FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
smoothstreamingenc.c
Go to the documentation of this file.
1 /*
2  * Live smooth streaming fragmenter
3  * Copyright (c) 2012 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 #include "config.h"
23 #include <float.h>
24 #if HAVE_UNISTD_H
25 #include <unistd.h>
26 #endif
27 
28 #include "avformat.h"
29 #include "internal.h"
30 #include "os_support.h"
31 #include "avc.h"
32 #include "url.h"
33 #include "isom.h"
34 
35 #include "libavutil/opt.h"
36 #include "libavutil/avstring.h"
37 #include "libavutil/file.h"
38 #include "libavutil/mathematics.h"
39 #include "libavutil/intreadwrite.h"
40 
41 typedef struct {
42  char file[1024];
43  char infofile[1024];
44  int64_t start_time, duration;
45  int n;
46  int64_t start_pos, size;
47 } Fragment;
48 
49 typedef struct {
50  AVFormatContext *ctx;
51  int ctx_inited;
52  char dirname[1024];
53  uint8_t iobuf[32768];
54  URLContext *out; // Current output stream where all output is written
55  URLContext *out2; // Auxiliary output stream where all output is also written
56  URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
57  int64_t tail_pos, cur_pos, cur_start_pos;
58  int packets_written;
59  const char *stream_type_tag;
60  int nb_fragments, fragments_size, fragment_index;
61  Fragment **fragments;
62 
63  const char *fourcc;
64  char *private_str;
66  int audio_tag;
67 } OutputStream;
68 
69 typedef struct {
70  const AVClass *class; /* Class for private options. */
77  int has_video, has_audio;
80 
81 static int ism_write(void *opaque, uint8_t *buf, int buf_size)
82 {
83  OutputStream *os = opaque;
84  if (os->out)
85  ffurl_write(os->out, buf, buf_size);
86  if (os->out2)
87  ffurl_write(os->out2, buf, buf_size);
88  os->cur_pos += buf_size;
89  if (os->cur_pos >= os->tail_pos)
90  os->tail_pos = os->cur_pos;
91  return buf_size;
92 }
93 
94 static int64_t ism_seek(void *opaque, int64_t offset, int whence)
95 {
96  OutputStream *os = opaque;
97  int i;
98  if (whence != SEEK_SET)
99  return AVERROR(ENOSYS);
100  if (os->tail_out) {
101  if (os->out) {
102  ffurl_close(os->out);
103  }
104  if (os->out2) {
105  ffurl_close(os->out2);
106  }
107  os->out = os->tail_out;
108  os->out2 = NULL;
109  os->tail_out = NULL;
110  }
111  if (offset >= os->cur_start_pos) {
112  if (os->out)
113  ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
114  os->cur_pos = offset;
115  return offset;
116  }
117  for (i = os->nb_fragments - 1; i >= 0; i--) {
118  Fragment *frag = os->fragments[i];
119  if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
120  int ret;
121  AVDictionary *opts = NULL;
122  os->tail_out = os->out;
123  av_dict_set(&opts, "truncate", "0", 0);
124  ret = ffurl_open(&os->out, frag->file, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
125  av_dict_free(&opts);
126  if (ret < 0) {
127  os->out = os->tail_out;
128  os->tail_out = NULL;
129  return ret;
130  }
131  av_dict_set(&opts, "truncate", "0", 0);
133  av_dict_free(&opts);
134  ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
135  if (os->out2)
136  ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
137  os->cur_pos = offset;
138  return offset;
139  }
140  }
141  return AVERROR(EIO);
142 }
143 
145 {
146  AVCodecContext *codec = os->ctx->streams[0]->codec;
147  uint8_t *ptr = codec->extradata;
148  int size = codec->extradata_size;
149  int i;
150  if (codec->codec_id == AV_CODEC_ID_H264) {
151  ff_avc_write_annexb_extradata(ptr, &ptr, &size);
152  if (!ptr)
153  ptr = codec->extradata;
154  }
155  if (!ptr)
156  return;
157  os->private_str = av_mallocz(2*size + 1);
158  if (!os->private_str)
