FFmpeg 4.2.2
muxing.c
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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>
39#include <libavutil/opt.h>
41#include <libavutil/timestamp.h>
43#include <libswscale/swscale.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
53typedef struct OutputStream {
56
57 /* pts of the next frame that will be generated */
58 int64_t next_pts;
60
63
64 float t, tincr, tincr2;
65
66 struct SwsContext *sws_ctx;
69
70static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
71{
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),
79}
80
81static int write_frame(AVFormatContext *fmt_ctx, const AVRational *time_base, AVStream *st, AVPacket *pkt)
82{
83 /* rescale output packet timestamp values from codec to stream timebase */
84 av_packet_rescale_ts(pkt, *time_base, st->time_base);
85 pkt->stream_index = st->index;
86
87 /* Write the compressed frame to the media file. */
90}
91
92/* Add an output stream. */
94 AVCodec **codec,
95 enum AVCodecID codec_id)
96{
98 int i;
99
100 /* find the encoder */
101 *codec = avcodec_find_encoder(codec_id);
102 if (!(*codec)) {
103 fprintf(stderr, "Could not find encoder for '%s'\n",
104 avcodec_get_name(codec_id));
105 exit(1);
106 }
107
108 ost->st = avformat_new_stream(oc, NULL);
109 if (!ost->st) {
110 fprintf(stderr, "Could not allocate stream\n");
111 exit(1);
112 }
113 ost->st->id = oc->nb_streams-1;
114 c = avcodec_alloc_context3(*codec);
115 if (!c) {
116 fprintf(stderr, "Could not alloc an encoding context\n");
117 exit(1);
118 }
119 ost->enc = c;
120
121 switch ((*codec)->type) {
123 c->sample_fmt = (*codec)->sample_fmts ?
124 (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
125 c->bit_rate = 64000;
126 c->sample_rate = 44100;
127 if ((*codec)->supported_samplerates) {
128 c->sample_rate = (*codec)->supported_samplerates[0];
129 for (i = 0; (*codec)->supported_samplerates[i]; i++) {
130 if ((*codec)->supported_samplerates[i] == 44100)
131 c->sample_rate = 44100;
132 }
133 }
136 if ((*codec)->channel_layouts) {
137 c->channel_layout = (*codec)->channel_layouts[0];
138 for (i = 0; (*codec)->channel_layouts[i]; i++) {
139 if ((*codec)->channel_layouts[i] == AV_CH_LAYOUT_STEREO)
141 }
142 }
144 ost->st->time_base = (AVRational){ 1, c->sample_rate };
145 break;
146
148 c->codec_id = codec_id;
149
150 c->bit_rate = 400000;
151 /* Resolution must be a multiple of two. */
152 c->width = 352;
153 c->height = 288;
154 /* timebase: This is the fundamental unit of time (in seconds) in terms
155 * of which frame timestamps are represented. For fixed-fps content,
156 * timebase should be 1/framerate and timestamp increments should be
157 * identical to 1. */
159 c->time_base = ost->st->time_base;
160
161 c->gop_size = 12; /* emit one intra frame every twelve frames at most */
164 /* just for testing, we also add B-frames */
165 c->max_b_frames = 2;
166 }
168 /* Needed to avoid using macroblocks in which some coeffs overflow.
