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hls.c
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1 /*
2  * Apple HTTP Live Streaming demuxer
3  * Copyright (c) 2010 Martin Storsjo
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  */
21 
22 /**
23  * @file
24  * Apple HTTP Live Streaming demuxer
25  * http://tools.ietf.org/html/draft-pantos-http-live-streaming
26  */
27 
28 #include "libavutil/avstring.h"
29 #include "libavutil/intreadwrite.h"
30 #include "libavutil/mathematics.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/dict.h"
33 #include "libavutil/time.h"
34 #include "avformat.h"
35 #include "internal.h"
36 #include "avio_internal.h"
37 #include "url.h"
38 
39 #define INITIAL_BUFFER_SIZE 32768
40 
41 /*
42  * An apple http stream consists of a playlist with media segment files,
43  * played sequentially. There may be several playlists with the same
44  * video content, in different bandwidth variants, that are played in
45  * parallel (preferably only one bandwidth variant at a time). In this case,
46  * the user supplied the url to a main playlist that only lists the variant
47  * playlists.
48  *
49  * If the main playlist doesn't point at any variants, we still create
50  * one anonymous toplevel variant for this, to maintain the structure.
51  */
52 
53 enum KeyType {
56 };
57 
58 struct segment {
59  int duration;
63  uint8_t iv[16];
64 };
65 
66 /*
67  * Each variant has its own demuxer. If it currently is active,
68  * it has an open AVIOContext too, and potentially an AVPacket
69  * containing the next packet from this stream.
70  */
71 struct variant {
72  int bandwidth;
78  int index;
82 
83  int finished;
87  struct segment **segments;
90  int64_t last_load_time;
91 
93  uint8_t key[16];
94 };
95 
96 typedef struct HLSContext {
98  struct variant **variants;
103  int64_t seek_timestamp;
106  char *user_agent; ///< holds HTTP user agent set as an AVOption to the HTTP protocol context
107  char *cookies; ///< holds HTTP cookie values set in either the initial response or as an AVOption to the HTTP protocol context
108 } HLSContext;
109 
110 static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
111 {
112  int len = ff_get_line(s, buf, maxlen);
113  while (len > 0 && av_isspace(buf[len - 1]))
114  buf[--len] = '\0';
115  return len;
116 }
117 
118 static void free_segment_list(struct variant *var)
119 {
120  int i;
121  for (i = 0; i < var->n_segments; i++)
122  av_free(var->segments[i]);
123  av_freep(&var->segments);
124  var->n_segments = 0;
125 }
126 
128 {
129  int i;
130  for (i = 0; i < c->n_variants; i++) {
131  struct variant *var = c->variants[i];
132  free_segment_list(var);
133  av_free_packet(&var->pkt);
134  av_free(var->pb.buffer);
135  if (var->input)
136  ffurl_close(var->input);
137  if (var->ctx) {
138  var->ctx->pb = NULL;
139  avformat_close_input(&var->ctx);
140  }
141  av_free(var);
142  }
143  av_freep(&c->variants);
144  av_freep(&c->cookies);
145  av_freep(&c->user_agent);
146  c->n_variants = 0;
147 }
148 
149 /*
150  * Used to reset a statically allocated AVPacket to a clean slate,
151  * containing no data.
