FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
hlsenc.c
Go to the documentation of this file.
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 
24 #include "libavutil/mathematics.h"
25 #include "libavutil/parseutils.h"
26 #include "libavutil/avstring.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/log.h"
29 
30 #include "avformat.h"
31 #include "internal.h"
32 
33 typedef struct ListEntry {
34  char name[1024];
35  int duration;
36  struct ListEntry *next;
37 } ListEntry;
38 
39 typedef struct HLSContext {
40  const AVClass *class; // Class for private options.
41  unsigned number;
42  int64_t sequence;
45  float time; // Set by a private option.
46  int size; // Set by a private option.
47  int wrap; // Set by a private option.
48  int64_t recording_time;
49  int has_video;
50  int64_t start_pts;
51  int64_t end_pts;
55  char *basename;
57 } HLSContext;
58 
60 {
61  HLSContext *hls = s->priv_data;
62  AVFormatContext *oc;
63  int i;
64 
65  hls->avf = oc = avformat_alloc_context();
66  if (!oc)
67  return AVERROR(ENOMEM);
68 
69  oc->oformat = hls->oformat;
71 
72  for (i = 0; i < s->nb_streams; i++) {
73  AVStream *st;
74  if (!(st = avformat_new_stream(oc, NULL)))
75  return AVERROR(ENOMEM);
78  }
79 
80  return 0;
81 }
82 
83 static int append_entry(HLSContext *hls, uint64_t duration)
84 {
85  ListEntry *en = av_malloc(sizeof(*en));
86 
87  if (!en)
88  return AVERROR(ENOMEM);
89 
90  av_strlcpy(en->name, av_basename(hls->avf->filename), sizeof(en->name));
91 
92  en->duration = duration;
93  en->next = NULL;
94 
95  if (!hls->list)
96  hls->list = en;
97  else
98  hls->end_list->next = en;
99 
100  hls->end_list = en;
101 
102  if (hls->nb_entries >= hls->size) {
103  en = hls->list;
104  hls->list = en->next;
105  av_free(en);
106  } else
107  hls->nb_entries++;
108 
109  hls->sequence++;
110 
111  return 0;
112 }
113 
114 static void free_entries(HLSContext *hls)
115 {
116  ListEntry *p = hls->list, *en;
117 
118  while(p) {
119  en = p;
120  p = p->next;
121  av_free(en);
122  }
123 }
124 
125 static int hls_window(AVFormatContext *s, int last)
126 {
127  HLSContext *hls = s->priv_data;
128  ListEntry *en;
129  int target_duration = 0;
130  int ret = 0;
131 
132  if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
133  &s->interrupt_callback, NULL)) < 0)
134  goto fail;
135 
136  for (en = hls->list; en; en = en->next) {
137  if (target_duration < en->duration)
138  target_duration = en->duration;
139  }
140 
141  avio_printf(hls->pb, "#EXTM3U\n");
142  avio_printf(hls->pb, "#EXT-X-VERSION:3\n");
143  avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", target_duration);
144  avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
145  FFMAX(0, hls->sequence - hls->size));
146 
147  for (en = hls->list; en; en = en->next) {
148  avio_printf(hls->pb, "#EXTINF:%d,\n", en->duration);
149  avio_printf(hls->pb, "%s\n", en->name);
150  }
151 
152  if (last)
153  avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
154 
155 fail:
156  avio_closep(&hls->pb);
157  return ret;
158 }
159 
161 {
162  HLSContext *c = s->priv_data;
163  AVFormatContext *oc = c->avf;
164  int err = 0;
165 
166  if (c->wrap)
167  c->number %= c->wrap;
168 
169  if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
170  c->basename, c->number++) < 0) {
171  av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->basename);
172  return AVERROR(EINVAL);
173  }
174 
175  if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
176  &s->interrupt_callback, NULL)) < 0)
177  return err;
178 
179  if (oc->oformat->priv_class && oc->priv_data)
180  av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
181 
182  return 0;