169 * This does not happen with normal video, it just happens here as
170 * the motion of the chroma plane does not match the luma plane. */
171 c->mb_decision = 2;
172 }
173 break;
174
175 default:
176 break;
177 }
178
179 /* Some formats want stream headers to be separate. */
182}
183
184/**************************************************************/
185/* audio output */
186
188 uint64_t channel_layout,
189 int sample_rate, int nb_samples)
190{
192 int ret;
193
194 if (!frame) {
195 fprintf(stderr, "Error allocating an audio frame\n");
196 exit(1);
197 }
198
199 frame->format = sample_fmt;
200 frame->channel_layout = channel_layout;
201 frame->sample_rate = sample_rate;
202 frame->nb_samples = nb_samples;
203
204 if (nb_samples) {
205 ret = av_frame_get_buffer(frame, 0);
206 if (ret < 0) {
207 fprintf(stderr, "Error allocating an audio buffer\n");
208 exit(1);
209 }
210 }
211
212 return frame;
213}
214
215static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
216{
218 int nb_samples;
219 int ret;
220 AVDictionary *opt = NULL;
221
222 c = ost->enc;
223
224 /* open it */
225 av_dict_copy(&opt, opt_arg, 0);
226 ret = avcodec_open2(c, codec, &opt);
227 av_dict_free(&opt);
228 if (ret < 0) {
229 fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
230 exit(1);
231 }
232
233 /* init signal generator */
234 ost->t = 0;
235 ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
236 /* increment frequency by 110 Hz per second */
237 ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
238
240 nb_samples = 10000;
241 else
242 nb_samples = c->frame_size;
243
245 c->sample_rate, nb_samples);
247 c->sample_rate, nb_samples);
248
249 /* copy the stream parameters to the muxer */
251 if (ret < 0) {
252 fprintf(stderr, "Could not copy the stream parameters\n");
253 exit(1);
254 }
255
256 /* create resampler context */
257 ost->swr_ctx = swr_alloc();
258 if (!ost->swr_ctx) {
259 fprintf(stderr, "Could not allocate resampler context\n");
260 exit(1);
261 }
262
263 /* set options */
264 av_opt_set_int (ost->swr_ctx, "in_channel_count", c->channels, 0);
265 av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
266 av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
267 av_opt_set_int (ost->swr_ctx, "out_channel_count", c->channels, 0);
268 av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
269 av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
270
271 /* initialize the resampling context */
272 if ((ret = swr_init(ost->swr_ctx)) < 0) {
273 fprintf(stderr, "Failed to initialize the resampling context\n");
274 exit(1);
275 }
276}
277
278/* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
279 * 'nb_channels' channels. */
281{
282 AVFrame *frame = ost->tmp_frame;
283 int j, i, v;
284 int16_t *q = (int16_t*)frame->data[0];
285
286 /* check if we want to generate more frames */
287 if (av_compare_ts(ost->next_pts, ost->enc->time_base,
288 STREAM_DURATION, (AVRational){ 1, 1 }) >= 0)
289 return NULL;
290
291 for (j = 0; j <frame->nb_samples; j++) {
292 v = (int)(sin(ost->t) * 10000);
293 for (i = 0; i < ost->enc->channels; i++)
294 *q++ = v;
295 ost->t += ost->tincr;
296 ost->tincr += ost->tincr2;
297 }
298
299 frame->pts = ost->next_pts;
300 ost->next_pts += frame->nb_samples;
301
302 return frame;
303}
304
305/*
306 * encode one audio frame and send it to the muxer
307 * return 1 when encoding is finished, 0 otherwise
308 */
310{
312 AVPacket pkt = { 0 }; // data and size must be 0;
313 AVFrame *frame;
314 int ret;
315 int got_packet;
316 int dst_nb_samples;
317
319 c = ost->enc;
320
322
323 if (frame) {
324 /* convert samples from native format to destination codec format, using the resampler */
325 /* compute destination number of samples */
326 dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
328 av_assert0(dst_nb_samples == frame->nb_samples);
329
330 /* when we pass a frame to the encoder, it may keep a reference to it
331 * internally;
332 * make sure we do not overwrite it here
333 */
334 ret = av_frame_make_writable(ost->frame);
335 if (ret < 0)
336 exit(1);
337
338 /* convert to destination format */
339 ret = swr_convert(ost->swr_ctx,
340 ost->frame->data, dst_nb_samples,
341 (const uint8_t **)frame->data, frame->nb_samples);
342 if (ret < 0) {
343 fprintf(stderr, "Error while converting\n");
