FFmpeg 6.1.1
mux.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 libavformat muxing API usage example
25 * @example mux.c
26 *
27 * Generate a synthetic audio and video signal and mux them to a media file in
28 * any supported libavformat format. The default codecs are used.
29 */
30
31#include <stdlib.h>
32#include <stdio.h>
33#include <string.h>
34#include <math.h>
35
36#include <libavutil/avassert.h>
38#include <libavutil/opt.h>
40#include <libavutil/timestamp.h>
41#include <libavcodec/avcodec.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
65
66 float t, tincr, tincr2;
67
68 struct SwsContext *sws_ctx;
71
72static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
73{
75
76 printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
77 av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
78 av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
81}
82
85{
86 int ret;
87
88 // send the frame to the encoder
89 ret = avcodec_send_frame(c, frame);
90 if (ret < 0) {
91 fprintf(stderr, "Error sending a frame to the encoder: %s\n",
92 av_err2str(ret));
93 exit(1);
94 }
95
96 while (ret >= 0) {
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 */
107 pkt->stream_index = st->index;
108
109 /* Write the compressed frame to the media file. */
112 /* pkt is now blank (av_interleaved_write_frame() takes ownership of
113 * its contents and resets pkt), so that no unreferencing is necessary.
114 * This would be different if one used av_write_frame(). */
115 if (ret < 0) {
116 fprintf(stderr, "Error while writing output packet: %s\n", av_err2str(ret));
117 exit(1);
118 }
119 }
120
121 return ret == AVERROR_EOF ? 1 : 0;
122}
123
124/* Add an output stream. */
126 const AVCodec **codec,
127 enum AVCodecID codec_id)
128{
130 int i;
131
132 /* find the encoder */
133 *codec = avcodec_find_encoder(codec_id);
134 if (!(*codec)) {
135 fprintf(stderr, "Could not find encoder for '%s'\n",
136 avcodec_get_name(codec_id));
137 exit(1);
138 }
139
140 ost->tmp_pkt = av_packet_alloc();
141 if (!ost->tmp_pkt) {
142 fprintf(stderr, "Could not allocate AVPacket\n");
143 exit(1);
144 }
145
146 ost->st = avformat_new_stream(oc, NULL);
147 if (!ost->st) {
148 fprintf(stderr, "Could not allocate stream\n");
149 exit(1);
150 }
151 ost->st->id = oc->nb_streams-1;
152 c = avcodec_alloc_context3(*codec);
153 if (!c) {
154 fprintf(stderr, "Could not alloc an encoding context\n");
155 exit(1);
156 }
157 ost->enc = c;
158
159 switch ((*codec)->type) {
161 c->sample_fmt = (*codec)->sample_fmts ?
162 (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
163 c->bit_rate = 64000;
164 c->sample_rate = 44100;
165 if ((*codec)->supported_samplerates) {
166 c->sample_rate = (*codec)->supported_samplerates[0];
167 for (i = 0; (*codec)->supported_samplerates[i]; i++) {
168 if ((*codec)->supported_samplerates[i] == 44100)
169 c->sample_rate = 44100;
170 }
171 }
173 ost->st->time_base = (AVRational){ 1, c->sample_rate };
174 break;
175
177 c->codec_id = codec_id;
178
179 c->bit_rate = 400000;
180 /* Resolution must be a multiple of two. */
181 c->width = 352;
182 c->height = 288;
183 /* timebase: This is the fundamental unit of time (in seconds) in terms
184 * of which frame timestamps are represented. For fixed-fps content,
185 * timebase should be 1/framerate and timestamp increments should be
186 * identical to 1. */
188 c->time_base = ost->st->time_base;
189
190 c->gop_size = 12; /* emit one intra frame every twelve frames at most */
193 /* just for testing, we also add B-frames */
194 c->max_b_frames = 2;
195 }
197 /* Needed to avoid using macroblocks in which some coeffs overflow.
