Libav
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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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/mathematics.h"
26 #include "libavutil/parseutils.h"
27 #include "libavutil/avstring.h"
28 #include "libavutil/opt.h"
29 #include "libavutil/log.h"
30 
31 #include "avformat.h"
32 #include "internal.h"
33 
34 typedef struct ListEntry {
35  char name[1024];
36  int duration;
37  struct ListEntry *next;
38 } ListEntry;
39 
40 typedef struct HLSContext {
41  const AVClass *class; // Class for private options.
42  unsigned number;
43  int64_t sequence;
46  float time; // Set by a private option.
47  int size; // Set by a private option.
48  int wrap; // Set by a private option.
49  int64_t recording_time;
50  int has_video;
51  int64_t start_pts;
52  int64_t end_pts;
53  int64_t duration; // last segment duration computed so far, in seconds
57  char *basename;
59 } HLSContext;
60 
62 {
63  HLSContext *hls = s->priv_data;
64  AVFormatContext *oc;
65  int i;
66 
67  hls->avf = oc = avformat_alloc_context();
68  if (!oc)
69  return AVERROR(ENOMEM);
70 
71  oc->oformat = hls->oformat;
73 
74  for (i = 0; i < s->nb_streams; i++) {
75  AVStream *st;
76  if (!(st = avformat_new_stream(oc, NULL)))
77  return AVERROR(ENOMEM);
80  }
81 
82  return 0;
83 }
84 
85 static int append_entry(HLSContext *hls, uint64_t duration)
86 {
87  ListEntry *en = av_malloc(sizeof(*en));
88 
89  if (!en)
90  return AVERROR(ENOMEM);
91 
92  av_strlcpy(en->name, av_basename(hls->avf->filename), sizeof(en->name));
93 
94  en->duration = duration;
95  en->next = NULL;
96 
97  if (!hls->list)
98  hls->list = en;
99  else
100  hls->end_list->next = en;
101 
102  hls->end_list = en;
103 
104  if (hls->nb_entries >= hls->size) {
105  en = hls->list;
106  hls->list = en->next;
107  av_free(en);
108  } else
109  hls->nb_entries++;
110 
111  hls->sequence++;
112 
113  return 0;
114 }
115 
116 static void free_entries(HLSContext *hls)
117 {
118  ListEntry *p = hls->list, *en;
119 
120  while(p) {
121  en = p;
122  p = p->next;
123  av_free(en);
124  }
125 }
126 
127 static int hls_window(AVFormatContext *s, int last)
128 {
129  HLSContext *hls = s->priv_data;
130  ListEntry *en;
131  int target_duration = 0;
132  int ret = 0;
133 
134  if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
135  &s->interrupt_callback, NULL)) < 0)
136  goto fail;
137 
138  for (en = hls->list; en; en = en->next) {
139  if (target_duration < en->duration)
140  target_duration = en->duration;
141  }
142 
143  avio_printf(hls->pb, "#EXTM3U\n");
144  avio_printf(hls->pb, "#EXT-X-VERSION:3\n");
145  avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", target_duration);
146  avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
147  FFMAX(0, hls->sequence - hls->size));
148 
149  for (en = hls->list; en; en = en->next) {
150  avio_printf(hls->pb, "#EXTINF:%d,\n", en->duration);
151  avio_printf(hls->pb, "%s\n", en->name);
152  }
153 
154  if (last)
155  avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
156 
157 fail:
158  avio_closep(&hls->pb);
159  return ret;
160 }
161 
163 {
164  HLSContext *c = s->priv_data;
165  AVFormatContext *oc = c->avf;
166  int err = 0;
167 
168  if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
169  c->basename, c->wrap ? c->number % c->wrap : c->number) < 0)
170  return AVERROR(EINVAL);
171  c->number++;
172 
173  if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
174  &s->interrupt_callback, NULL)) < 0)
175  return err;
176 
177  if (oc->oformat->priv_class && oc->priv_data)
178  av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
179 
180  return 0;
181 }
182 
184 {
185  HLSContext *hls = s->priv_data;
186  int ret, i;
187  char *p;