152  */
153 static void reset_packet(AVPacket *pkt)
154 {
155  av_init_packet(pkt);
156  pkt->data = NULL;
157 }
158 
159 static struct variant *new_variant(HLSContext *c, int bandwidth,
160  const char *url, const char *base)
161 {
162  struct variant *var = av_mallocz(sizeof(struct variant));
163  if (!var)
164  return NULL;
165  reset_packet(&var->pkt);
166  var->bandwidth = bandwidth;
167  ff_make_absolute_url(var->url, sizeof(var->url), base, url);
168  dynarray_add(&c->variants, &c->n_variants, var);
169  return var;
170 }
171 
172 struct variant_info {
173  char bandwidth[20];
174 };
175 
176 static void handle_variant_args(struct variant_info *info, const char *key,
177  int key_len, char **dest, int *dest_len)
178 {
179  if (!strncmp(key, "BANDWIDTH=", key_len)) {
180  *dest = info->bandwidth;
181  *dest_len = sizeof(info->bandwidth);
182  }
183 }
184 
185 struct key_info {
187  char method[10];
188  char iv[35];
189 };
190 
191 static void handle_key_args(struct key_info *info, const char *key,
192  int key_len, char **dest, int *dest_len)
193 {
194  if (!strncmp(key, "METHOD=", key_len)) {
195  *dest = info->method;
196  *dest_len = sizeof(info->method);
197  } else if (!strncmp(key, "URI=", key_len)) {
198  *dest = info->uri;
199  *dest_len = sizeof(info->uri);
200  } else if (!strncmp(key, "IV=", key_len)) {
201  *dest = info->iv;
202  *dest_len = sizeof(info->iv);
203  }
204 }
205 
206 static int parse_playlist(HLSContext *c, const char *url,
207  struct variant *var, AVIOContext *in)
208 {
209  int ret = 0, duration = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
210  enum KeyType key_type = KEY_NONE;
211  uint8_t iv[16] = "";
212  int has_iv = 0;
213  char key[MAX_URL_SIZE] = "";
214  char line[1024];
215  const char *ptr;
216  int close_in = 0;
217 
218  if (!in) {
219  AVDictionary *opts = NULL;
220  close_in = 1;
221  /* Some HLS servers dont like being sent the range header */
222  av_dict_set(&opts, "seekable", "0", 0);
223 
224  // broker prior HTTP options that should be consistent across requests
225  av_dict_set(&opts, "user-agent", c->user_agent, 0);
226  av_dict_set(&opts, "cookies", c->cookies, 0);
227 
228  ret = avio_open2(&in, url, AVIO_FLAG_READ,
229  c->interrupt_callback, &opts);
230  av_dict_free(&opts);
231  if (ret < 0)
232  return ret;
233  }
234 
235  read_chomp_line(in, line, sizeof(line));
236  if (strcmp(line, "#EXTM3U")) {
237  ret = AVERROR_INVALIDDATA;
238  goto fail;
239  }
240 
241  if (var) {
242  free_segment_list(var);
243  var->finished = 0;
244  }
245  while (!url_feof(in)) {
246  read_chomp_line(in, line, sizeof(line));
247  if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
248  struct variant_info info = {{0}};
249  is_variant = 1;
251  &info);
252  bandwidth = atoi(info.bandwidth);
253  } else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {
254  struct key_info info = {{0}};
256  &info);
257  key_type = KEY_NONE;
258  has_iv = 0;
259  if (!strcmp(info.method, "AES-128"))
260  key_type = KEY_AES_128;
261  if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {
262  ff_hex_to_data(iv, info.iv + 2);
263  has_iv = 1;
264  }
265  av_strlcpy(key, info.uri, sizeof(key));
266  } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
267  if (!var) {
268  var = new_variant(c, 0, url, NULL);
269  if (!var) {
270  ret = AVERROR(ENOMEM);
271  goto fail;
272  }
273  }
274  var->target_duration = atoi(ptr);
275  } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
276  if (!var) {
277  var = new_variant(c, 0, url, NULL);
278  if (!var) {
279  ret = AVERROR(ENOMEM);
280  goto fail;
281  }
282  }
283  var->start_seq_no = atoi(ptr);
284  } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
285  if (var)
286  var->finished = 1;
287  } else if (av_strstart(line, "#EXTINF:", &ptr)) {