344 exit(1);
345 }
346 frame = ost->frame;
347
348 frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
349 ost->samples_count += dst_nb_samples;
350 }
351
352 ret = avcodec_encode_audio2(c, &pkt, frame, &got_packet);
353 if (ret < 0) {
354 fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret));
355 exit(1);
356 }
357
358 if (got_packet) {
359 ret = write_frame(oc, &c->time_base, ost->st, &pkt);
360 if (ret < 0) {
361 fprintf(stderr, "Error while writing audio frame: %s\n",
362 av_err2str(ret));
363 exit(1);
364 }
365 }
366
367 return (frame || got_packet) ? 0 : 1;
368}
369
370/**************************************************************/
371/* video output */
372
374{
375 AVFrame *picture;
376 int ret;
377
378 picture = av_frame_alloc();
379 if (!picture)
380 return NULL;
381
382 picture->format = pix_fmt;
383 picture->width = width;
384 picture->height = height;
385
386 /* allocate the buffers for the frame data */
387 ret = av_frame_get_buffer(picture, 32);
388 if (ret < 0) {
389 fprintf(stderr, "Could not allocate frame data.\n");
390 exit(1);
391 }
392
393 return picture;
394}
395
396static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
397{
398 int ret;
399 AVCodecContext *c = ost->enc;
400 AVDictionary *opt = NULL;
401
402 av_dict_copy(&opt, opt_arg, 0);
403
404 /* open the codec */
405 ret = avcodec_open2(c, codec, &opt);
406 av_dict_free(&opt);
407 if (ret < 0) {
408 fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
409 exit(1);
410 }
411
412 /* allocate and init a re-usable frame */
413 ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
414 if (!ost->frame) {
415 fprintf(stderr, "Could not allocate video frame\n");
416 exit(1);
417 }
418
419 /* If the output format is not YUV420P, then a temporary YUV420P
420 * picture is needed too. It is then converted to the required
421 * output format. */
422 ost->tmp_frame = NULL;
423 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
424 ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
425 if (!ost->tmp_frame) {
426 fprintf(stderr, "Could not allocate temporary picture\n");
427 exit(1);
428 }
429 }
430
431 /* copy the stream parameters to the muxer */
433 if (ret < 0) {
434 fprintf(stderr, "Could not copy the stream parameters\n");
435 exit(1);
436 }
437}
438
439/* Prepare a dummy image. */
440static void fill_yuv_image(AVFrame *pict, int frame_index,
441 int width, int height)
442{
443 int x, y, i;
444
445 i = frame_index;
446
447 /* Y */
448 for (y = 0; y < height; y++)
449 for (x = 0; x < width; x++)
450 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
451
452 /* Cb and Cr */
453 for (y = 0; y < height / 2; y++) {
454 for (x = 0; x < width / 2; x++) {
455 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
456 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
457 }
458 }
459}
460
462{
463 AVCodecContext *c = ost->enc;
464
465 /* check if we want to generate more frames */
466 if (av_compare_ts(ost->next_pts, c->time_base,
467 STREAM_DURATION, (AVRational){ 1, 1 }) >= 0)
468 return NULL;
469
470 /* when we pass a frame to the encoder, it may keep a reference to it
471 * internally; make sure we do not overwrite it here */
472 if (av_frame_make_writable(ost->frame) < 0)
473 exit(1);
474
475 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
476 /* as we only generate a YUV420P picture, we must convert it
477 * to the codec pixel format if needed */
478 if (!ost->sws_ctx) {
479 ost->sws_ctx = sws_getContext(c->width, c->height,
481 c->width, c->height,
482 c->pix_fmt,
483 SCALE_FLAGS, NULL, NULL, NULL);
484 if (!ost->sws_ctx) {
485 fprintf(stderr,
486 "Could not initialize the conversion context\n");
487 exit(1);
488 }
489 }
490 fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
491 sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
492 ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
493 ost->frame->linesize);
494 } else {
495 fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
496 }
497
498 ost->frame->pts = ost->next_pts++;
499
500 return ost->frame;
501}
502
503/*
504 * encode one video frame and send it to the muxer
505 * return 1 when encoding is finished, 0 otherwise
506 */
508{
509 int ret;
511 AVFrame *frame;
512 int got_packet = 0;
513 AVPacket pkt = { 0 };
514
