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hlsenc.c
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1 /*
2  * Apple HTTP Live Streaming segmenter
3  * Copyright (c) 2012, Luca Barbato
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 #include "config.h"
23 #include <float.h>
24 #include <stdint.h>
25 #if HAVE_UNISTD_H
26 #include <unistd.h>
27 #endif
28 
29 #include "libavutil/avassert.h"
30 #include "libavutil/mathematics.h"
31 #include "libavutil/parseutils.h"
32 #include "libavutil/avstring.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/log.h"
35 
36 #include "avformat.h"
37 #include "internal.h"
38 #include "os_support.h"
39 
40 typedef struct HLSSegment {
41  char filename[1024];
42  double duration; /* in seconds */
43  int64_t pos;
44  int64_t size;
45 
46  struct HLSSegment *next;
47 } HLSSegment;
48 
49 typedef enum HLSFlags {
50  // Generate a single media file and use byte ranges in the playlist.
51  HLS_SINGLE_FILE = (1 << 0),
52  HLS_DELETE_SEGMENTS = (1 << 1),
53  HLS_ROUND_DURATIONS = (1 << 2),
54  HLS_DISCONT_START = (1 << 3),
55  HLS_OMIT_ENDLIST = (1 << 4),
56 } HLSFlags;
57 
58 typedef struct HLSContext {
59  const AVClass *class; // Class for private options.
60  unsigned number;
61  int64_t sequence;
62  int64_t start_sequence;
64 
66 
67  float time; // Set by a private option.
68  int max_nb_segments; // Set by a private option.
69  int wrap; // Set by a private option.
70  uint32_t flags; // enum HLSFlags
72 
74  int64_t recording_time;
75  int has_video;
76  int64_t start_pts;
77  int64_t end_pts;
78  double duration; // last segment duration computed so far, in seconds
79  int64_t start_pos; // last segment starting position
80  int64_t size; // last segment size
83 
87 
88  char *basename;
89  char *baseurl;
92 } HLSContext;
93 
95 
96  HLSSegment *segment, *previous_segment = NULL;
97  float playlist_duration = 0.0f;
98  int ret = 0, path_size;
99  char *dirname = NULL, *p, *path;
100 
101  segment = hls->segments;
102  while (segment) {
103  playlist_duration += segment->duration;
104  segment = segment->next;
105  }
106 
107  segment = hls->old_segments;
108  while (segment) {
109  playlist_duration -= segment->duration;
110  previous_segment = segment;
111  segment = previous_segment->next;
112  if (playlist_duration <= -previous_segment->duration) {
113  previous_segment->next = NULL;
114  break;
115  }
116  }
117 
118  if (segment) {
119  if (hls->segment_filename) {
120  dirname = av_strdup(hls->segment_filename);
121  } else {
122  dirname = av_strdup(hls->avf->filename);
123  }
124  if (!dirname) {
125  ret = AVERROR(ENOMEM);
126  goto fail;
127  }
128  p = (char *)av_basename(dirname);
129  *p = '\0';
130  }
131 
132  while (segment) {
133  av_log(hls, AV_LOG_DEBUG, "deleting old segment %s\n",
134  segment->filename);
135  path_size = strlen(dirname) + strlen(segment->filename) + 1;
136  path = av_malloc(path_size);
137  if (!path) {
138  ret = AVERROR(ENOMEM);
139  goto fail;
140  }
141  av_strlcpy(path, dirname, path_size);
142  av_strlcat(path, segment->filename, path_size);
143  if (unlink(path) < 0) {
144  av_log(hls, AV_LOG_ERROR, "failed to delete old segment %s: %s\n",
145  path, strerror(errno));
146  }
147  av_free(path);
148  previous_segment = segment;
149  segment = previous_segment->next;
150  av_free(previous_segment);
151  }
152 
153 fail:
154  av_free(dirname);
155 
156  return ret;
157 }
158 
160 {
161  HLSContext *hls = s->priv_data;
162  AVFormatContext *oc;
163  int i, ret;
164 
165  ret = avformat_alloc_output_context2(&hls->avf, hls->oformat, NULL, NULL);
166  if (ret < 0)
167  return ret;
168  oc = hls->avf;
169 
170  oc->oformat = hls->oformat;
172  oc->max_delay = s->max_delay;
173  av_dict_copy(&oc->metadata, s->metadata, 0);
174 
175  for (i = 0; i < s->nb_streams; i++) {
176  AVStream *st;
177  if (!(st = avformat_new_stream(oc, NULL)))