288  is_segment = 1;
289  duration = atoi(ptr);
290  } else if (av_strstart(line, "#", NULL)) {
291  continue;
292  } else if (line[0]) {
293  if (is_variant) {
294  if (!new_variant(c, bandwidth, line, url)) {
295  ret = AVERROR(ENOMEM);
296  goto fail;
297  }
298  is_variant = 0;
299  bandwidth = 0;
300  }
301  if (is_segment) {
302  struct segment *seg;
303  if (!var) {
304  var = new_variant(c, 0, url, NULL);
305  if (!var) {
306  ret = AVERROR(ENOMEM);
307  goto fail;
308  }
309  }
310  seg = av_malloc(sizeof(struct segment));
311  if (!seg) {
312  ret = AVERROR(ENOMEM);
313  goto fail;
314  }
315  seg->duration = duration;
316  seg->key_type = key_type;
317  if (has_iv) {
318  memcpy(seg->iv, iv, sizeof(iv));
319  } else {
320  int seq = var->start_seq_no + var->n_segments;
321  memset(seg->iv, 0, sizeof(seg->iv));
322  AV_WB32(seg->iv + 12, seq);
323  }
324  ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);
325  ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
326  dynarray_add(&var->segments, &var->n_segments, seg);
327  is_segment = 0;
328  }
329  }
330  }
331  if (var)
332  var->last_load_time = av_gettime();
333 
334 fail:
335  if (close_in)
336  avio_close(in);
337  return ret;
338 }
339 
340 static int open_input(HLSContext *c, struct variant *var)
341 {
342  AVDictionary *opts = NULL;
343  int ret;
344  struct segment *seg = var->segments[var->cur_seq_no - var->start_seq_no];
345 
346  // broker prior HTTP options that should be consistent across requests
347  av_dict_set(&opts, "user-agent", c->user_agent, 0);
348  av_dict_set(&opts, "cookies", c->cookies, 0);
349  av_dict_set(&opts, "seekable", "0", 0);
350 
351  if (seg->key_type == KEY_NONE) {
352  ret = ffurl_open(&var->input, seg->url, AVIO_FLAG_READ,
353  &var->parent->interrupt_callback, &opts);
354  goto cleanup;
355  } else if (seg->key_type == KEY_AES_128) {
356  char iv[33], key[33], url[MAX_URL_SIZE];
357  if (strcmp(seg->key, var->key_url)) {
358  URLContext *uc;
359  if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
360  &var->parent->interrupt_callback, &opts) == 0) {
361  if (ffurl_read_complete(uc, var->key, sizeof(var->key))
362  != sizeof(var->key)) {
363  av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
364  seg->key);
365  }
366  ffurl_close(uc);
367  } else {
368  av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
369  seg->key);
370  }
371  av_strlcpy(var->key_url, seg->key, sizeof(var->key_url));
372  }
373  ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
374  ff_data_to_hex(key, var->key, sizeof(var->key), 0);
375  iv[32] = key[32] = '\0';
376  if (strstr(seg->url, "://"))
377  snprintf(url, sizeof(url), "crypto+%s", seg->url);
378  else
379  snprintf(url, sizeof(url), "crypto:%s", seg->url);
380  if ((ret = ffurl_alloc(&var->input, url, AVIO_FLAG_READ,
381  &var->parent->interrupt_callback)) < 0)
382  goto cleanup;
383  av_opt_set(var->input->priv_data, "key", key, 0);
384  av_opt_set(var->input->priv_data, "iv", iv, 0);
385  /* Need to repopulate options */
386  av_dict_free(&opts);
387  av_dict_set(&opts, "seekable", "0", 0);
388  if ((ret = ffurl_connect(var->input, &opts)) < 0) {
389  ffurl_close(var->input);
390  var->input = NULL;
391  goto cleanup;
392  }
393  ret = 0;
394  }
395  else
396  ret = AVERROR(ENOSYS);
397 
398 cleanup:
399  av_dict_free(&opts);
400  return ret;
401 }
402 
403 static int read_data(void *opaque, uint8_t *buf, int buf_size)
404 {
405  struct variant *v = opaque;
406  HLSContext *c = v->parent->priv_data;
407  int ret, i;
408 
409 restart:
410  if (!v->input) {
411  /* If this is a live stream and the reload interval has elapsed since
412  * the last playlist reload, reload the variant playlists now. */
413  int64_t reload_interval = v->n_segments > 0 ?