515 c = ost->enc;
516
518
520
521 /* encode the image */
522 ret = avcodec_encode_video2(c, &pkt, frame, &got_packet);
523 if (ret < 0) {
524 fprintf(stderr, "Error encoding video frame: %s\n", av_err2str(ret));
525 exit(1);
526 }
527
528 if (got_packet) {
529 ret = write_frame(oc, &c->time_base, ost->st, &pkt);
530 } else {
531 ret = 0;
532 }
533
534 if (ret < 0) {
535 fprintf(stderr, "Error while writing video frame: %s\n", av_err2str(ret));
536 exit(1);
537 }
538
539 return (frame || got_packet) ? 0 : 1;
540}
541
543{
545 av_frame_free(&ost->frame);
546 av_frame_free(&ost->tmp_frame);
547 sws_freeContext(ost->sws_ctx);
548 swr_free(&ost->swr_ctx);
549}
550
551/**************************************************************/
552/* media file output */
553
554int main(int argc, char **argv)
555{
556 OutputStream video_st = { 0 }, audio_st = { 0 };
557 const char *filename;
558 AVOutputFormat *fmt;
559 AVFormatContext *oc;
560 AVCodec *audio_codec, *video_codec;
561 int ret;
562 int have_video = 0, have_audio = 0;
563 int encode_video = 0, encode_audio = 0;
564 AVDictionary *opt = NULL;
565 int i;
566
567 if (argc < 2) {
568 printf("usage: %s output_file\n"
569 "API example program to output a media file with libavformat.\n"
570 "This program generates a synthetic audio and video stream, encodes and\n"
571 "muxes them into a file named output_file.\n"
572 "The output format is automatically guessed according to the file extension.\n"
573 "Raw images can also be output by using '%%d' in the filename.\n"
574 "\n", argv[0]);
575 return 1;
576 }
577
578 filename = argv[1];
579 for (i = 2; i+1 < argc; i+=2) {
580 if (!strcmp(argv[i], "-flags") || !strcmp(argv[i], "-fflags"))
581 av_dict_set(&opt, argv[i]+1, argv[i+1], 0);
582 }
583
584 /* allocate the output media context */
585 avformat_alloc_output_context2(&oc, NULL, NULL, filename);
586 if (!oc) {
587 printf("Could not deduce output format from file extension: using MPEG.\n");
588 avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
589 }
590 if (!oc)
591 return 1;
592
593 fmt = oc->oformat;
594
595 /* Add the audio and video streams using the default format codecs
596 * and initialize the codecs. */
597 if (fmt->video_codec != AV_CODEC_ID_NONE) {
598 add_stream(&video_st, oc, &video_codec, fmt->video_codec);
599 have_video = 1;
600 encode_video = 1;
601 }
602 if (fmt->audio_codec != AV_CODEC_ID_NONE) {
603 add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
604 have_audio = 1;
605 encode_audio = 1;
606 }
607
608 /* Now that all the parameters are set, we can open the audio and
609 * video codecs and allocate the necessary encode buffers. */
610 if (have_video)
611 open_video(oc, video_codec, &video_st, opt);
612
613 if (have_audio)
614 open_audio(oc, audio_codec, &audio_st, opt);
615
616 av_dump_format(oc, 0, filename, 1);
617
618 /* open the output file, if needed */
619 if (!(fmt->flags & AVFMT_NOFILE)) {
620 ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
621 if (ret < 0) {
622 fprintf(stderr, "Could not open '%s': %s\n", filename,
623 av_err2str(ret));
624 return 1;
625 }
626 }
627
628 /* Write the stream header, if any. */
629 ret = avformat_write_header(oc, &opt);
630 if (ret < 0) {
631 fprintf(stderr, "Error occurred when opening output file: %s\n",
632 av_err2str(ret));
633 return 1;
634 }
635
636 while (encode_video || encode_audio) {
637 /* select the stream to encode */
638 if (encode_video &&
639 (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
640 audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
641 encode_video = !write_video_frame(oc, &video_st);
642 } else {
643 encode_audio = !write_audio_frame(oc, &audio_st);
644 }
645 }
646
647 /* Write the trailer, if any. The trailer must be written before you
648 * close the CodecContexts open when you wrote the header; otherwise
649 * av_write_trailer() may try to use memory that was freed on
650 * av_codec_close(). */
652
653 /* Close each codec. */
654 if (have_video)
655 close_stream(oc, &video_st);
656 if (have_audio)
657 close_stream(oc, &audio_st);
658
659 if (!(fmt->flags & AVFMT_NOFILE))
660 /* Close the output file. */
661 avio_closep(&oc->pb);
662
663 /* free the stream */
665
666 return 0;
667}
simple assert() macros that are a bit more flexible than ISO C assert().
