smoothstreamingenc: Don't assume streams start from timestamp 0
[libav.git] / libavformat / smoothstreamingenc.c
1 /*
2 * Live smooth streaming fragmenter
3 * Copyright (c) 2012 Martin Storsjo
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 "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/mathematics.h"
38 #include "libavutil/intreadwrite.h"
39
40 typedef struct {
41 char file[1024];
42 char infofile[1024];
43 int64_t start_time, duration;
44 int n;
45 int64_t start_pos, size;
46 } Fragment;
47
48 typedef struct {
49 AVFormatContext *ctx;
50 int ctx_inited;
51 char dirname[1024];
52 uint8_t iobuf[32768];
53 URLContext *out; // Current output stream where all output is written
54 URLContext *out2; // Auxillary output stream where all output also is written
55 URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
56 int64_t tail_pos, cur_pos, cur_start_pos;
57 int packets_written;
58 const char *stream_type_tag;
59 int nb_fragments, fragments_size, fragment_index;
60 Fragment **fragments;
61
62 const char *fourcc;
63 char *private_str;
64 int packet_size;
65 int audio_tag;
66 } OutputStream;
67
68 typedef struct {
69 const AVClass *class; /* Class for private options. */
70 int window_size;
71 int extra_window_size;
72 int lookahead_count;
73 int min_frag_duration;
74 int remove_at_exit;
75 OutputStream *streams;
76 int has_video, has_audio;
77 int nb_fragments;
78 } SmoothStreamingContext;
79
80 static int ism_write(void *opaque, uint8_t *buf, int buf_size)
81 {
82 OutputStream *os = opaque;
83 if (os->out)
84 ffurl_write(os->out, buf, buf_size);
85 if (os->out2)
86 ffurl_write(os->out2, buf, buf_size);
87 os->cur_pos += buf_size;
88 if (os->cur_pos >= os->tail_pos)
89 os->tail_pos = os->cur_pos;
90 return buf_size;
91 }
92
93 static int64_t ism_seek(void *opaque, int64_t offset, int whence)
94 {
95 OutputStream *os = opaque;
96 int i;
97 if (whence != SEEK_SET)
98 return AVERROR(ENOSYS);
99 if (os->tail_out) {
100 if (os->out) {
101 ffurl_close(os->out);
102 }
103 if (os->out2) {
104 ffurl_close(os->out2);
105 }
106 os->out = os->tail_out;
107 os->out2 = NULL;
108 os->tail_out = NULL;
109 }
110 if (offset >= os->cur_start_pos) {
111 if (os->out)
112 ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
113 os->cur_pos = offset;
114 return offset;
115 }
116 for (i = os->nb_fragments - 1; i >= 0; i--) {
117 Fragment *frag = os->fragments[i];
118 if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
119 int ret;
120 AVDictionary *opts = NULL;
121 os->tail_out = os->out;
122 av_dict_set(&opts, "truncate", "0", 0);
123 ret = ffurl_open(&os->out, frag->file, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
124 av_dict_free(&opts);
125 if (ret < 0) {
126 os->out = os->tail_out;
127 os->tail_out = NULL;
128 return ret;
129 }
130 av_dict_set(&opts, "truncate", "0", 0);
131 ffurl_open(&os->out2, frag->infofile, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
132 av_dict_free(&opts);
133 ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
134 if (os->out2)
135 ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
136 os->cur_pos = offset;
137 return offset;
138 }
139 }
140 return AVERROR(EIO);
141 }
142
143 static void get_private_data(OutputStream *os)
144 {
145 AVCodecContext *codec = os->ctx->streams[0]->codec;
146 uint8_t *ptr = codec->extradata;
147 int size = codec->extradata_size;
148 int i;
149 if (codec->codec_id == AV_CODEC_ID_H264) {
150 ff_avc_write_annexb_extradata(ptr, &ptr, &size);
151 if (!ptr)
152 ptr = codec->extradata;
153 }
154 if (!ptr)
155 return;
156 os->private_str = av_mallocz(2*size + 1);
157 for (i = 0; i < size; i++)
158 snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
159 if (ptr != codec->extradata)
160 av_free(ptr);
161 }
162
163 static void ism_free(AVFormatContext *s)
164 {
165 SmoothStreamingContext *c = s->priv_data;
166 int i, j;
167 if (!c->streams)
168 return;
169 for (i = 0; i < s->nb_streams; i++) {
170 OutputStream *os = &c->streams[i];
171 ffurl_close(os->out);
172 ffurl_close(os->out2);
173 ffurl_close(os->tail_out);
174 os->out = os->out2 = os->tail_out = NULL;
175 if (os->ctx && os->ctx_inited)
176 av_write_trailer(os->ctx);
177 if (os->ctx && os->ctx->pb)
178 av_free(os->ctx->pb);
179 if (os->ctx)
180 avformat_free_context(os->ctx);
181 av_free(os->private_str);
182 for (j = 0; j < os->nb_fragments; j++)
183 av_free(os->fragments[j]);
184 av_free(os->fragments);
185 }