198 * This does not happen with normal video, it just happens here as
199 * the motion of the chroma plane does not match the luma plane. */
200 c->mb_decision = 2;
201 }
202 break;
203
204 default:
205 break;
206 }
207
208 /* Some formats want stream headers to be separate. */
211}
212
213/**************************************************************/
214/* audio output */
215
217 const AVChannelLayout *channel_layout,
218 int sample_rate, int nb_samples)
219{
221 if (!frame) {
222 fprintf(stderr, "Error allocating an audio frame\n");
223 exit(1);
224 }
225
226 frame->format = sample_fmt;
227 av_channel_layout_copy(&frame->ch_layout, channel_layout);
228 frame->sample_rate = sample_rate;
229 frame->nb_samples = nb_samples;
230
231 if (nb_samples) {
232 if (av_frame_get_buffer(frame, 0) < 0) {
233 fprintf(stderr, "Error allocating an audio buffer\n");
234 exit(1);
235 }
236 }
237
238 return frame;
239}
240
241static void open_audio(AVFormatContext *oc, const AVCodec *codec,
242 OutputStream *ost, AVDictionary *opt_arg)
243{
245 int nb_samples;
246 int ret;
247 AVDictionary *opt = NULL;
248
249 c = ost->enc;
250
251 /* open it */
252 av_dict_copy(&opt, opt_arg, 0);
253 ret = avcodec_open2(c, codec, &opt);
254 av_dict_free(&opt);
255 if (ret < 0) {
256 fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
257 exit(1);
258 }
259
260 /* init signal generator */
261 ost->t = 0;
262 ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
263 /* increment frequency by 110 Hz per second */
264 ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
265
267 nb_samples = 10000;
268 else
269 nb_samples = c->frame_size;
270
271 ost->frame = alloc_audio_frame(c->sample_fmt, &c->ch_layout,
272 c->sample_rate, nb_samples);
274 c->sample_rate, nb_samples);
275
276 /* copy the stream parameters to the muxer */
278 if (ret < 0) {
279 fprintf(stderr, "Could not copy the stream parameters\n");
280 exit(1);
281 }
282
283 /* create resampler context */
284 ost->swr_ctx = swr_alloc();
285 if (!ost->swr_ctx) {
286 fprintf(stderr, "Could not allocate resampler context\n");
287 exit(1);
288 }
289
290 /* set options */
291 av_opt_set_chlayout (ost->swr_ctx, "in_chlayout", &c->ch_layout, 0);
292 av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
293 av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
294 av_opt_set_chlayout (ost->swr_ctx, "out_chlayout", &c->ch_layout, 0);
295 av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
296 av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
297
298 /* initialize the resampling context */
299 if ((ret = swr_init(ost->swr_ctx)) < 0) {
300 fprintf(stderr, "Failed to initialize the resampling context\n");
301 exit(1);
302 }
303}
304
305/* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
306 * 'nb_channels' channels. */
308{
309 AVFrame *frame = ost->tmp_frame;
310 int j, i, v;
311 int16_t *q = (int16_t*)frame->data[0];
312
313 /* check if we want to generate more frames */
314 if (av_compare_ts(ost->next_pts, ost->enc->time_base,
315 STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
316 return NULL;
317
318 for (j = 0; j <frame->nb_samples; j++) {
319 v = (int)(sin(ost->t) * 10000);
320 for (i = 0; i < ost->enc->ch_layout.nb_channels; i++)
321 *q++ = v;
322 ost->t += ost->tincr;
323 ost->tincr += ost->tincr2;
324 }
325
326 frame->pts = ost->next_pts;
327 ost->next_pts += frame->nb_samples;
328
329 return frame;
330}
331
332/*
333 * encode one audio frame and send it to the muxer
334 * return 1 when encoding is finished, 0 otherwise
335 */
337{
339 AVFrame *frame;
340 int ret;
341 int dst_nb_samples;
342
343 c = ost->enc;
344
346
347 if (frame) {
348 /* convert samples from native format to destination codec format, using the resampler */
349 /* compute destination number of samples */
350 dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
352 av_assert0(dst_nb_samples == frame->nb_samples);
353
354 /* when we pass a frame to the encoder, it may keep a reference to it
355 * internally;
356 * make sure we do not overwrite it here
357 */
358 ret = av_frame_make_writable(ost->frame);
359 if (ret < 0)
360 exit(1);
361
362 /* convert to destination format */
363 ret = swr_convert(ost->swr_ctx,
364 ost->frame->data, dst_nb_samples,
365 (const uint8_t **)frame->data, frame->nb_samples);
366 if (ret < 0) {
367 fprintf(stderr, "Error while converting\n");
368 exit(1);
369 }
370 frame = ost->frame;
371
372 frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
373 ost->samples_count += dst_nb_samples;
374 }
375
376 return write_frame(oc, c, ost->st, frame, ost->tmp_pkt);
377}
378
379/**************************************************************/
380/* video output */
381
383{
384 AVFrame *frame;