159  goto fail;
160  for (i = 0; i < size; i++)
161  snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
162 fail:
163  if (ptr != codec->extradata)
164  av_free(ptr);
165 }
166 
168 {
170  int i, j;
171  if (!c->streams)
172  return;
173  for (i = 0; i < s->nb_streams; i++) {
174  OutputStream *os = &c->streams[i];
175  ffurl_close(os->out);
176  ffurl_close(os->out2);
177  ffurl_close(os->tail_out);
178  os->out = os->out2 = os->tail_out = NULL;
179  if (os->ctx && os->ctx_inited)
180  av_write_trailer(os->ctx);
181  if (os->ctx && os->ctx->pb)
182  av_freep(&os->ctx->pb);
183  if (os->ctx)
185  av_freep(&os->private_str);
186  for (j = 0; j < os->nb_fragments; j++)
187  av_freep(&os->fragments[j]);
188  av_freep(&os->fragments);
189  }
190  av_freep(&c->streams);
191 }
192 
193 static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
194 {
195  int removed = 0, i, start = 0;
196  if (os->nb_fragments <= 0)
197  return;
198  if (os->fragments[0]->n > 0)
199  removed = 1;
200  if (final)
201  skip = 0;
202  if (window_size)
203  start = FFMAX(os->nb_fragments - skip - window_size, 0);
204  for (i = start; i < os->nb_fragments - skip; i++) {
205  Fragment *frag = os->fragments[i];
206  if (!final || removed)
207  avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
208  else
209  avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
210  }
211 }
212 
213 static int write_manifest(AVFormatContext *s, int final)
214 {
216  AVIOContext *out;
217  char filename[1024], temp_filename[1024];
218  int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
219  int64_t duration = 0;
220 
221  snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
222  snprintf(temp_filename, sizeof(temp_filename), "%s/Manifest.tmp", s->filename);
223  ret = avio_open2(&out, temp_filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
224  if (ret < 0) {
225  av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
226  return ret;
227  }
228  avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
229  for (i = 0; i < s->nb_streams; i++) {
230  OutputStream *os = &c->streams[i];
231  if (os->nb_fragments > 0) {
232  Fragment *last = os->fragments[os->nb_fragments - 1];
233  duration = last->start_time + last->duration;
234  }
235  if (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
236  video_chunks = os->nb_fragments;
237  video_streams++;
238  } else {
239  audio_chunks = os->nb_fragments;
240  audio_streams++;
241  }
242  }
243  if (!final) {
244  duration = 0;
245  video_chunks = audio_chunks = 0;
246  }
247  if (c->window_size) {
248  video_chunks = FFMIN(video_chunks, c->window_size);
249  audio_chunks = FFMIN(audio_chunks, c->window_size);
250  }
251  avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
252  if (!final)
253  avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
254  avio_printf(out, ">\n");
255  if (c->has_video) {
256  int last = -1, index = 0;
257  avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
258  for (i = 0; i < s->nb_streams; i++) {
259  OutputStream *os = &c->streams[i];
261  continue;
262  last = i;
263  avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%d\" FourCC=\"%s\" MaxWidth=\"%d\" MaxHeight=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codec->bit_rate, os->fourcc, s->streams[i]->codec->width, s->streams[i]->codec->height, os->private_str);
264  index++;
265  }
266  output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
267  avio_printf(out, "</StreamIndex>\n");
268  }
269  if (c->has_audio) {
270  int last = -1, index = 0;
271  avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
272  for (i = 0; i < s->nb_streams; i++) {
