(struct playlist *pls)

1477 {

1478 if (pls->id3_offset >= 0) {

1479 pls->pkt.dts = pls->id3_mpegts_timestamp +

1480 av_rescale_q(pls->id3_offset,

1481 pls->ctx->streams[pls->pkt.stream_index]->time_base,

1482 MPEG_TIME_BASE_Q);

1483 if (pls->pkt.duration)

1484 pls->id3_offset += pls->pkt.duration;

1485 else

1486 pls->id3_offset = -1;

1487 } else {

1488 /* there have been packets with unknown duration

1489 * since the last id3 tag, should not normally happen */

1490 pls->pkt.dts = AV_NOPTS_VALUE;

1491 }

1492

1493 if (pls->pkt.duration)

1494 pls->pkt.duration = av_rescale_q(pls->pkt.duration,

1495 pls->ctx->streams[pls->pkt.stream_index]->time_base,

1496 MPEG_TIME_BASE_Q);

1497

1498 pls->pkt.pts = AV_NOPTS_VALUE;

1499 }

1500

1501 static AVRational get_timebase(struct playlist *pls)

1502 {

1503 if (pls->is_id3_timestamped)

1504 return MPEG_TIME_BASE_Q;

1505

1506 return pls->ctx->streams[pls->pkt.stream_index]->time_base;

1507 }

1508

1509 static int compare_ts_with_wrapdetect(int64_t ts_a, struct playlist *pls_a,

1510 int64_t ts_b, struct playlist *pls_b)

1511 {

1512 int64_t scaled_ts_a = av_rescale_q(ts_a, get_timebase(pls_a), MPEG_TIME_BASE_Q);

1513 int64_t scaled_ts_b = av_rescale_q(ts_b, get_timebase(pls_b), MPEG_TIME_BASE_Q);

1514

1515 return av_compare_mod(scaled_ts_a, scaled_ts_b, 1LL << 33);

1516 }

1517

1518 static int hls_read_packet(AVFormatContext *s, AVPacket *pkt)

1519 {

1520 HLSContext *c = s->priv_data;

1521 int ret, i, minplaylist = -1;

1522

1523 recheck_discard_flags(s, c->first_packet);

1524

1525 for (i = 0; i < c->n_playlists; i++) {

1526 struct playlist *pls = c->playlists[i];

1527 /* Make sure we've got one buffered packet from each open playlist

1528 * stream */

1529 if (pls->needed && !pls->pkt.data) {

1530 while (1) {

1531 int64_t ts_diff;

1532 AVRational tb;

1533 ret = av_read_frame(pls->ctx, &pls->pkt);

1534 if (ret < 0) {

1535 if (!url_feof(&pls->pb) && ret != AVERROR_EOF)

1536 return ret;

1537 reset_packet(&pls->pkt);

1538 break;

1539 } else {

1540 /* stream_index check prevents matching picture attachments etc. */

1541 if (pls->is_id3_timestamped && pls->pkt.stream_index == 0) {

1542 /* audio elementary streams are id3 timestamped */

1543 fill_timing_for_id3_timestamped_stream(pls);

1544 }

1545

1546 if (c->first_timestamp == AV_NOPTS_VALUE &&

1547 pls->pkt.dts != AV_NOPTS_VALUE)

1548 c->first_timestamp = av_rescale_q(pls->pkt.dts,

1549 get_timebase(pls), AV_TIME_BASE_Q);

1550 }

1551

1552 if (pls->seek_timestamp == AV_NOPTS_VALUE)

1553 break;

1554

1555 if (pls->seek_stream_index < 0 ||

1556 pls->seek_stream_index == pls->pkt.stream_index) {

1557

1558 if (pls->pkt.dts == AV_NOPTS_VALUE) {

1559 pls->seek_timestamp = AV_NOPTS_VALUE;

1560 break;

1561 }

1562

1563 tb = get_timebase(pls);

1564 ts_diff = av_rescale_rnd(pls->pkt.dts, AV_TIME_BASE,

1565 tb.den, AV_ROUND_DOWN) -

1566 pls->seek_timestamp;

1567 if (ts_diff >= 0 && (pls->seek_flags & AVSEEK_FLAG_ANY ||

1568 pls->pkt.flags & AV_PKT_FLAG_KEY)) {

1569 pls->seek_timestamp = AV_NOPTS_VALUE;

1570 break;

1571 }

1572 }

1573 av_free_packet(&pls->pkt);

1574 reset_packet(&pls->pkt);

1575 }

1576 }

1577 /* Check if this stream has the packet with the lowest dts */

1578 if (pls->pkt.data) {

1579 struct playlist *minpls = minplaylist < 0 ?

