1 /*
2 * Copyright (c) 2003 Fabrice Bellard
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23 /**
24 * @file
25 * libavformat API example.
26 *
27 * Output a media file in any supported libavformat format. The default
28 * codecs are used.
29 * @example muxing.c
30 */
31
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <math.h>
36
37 #include <libavutil/avassert.h>
38 #include <libavutil/channel_layout.h>
39 #include <libavutil/opt.h>
40 #include <libavutil/mathematics.h>
41 #include <libavutil/timestamp.h>
42 #include <libavformat/avformat.h>
43 #include <libswscale/swscale.h>
44 #include <libswresample/swresample.h>
45
46 #define STREAM_DURATION 10.0
47 #define STREAM_FRAME_RATE 25 /* 25 images/s */
48 #define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */
49
50 #define SCALE_FLAGS SWS_BICUBIC
51
52 // a wrapper around a single output AVStream
53 typedef struct OutputStream {
54 AVStream *st;
55 AVCodecContext *enc;
56
57 /* pts of the next frame that will be generated */
58 int64_t next_pts;
59 int samples_count;
60
61 AVFrame *frame;
62 AVFrame *tmp_frame;
63
64 float t, tincr, tincr2;
65
66 struct SwsContext *sws_ctx;
67 struct SwrContext *swr_ctx;
68 } OutputStream;
69
log_packet(const AVFormatContext * fmt_ctx,const AVPacket * pkt)70 static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
71 {
72 AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;
73
74 printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
75 av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
76 av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
77 av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
78 pkt->stream_index);
79 }
80
write_frame(AVFormatContext * fmt_ctx,AVCodecContext * c,AVStream * st,AVFrame * frame)81 static int write_frame(AVFormatContext *fmt_ctx, AVCodecContext *c,
82 AVStream *st, AVFrame *frame)
83 {
84 int ret;
85
86 // send the frame to the encoder
87 ret = avcodec_send_frame(c, frame);
88 if (ret < 0) {
89 fprintf(stderr, "Error sending a frame to the encoder: %s\n",
90 av_err2str(ret));
91 exit(1);
92 }
93
94 while (ret >= 0) {
95 AVPacket pkt = { 0 };
96
97 ret = avcodec_receive_packet(c, &pkt);
98 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
99 break;
100 else if (ret < 0) {
101 fprintf(stderr, "Error encoding a frame: %s\n", av_err2str(ret));
102 exit(1);
103 }
104
105 /* rescale output packet timestamp values from codec to stream timebase */
106 av_packet_rescale_ts(&pkt, c->time_base, st->time_base);
107 pkt.stream_index = st->index;
108
109 /* Write the compressed frame to the media file. */
110 log_packet(fmt_ctx, &pkt);
111 ret = av_interleaved_write_frame(fmt_ctx, &pkt);
112 av_packet_unref(&pkt);
113 if (ret < 0) {
114 fprintf(stderr, "Error while writing output packet: %s\n", av_err2str(ret));
115 exit(1);
116 }
117 }
118
119 return ret == AVERROR_EOF ? 1 : 0;
120 }
121
122 /* Add an output stream. */
add_stream(OutputStream * ost,AVFormatContext * oc,AVCodec ** codec,enum AVCodecID codec_id)123 static void add_stream(OutputStream *ost, AVFormatContext *oc,
124 AVCodec **codec,
125 enum AVCodecID codec_id)
126 {
127 AVCodecContext *c;
128 int i;
129
130 /* find the encoder */
131 *codec = avcodec_find_encoder(codec_id);
132 if (!(*codec)) {
133 fprintf(stderr, "Could not find encoder for '%s'\n",
134 avcodec_get_name(codec_id));
135 exit(1);
136 }
137
138 ost->st = avformat_new_stream(oc, NULL);
139 if (!ost->st) {
140 fprintf(stderr, "Could not allocate stream\n");
141 exit(1);
142 }
143 ost->st->id = oc->nb_streams-1;
144 c = avcodec_alloc_context3(*codec);
145 if (!c) {
146 fprintf(stderr, "Could not alloc an encoding context\n");
147 exit(1);
148 }
149 ost->enc = c;
150
151 switch ((*codec)->type) {
152 case AVMEDIA_TYPE_AUDIO:
153 c->sample_fmt = (*codec)->sample_fmts ?