414  v->segments[v->n_segments - 1]->duration :
415  v->target_duration;
416  reload_interval *= 1000000;
417 
418 reload:
419  if (!v->finished &&
420  av_gettime() - v->last_load_time >= reload_interval) {
421  if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
422  return ret;
423  /* If we need to reload the playlist again below (if
424  * there's still no more segments), switch to a reload
425  * interval of half the target duration. */
426  reload_interval = v->target_duration * 500000LL;
427  }
428  if (v->cur_seq_no < v->start_seq_no) {
430  "skipping %d segments ahead, expired from playlists\n",
431  v->start_seq_no - v->cur_seq_no);
432  v->cur_seq_no = v->start_seq_no;
433  }
434  if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
435  if (v->finished)
436  return AVERROR_EOF;
437  while (av_gettime() - v->last_load_time < reload_interval) {
439  return AVERROR_EXIT;
440  av_usleep(100*1000);
441  }
442  /* Enough time has elapsed since the last reload */
443  goto reload;
444  }
445 
446  ret = open_input(c, v);
447  if (ret < 0)
448  return ret;
449  }
450  ret = ffurl_read(v->input, buf, buf_size);
451  if (ret > 0)
452  return ret;
453  ffurl_close(v->input);
454  v->input = NULL;
455  v->cur_seq_no++;
456 
457  c->end_of_segment = 1;
458  c->cur_seq_no = v->cur_seq_no;
459 
460  if (v->ctx && v->ctx->nb_streams && v->parent->nb_streams >= v->stream_offset + v->ctx->nb_streams) {
461  v->needed = 0;
462  for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;
463  i++) {
464  if (v->parent->streams[i]->discard < AVDISCARD_ALL)
465  v->needed = 1;
466  }
467  }
468  if (!v->needed) {
469  av_log(v->parent, AV_LOG_INFO, "No longer receiving variant %d\n",
470  v->index);
471  return AVERROR_EOF;
472  }
473  goto restart;
474 }
475 
477 {
478  URLContext *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb->opaque;
479  HLSContext *c = s->priv_data;
480  int ret = 0, i, j, stream_offset = 0;
481 
482  c->interrupt_callback = &s->interrupt_callback;
483 
484  // if the URL context is good, read important options we must broker later
485  if (u && u->prot->priv_data_class) {
486  // get the previous user agent & set back to null if string size is zero
487  av_freep(&c->user_agent);
488  av_opt_get(u->priv_data, "user-agent", 0, (uint8_t**)&(c->user_agent));
489  if (c->user_agent && !strlen(c->user_agent))
490  av_freep(&c->user_agent);
491 
492  // get the previous cookies & set back to null if string size is zero
493  av_freep(&c->cookies);
494  av_opt_get(u->priv_data, "cookies", 0, (uint8_t**)&(c->cookies));
495  if (c->cookies && !strlen(c->cookies))
496  av_freep(&c->cookies);
497  }
498 
499  if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)
500  goto fail;
501 
502  if (c->n_variants == 0) {
503  av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
504  ret = AVERROR_EOF;
505  goto fail;
506  }
507  /* If the playlist only contained variants, parse each individual
508  * variant playlist. */
509  if (c->n_variants > 1 || c->variants[0]->n_segments == 0) {
510  for (i = 0; i < c->n_variants; i++) {
511  struct variant *v = c->variants[i];
512  if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
513  goto fail;
514  }
515  }
516 
517  if (c->variants[0]->n_segments == 0) {
518  av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
519  ret = AVERROR_EOF;
520  goto fail;
521  }
522 
523  /* If this isn't a live stream, calculate the total duration of the
524  * stream. */
525  if (c->variants[0]->finished) {
526  int64_t duration = 0;
527  for (i = 0; i < c->variants[0]->n_segments; i++)
528  duration += c->variants[0]->segments[i]->duration;
529  s->duration = duration * AV_TIME_BASE;
530  }
531 
532  /* Open the demuxer for each variant */
533  for (i = 0; i < c->n_variants; i++) {
534  struct variant *v = c->variants[i];
535  AVInputFormat *in_fmt = NULL;
536  char bitrate_str[20];
