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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 <float.h>
23 #include <stdint.h>
24 
25 #include "libavutil/avassert.h"
26 #include "libavutil/mathematics.h"
27 #include "libavutil/parseutils.h"
28 #include "libavutil/avstring.h"
29 #include "libavutil/opt.h"
30 #include "libavutil/log.h"
31 
32 #include "avformat.h"
33 #include "internal.h"
34 
35 typedef struct HLSSegment {
36  char filename[1024];
37  double duration; /* in seconds */
38  int64_t pos;
39  int64_t size;
40 
41  struct HLSSegment *next;
42 } HLSSegment;
43 
44 typedef enum HLSFlags {
45  // Generate a single media file and use byte ranges in the playlist.
46  HLS_SINGLE_FILE = (1 << 0),
47 } HLSFlags;
48 
49 typedef struct HLSContext {
50  const AVClass *class; // Class for private options.
51  unsigned number;
52  int64_t sequence;
53  int64_t start_sequence;
55 
57 
58  float time; // Set by a private option.
59  int max_nb_segments; // Set by a private option.
60  int wrap; // Set by a private option.
61  uint32_t flags; // enum HLSFlags
62 
64  int64_t recording_time;
65  int has_video;
66  int64_t start_pts;
67  int64_t end_pts;
68  double duration; // last segment duration computed so far, in seconds
69  int64_t start_pos; // last segment starting position
70  int64_t size; // last segment size
72 
75 
76  char *basename;
77  char *baseurl;
80 
82 } HLSContext;
83 
85 {
86  HLSContext *hls = s->priv_data;
87  AVFormatContext *oc;
88  int i, ret;
89 
90  ret = avformat_alloc_output_context2(&hls->avf, hls->oformat, NULL, NULL);
91  if (ret < 0)
92  return ret;
93  oc = hls->avf;
94 
95  oc->oformat = hls->oformat;
97  oc->max_delay = s->max_delay;
98  av_dict_copy(&oc->metadata, s->metadata, 0);
99 
100  for (i = 0; i < s->nb_streams; i++) {
101  AVStream *st;
102  if (!(st = avformat_new_stream(oc, NULL)))
103  return AVERROR(ENOMEM);
106  st->time_base = s->streams[i]->time_base;
107  }
108  hls->start_pos = 0;
109 
110  return 0;
111 }
112 
113 /* Create a new segment and append it to the segment list */
114 static int hls_append_segment(HLSContext *hls, double duration, int64_t pos,
115  int64_t size)
116 {
117  HLSSegment *en = av_malloc(sizeof(*en));
118 
119  if (!en)
120  return AVERROR(ENOMEM);
121 
122  av_strlcpy(en->filename, av_basename(hls->avf->filename), sizeof(en->filename));
123 
124  en->duration = duration;
125  en->pos = pos;
126  en->size = size;
127  en->next = NULL;
128 
129  if (!hls->segments)
130  hls->segments = en;
131  else
132  hls->last_segment->next = en;
133 
134  hls->last_segment = en;
135 
136  if (hls->max_nb_segments && hls->nb_entries >= hls->max_nb_segments) {
137  en = hls->segments;
138  hls->segments = en->next;
139  av_free(en);
140  } else
141  hls->nb_entries++;
142 
143  hls->sequence++;
144 
145  return 0;
146 }
147 
148 static void hls_free_segments(HLSContext *hls)
149 {
150  HLSSegment *p = hls->segments, *en;
151 
152  while(p) {
153  en = p;
154  p = p->next;
155  av_free(en);
156  }
157 }
158 
159 static int hls_window(AVFormatContext *s, int last)
160 {
161  HLSContext *hls = s->priv_data;
162  HLSSegment *en;
163  int target_duration = 0;
164  int ret = 0;
165  int64_t sequence = FFMAX(hls->start_sequence, hls->sequence - hls->nb_entries);
166  int version = hls->flags & HLS_SINGLE_FILE ? 4 : 3;
167 
168  if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
169  &s->interrupt_callback, NULL)) < 0)
170  goto fail;
171 
172  for (en = hls->segments; en; en = en->next) {
173  if (target_duration < en->duration)
174  target_duration = ceil(en->duration);
175  }
176 
177  avio_printf(hls->pb, "#EXTM3U\n");
178  avio_printf(hls->pb, "#EXT-X-VERSION:%d\n", version);