273  OutputStream *os = &c->streams[i];
275  continue;
276  last = i;
277  avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%d\" FourCC=\"%s\" SamplingRate=\"%d\" Channels=\"%d\" BitsPerSample=\"16\" PacketSize=\"%d\" AudioTag=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codec->bit_rate, os->fourcc, s->streams[i]->codec->sample_rate, s->streams[i]->codec->channels, os->packet_size, os->audio_tag, os->private_str);
278  index++;
279  }
280  output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
281  avio_printf(out, "</StreamIndex>\n");
282  }
283  avio_printf(out, "</SmoothStreamingMedia>\n");
284  avio_flush(out);
285  avio_close(out);
286  return ff_rename(temp_filename, filename, s);
287 }
288 
290 {
292  int ret = 0, i;
293  AVOutputFormat *oformat;
294 
295  if (mkdir(s->filename, 0777) == -1 && errno != EEXIST) {
296  ret = AVERROR(errno);
297  av_log(s, AV_LOG_ERROR, "mkdir failed\n");
298  goto fail;
299  }
300 
301  oformat = av_guess_format("ismv", NULL, NULL);
302  if (!oformat) {
304  goto fail;
305  }
306 
307  c->streams = av_mallocz_array(s->nb_streams, sizeof(*c->streams));
308  if (!c->streams) {
309  ret = AVERROR(ENOMEM);
310  goto fail;
311  }
312 
313  for (i = 0; i < s->nb_streams; i++) {
314  OutputStream *os = &c->streams[i];
315  AVFormatContext *ctx;
316  AVStream *st;
317  AVDictionary *opts = NULL;
318 
319  if (!s->streams[i]->codec->bit_rate) {
320  av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
321  ret = AVERROR(EINVAL);
322  goto fail;
323  }
324  snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%d)", s->filename, s->streams[i]->codec->bit_rate);
325  if (mkdir(os->dirname, 0777) == -1 && errno != EEXIST) {
326  ret = AVERROR(errno);
327  av_log(s, AV_LOG_ERROR, "mkdir failed\n");
328  goto fail;
329  }
330 
331  ctx = avformat_alloc_context();
332  if (!ctx) {
333  ret = AVERROR(ENOMEM);
334  goto fail;
335  }
336  os->ctx = ctx;
337  ctx->oformat = oformat;
339 
340  if (!(st = avformat_new_stream(ctx, NULL))) {
341  ret = AVERROR(ENOMEM);
342  goto fail;
343  }
346  st->time_base = s->streams[i]->time_base;
347 
348  ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, ism_write, ism_seek);
349  if (!ctx->pb) {
350  ret = AVERROR(ENOMEM);
351  goto fail;
352  }
353 
354  av_dict_set_int(&opts, "ism_lookahead", c->lookahead_count, 0);
355  av_dict_set(&opts, "movflags", "frag_custom", 0);
356  if ((ret = avformat_write_header(ctx, &opts)) < 0) {
357  goto fail;
358  }
359  os->ctx_inited = 1;
360  avio_flush(ctx->pb);
361  av_dict_free(&opts);
362  s->streams[i]->time_base = st->time_base;
363  if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
364  c->has_video = 1;
365  os->stream_type_tag = "video";
366  if (st->codec->codec_id == AV_CODEC_ID_H264) {
367  os->fourcc = "H264";
368  } else if (st->codec->codec_id == AV_CODEC_ID_VC1) {
369  os->fourcc = "WVC1";
370  } else {
371  av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
372  ret = AVERROR(EINVAL);
373  goto fail;
374  }
375  } else {
376  c->has_audio = 1;
377  os->stream_type_tag = "audio";
378  if (st->codec->codec_id == AV_CODEC_ID_AAC) {
379  os->fourcc = "AACL";
380  os->audio_tag = 0xff;
381  } else if (st->codec->codec_id == AV_CODEC_ID_WMAPRO) {
382  os->fourcc = "WMAP";
383  os->audio_tag = 0x0162;
384  } else {
385  av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
386  ret = AVERROR(EINVAL);
387  goto fail;
388  }
389  os->packet_size = st->codec->block_align ? st->codec->block_align : 4;
390  }
391  get_private_data(os);
392  }
393 
394  if (!c->has_video && c->min_frag_duration <= 0) {