186 av_freep(&c->streams);
187 }
188
189 static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
190 {
191 int removed = 0, i, start = 0;
192 if (os->nb_fragments <= 0)
193 return;
194 if (os->fragments[0]->n > 0)
195 removed = 1;
196 if (final)
197 skip = 0;
198 if (window_size)
199 start = FFMAX(os->nb_fragments - skip - window_size, 0);
200 for (i = start; i < os->nb_fragments - skip; i++) {
201 Fragment *frag = os->fragments[i];
202 if (!final || removed)
203 avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
204 else
205 avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
206 }
207 }
208
209 static int write_manifest(AVFormatContext *s, int final)
210 {
211 SmoothStreamingContext *c = s->priv_data;
212 AVIOContext *out;
213 char filename[1024];
214 int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
215 int64_t duration = 0;
216
217 snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
218 ret = avio_open2(&out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
219 if (ret < 0) {
220 av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", filename);
221 return ret;
222 }
223 avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
224 for (i = 0; i < s->nb_streams; i++) {
225 OutputStream *os = &c->streams[i];
226 if (os->nb_fragments > 0) {
227 Fragment *last = os->fragments[os->nb_fragments - 1];
228 duration = last->start_time + last->duration;
229 }
230 if (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
231 video_chunks = os->nb_fragments;
232 video_streams++;
233 } else {
234 audio_chunks = os->nb_fragments;
235 audio_streams++;
236 }
237 }
238 if (!final) {
239 duration = 0;
240 video_chunks = audio_chunks = 0;
241 }
242 if (c->window_size) {
243 video_chunks = FFMIN(video_chunks, c->window_size);
244 audio_chunks = FFMIN(audio_chunks, c->window_size);
245 }
246 avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
247 if (!final)
248 avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
249 avio_printf(out, ">\n");
250 if (c->has_video) {
251 int last = -1, index = 0;
252 avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
253 for (i = 0; i < s->nb_streams; i++) {
254 OutputStream *os = &c->streams[i];
255 if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
256 continue;
257 last = i;
258 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);
259 index++;
260 }
261 output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
262 avio_printf(out, "</StreamIndex>\n");
263 }
264 if (c->has_audio) {
265 int last = -1, index = 0;
266 avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
267 for (i = 0; i < s->nb_streams; i++) {
268 OutputStream *os = &c->streams[i];
269 if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
270 continue;
271 last = i;
272 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);
273 index++;
274 }
275 output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
276 avio_printf(out, "</StreamIndex>\n");
277 }
278 avio_printf(out, "</SmoothStreamingMedia>\n");
279 avio_flush(out);
280 avio_close(out);
281 return 0;
282 }
283
284 static int ism_write_header(AVFormatContext *s)
285 {
286 SmoothStreamingContext *c = s->priv_data;
287 int ret = 0, i;
288 AVOutputFormat *oformat;
289
290 mkdir(s->filename, 0777);
291
292 oformat = av_guess_format("ismv", NULL, NULL);
293 if (!oformat) {
294 ret = AVERROR_MUXER_NOT_FOUND;
295 goto fail;
296 }
297
298 c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams);
299 if (!c->streams) {
300 ret = AVERROR(ENOMEM);
301 goto fail;
302 }
303
304 for (i = 0; i < s->nb_streams; i++) {
305 OutputStream *os = &c->streams[i];
306 AVFormatContext *ctx;
307 AVStream *st;
308 AVDictionary *opts = NULL;
309 char buf[10];
310
311 if (!s->streams[i]->codec->bit_rate) {
312 av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
313 ret = AVERROR(EINVAL);
314 goto fail;
315 }
316 snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%d)", s->filename, s->streams[i]->codec->bit_rate);
317 mkdir(os->dirname, 0777);
318
319 ctx = avformat_alloc_context();
320 if (!ctx) {
321 ret = AVERROR(ENOMEM);
322 goto fail;
323 }
324 os->ctx = ctx;
325 ctx->oformat = oformat;
326 ctx->interrupt_callback = s->interrupt_callback;
327
328 if (!(st = avformat_new_stream(ctx, NULL))) {
329 ret = AVERROR(ENOMEM);
330 goto fail;
331 }
332 avcodec_copy_context(st->codec, s->streams[i]->codec);
333 st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