179  if (hls->allowcache == 0 || hls->allowcache == 1) {
180  avio_printf(hls->pb, "#EXT-X-ALLOW-CACHE:%s\n", hls->allowcache == 0 ? "NO" : "YES");
181  }
182  avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", target_duration);
183  avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
184 
185  av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
186  sequence);
187 
188  for (en = hls->segments; en; en = en->next) {
189  avio_printf(hls->pb, "#EXTINF:%f,\n", en->duration);
190  if (hls->flags & HLS_SINGLE_FILE)
191  avio_printf(hls->pb, "#EXT-X-BYTERANGE:%"PRIi64"@%"PRIi64"\n",
192  en->size, en->pos);
193  if (hls->baseurl)
194  avio_printf(hls->pb, "%s", hls->baseurl);
195  avio_printf(hls->pb, "%s\n", en->filename);
196  }
197 
198  if (last)
199  avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
200 
201 fail:
202  avio_closep(&hls->pb);
203  return ret;
204 }
205 
207 {
208  HLSContext *c = s->priv_data;
209  AVFormatContext *oc = c->avf;
210  int err = 0;
211 
212  if (c->flags & HLS_SINGLE_FILE)
213  av_strlcpy(oc->filename, c->basename,
214  sizeof(oc->filename));
215  else
216  if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
217  c->basename, c->wrap ? c->sequence % c->wrap : c->sequence) < 0) {
218  av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->basename);
219  return AVERROR(EINVAL);
220  }
221  c->number++;
222 
223  if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
224  &s->interrupt_callback, NULL)) < 0)
225  return err;
226 
227  if (oc->oformat->priv_class && oc->priv_data)
228  av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
229 
230  return 0;
231 }
232 
234 {
235  HLSContext *hls = s->priv_data;
236  int ret, i;
237  char *p;
238  const char *pattern = "%d.ts";
239  AVDictionary *options = NULL;
240  int basename_size = strlen(s->filename) + strlen(pattern) + 1;
241 
242  hls->sequence = hls->start_sequence;
243  hls->recording_time = hls->time * AV_TIME_BASE;
244  hls->start_pts = AV_NOPTS_VALUE;
245 
246  if (hls->flags & HLS_SINGLE_FILE)
247  pattern = ".ts";
248 
249  if (hls->format_options_str) {
250  ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
251  if (ret < 0) {
252  av_log(s, AV_LOG_ERROR, "Could not parse format options list '%s'\n", hls->format_options_str);
253  goto fail;
254  }
255  }
256 
257  for (i = 0; i < s->nb_streams; i++)
258  hls->has_video +=
260 
261  if (hls->has_video > 1)
263  "More than a single video stream present, "
264  "expect issues decoding it.\n");
265 
266  hls->oformat = av_guess_format("mpegts", NULL, NULL);
267 
268  if (!hls->oformat) {
270  goto fail;
271  }
272 
273  hls->basename = av_malloc(basename_size);
274 
275  if (!hls->basename) {
276  ret = AVERROR(ENOMEM);
277  goto fail;
278  }
279 
280  strcpy(hls->basename, s->filename);
281 
282  p = strrchr(hls->basename, '.');
283 
284  if (p)
285  *p = '\0';
286 
287  av_strlcat(hls->basename, pattern, basename_size);
288 
289  if ((ret = hls_mux_init(s)) < 0)
290  goto fail;
291 
292  if ((ret = hls_start(s)) < 0)
293  goto fail;
294 
295  av_dict_copy(&options, hls->format_options, 0);
296  ret = avformat_write_header(hls->avf, &options);
297  if (av_dict_count(options)) {
298  av_log(s, AV_LOG_ERROR, "Some of provided format options in '%s' are not recognized\n", hls->format_options_str);
299  ret = AVERROR(EINVAL);
300  goto fail;
301  }
302  av_assert0(s->nb_streams == hls->avf->nb_streams);
303  for (i = 0; i < s->nb_streams; i++) {
304  AVStream *inner_st = hls->avf->streams[i];
305  AVStream *outer_st = s->streams[i];
306  avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);
307  }
308 fail:
309 
310  av_dict_free(&options);
311  if (ret) {
312  av_free(hls->basename);
313  if (hls->avf)
315  }