178  return AVERROR(ENOMEM);
181  st->time_base = s->streams[i]->time_base;
182  }
183  hls->start_pos = 0;
184 
185  return 0;
186 }
187 
188 /* Create a new segment and append it to the segment list */
189 static int hls_append_segment(HLSContext *hls, double duration, int64_t pos,
190  int64_t size)
191 {
192  HLSSegment *en = av_malloc(sizeof(*en));
193  int ret;
194 
195  if (!en)
196  return AVERROR(ENOMEM);
197 
198  av_strlcpy(en->filename, av_basename(hls->avf->filename), sizeof(en->filename));
199 
200  en->duration = duration;
201  en->pos = pos;
202  en->size = size;
203  en->next = NULL;
204 
205  if (!hls->segments)
206  hls->segments = en;
207  else
208  hls->last_segment->next = en;
209 
210  hls->last_segment = en;
211 
212  if (hls->max_nb_segments && hls->nb_entries >= hls->max_nb_segments) {
213  en = hls->segments;
214  hls->segments = en->next;
215  if (en && hls->flags & HLS_DELETE_SEGMENTS &&
216  !(hls->flags & HLS_SINGLE_FILE || hls->wrap)) {
217  en->next = hls->old_segments;
218  hls->old_segments = en;
219  if ((ret = hls_delete_old_segments(hls)) < 0)
220  return ret;
221  } else
222  av_free(en);
223  } else
224  hls->nb_entries++;
225 
226  hls->sequence++;
227 
228  return 0;
229 }
230 
232 {
233  HLSSegment *en;
234 
235  while(p) {
236  en = p;
237  p = p->next;
238  av_free(en);
239  }
240 }
241 
242 static int hls_window(AVFormatContext *s, int last)
243 {
244  HLSContext *hls = s->priv_data;
245  HLSSegment *en;
246  int target_duration = 0;
247  int ret = 0;
248  AVIOContext *out = NULL;
249  char temp_filename[1024];
250  int64_t sequence = FFMAX(hls->start_sequence, hls->sequence - hls->nb_entries);
251  int version = hls->flags & HLS_SINGLE_FILE ? 4 : 3;
252  const char *proto = avio_find_protocol_name(s->filename);
253  int use_rename = proto && !strcmp(proto, "file");
254  static unsigned warned_non_file;
255 
256  if (!use_rename && !warned_non_file++)
257  av_log(s, AV_LOG_ERROR, "Cannot use rename on non file protocol, this may lead to races and temporarly partial files\n");
258 
259  snprintf(temp_filename, sizeof(temp_filename), use_rename ? "%s.tmp" : "%s", s->filename);
260  if ((ret = avio_open2(&out, temp_filename, AVIO_FLAG_WRITE,
261  &s->interrupt_callback, NULL)) < 0)
262  goto fail;
263 
264  for (en = hls->segments; en; en = en->next) {
265  if (target_duration < en->duration)
266  target_duration = ceil(en->duration);
267  }
268 
269  hls->discontinuity_set = 0;
270  avio_printf(out, "#EXTM3U\n");
271  avio_printf(out, "#EXT-X-VERSION:%d\n", version);
272  if (hls->allowcache == 0 || hls->allowcache == 1) {
273  avio_printf(out, "#EXT-X-ALLOW-CACHE:%s\n", hls->allowcache == 0 ? "NO" : "YES");
274  }
275  avio_printf(out, "#EXT-X-TARGETDURATION:%d\n", target_duration);
276  avio_printf(out, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
277 
278  av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
279  sequence);
280  if((hls->flags & HLS_DISCONT_START) && sequence==hls->start_sequence && hls->discontinuity_set==0 ){
281  avio_printf(out, "#EXT-X-DISCONTINUITY\n");
282  hls->discontinuity_set = 1;
283  }
284  for (en = hls->segments; en; en = en->next) {
285  if (hls->flags & HLS_ROUND_DURATIONS)
286  avio_printf(out, "#EXTINF:%d,\n", (int)round(en->duration));
287  else
288  avio_printf(out, "#EXTINF:%f,\n", en->duration);
289  if (hls->flags & HLS_SINGLE_FILE)
290  avio_printf(out, "#EXT-X-BYTERANGE:%"PRIi64"@%"PRIi64"\n",
291  en->size, en->pos);
292  if (hls->baseurl)
293  avio_printf(out, "%s", hls->baseurl);
294  avio_printf(out, "%s\n", en->filename);
295  }
296 
297  if (last && (hls->flags & HLS_OMIT_ENDLIST)==0)
298  avio_printf(out, "#EXT-X-ENDLIST\n");
299 
300 fail:
301  avio_closep(&out);
302  if (ret >= 0 && use_rename)
303  ff_rename(temp_filename, s->filename, s);
304  return ret;
305 }
306 
308 {
309  HLSContext *c = s->priv_data;
310  AVFormatContext *oc = c->avf;