154 (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
155 c->bit_rate = 64000;
156 c->sample_rate = 44100;
157 if ((*codec)->supported_samplerates) {
158 c->sample_rate = (*codec)->supported_samplerates[0];
159 for (i = 0; (*codec)->supported_samplerates[i]; i++) {
160 if ((*codec)->supported_samplerates[i] == 44100)
161 c->sample_rate = 44100;
162 }
163 }
164 c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
165 c->channel_layout = AV_CH_LAYOUT_STEREO;
166 if ((*codec)->channel_layouts) {
167 c->channel_layout = (*codec)->channel_layouts[0];
168 for (i = 0; (*codec)->channel_layouts[i]; i++) {
169 if ((*codec)->channel_layouts[i] == AV_CH_LAYOUT_STEREO)
170 c->channel_layout = AV_CH_LAYOUT_STEREO;
171 }
172 }
173 c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
174 ost->st->time_base = (AVRational){ 1, c->sample_rate };
175 break;
176
177 case AVMEDIA_TYPE_VIDEO:
178 c->codec_id = codec_id;
179
180 c->bit_rate = 400000;
181 /* Resolution must be a multiple of two. */
182 c->width = 352;
183 c->height = 288;
184 /* timebase: This is the fundamental unit of time (in seconds) in terms
185 * of which frame timestamps are represented. For fixed-fps content,
186 * timebase should be 1/framerate and timestamp increments should be
187 * identical to 1. */
188 ost->st->time_base = (AVRational){ 1, STREAM_FRAME_RATE };
189 c->time_base = ost->st->time_base;
190
191 c->gop_size = 12; /* emit one intra frame every twelve frames at most */
192 c->pix_fmt = STREAM_PIX_FMT;
193 if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
194 /* just for testing, we also add B-frames */
195 c->max_b_frames = 2;
196 }
197 if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
198 /* Needed to avoid using macroblocks in which some coeffs overflow.
199 * This does not happen with normal video, it just happens here as
200 * the motion of the chroma plane does not match the luma plane. */
201 c->mb_decision = 2;
202 }
203 break;
204
205 default:
206 break;
207 }
208
209 /* Some formats want stream headers to be separate. */
210 if (oc->oformat->flags & AVFMT_GLOBALHEADER)
211 c->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
212 }
213
214 /**************************************************************/
215 /* audio output */
216
alloc_audio_frame(enum AVSampleFormat sample_fmt,uint64_t channel_layout,int sample_rate,int nb_samples)217 static AVFrame *alloc_audio_frame(enum AVSampleFormat sample_fmt,
218 uint64_t channel_layout,
219 int sample_rate, int nb_samples)
220 {
221 AVFrame *frame = av_frame_alloc();
222 int ret;
223
224 if (!frame) {
225 fprintf(stderr, "Error allocating an audio frame\n");
226 exit(1);
227 }
228
229 frame->format = sample_fmt;
230 frame->channel_layout = channel_layout;
231 frame->sample_rate = sample_rate;
232 frame->nb_samples = nb_samples;
233
234 if (nb_samples) {
235 ret = av_frame_get_buffer(frame, 0);
236 if (ret < 0) {
237 fprintf(stderr, "Error allocating an audio buffer\n");
238 exit(1);
239 }
240 }
241
242 return frame;
243 }
244
open_audio(AVFormatContext * oc,AVCodec * codec,OutputStream * ost,AVDictionary * opt_arg)245 static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
246 {
247 AVCodecContext *c;
248 int nb_samples;
249 int ret;
250 AVDictionary *opt = NULL;
251
252 c = ost->enc;
253
254 /* open it */
255 av_dict_copy(&opt, opt_arg, 0);
256 ret = avcodec_open2(c, codec, &opt);
257 av_dict_free(&opt);
258 if (ret < 0) {
259 fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
260 exit(1);
261 }
262
263 /* init signal generator */
264 ost->t = 0;
265 ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
266 /* increment frequency by 110 Hz per second */
267 ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
268
269 if (c->codec->capabilities & AV_CODEC_CAP_VARIABLE_FRAME_SIZE)
270 nb_samples = 10000;
271 else
272 nb_samples = c->frame_size;
273