316  return ret;
317 }
318 
320 {
321  HLSContext *hls = s->priv_data;
322  AVFormatContext *oc = hls->avf;
323  AVStream *st = s->streams[pkt->stream_index];
324  int64_t end_pts = hls->recording_time * hls->number;
325  int is_ref_pkt = 1;
326  int ret, can_split = 1;
327 
328  if (hls->start_pts == AV_NOPTS_VALUE) {
329  hls->start_pts = pkt->pts;
330  hls->end_pts = pkt->pts;
331  }
332 
333  if (hls->has_video) {
334  can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
335  pkt->flags & AV_PKT_FLAG_KEY;
336  is_ref_pkt = st->codec->codec_type == AVMEDIA_TYPE_VIDEO;
337  }
338  if (pkt->pts == AV_NOPTS_VALUE)
339  is_ref_pkt = can_split = 0;
340 
341  if (is_ref_pkt)
342  hls->duration = (double)(pkt->pts - hls->end_pts)
343  * st->time_base.num / st->time_base.den;
344 
345  if (can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,
346  end_pts, AV_TIME_BASE_Q) >= 0) {
347  int64_t new_start_pos;
348  av_write_frame(oc, NULL); /* Flush any buffered data */
349 
350  new_start_pos = avio_tell(hls->avf->pb);
351  hls->size = new_start_pos - hls->start_pos;
352  ret = hls_append_segment(hls, hls->duration, hls->start_pos, hls->size);
353  hls->start_pos = new_start_pos;
354  if (ret)
355  return ret;
356 
357  hls->end_pts = pkt->pts;
358  hls->duration = 0;
359 
360  if (hls->flags & HLS_SINGLE_FILE) {
361  if (hls->avf->oformat->priv_class && hls->avf->priv_data)
362  av_opt_set(hls->avf->priv_data, "mpegts_flags", "resend_headers", 0);
363  hls->number++;
364  } else {
365  avio_close(oc->pb);
366 
367  ret = hls_start(s);
368  }
369 
370  if (ret)
371  return ret;
372 
373  oc = hls->avf;
374 
375  if ((ret = hls_window(s, 0)) < 0)
376  return ret;
377  }
378 
379  ret = ff_write_chained(oc, pkt->stream_index, pkt, s, 0);
380 
381  return ret;
382 }
383 
385 {
386  HLSContext *hls = s->priv_data;
387  AVFormatContext *oc = hls->avf;
388 
389  av_write_trailer(oc);
390  hls->size = avio_tell(hls->avf->pb) - hls->start_pos;
391  avio_closep(&oc->pb);
393  av_free(hls->basename);
394  hls_append_segment(hls, hls->duration, hls->start_pos, hls->size);
395  hls_window(s, 1);
396 
397  hls_free_segments(hls);
398  avio_close(hls->pb);
399  return 0;
400 }
401 
402 #define OFFSET(x) offsetof(HLSContext, x)
403 #define E AV_OPT_FLAG_ENCODING_PARAM
404 static const AVOption options[] = {
405  {"start_number", "set first number in the sequence", OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, E},
406  {"hls_time", "set segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
407  {"hls_list_size", "set maximum number of playlist entries", OFFSET(max_nb_segments), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
408  {"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},
409  {"hls_wrap", "set number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
410  {"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},
411  {"hls_base_url", "url to prepend to each playlist entry", OFFSET(baseurl), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
412  {"hls_flags", "set flags affecting HLS playlist and media file generation", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0 }, 0, UINT_MAX, E, "flags"},
413  {"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"},
414 
415  { NULL },
416 };
417 
418 static const AVClass hls_class = {
419  .class_name = "hls muxer",
420  .item_name = av_default_item_name,
421  .option = options,
422  .version = LIBAVUTIL_VERSION_INT,
423 };
424 
425 
427  .name = "hls",
428  .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
429  .extensions = "m3u8",
430  .priv_data_size = sizeof(HLSContext),
431  .audio_codec = AV_CODEC_ID_AAC,
432  .video_codec = AV_CODEC_ID_H264,
437  .priv_class = &hls_class,
438 };