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
Main libavformat public API header.
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:463
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:466
int avio_open(AVIOContext **s, const char *url, int flags)
Create and initialize a AVIOContext for accessing the resource indicated by url.
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:655
int avio_closep(AVIOContext **s)
Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL...
audio channel layout utility functions
static int width
static AVPacket pkt
static AVFormatContext * fmt_ctx
static enum AVPixelFormat pix_fmt
static int height
static AVFrame * frame
#define AV_CH_LAYOUT_STEREO
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
int avcodec_parameters_from_context(AVCodecParameters *par, const AVCodecContext *codec)
Fill the parameters struct based on the values from the supplied codec context.
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
#define AV_CODEC_CAP_VARIABLE_FRAME_SIZE
Audio encoder supports receiving a different number of samples in each call.
Definition: avcodec.h:1053
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
#define AV_CODEC_FLAG_GLOBAL_HEADER
Place global headers in extradata instead of every keyframe.
Definition: avcodec.h:904
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:215
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer.
@ AV_CODEC_ID_NONE
Definition: avcodec.h:216
@ AV_CODEC_ID_MPEG1VIDEO
Definition: avcodec.h:219
@ AV_CODEC_ID_MPEG2VIDEO
preferred ID for MPEG-1/2 video decoding
Definition: avcodec.h:220
attribute_deprecated int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Encode a frame of video.
AVCodec * avcodec_find_encoder(enum AVCodecID id)
Find a registered encoder with a matching codec ID.
attribute_deprecated int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Encode a frame of audio.
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst)
Convert valid timing fields (timestamps / durations) in a packet from one timebase to another.
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
av_warn_unused_result int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Print detailed information about the input or output format, such as duration, bitrate,...
void av_dict_free(AVDictionary **m)
Free all the memory allocated for an AVDictionary struct and all keys and values.
struct AVDictionary AVDictionary
Definition: dict.h:86
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
int av_frame_get_buffer(AVFrame *frame, int align)
Allocate new buffer(s) for audio or video data.
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
int av_frame_make_writable(AVFrame *frame)
Ensure that the frame data is writable, avoiding data copy if possible.
int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b)
Compare two timestamps each in its own time base.
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd) av_const
Rescale a 64-bit integer with specified rounding.
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const
Rescale a 64-bit integer by 2 rational numbers.
@ AV_ROUND_UP
Round toward +infinity.
Definition: mathematics.h:83
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
@ AV_SAMPLE_FMT_FLTP
float, planar
Definition: samplefmt.h:69
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:61
struct SwsContext * sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter *srcFilter, SwsFilter *dstFilter, const double *param)
Allocate and return an SwsContext.
void sws_freeContext(struct SwsContext *swsContext)
Free the swscaler context swsContext.
int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[], const int srcStride[], int srcSliceY, int srcSliceH, uint8_t *const dst[], const int dstStride[])
Scale the image slice in srcSlice and put the resulting scaled slice in the image in dst.
struct SwrContext * swr_alloc(void)
Allocate SwrContext.
struct SwrContext SwrContext
The libswresample context.