183 }
184 
186 {
187  HLSContext *hls = s->priv_data;
188  int ret, i;
189  char *p;
190  const char *pattern = "%d.ts";
191  int basename_size = strlen(s->filename) + strlen(pattern) + 1;
192 
193  hls->number = 0;
194 
195  hls->recording_time = hls->time * AV_TIME_BASE;
196  hls->start_pts = AV_NOPTS_VALUE;
197 
198  for (i = 0; i < s->nb_streams; i++)
199  hls->has_video +=
201 
202  if (hls->has_video > 1)
204  "More than a single video stream present, "
205  "expect issues decoding it.\n");
206 
207  hls->oformat = av_guess_format("mpegts", NULL, NULL);
208 
209  if (!hls->oformat) {
211  goto fail;
212  }
213 
214  hls->basename = av_malloc(basename_size);
215 
216  if (!hls->basename) {
217  ret = AVERROR(ENOMEM);
218  goto fail;
219  }
220 
221  strcpy(hls->basename, s->filename);
222 
223  p = strrchr(hls->basename, '.');
224 
225  if (p)
226  *p = '\0';
227 
228  av_strlcat(hls->basename, pattern, basename_size);
229 
230  if ((ret = hls_mux_init(s)) < 0)
231  goto fail;
232 
233  if ((ret = hls_start(s)) < 0)
234  goto fail;
235 
236  if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
237  return ret;
238 
239 
240 fail:
241  if (ret) {
242  av_free(hls->basename);
243  if (hls->avf)
245  }
246  return ret;
247 }
248 
250 {
251  HLSContext *hls = s->priv_data;
252  AVFormatContext *oc = hls->avf;
253  AVStream *st = s->streams[pkt->stream_index];
254  int64_t end_pts = hls->recording_time * hls->number;
255  int ret, can_split = 1;
256 
257  if (hls->start_pts == AV_NOPTS_VALUE) {
258  hls->start_pts = pkt->pts;
259  hls->end_pts = pkt->pts;
260  }
261 
262  if (hls->has_video) {
263  can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
264  pkt->flags & AV_PKT_FLAG_KEY;
265  }
266 
267  if (can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,
268  end_pts, AV_TIME_BASE_Q) >= 0) {
269  ret = append_entry(hls, av_rescale(pkt->pts - hls->end_pts,
270  st->time_base.num,
271  st->time_base.den));
272  if (ret)
273  return ret;
274 
275  hls->end_pts = pkt->pts;
276 
277  av_write_frame(oc, NULL); /* Flush any buffered data */
278  avio_close(oc->pb);
279 
280  ret = hls_start(s);
281 
282  if (ret)
283  return ret;
284 
285  oc = hls->avf;
286 
287  if ((ret = hls_window(s, 0)) < 0)
288  return ret;
289  }
290 
291  ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
292 
293  return ret;
294 }
295 
296 static int hls_write_trailer(struct AVFormatContext *s)
297 {
298  HLSContext *hls = s->priv_data;
299  AVFormatContext *oc = hls->avf;
300 
301  av_write_trailer(oc);
302  avio_closep(&oc->pb);
304  av_free(hls->basename);
305  hls_window(s, 1);
306 
307  free_entries(hls);
308  avio_close(hls->pb);
309  return 0;
310 }
311 
312 #define OFFSET(x) offsetof(HLSContext, x)
313 #define E AV_OPT_FLAG_ENCODING_PARAM
314 static const AVOption options[] = {
315  { "start_number", "set first number in the sequence", OFFSET(number), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
316  { "hls_time", "set segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
317  { "hls_list_size","set maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
318  { "hls_wrap", "set number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
319  { NULL },
320 };
321 
322 static const AVClass hls_class = {
323  .class_name = "hls muxer",
324  .item_name = av_default_item_name,
325  .option = options,
326  .version = LIBAVUTIL_VERSION_INT,
327 };
328 
329 
331  .name = "hls",
332  .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
333  .extensions = "m3u8",
334  .priv_data_size = sizeof(HLSContext),
335  .audio_codec = AV_CODEC_ID_MP2,
336  .video_codec = AV_CODEC_ID_MPEG2VIDEO,
341  .priv_class = &hls_class,
342 };