274 ost->frame = alloc_audio_frame(c->sample_fmt, c->channel_layout,
275 c->sample_rate, nb_samples);
276 ost->tmp_frame = alloc_audio_frame(AV_SAMPLE_FMT_S16, c->channel_layout,
277 c->sample_rate, nb_samples);
278
279 /* copy the stream parameters to the muxer */
280 ret = avcodec_parameters_from_context(ost->st->codecpar, c);
281 if (ret < 0) {
282 fprintf(stderr, "Could not copy the stream parameters\n");
283 exit(1);
284 }
285
286 /* create resampler context */
287 ost->swr_ctx = swr_alloc();
288 if (!ost->swr_ctx) {
289 fprintf(stderr, "Could not allocate resampler context\n");
290 exit(1);
291 }
292
293 /* set options */
294 av_opt_set_int (ost->swr_ctx, "in_channel_count", c->channels, 0);
295 av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
296 av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
297 av_opt_set_int (ost->swr_ctx, "out_channel_count", c->channels, 0);
298 av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
299 av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
300
301 /* initialize the resampling context */
302 if ((ret = swr_init(ost->swr_ctx)) < 0) {
303 fprintf(stderr, "Failed to initialize the resampling context\n");
304 exit(1);
305 }
306 }
307
308 /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
309 * 'nb_channels' channels. */
get_audio_frame(OutputStream * ost)310 static AVFrame *get_audio_frame(OutputStream *ost)
311 {
312 AVFrame *frame = ost->tmp_frame;
313 int j, i, v;
314 int16_t *q = (int16_t*)frame->data[0];
315
316 /* check if we want to generate more frames */
317 if (av_compare_ts(ost->next_pts, ost->enc->time_base,
318 STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
319 return NULL;
320
321 for (j = 0; j <frame->nb_samples; j++) {
322 v = (int)(sin(ost->t) * 10000);
323 for (i = 0; i < ost->enc->channels; i++)
324 *q++ = v;
325 ost->t += ost->tincr;
326 ost->tincr += ost->tincr2;
327 }
328
329 frame->pts = ost->next_pts;
330 ost->next_pts += frame->nb_samples;
331
332 return frame;
333 }
334
335 /*
336 * encode one audio frame and send it to the muxer
337 * return 1 when encoding is finished, 0 otherwise
338 */
write_audio_frame(AVFormatContext * oc,OutputStream * ost)339 static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
340 {
341 AVCodecContext *c;
342 AVFrame *frame;
343 int ret;
344 int dst_nb_samples;
345
346 c = ost->enc;
347
348 frame = get_audio_frame(ost);
349
350 if (frame) {
351 /* convert samples from native format to destination codec format, using the resampler */
352 /* compute destination number of samples */
353 dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
354 c->sample_rate, c->sample_rate, AV_ROUND_UP);
355 av_assert0(dst_nb_samples == frame->nb_samples);
356
357 /* when we pass a frame to the encoder, it may keep a reference to it
358 * internally;
359 * make sure we do not overwrite it here
360 */
361 ret = av_frame_make_writable(ost->frame);
362 if (ret < 0)
363 exit(1);
364
365 /* convert to destination format */
366 ret = swr_convert(ost->swr_ctx,
367 ost->frame->data, dst_nb_samples,
368 (const uint8_t **)frame->data, frame->nb_samples);
369 if (ret < 0) {
370 fprintf(stderr, "Error while converting\n");
371 exit(1);
372 }
373 frame = ost->frame;
374
375 frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
376 ost->samples_count += dst_nb_samples;
377 }
378
379 return write_frame(oc, c, ost->st, frame);
380 }
381
382 /**************************************************************/
383 /* video output */
384
alloc_picture(enum AVPixelFormat pix_fmt,int width,int height)385 static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
386 {
387 AVFrame *picture;
388 int ret;
389
390 picture = av_frame_alloc();
391 if (!picture)
392 return NULL;
393
394 picture->format = pix_fmt;
395 picture->width = width;
396 picture->height = height;
397
398 /* allocate the buffers for the frame data */