385 int ret;
386
388 if (!frame)
389 return NULL;
390
392 frame->width = width;
394
395 /* allocate the buffers for the frame data */
396 ret = av_frame_get_buffer(frame, 0);
397 if (ret < 0) {
398 fprintf(stderr, "Could not allocate frame data.\n");
399 exit(1);
400 }
401
402 return frame;
403}
404
405static void open_video(AVFormatContext *oc, const AVCodec *codec,
406 OutputStream *ost, AVDictionary *opt_arg)
407{
408 int ret;
409 AVCodecContext *c = ost->enc;
410 AVDictionary *opt = NULL;
411
412 av_dict_copy(&opt, opt_arg, 0);
413
414 /* open the codec */
415 ret = avcodec_open2(c, codec, &opt);
416 av_dict_free(&opt);
417 if (ret < 0) {
418 fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
419 exit(1);
420 }
421
422 /* allocate and init a re-usable frame */
423 ost->frame = alloc_frame(c->pix_fmt, c->width, c->height);
424 if (!ost->frame) {
425 fprintf(stderr, "Could not allocate video frame\n");
426 exit(1);
427 }
428
429 /* If the output format is not YUV420P, then a temporary YUV420P
430 * picture is needed too. It is then converted to the required
431 * output format. */
432 ost->tmp_frame = NULL;
433 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
434 ost->tmp_frame = alloc_frame(AV_PIX_FMT_YUV420P, c->width, c->height);
435 if (!ost->tmp_frame) {
436 fprintf(stderr, "Could not allocate temporary video frame\n");
437 exit(1);
438 }
439 }
440
441 /* copy the stream parameters to the muxer */
443 if (ret < 0) {
444 fprintf(stderr, "Could not copy the stream parameters\n");
445 exit(1);
446 }
447}
448
449/* Prepare a dummy image. */
450static void fill_yuv_image(AVFrame *pict, int frame_index,
451 int width, int height)
452{
453 int x, y, i;
454
455 i = frame_index;
456
457 /* Y */
458 for (y = 0; y < height; y++)
459 for (x = 0; x < width; x++)
460 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
461
462 /* Cb and Cr */
463 for (y = 0; y < height / 2; y++) {
464 for (x = 0; x < width / 2; x++) {
465 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
466 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
467 }
468 }
469}
470
472{
473 AVCodecContext *c = ost->enc;
474
475 /* check if we want to generate more frames */
476 if (av_compare_ts(ost->next_pts, c->time_base,
477 STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
478 return NULL;
479
480 /* when we pass a frame to the encoder, it may keep a reference to it
481 * internally; make sure we do not overwrite it here */
482 if (av_frame_make_writable(ost->frame) < 0)
483 exit(1);
484
485 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
486 /* as we only generate a YUV420P picture, we must convert it
487 * to the codec pixel format if needed */
488 if (!ost->sws_ctx) {
489 ost->sws_ctx = sws_getContext(c->width, c->height,
491 c->width, c->height,
492 c->pix_fmt,
493 SCALE_FLAGS, NULL, NULL, NULL);
494 if (!ost->sws_ctx) {
495 fprintf(stderr,
496 "Could not initialize the conversion context\n");
497 exit(1);
498 }
499 }
500 fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
501 sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
502 ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
503 ost->frame->linesize);
504 } else {
505 fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
506 }
507
508 ost->frame->pts = ost->next_pts++;
509
510 return ost->frame;
511}
512
513/*
514 * encode one video frame and send it to the muxer
515 * return 1 when encoding is finished, 0 otherwise
516 */
518{
519 return write_frame(oc, ost->enc, ost->st, get_video_frame(ost), ost->tmp_pkt);
520}
521
523{
525 av_frame_free(&ost->frame);
526 av_frame_free(&ost->tmp_frame);
527 av_packet_free(&ost->tmp_pkt);
528 sws_freeContext(ost->sws_ctx);
529 swr_free(&ost->swr_ctx);
530}
531
532/**************************************************************/
533/* media file output */
534
535int main(int argc, char **argv)
536{
537 OutputStream video_st = { 0 }, audio_st = { 0 };
538 const AVOutputFormat *fmt;
539 const char *filename;
540 AVFormatContext *oc;
541 const AVCodec *audio_codec, *video_codec;
542 int ret;
543 int have_video = 0, have_audio = 0;
544 int encode_video = 0, encode_audio = 0;
545 AVDictionary *opt = NULL;
546 int i;
547
548 if (argc < 2) {
549 printf("usage: %s output_file\n"
550 "API example program to output a media file with libavformat.\n"
551 "This program generates a synthetic audio and video stream, encodes and\n"
552 "muxes them into a file named output_file.\n"
553 "The output format is automatically guessed according to the file extension.\n"
554 "Raw images can also be output by using '%%d' in the filename.\n"
555 "\n", argv[0]);
556 return 1;
557 }
558
559 filename = argv[1];
560 for (i = 2; i+1 < argc; i+=2) {