1580 NULL : c->playlists[minplaylist];

1581 if (minplaylist < 0) {

1582 minplaylist = i;

1583 } else {

1584 int64_t dts = pls->pkt.dts;

1585 int64_t mindts = minpls->pkt.dts;

1586

1587 if (dts == AV_NOPTS_VALUE ||

1588 (mindts != AV_NOPTS_VALUE && compare_ts_with_wrapdetect(dts, pls, mindts, minpls) < 0))

1589 minplaylist = i;

1590 }

1591 }

1592 }

1593

1594 /* If we got a packet, return it */

1595 if (minplaylist >= 0) {

1596 struct playlist *pls = c->playlists[minplaylist];

1597 *pkt = pls->pkt;

1598 pkt->stream_index += pls->stream_offset;

1599 reset_packet(&c->playlists[minplaylist]->pkt);

1600

1601 if (pkt->dts != AV_NOPTS_VALUE)

1602 c->cur_timestamp = av_rescale_q(pkt->dts,

1603 pls->ctx->streams[pls->pkt.stream_index]->time_base,

1604 AV_TIME_BASE_Q);

1605

1606 return 0;

1607 }

1608 return AVERROR_EOF;

1609 }

1610

1611 static int hls_close(AVFormatContext *s)

1612 {

1613 HLSContext *c = s->priv_data;

1614

1615 free_playlist_list(c);

1616 free_variant_list(c);

1617 free_rendition_list(c);

1618 return 0;

1619 }

1620

1621 static int hls_read_seek(AVFormatContext *s, int stream_index,

1622 int64_t timestamp, int flags)

1623 {

1624 HLSContext *c = s->priv_data;

1625 struct playlist *seek_pls = NULL;

1626 int i, seq_no;

1627 int64_t first_timestamp, seek_timestamp, duration;

1628

1629 if ((flags & AVSEEK_FLAG_BYTE) ||

1630 !(c->variants[0]->playlists[0]->finished || c->variants[0]->playlists[0]->type == PLS_TYPE_EVENT))

1631 return AVERROR(ENOSYS);

1632

1633 first_timestamp = c->first_timestamp == AV_NOPTS_VALUE ?

1634 0 : c->first_timestamp;

1635

1636 seek_timestamp = av_rescale_rnd(timestamp, AV_TIME_BASE,

1637 s->streams[stream_index]->time_base.den,

1638 flags & AVSEEK_FLAG_BACKWARD ?

1639 AV_ROUND_DOWN : AV_ROUND_UP);

1640

1641 duration = s->duration == AV_NOPTS_VALUE ?

1642 0 : s->duration;

1643

1644 if (0 < duration && duration < seek_timestamp - first_timestamp)

1645 return AVERROR(EIO);

1646

1647 /* find the playlist with the specified stream */

1648 for (i = 0; i < c->n_playlists; i++) {

1649 struct playlist *pls = c->playlists[i];

1650 if (stream_index >= pls->stream_offset &&

1651 stream_index - pls->stream_offset < pls->ctx->nb_streams) {

1652 seek_pls = pls;

1653 break;

1654 }

1655 }

1656 /* check if the timestamp is valid for the playlist with the

1657 * specified stream index */

1658 if (!seek_pls || !find_timestamp_in_playlist(c, seek_pls, seek_timestamp, &seq_no))

1659 return AVERROR(EIO);

1660

1661 /* set segment now so we do not need to search again below */

1662 seek_pls->cur_seq_no = seq_no;

1663 seek_pls->seek_stream_index = stream_index - seek_pls->stream_offset;

1664

1665 for (i = 0; i < c->n_playlists; i++) {

1666 /* Reset reading */

1667 struct playlist *pls = c->playlists[i];

1668 if (pls->input) {

1669 ffurl_close(pls->input);

1670 pls->input = NULL;

1671 }

1672 av_free_packet(&pls->pkt);

1673 reset_packet(&pls->pkt);

1674 pls->pb.eof_reached = 0;

1675 /* Clear any buffered data */

1676 pls->pb.buf_end = pls->pb.buf_ptr = pls->pb.buffer;

1677 /* Reset the pos, to let the mpegts demuxer know we've seeked. */

1678 pls->pb.pos = 0;

1679 /* Flush the packet queue of the subdemuxer. */

1680 ff_read_frame_flush(pls->ctx);

1681

1682 pls->seek_timestamp = seek_timestamp;

1683 pls->seek_flags = flags;

1684

1685 if (pls != seek_pls) {

1686 /* set closest segment seq_no for playlists not handled above */

1687 find_timestamp_in_playlist(c, pls, seek_timestamp, &pls->cur_seq_no);

1688 /* seek the playlist to the given position without taking

1689 * keyframes into account since this playlist does not have the

1690 * specified stream where we should look for the keyframes */

1691 pls->seek_stream_index = -1;

1692 pls->seek_flags |= AVSEEK_FLAG_ANY;

1693 }

1694 }

1695

1696 c->cur_timestamp = seek_timestamp;

1697

1698 return 0;

1699 }

1700

1701 static int hls_probe(AVProbeData *p)

1702 {

1703 /* Require #EXTM3U at the start, and either one of the ones below

1704 * somewhere for a proper match. */

1705 if (strncmp(p->buf, "#EXTM3U", 7))

1706 return 0;

1707 if (strstr(p->buf, "#EXT-X-STREAM-INF:") ||

1708 strstr(p->buf, "#EXT-X-TARGETDURATION:") ||

1709 strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))

1710 return AVPROBE_SCORE_MAX;

1711 return 0;

1712 }

1713

1714 AVInputFormat ff_hls_demuxer = {

1715 .name = "hls,applehttp",

1716 .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),

1717 .priv_data_size = sizeof(HLSContext),

1718 .read_probe = hls_probe,

1719 .read_header = hls_read_header,

1720 .read_packet = hls_read_packet,

1721 .read_close = hls_close,

1722 .read_seek = hls_read_seek,

1723 };

Generated on Sun Jul 20 2014 23:06:03 for FFmpeg by doxygen 1.8.2