188  const char *pattern = "%d.ts";
189  int basename_size = strlen(s->filename) + strlen(pattern) + 1;
190 
191  hls->number = 0;
192 
193  hls->recording_time = hls->time * AV_TIME_BASE;
194  hls->start_pts = AV_NOPTS_VALUE;
195 
196  for (i = 0; i < s->nb_streams; i++)
197  hls->has_video +=
199 
200  if (hls->has_video > 1)
202  "More than a single video stream present, "
203  "expect issues decoding it.\n");
204 
205  hls->oformat = av_guess_format("mpegts", NULL, NULL);
206 
207  if (!hls->oformat) {
209  goto fail;
210  }
211 
212  hls->basename = av_malloc(basename_size);
213 
214  if (!hls->basename) {
215  ret = AVERROR(ENOMEM);
216  goto fail;
217  }
218 
219  strcpy(hls->basename, s->filename);
220 
221  p = strrchr(hls->basename, '.');
222 
223  if (p)
224  *p = '\0';
225 
226  av_strlcat(hls->basename, pattern, basename_size);
227 
228  if ((ret = hls_mux_init(s)) < 0)
229  goto fail;
230 
231  if ((ret = hls_start(s)) < 0)
232  goto fail;
233 
234  if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
235  return ret;
236 
237 
238 fail:
239  if (ret) {
240  av_free(hls->basename);
241  if (hls->avf)
243  }
244  return ret;
245 }
246 
248 {
249  HLSContext *hls = s->priv_data;
250  AVFormatContext *oc = hls->avf;
251  AVStream *st = s->streams[pkt->stream_index];
252  int64_t end_pts = hls->recording_time * hls->number;
253  int ret, can_split = 1;
254 
255  if (hls->start_pts == AV_NOPTS_VALUE) {
256  hls->start_pts = pkt->pts;
257  hls->end_pts = pkt->pts;
258  }
259 
260  if (hls->has_video) {
261  can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
262  pkt->flags & AV_PKT_FLAG_KEY;
263  }
264  if (pkt->pts == AV_NOPTS_VALUE)
265  can_split = 0;
266  else
267  hls->duration = av_rescale(pkt->pts - hls->end_pts,
268  st->time_base.num, st->time_base.den);
269 
270  if (can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,
271  end_pts, AV_TIME_BASE_Q) >= 0) {
272  ret = append_entry(hls, hls->duration);
273  if (ret)
274  return ret;
275 
276  hls->end_pts = pkt->pts;
277  hls->duration = 0;
278 
279  av_write_frame(oc, NULL); /* Flush any buffered data */
280  avio_close(oc->pb);
281 
282  ret = hls_start(s);
283 
284  if (ret)
285  return ret;
286 
287  oc = hls->avf;
288 
289  if ((ret = hls_window(s, 0)) < 0)
290  return ret;
291  }
292 
293  ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
294 
295  return ret;
296 }
297 
298 static int hls_write_trailer(struct AVFormatContext *s)
299 {
300  HLSContext *hls = s->priv_data;
301  AVFormatContext *oc = hls->avf;
302 
303  av_write_trailer(oc);
304  avio_closep(&oc->pb);
306  av_free(hls->basename);
307  append_entry(hls, hls->duration);
308  hls_window(s, 1);
309 
310  free_entries(hls);
311  avio_close(hls->pb);
312  return 0;
313 }
314 
315 #define OFFSET(x) offsetof(HLSContext, x)
316 #define E AV_OPT_FLAG_ENCODING_PARAM
317 static const AVOption options[] = {
318  {"start_number", "first number in the sequence", OFFSET(sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, E},
319  {"hls_time", "segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
320  {"hls_list_size", "maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
321  {"hls_wrap", "number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
322  { NULL },
323 };
324 
325 static const AVClass hls_class = {
326  .class_name = "hls muxer",
327  .item_name = av_default_item_name,
328  .option = options,
329  .version = LIBAVUTIL_VERSION_INT,
330 };
331 
332 
334  .name = "hls",
335  .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
336  .extensions = "m3u8",
337  .priv_data_size = sizeof(HLSContext),
338  .audio_codec = AV_CODEC_ID_MP2,
339  .video_codec = AV_CODEC_ID_MPEG2VIDEO,
344  .priv_class = &hls_class,
345 };