311  int err = 0;
312 
313  if (c->flags & HLS_SINGLE_FILE)
314  av_strlcpy(oc->filename, c->basename,
315  sizeof(oc->filename));
316  else
317  if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
318  c->basename, c->wrap ? c->sequence % c->wrap : c->sequence) < 0) {
319  av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->basename);
320  return AVERROR(EINVAL);
321  }
322  c->number++;
323 
324  if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
325  &s->interrupt_callback, NULL)) < 0)
326  return err;
327 
328  if (oc->oformat->priv_class && oc->priv_data)
329  av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
330 
331  return 0;
332 }
333 
335 {
336  HLSContext *hls = s->priv_data;
337  int ret, i;
338  char *p;
339  const char *pattern = "%d.ts";
341  int basename_size;
342 
343  hls->sequence = hls->start_sequence;
344  hls->recording_time = hls->time * AV_TIME_BASE;
345  hls->start_pts = AV_NOPTS_VALUE;
346 
347  if (hls->format_options_str) {
348  ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
349  if (ret < 0) {
350  av_log(s, AV_LOG_ERROR, "Could not parse format options list '%s'\n", hls->format_options_str);
351  goto fail;
352  }
353  }
354 
355  for (i = 0; i < s->nb_streams; i++)
356  hls->has_video +=
358 
359  if (hls->has_video > 1)
361  "More than a single video stream present, "
362  "expect issues decoding it.\n");
363 
364  hls->oformat = av_guess_format("mpegts", NULL, NULL);
365 
366  if (!hls->oformat) {
368  goto fail;
369  }
370 
371  if (hls->segment_filename) {
372  hls->basename = av_strdup(hls->segment_filename);
373  if (!hls->basename) {
374  ret = AVERROR(ENOMEM);
375  goto fail;
376  }
377  } else {
378  if (hls->flags & HLS_SINGLE_FILE)
379  pattern = ".ts";
380 
381  basename_size = strlen(s->filename) + strlen(pattern) + 1;
382  hls->basename = av_malloc(basename_size);
383  if (!hls->basename) {
384  ret = AVERROR(ENOMEM);
385  goto fail;
386  }
387 
388  av_strlcpy(hls->basename, s->filename, basename_size);
389 
390  p = strrchr(hls->basename, '.');
391  if (p)
392  *p = '\0';
393  av_strlcat(hls->basename, pattern, basename_size);
394  }
395 
396  if ((ret = hls_mux_init(s)) < 0)
397  goto fail;
398 
399  if ((ret = hls_start(s)) < 0)
400  goto fail;
401 
402  av_dict_copy(&options, hls->format_options, 0);
403  ret = avformat_write_header(hls->avf, &options);
404  if (av_dict_count(options)) {
405  av_log(s, AV_LOG_ERROR, "Some of provided format options in '%s' are not recognized\n", hls->format_options_str);
406  ret = AVERROR(EINVAL);
407  goto fail;
408  }
409  av_assert0(s->nb_streams == hls->avf->nb_streams);
410  for (i = 0; i < s->nb_streams; i++) {
411  AVStream *inner_st = hls->avf->streams[i];
412  AVStream *outer_st = s->streams[i];
413  avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);
414  }
415 fail:
416 
417  av_dict_free(&options);
418  if (ret < 0) {
419  av_freep(&hls->basename);
420  if (hls->avf)
422  }
423  return ret;
424 }
425 
427 {
428  HLSContext *hls = s->priv_data;
429  AVFormatContext *oc = hls->avf;
430  AVStream *st = s->streams[pkt->stream_index];
431  int64_t end_pts = hls->recording_time * hls->number;
432  int is_ref_pkt = 1;
433  int ret, can_split = 1;
434 
435  if (hls->start_pts == AV_NOPTS_VALUE) {
436  hls->start_pts = pkt->pts;
437  hls->end_pts = pkt->pts;
438  }
439 
440  if (hls->has_video) {
441  can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
442  pkt->flags & AV_PKT_FLAG_KEY;
443  is_ref_pkt = st->codec->codec_type == AVMEDIA_TYPE_VIDEO;
444  }
445  if (pkt->pts == AV_NOPTS_VALUE)
446  is_ref_pkt = can_split = 0;
447 
448  if (is_ref_pkt)
449  hls->duration = (double)(pkt->pts - hls->end_pts)
450  * st->time_base.num / st->time_base.den;
451 
452  if (can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,
453  end_pts, AV_TIME_BASE_Q) >= 0) {
454  int64_t new_start_pos;
455  av_write_frame(oc, NULL); /* Flush any buffered data */