395  av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
396  ret = AVERROR(EINVAL);
397  goto fail;
398  }
399  ret = write_manifest(s, 0);
400 
401 fail:
402  if (ret)
403  ism_free(s);
404  return ret;
405 }
406 
407 static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
408 {
409  AVIOContext *in;
410  int ret;
411  uint32_t len;
412  if ((ret = avio_open2(&in, filename, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
413  return ret;
414  ret = AVERROR(EIO);
415  *moof_size = avio_rb32(in);
416  if (*moof_size < 8 || *moof_size > size)
417  goto fail;
418  if (avio_rl32(in) != MKTAG('m','o','o','f'))
419  goto fail;
420  len = avio_rb32(in);
421  if (len > *moof_size)
422  goto fail;
423  if (avio_rl32(in) != MKTAG('m','f','h','d'))
424  goto fail;
425  avio_seek(in, len - 8, SEEK_CUR);
426  avio_rb32(in); /* traf size */
427  if (avio_rl32(in) != MKTAG('t','r','a','f'))
428  goto fail;
429  while (avio_tell(in) < *moof_size) {
430  uint32_t len = avio_rb32(in);
431  uint32_t tag = avio_rl32(in);
432  int64_t end = avio_tell(in) + len - 8;
433  if (len < 8 || len >= *moof_size)
434  goto fail;
435  if (tag == MKTAG('u','u','i','d')) {
436  static const uint8_t tfxd[] = {
437  0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
438  0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
439  };
440  uint8_t uuid[16];
441  avio_read(in, uuid, 16);
442  if (!memcmp(uuid, tfxd, 16) && len >= 8 + 16 + 4 + 16) {
443  avio_seek(in, 4, SEEK_CUR);
444  *start_ts = avio_rb64(in);
445  *duration = avio_rb64(in);
446  ret = 0;
447  break;
448  }
449  }
450  avio_seek(in, end, SEEK_SET);
451  }
452 fail:
453  avio_close(in);
454  return ret;
455 }
456 
457 static int add_fragment(OutputStream *os, const char *file, const char *infofile, int64_t start_time, int64_t duration, int64_t start_pos, int64_t size)
458 {
459  int err;
460  Fragment *frag;
461  if (os->nb_fragments >= os->fragments_size) {
462  os->fragments_size = (os->fragments_size + 1) * 2;
463  if ((err = av_reallocp(&os->fragments, sizeof(*os->fragments) *
464  os->fragments_size)) < 0) {
465  os->fragments_size = 0;
466  os->nb_fragments = 0;
467  return err;
468  }
469  }
470  frag = av_mallocz(sizeof(*frag));
471  if (!frag)
472  return AVERROR(ENOMEM);
473  av_strlcpy(frag->file, file, sizeof(frag->file));
474  av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
475  frag->start_time = start_time;
476  frag->duration = duration;
477  frag->start_pos = start_pos;
478  frag->size = size;
479  frag->n = os->fragment_index;
480  os->fragments[os->nb_fragments++] = frag;
481  os->fragment_index++;
482  return 0;
483 }
484 
485 static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
486 {
487  AVIOContext *in, *out;
488  int ret = 0;
489  if ((ret = avio_open2(&in, infile, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
490  return ret;
491  if ((ret = avio_open2(&out, outfile, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL)) < 0) {
492  avio_close(in);
493  return ret;
494  }
495  while (size > 0) {
496  uint8_t buf[8192];
497  int n = FFMIN(size, sizeof(buf));
498  n = avio_read(in, buf, n);
499  if (n <= 0) {
500  ret = AVERROR(EIO);
501  break;
502  }
503  avio_write(out, buf, n);
504  size -= n;
505  }
506  avio_flush(out);
507  avio_close(out);
508  avio_close(in);
509  return ret;
510 }
511 
512 static int ism_flush(AVFormatContext *s, int final)
513 {
515  int i, ret = 0;
516 
517  for (i = 0; i < s->nb_streams; i++) {
518  OutputStream *os = &c->streams[i];
519  char filename[1024], target_filename[1024], header_filename[1024];
520  int64_t size;
521  int64_t start_ts, duration, moof_size;