334
335 ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, ism_write, ism_seek);
336 if (!ctx->pb) {
337 ret = AVERROR(ENOMEM);
338 goto fail;
339 }
340
341 snprintf(buf, sizeof(buf), "%d", c->lookahead_count);
342 av_dict_set(&opts, "ism_lookahead", buf, 0);
343 av_dict_set(&opts, "movflags", "frag_custom", 0);
344 if ((ret = avformat_write_header(ctx, &opts)) < 0) {
345 goto fail;
346 }
347 os->ctx_inited = 1;
348 avio_flush(ctx->pb);
349 av_dict_free(&opts);
350 s->streams[i]->time_base = st->time_base;
351 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
352 c->has_video = 1;
353 os->stream_type_tag = "video";
354 if (st->codec->codec_id == AV_CODEC_ID_H264) {
355 os->fourcc = "H264";
356 } else if (st->codec->codec_id == AV_CODEC_ID_VC1) {
357 os->fourcc = "WVC1";
358 } else {
359 av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
360 ret = AVERROR(EINVAL);
361 goto fail;
362 }
363 } else {
364 c->has_audio = 1;
365 os->stream_type_tag = "audio";
366 if (st->codec->codec_id == AV_CODEC_ID_AAC) {
367 os->fourcc = "AACL";
368 os->audio_tag = 0xff;
369 } else if (st->codec->codec_id == AV_CODEC_ID_WMAPRO) {
370 os->fourcc = "WMAP";
371 os->audio_tag = 0x0162;
372 } else {
373 av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
374 ret = AVERROR(EINVAL);
375 goto fail;
376 }
377 os->packet_size = st->codec->block_align ? st->codec->block_align : 4;
378 }
379 get_private_data(os);
380 }
381
382 if (!c->has_video && c->min_frag_duration <= 0) {
383 av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
384 ret = AVERROR(EINVAL);
385 }
386 ret = write_manifest(s, 0);
387
388 fail:
389 if (ret)
390 ism_free(s);
391 return ret;
392 }
393
394 static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
395 {
396 AVIOContext *in;
397 int ret;
398 uint32_t len;
399 if ((ret = avio_open2(&in, filename, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
400 return ret;
401 ret = AVERROR(EIO);
402 *moof_size = avio_rb32(in);
403 if (*moof_size < 8 || *moof_size > size)
404 goto fail;
405 if (avio_rl32(in) != MKTAG('m','o','o','f'))
406 goto fail;
407 len = avio_rb32(in);
408 if (len > *moof_size)
409 goto fail;
410 if (avio_rl32(in) != MKTAG('m','f','h','d'))
411 goto fail;
412 avio_seek(in, len - 8, SEEK_CUR);
413 avio_rb32(in); /* traf size */
414 if (avio_rl32(in) != MKTAG('t','r','a','f'))
415 goto fail;
416 while (avio_tell(in) < *moof_size) {
417 uint32_t len = avio_rb32(in);
418 uint32_t tag = avio_rl32(in);
419 int64_t end = avio_tell(in) + len - 8;
420 if (len < 8 || len >= *moof_size)
421 goto fail;
422 if (tag == MKTAG('u','u','i','d')) {
423 const uint8_t tfxd[] = {
424 0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
425 0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
426 };
427 uint8_t uuid[16];
428 avio_read(in, uuid, 16);
429 if (!memcmp(uuid, tfxd, 16) && len >= 8 + 16 + 4 + 16) {
430 avio_seek(in, 4, SEEK_CUR);
431 *start_ts = avio_rb64(in);
432 *duration = avio_rb64(in);
433 ret = 0;
434 break;
435 }
436 }
437 avio_seek(in, end, SEEK_SET);
438 }
439 fail:
440 avio_close(in);
441 return ret;
442 }
443
444 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)
445 {
446 Fragment *frag;
447 if (os->nb_fragments >= os->fragments_size) {
448 os->fragments_size = (os->fragments_size + 1) * 2;
449 os->fragments = av_realloc(os->fragments, sizeof(*os->fragments)*os->fragments_size);
450 if (!os->fragments)
451 return AVERROR(ENOMEM);
452 }
453 frag = av_mallocz(sizeof(*frag));
454 if (!frag)
455 return AVERROR(ENOMEM);
456 av_strlcpy(frag->file, file, sizeof(frag->file));
457 av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
458 frag->start_time = start_time;
459 frag->duration = duration;
460 frag->start_pos = start_pos;
461 frag->size = size;
462 frag->n = os->fragment_index;
463 os->fragments[os->nb_fragments++] = frag;
464 os->fragment_index++;
465 return 0;
466 }
467
468 static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
469 {
470 AVIOContext *in, *out;
471 int ret = 0;
472 if ((ret = avio_open2(&in, infile, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
473 return ret;
474 if ((ret = avio_open2(&out, outfile, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL)) < 0) {
475 avio_close(in);
476 return ret;
477 }
478 while (size > 0) {
479 uint8_t buf[8192];
480 int n = FFMIN(size, sizeof(buf));
481 n = avio_read(in, buf, n);
482 if (n <= 0) {
483 ret = AVERROR(EIO);
484 break;