456 
457  new_start_pos = avio_tell(hls->avf->pb);
458  hls->size = new_start_pos - hls->start_pos;
459  ret = hls_append_segment(hls, hls->duration, hls->start_pos, hls->size);
460  hls->start_pos = new_start_pos;
461  if (ret < 0)
462  return ret;
463 
464  hls->end_pts = pkt->pts;
465  hls->duration = 0;
466 
467  if (hls->flags & HLS_SINGLE_FILE) {
468  if (hls->avf->oformat->priv_class && hls->avf->priv_data)
469  av_opt_set(hls->avf->priv_data, "mpegts_flags", "resend_headers", 0);
470  hls->number++;
471  } else {
472  avio_closep(&oc->pb);
473 
474  ret = hls_start(s);
475  }
476 
477  if (ret < 0)
478  return ret;
479 
480  oc = hls->avf;
481 
482  if ((ret = hls_window(s, 0)) < 0)
483  return ret;
484  }
485 
486  ret = ff_write_chained(oc, pkt->stream_index, pkt, s, 0);
487 
488  return ret;
489 }
490 
492 {
493  HLSContext *hls = s->priv_data;
494  AVFormatContext *oc = hls->avf;
495 
496  av_write_trailer(oc);
497  if (oc->pb) {
498  hls->size = avio_tell(hls->avf->pb) - hls->start_pos;
499  avio_closep(&oc->pb);
500  hls_append_segment(hls, hls->duration, hls->start_pos, hls->size);
501  }
502  av_freep(&hls->basename);
504  hls->avf = NULL;
505  hls_window(s, 1);
506 
509  return 0;
510 }
511 
512 #define OFFSET(x) offsetof(HLSContext, x)
513 #define E AV_OPT_FLAG_ENCODING_PARAM
514 static const AVOption options[] = {
515  {"start_number", "set first number in the sequence", OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, E},
516  {"hls_time", "set segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
517  {"hls_list_size", "set maximum number of playlist entries", OFFSET(max_nb_segments), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
518  {"hls_ts_options","set hls mpegts list of options for the container format used for hls", OFFSET(format_options_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
519  {"hls_wrap", "set number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
520  {"hls_allow_cache", "explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments", OFFSET(allowcache), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, E},
521  {"hls_base_url", "url to prepend to each playlist entry", OFFSET(baseurl), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
522  {"hls_segment_filename", "filename template for segment files", OFFSET(segment_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
523  {"hls_flags", "set flags affecting HLS playlist and media file generation", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0 }, 0, UINT_MAX, E, "flags"},
524  {"single_file", "generate a single media file indexed with byte ranges", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SINGLE_FILE }, 0, UINT_MAX, E, "flags"},
525  {"delete_segments", "delete segment files that are no longer part of the playlist", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_DELETE_SEGMENTS }, 0, UINT_MAX, E, "flags"},
526  {"round_durations", "round durations in m3u8 to whole numbers", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_ROUND_DURATIONS }, 0, UINT_MAX, E, "flags"},
527  {"discont_start", "start the playlist with a discontinuity tag", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_DISCONT_START }, 0, UINT_MAX, E, "flags"},
528  {"omit_endlist", "Do not append an endlist when ending stream", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_OMIT_ENDLIST }, 0, UINT_MAX, E, "flags"},
529 
530  { NULL },
531 };
532 
533 static const AVClass hls_class = {
534  .class_name = "hls muxer",
535  .item_name = av_default_item_name,
536  .option = options,
537  .version = LIBAVUTIL_VERSION_INT,
538 };
539 
540 
542  .name = "hls",
543  .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
544  .extensions = "m3u8",
545  .priv_data_size = sizeof(HLSContext),
546  .audio_codec = AV_CODEC_ID_AAC,
547  .video_codec = AV_CODEC_ID_H264,
552  .priv_class = &hls_class,
553 };