522  if (!os->packets_written)
523  continue;
524 
525  snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
526  ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
527  if (ret < 0)
528  break;
529  os->cur_start_pos = os->tail_pos;
530  av_write_frame(os->ctx, NULL);
531  avio_flush(os->ctx->pb);
532  os->packets_written = 0;
533  if (!os->out || os->tail_out)
534  return AVERROR(EIO);
535 
536  ffurl_close(os->out);
537  os->out = NULL;
538  size = os->tail_pos - os->cur_start_pos;
539  if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
540  break;
541  snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
542  snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
543  copy_moof(s, filename, header_filename, moof_size);
544  ret = ff_rename(filename, target_filename, s);
545  if (ret < 0)
546  break;
547  add_fragment(os, target_filename, header_filename, start_ts, duration,
548  os->cur_start_pos, size);
549  }
550 
551  if (c->window_size || (final && c->remove_at_exit)) {
552  for (i = 0; i < s->nb_streams; i++) {
553  OutputStream *os = &c->streams[i];
554  int j;
555  int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
556  if (final && c->remove_at_exit)
557  remove = os->nb_fragments;
558  if (remove > 0) {
559  for (j = 0; j < remove; j++) {
560  unlink(os->fragments[j]->file);
561  unlink(os->fragments[j]->infofile);
562  av_freep(&os->fragments[j]);
563  }
564  os->nb_fragments -= remove;
565  memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
566  }
567  if (final && c->remove_at_exit)
568  rmdir(os->dirname);
569  }
570  }
571 
572  if (ret >= 0)
573  ret = write_manifest(s, final);
574  return ret;
575 }
576 
578 {
580  AVStream *st = s->streams[pkt->stream_index];
581  OutputStream *os = &c->streams[pkt->stream_index];
582  int64_t end_dts = (c->nb_fragments + 1) * (int64_t) c->min_frag_duration;
583  int ret;
584 
585  if (st->first_dts == AV_NOPTS_VALUE)
586  st->first_dts = pkt->dts;
587 
588  if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
589  av_compare_ts(pkt->dts - st->first_dts, st->time_base,
590  end_dts, AV_TIME_BASE_Q) >= 0 &&
591  pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
592 
593  if ((ret = ism_flush(s, 0)) < 0)
594  return ret;
595  c->nb_fragments++;
596  }
597 
598  os->packets_written++;
599  return ff_write_chained(os->ctx, 0, pkt, s, 0);
600 }
601 
603 {
605  ism_flush(s, 1);
606 
607  if (c->remove_at_exit) {
608  char filename[1024];
609  snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
610  unlink(filename);
611  rmdir(s->filename);
612  }
613 
614  ism_free(s);
615  return 0;
616 }
617 
618 #define OFFSET(x) offsetof(SmoothStreamingContext, x)
619 #define E AV_OPT_FLAG_ENCODING_PARAM
620 static const AVOption options[] = {
621  { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
622  { "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
623  { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
624  { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
625  { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
626  { NULL },
627 };
628 
629 static const AVClass ism_class = {
630  .class_name = "smooth streaming muxer",
631  .item_name = av_default_item_name,
632  .option = options,
633  .version = LIBAVUTIL_VERSION_INT,
634 };
635 
636 
638  .name = "smoothstreaming",
639  .long_name = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
640  .priv_data_size = sizeof(SmoothStreamingContext),
641  .audio_codec = AV_CODEC_ID_AAC,
642  .video_codec = AV_CODEC_ID_H264,
647  .codec_tag = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
648  .priv_class = &ism_class,
649 };