537  AVProgram *program = NULL;
538  if (v->n_segments == 0)
539  continue;
540 
541  if (!(v->ctx = avformat_alloc_context())) {
542  ret = AVERROR(ENOMEM);
543  goto fail;
544  }
545 
546  v->index = i;
547  v->needed = 1;
548  v->parent = s;
549 
550  /* If this is a live stream with more than 3 segments, start at the
551  * third last segment. */
552  v->cur_seq_no = v->start_seq_no;
553  if (!v->finished && v->n_segments > 3)
554  v->cur_seq_no = v->start_seq_no + v->n_segments - 3;
555 
558  read_data, NULL, NULL);
559  v->pb.seekable = 0;
560  ret = av_probe_input_buffer(&v->pb, &in_fmt, v->segments[0]->url,
561  NULL, 0, 0);
562  if (ret < 0) {
563  /* Free the ctx - it isn't initialized properly at this point,
564  * so avformat_close_input shouldn't be called. If
565  * avformat_open_input fails below, it frees and zeros the
566  * context, so it doesn't need any special treatment like this. */
567  av_log(s, AV_LOG_ERROR, "Error when loading first segment '%s'\n", v->segments[0]->url);
569  v->ctx = NULL;
570  goto fail;
571  }
572  v->ctx->pb = &v->pb;
573  ret = avformat_open_input(&v->ctx, v->segments[0]->url, in_fmt, NULL);
574  if (ret < 0)
575  goto fail;
576 
580  if (ret < 0)
581  goto fail;
582  snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);
583 
584  /* Create new AVprogram for variant i */
585  program = av_new_program(s, i);
586  if (!program)
587  goto fail;
588  av_dict_set(&program->metadata, "variant_bitrate", bitrate_str, 0);
589 
590  /* Create new AVStreams for each stream in this variant */
591  for (j = 0; j < v->ctx->nb_streams; j++) {
593  AVStream *ist = v->ctx->streams[j];
594  if (!st) {
595  ret = AVERROR(ENOMEM);
596  goto fail;
597  }
599  st->id = i;
602  if (v->bandwidth)
603  av_dict_set(&st->metadata, "variant_bitrate", bitrate_str,
604  0);
605  }
607  }
608 
609  c->first_packet = 1;
610  c->first_timestamp = AV_NOPTS_VALUE;
611  c->seek_timestamp = AV_NOPTS_VALUE;
612 
613  return 0;
614 fail:
616  return ret;
617 }
618 
619 static int recheck_discard_flags(AVFormatContext *s, int first)
620 {
621  HLSContext *c = s->priv_data;
622  int i, changed = 0;
623 
624  /* Check if any new streams are needed */
625  for (i = 0; i < c->n_variants; i++)
626  c->variants[i]->cur_needed = 0;
627 
628  for (i = 0; i < s->nb_streams; i++) {
629  AVStream *st = s->streams[i];
630  struct variant *var = c->variants[s->streams[i]->id];
631  if (st->discard < AVDISCARD_ALL)
632  var->cur_needed = 1;
633  }
634  for (i = 0; i < c->n_variants; i++) {
635  struct variant *v = c->variants[i];
636  if (v->cur_needed && !v->needed) {
637  v->needed = 1;
638  changed = 1;
639  v->cur_seq_no = c->cur_seq_no;
640  v->pb.eof_reached = 0;
641  av_log(s, AV_LOG_INFO, "Now receiving variant %d\n", i);
642  } else if (first && !v->cur_needed && v->needed) {
643  if (v->input)
644  ffurl_close(v->input);
645  v->input = NULL;
646  v->needed = 0;
647  changed = 1;
648  av_log(s, AV_LOG_INFO, "No longer receiving variant %d\n", i);
649  }
650  }
651  return changed;
652 }
653 
655 {
656  HLSContext *c = s->priv_data;
657  int ret, i, minvariant = -1;
658 
659  if (c->first_packet) {
660  recheck_discard_flags(s, 1);
661  c->first_packet = 0;
662  }
663 
664 start:
665  c->end_of_segment = 0;
666  for (i = 0; i < c->n_variants; i++) {
667  struct variant *var = c->variants[i];
668  /* Make sure we've got one buffered packet from each open variant
669  * stream */
670  if (var->needed && !var->pkt.data) {
671  while (1) {
672  int64_t ts_diff;
673  AVStream *st;
674  ret = av_read_frame(var->ctx, &var->pkt);
675  if (ret < 0) {
676  if (!url_feof(&var->pb) && ret != AVERROR_EOF)
677  return ret;
678  reset_packet(&var->pkt);
679  break;
680  } else {
682  c->first_timestamp = var->pkt.dts;
683  }
684 
685  if (c->seek_timestamp == AV_NOPTS_VALUE)
686  break;
687 
688  if (var->pkt.dts == AV_NOPTS_VALUE) {