485 }
486 avio_write(out, buf, n);
487 size -= n;
488 }
489 avio_flush(out);
490 avio_close(out);
491 avio_close(in);
492 return ret;
493 }
494
495 static int ism_flush(AVFormatContext *s, int final)
496 {
497 SmoothStreamingContext *c = s->priv_data;
498 int i, ret = 0;
499
500 for (i = 0; i < s->nb_streams; i++) {
501 OutputStream *os = &c->streams[i];
502 char filename[1024], target_filename[1024], header_filename[1024];
503 int64_t start_pos = os->tail_pos, size;
504 int64_t start_ts, duration, moof_size;
505 if (!os->packets_written)
506 continue;
507
508 snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
509 ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
510 if (ret < 0)
511 break;
512 os->cur_start_pos = os->tail_pos;
513 av_write_frame(os->ctx, NULL);
514 avio_flush(os->ctx->pb);
515 os->packets_written = 0;
516 if (!os->out || os->tail_out)
517 return AVERROR(EIO);
518
519 ffurl_close(os->out);
520 os->out = NULL;
521 size = os->tail_pos - start_pos;
522 if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
523 break;
524 snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
525 snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
526 copy_moof(s, filename, header_filename, moof_size);
527 rename(filename, target_filename);
528 add_fragment(os, target_filename, header_filename, start_ts, duration, start_pos, size);
529 }
530
531 if (c->window_size || (final && c->remove_at_exit)) {
532 for (i = 0; i < s->nb_streams; i++) {
533 OutputStream *os = &c->streams[i];
534 int j;
535 int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
536 if (final && c->remove_at_exit)
537 remove = os->nb_fragments;
538 if (remove > 0) {
539 for (j = 0; j < remove; j++) {
540 unlink(os->fragments[j]->file);
541 unlink(os->fragments[j]->infofile);
542 av_free(os->fragments[j]);
543 }
544 os->nb_fragments -= remove;
545 memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
546 }
547 if (final && c->remove_at_exit)
548 rmdir(os->dirname);
549 }
550 }
551
552 if (ret >= 0)
553 ret = write_manifest(s, final);
554 return ret;
555 }
556
557 static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
558 {
559 SmoothStreamingContext *c = s->priv_data;
560 AVStream *st = s->streams[pkt->stream_index];
561 OutputStream *os = &c->streams[pkt->stream_index];
562 int64_t end_dts = (c->nb_fragments + 1) * c->min_frag_duration;
563 int ret;
564
565 if (st->first_dts == AV_NOPTS_VALUE)
566 st->first_dts = pkt->dts;
567
568 if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
569 av_compare_ts(pkt->dts - st->first_dts, st->time_base,
570 end_dts, AV_TIME_BASE_Q) >= 0 &&
571 pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
572
573 if ((ret = ism_flush(s, 0)) < 0)
574 return ret;
575 c->nb_fragments++;
576 }
577
578 os->packets_written++;
579 return ff_write_chained(os->ctx, 0, pkt, s);
580 }
581
582 static int ism_write_trailer(AVFormatContext *s)
583 {
584 SmoothStreamingContext *c = s->priv_data;
585 ism_flush(s, 1);
586
587 if (c->remove_at_exit) {
588 char filename[1024];
589 snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
590 unlink(filename);
591 rmdir(s->filename);
592 }
593
594 ism_free(s);
595 return 0;
596 }
597
598 #define OFFSET(x) offsetof(SmoothStreamingContext, x)
599 #define E AV_OPT_FLAG_ENCODING_PARAM
600 static const AVOption options[] = {
601 { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
602 { "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 },
603 { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
604 { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
605 { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
606 { NULL },
607 };
608
609 static const AVClass ism_class = {
610 .class_name = "smooth streaming muxer",
611 .item_name = av_default_item_name,
612 .option = options,
613 .version = LIBAVUTIL_VERSION_INT,
614 };
615
616
617 AVOutputFormat ff_smoothstreaming_muxer = {
618 .name = "smoothstreaming",
619 .long_name = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
620 .priv_data_size = sizeof(SmoothStreamingContext),
621 .audio_codec = AV_CODEC_ID_AAC,
622 .video_codec = AV_CODEC_ID_H264,
623 .flags = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
624 .write_header = ism_write_header,
625 .write_packet = ism_write_packet,
626 .write_trailer = ism_write_trailer,
627 .codec_tag = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
628 .priv_class = &ism_class,
629 };