Definition: swresample.h:182
int64_t swr_get_delay(struct SwrContext *s, int64_t base)
Gets the delay the next input sample will experience relative to the next output sample.
void swr_free(struct SwrContext **s)
Free the given SwrContext and set the pointer to NULL.
int swr_convert(struct SwrContext *s, uint8_t **out, int out_count, const uint8_t **in, int in_count)
Convert audio.
int swr_init(struct SwrContext *s)
Initialize context after user parameters have been set.
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags)
#define M_PI
Definition: mathematics.h:52
static AVFrame * alloc_audio_frame(enum AVSampleFormat sample_fmt, uint64_t channel_layout, int sample_rate, int nb_samples)
Definition: muxing.c:187
static AVFrame * get_video_frame(OutputStream *ost)
Definition: muxing.c:461
static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:396
int main(int argc, char **argv)
Definition: muxing.c:554
static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:507
static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:309
static AVFrame * alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
Definition: muxing.c:373
static void close_stream(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:542
static AVFrame * get_audio_frame(OutputStream *ost)
Definition: muxing.c:280
#define SCALE_FLAGS
Definition: muxing.c:50
static int write_frame(AVFormatContext *fmt_ctx, const AVRational *time_base, AVStream *st, AVPacket *pkt)
Definition: muxing.c:81
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
Definition: muxing.c:70
static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
Definition: muxing.c:440
#define STREAM_DURATION
Definition: muxing.c:46
#define STREAM_FRAME_RATE
Definition: muxing.c:47
#define STREAM_PIX_FMT
Definition: muxing.c:48
static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:215
static void add_stream(OutputStream *ost, AVFormatContext *oc, AVCodec **codec, enum AVCodecID codec_id)
Definition: muxing.c:93
AVOptions.
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
main external API structure.
Definition: avcodec.h:1565
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1775
int width
picture width / height.
Definition: avcodec.h:1738
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2233
int max_b_frames
maximum number of B-frames between non-B-frames Note: The output will be delayed by max_b_frames+1 re...
Definition: avcodec.h:1825
int mb_decision
macroblock decision mode
Definition: avcodec.h:2053
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1615
const struct AVCodec * codec
Definition: avcodec.h:1574
int sample_rate
samples per second
Definition: avcodec.h:2225
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:1760
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:1688
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1645
int channels
number of audio channels
Definition: avcodec.h:2226
enum AVCodecID codec_id
Definition: avcodec.h:1575
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2276
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:2245
AVCodec.
Definition: avcodec.h:3481
int capabilities
Codec capabilities.
Definition: avcodec.h:3500
Format I/O context.
Definition: avformat.h:1342
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1398
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
ff_const59 struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1361
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1410
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:361
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:388
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
int width
Definition: frame.h:353
int height
Definition: frame.h:353
uint64_t channel_layout
Channel layout of the audio data.
Definition: frame.h:472
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
int sample_rate
Sample rate of the audio data.
Definition: frame.h:467
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:368
enum AVCodecID video_codec
default video codec
Definition: avformat.h:507
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:506
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:515
This structure stores compressed data.
Definition: avcodec.h:1454
int stream_index
Definition: avcodec.h:1479
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: avcodec.h:1476
Rational number (pair of numerator and denominator).
Definition: rational.h:58
Stream structure.
Definition: avformat.h:870
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1017
int id
Format-specific stream ID.
Definition: avformat.h:877
int index
stream index in AVFormatContext
Definition: avformat.h:871
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:899
float tincr2
Definition: muxing.c:64
AVFrame * frame
Definition: muxing.c:61
int samples_count
Definition: muxing.c:59
struct SwrContext * swr_ctx
Definition: muxing.c:67
AVFrame * tmp_frame
Definition: muxing.c:62
struct SwsContext * sws_ctx
Definition: muxing.c:66
int64_t next_pts
Definition: muxing.c:58
float t
Definition: muxing.c:64
AVStream * st
Definition: muxing.c:54
AVCodecContext * enc
Definition: muxing.c:55
float tincr
Definition: muxing.c:64
libswresample public header
external API header
timestamp utils, mostly useful for debugging/logging purposes
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:76
static AVStream * ost