690  break;
691  }
692 
693  st = var->ctx->streams[var->pkt.stream_index];
694  ts_diff = av_rescale_rnd(var->pkt.dts, AV_TIME_BASE,
695  st->time_base.den, AV_ROUND_DOWN) -
696  c->seek_timestamp;
697  if (ts_diff >= 0 && (c->seek_flags & AVSEEK_FLAG_ANY ||
698  var->pkt.flags & AV_PKT_FLAG_KEY)) {
700  break;
701  }
702  }
703  }
704  /* Check if this stream has the packet with the lowest dts */
705  if (var->pkt.data) {
706  if(minvariant < 0) {
707  minvariant = i;
708  } else {
709  struct variant *minvar = c->variants[minvariant];
710  int64_t dts = var->pkt.dts;
711  int64_t mindts = minvar->pkt.dts;
712  AVStream *st = var->ctx->streams[ var->pkt.stream_index];
713  AVStream *minst= minvar->ctx->streams[minvar->pkt.stream_index];
714 
715  if( st->start_time != AV_NOPTS_VALUE) dts -= st->start_time;
716  if(minst->start_time != AV_NOPTS_VALUE) mindts -= minst->start_time;
717 
718  if (av_compare_ts(dts, st->time_base, mindts, minst->time_base) < 0)
719  minvariant = i;
720  }
721  }
722  }
723  if (c->end_of_segment) {
724  if (recheck_discard_flags(s, 0))
725  goto start;
726  }
727  /* If we got a packet, return it */
728  if (minvariant >= 0) {
729  *pkt = c->variants[minvariant]->pkt;
730  pkt->stream_index += c->variants[minvariant]->stream_offset;
731  reset_packet(&c->variants[minvariant]->pkt);
732  return 0;
733  }
734  return AVERROR_EOF;
735 }
736 
738 {
739  HLSContext *c = s->priv_data;
740 
742  return 0;
743 }
744 
745 static int hls_read_seek(AVFormatContext *s, int stream_index,
746  int64_t timestamp, int flags)
747 {
748  HLSContext *c = s->priv_data;
749  int i, j, ret;
750 
751  if ((flags & AVSEEK_FLAG_BYTE) || !c->variants[0]->finished)
752  return AVERROR(ENOSYS);
753 
754  c->seek_flags = flags;
755  c->seek_timestamp = stream_index < 0 ? timestamp :
756  av_rescale_rnd(timestamp, AV_TIME_BASE,
757  s->streams[stream_index]->time_base.den,
758  flags & AVSEEK_FLAG_BACKWARD ?
760  timestamp = av_rescale_rnd(timestamp, 1, stream_index >= 0 ?
761  s->streams[stream_index]->time_base.den :
763  AV_ROUND_DOWN : AV_ROUND_UP);
764  if (s->duration < c->seek_timestamp) {
766  return AVERROR(EIO);
767  }
768 
769  ret = AVERROR(EIO);
770  for (i = 0; i < c->n_variants; i++) {
771  /* Reset reading */
772  struct variant *var = c->variants[i];
773  int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ? 0 :
774  av_rescale_rnd(c->first_timestamp, 1, stream_index >= 0 ?
775  s->streams[stream_index]->time_base.den :
776  AV_TIME_BASE, flags & AVSEEK_FLAG_BACKWARD ?
777  AV_ROUND_DOWN : AV_ROUND_UP);
778  if (var->input) {
779  ffurl_close(var->input);
780  var->input = NULL;
781  }
782  av_free_packet(&var->pkt);
783  reset_packet(&var->pkt);
784  var->pb.eof_reached = 0;
785  /* Clear any buffered data */
786  var->pb.buf_end = var->pb.buf_ptr = var->pb.buffer;
787  /* Reset the pos, to let the mpegts demuxer know we've seeked. */
788  var->pb.pos = 0;
789 
790  /* Locate the segment that contains the target timestamp */
791  for (j = 0; j < var->n_segments; j++) {
792  if (timestamp >= pos &&
793  timestamp < pos + var->segments[j]->duration) {
794  var->cur_seq_no = var->start_seq_no + j;
795  ret = 0;
796  break;
797  }
798  pos += var->segments[j]->duration;
799  }
800  if (ret)
802  }
803  return ret;
804 }
805 
806 static int hls_probe(AVProbeData *p)
807 {
808  /* Require #EXTM3U at the start, and either one of the ones below
809  * somewhere for a proper match. */
810  if (strncmp(p->buf, "#EXTM3U", 7))
811  return 0;
812  if (strstr(p->buf, "#EXT-X-STREAM-INF:") ||
813  strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
814  strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
815  return AVPROBE_SCORE_MAX;
816  return 0;
817 }
818 
820  .name = "hls,applehttp",
821  .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
822  .priv_data_size = sizeof(HLSContext),
828 };