399 ret = av_frame_get_buffer(picture, 0);
400 if (ret < 0) {
401 fprintf(stderr, "Could not allocate frame data.\n");
402 exit(1);
403 }
404
405 return picture;
406 }
407
open_video(AVFormatContext * oc,AVCodec * codec,OutputStream * ost,AVDictionary * opt_arg)408 static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
409 {
410 int ret;
411 AVCodecContext *c = ost->enc;
412 AVDictionary *opt = NULL;
413
414 av_dict_copy(&opt, opt_arg, 0);
415
416 /* open the codec */
417 ret = avcodec_open2(c, codec, &opt);
418 av_dict_free(&opt);
419 if (ret < 0) {
420 fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
421 exit(1);
422 }
423
424 /* allocate and init a re-usable frame */
425 ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
426 if (!ost->frame) {
427 fprintf(stderr, "Could not allocate video frame\n");
428 exit(1);
429 }
430
431 /* If the output format is not YUV420P, then a temporary YUV420P
432 * picture is needed too. It is then converted to the required
433 * output format. */
434 ost->tmp_frame = NULL;
435 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
436 ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
437 if (!ost->tmp_frame) {
438 fprintf(stderr, "Could not allocate temporary picture\n");
439 exit(1);
440 }
441 }
442
443 /* copy the stream parameters to the muxer */
444 ret = avcodec_parameters_from_context(ost->st->codecpar, c);
445 if (ret < 0) {
446 fprintf(stderr, "Could not copy the stream parameters\n");
447 exit(1);
448 }
449 }
450
451 /* Prepare a dummy image. */
fill_yuv_image(AVFrame * pict,int frame_index,int width,int height)452 static void fill_yuv_image(AVFrame *pict, int frame_index,
453 int width, int height)
454 {
455 int x, y, i;
456
457 i = frame_index;
458
459 /* Y */
460 for (y = 0; y < height; y++)
461 for (x = 0; x < width; x++)
462 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
463
464 /* Cb and Cr */
465 for (y = 0; y < height / 2; y++) {
466 for (x = 0; x < width / 2; x++) {
467 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
468 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
469 }
470 }
471 }
472
get_video_frame(OutputStream * ost)473 static AVFrame *get_video_frame(OutputStream *ost)
474 {
475 AVCodecContext *c = ost->enc;
476
477 /* check if we want to generate more frames */
478 if (av_compare_ts(ost->next_pts, c->time_base,
479 STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
480 return NULL;
481
482 /* when we pass a frame to the encoder, it may keep a reference to it
483 * internally; make sure we do not overwrite it here */
484 if (av_frame_make_writable(ost->frame) < 0)
485 exit(1);
486
487 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
488 /* as we only generate a YUV420P picture, we must convert it
489 * to the codec pixel format if needed */
490 if (!ost->sws_ctx) {
491 ost->sws_ctx = sws_getContext(c->width, c->height,
492 AV_PIX_FMT_YUV420P,
493 c->width, c->height,
494 c->pix_fmt,
495 SCALE_FLAGS, NULL, NULL, NULL);
496 if (!ost->sws_ctx) {
497 fprintf(stderr,
498 "Could not initialize the conversion context\n");
499 exit(1);
500 }
501 }
502 fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
503 sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
504 ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
505 ost->frame->linesize);
506 } else {
507 fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
508 }
509
510 ost->frame->pts = ost->next_pts++;
511
512 return ost->frame;
513 }
514
515 /*
516 * encode one video frame and send it to the muxer
517 * return 1 when encoding is finished, 0 otherwise
518 */
write_video_frame(AVFormatContext * oc,OutputStream * ost)519 static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
520 {
521 return write_frame(oc, ost->enc, ost->st, get_video_frame(ost));
522 }
523
close_stream(AVFormatContext * oc,OutputStream * ost)524 static void close_stream(AVFormatContext *oc, OutputStream *ost)
525 {
526 avcodec_free_context(&ost->enc);
527 av_frame_free(&ost->frame);
528 av_frame_free(&ost->tmp_frame);
529 sws_freeContext(ost->sws_ctx);
530 swr_free(&ost->swr_ctx);
531 }
532
533 /**************************************************************/
534 /* media file output */
535
main(int argc,char ** argv)536 int main(int argc, char **argv)
537 {
538 OutputStream video_st = { 0 }, audio_st = { 0 };
539 const char *filename;
540 AVOutputFormat *fmt;
541 AVFormatContext *oc;
542 AVCodec *audio_codec, *video_codec;
543 int ret;
544 int have_video = 0, have_audio = 0;
545 int encode_video = 0, encode_audio = 0;
546 AVDictionary *opt = NULL;
547 int i;
548
549 if (argc < 2) {
550 printf("usage: %s output_file\n"
551 "API example program to output a media file with libavformat.\n"
552 "This program generates a synthetic audio and video stream, encodes and\n"
553 "muxes them into a file named output_file.\n"
554 "The output format is automatically guessed according to the file extension.\n"
555 "Raw images can also be output by using '%%d' in the filename.\n"
556 "\n", argv[0]);
557 return 1;
558 }
559
560 filename = argv[1];
561 for (i = 2; i+1 < argc; i+=2) {
562 if (!strcmp(argv[i], "-flags") || !strcmp(argv[i], "-fflags"))
563 av_dict_set(&opt, argv[i]+1, argv[i+1], 0);
564 }
565
566 /* allocate the output media context */
567 avformat_alloc_output_context2(&oc, NULL, NULL, filename);
568 if (!oc) {
569 printf("Could not deduce output format from file extension: using MPEG.\n");
570 avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
571 }
572 if (!oc)
573 return 1;
574
575 fmt = oc->oformat;
576
577 /* Add the audio and video streams using the default format codecs
578 * and initialize the codecs. */
579 if (fmt->video_codec != AV_CODEC_ID_NONE) {
580 add_stream(&video_st, oc, &video_codec, fmt->video_codec);
581 have_video = 1;
582 encode_video = 1;
583 }
584 if (fmt->audio_codec != AV_CODEC_ID_NONE) {
585 add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
586 have_audio = 1;
587 encode_audio = 1;
588 }
589
590 /* Now that all the parameters are set, we can open the audio and
591 * video codecs and allocate the necessary encode buffers. */
592 if (have_video)
593 open_video(oc, video_codec, &video_st, opt);
594
595 if (have_audio)
596 open_audio(oc, audio_codec, &audio_st, opt);
597
598 av_dump_format(oc, 0, filename, 1);
599
600 /* open the output file, if needed */
601 if (!(fmt->flags & AVFMT_NOFILE)) {
602 ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
603 if (ret < 0) {
604 fprintf(stderr, "Could not open '%s': %s\n", filename,
605 av_err2str(ret));
606 return 1;
607 }
608 }
609
610 /* Write the stream header, if any. */
611 ret = avformat_write_header(oc, &opt);
612 if (ret < 0) {
613 fprintf(stderr, "Error occurred when opening output file: %s\n",
614 av_err2str(ret));
615 return 1;
616 }
617
618 while (encode_video || encode_audio) {
619 /* select the stream to encode */
620 if (encode_video &&
621 (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
622 audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
623 encode_video = !write_video_frame(oc, &video_st);
624 } else {
625 encode_audio = !write_audio_frame(oc, &audio_st);
626 }
627 }
628
629 /* Write the trailer, if any. The trailer must be written before you
630 * close the CodecContexts open when you wrote the header; otherwise
631 * av_write_trailer() may try to use memory that was freed on
632 * av_codec_close(). */
633 av_write_trailer(oc);
634
635 /* Close each codec. */
636 if (have_video)
637 close_stream(oc, &video_st);
638 if (have_audio)
639 close_stream(oc, &audio_st);
640
641 if (!(fmt->flags & AVFMT_NOFILE))
642 /* Close the output file. */
643 avio_closep(&oc->pb);
644
645 /* free the stream */
646 avformat_free_context(oc);
647
648 return 0;
649 }
650