561 if (!strcmp(argv[i], "-flags") || !strcmp(argv[i], "-fflags"))
562 av_dict_set(&opt, argv[i]+1, argv[i+1], 0);
563 }
564
565 /* allocate the output media context */
566 avformat_alloc_output_context2(&oc, NULL, NULL, filename);
567 if (!oc) {
568 printf("Could not deduce output format from file extension: using MPEG.\n");
569 avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
570 }
571 if (!oc)
572 return 1;
573
574 fmt = oc->oformat;
575
576 /* Add the audio and video streams using the default format codecs
577 * and initialize the codecs. */
578 if (fmt->video_codec != AV_CODEC_ID_NONE) {
579 add_stream(&video_st, oc, &video_codec, fmt->video_codec);
580 have_video = 1;
581 encode_video = 1;
582 }
583 if (fmt->audio_codec != AV_CODEC_ID_NONE) {
584 add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
585 have_audio = 1;
586 encode_audio = 1;
587 }
588
589 /* Now that all the parameters are set, we can open the audio and
590 * video codecs and allocate the necessary encode buffers. */
591 if (have_video)
592 open_video(oc, video_codec, &video_st, opt);
593
594 if (have_audio)
595 open_audio(oc, audio_codec, &audio_st, opt);
596
597 av_dump_format(oc, 0, filename, 1);
598
599 /* open the output file, if needed */
600 if (!(fmt->flags & AVFMT_NOFILE)) {
601 ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
602 if (ret < 0) {
603 fprintf(stderr, "Could not open '%s': %s\n", filename,
604 av_err2str(ret));
605 return 1;
606 }
607 }
608
609 /* Write the stream header, if any. */
610 ret = avformat_write_header(oc, &opt);
611 if (ret < 0) {
612 fprintf(stderr, "Error occurred when opening output file: %s\n",
613 av_err2str(ret));
614 return 1;
615 }
616
617 while (encode_video || encode_audio) {
618 /* select the stream to encode */
619 if (encode_video &&
620 (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
621 audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
622 encode_video = !write_video_frame(oc, &video_st);
623 } else {
624 encode_audio = !write_audio_frame(oc, &audio_st);
625 }
626 }
627
629
630 /* Close each codec. */
631 if (have_video)
632 close_stream(oc, &video_st);
633 if (have_audio)
634 close_stream(oc, &audio_st);
635
636 if (!(fmt->flags & AVFMT_NOFILE))
637 /* Close the output file. */
638 avio_closep(&oc->pb);
639
640 /* free the stream */
642
643 return 0;
644}
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:40
Libavcodec external API header.
Main libavformat public API header.
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:469
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:479
int avformat_alloc_output_context2(AVFormatContext **ctx, const AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
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:637
int avio_closep(AVIOContext **s)
Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL...
Public libavutil channel layout APIs header.
static AVFormatContext * fmt_ctx
static int width
Definition: demux_decode.c:40
static AVPacket * pkt
Definition: demux_decode.c:55
static enum AVPixelFormat pix_fmt
Definition: demux_decode.c:41
static int height
Definition: demux_decode.c:40
static AVFrame * frame
Definition: demux_decode.c:54
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: codec.h:128
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
int avcodec_parameters_from_context(struct AVCodecParameters *par, const AVCodecContext *codec)
Fill the parameters struct based on the values from the supplied codec context.
const AVCodec * avcodec_find_encoder(enum AVCodecID id)
Find a registered encoder with a matching codec ID.
#define AV_CODEC_FLAG_GLOBAL_HEADER
Place global headers in extradata instead of every keyframe.
Definition: avcodec.h:334
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
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: codec_id.h:50
@ AV_CODEC_ID_MPEG1VIDEO
Definition: codec_id.h:53
@ AV_CODEC_ID_MPEG2VIDEO
preferred ID for MPEG-1/2 video decoding
Definition: codec_id.h:54
int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
Read encoded data from the encoder.
int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame)
Supply a raw video or audio frame to the encoder.
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to 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 struct 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,...
#define AV_CHANNEL_LAYOUT_STEREO
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
Make a copy of a channel layout.
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:94
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 AVERROR_EOF
End of file.
Definition: error.h:57
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:121
#define AVERROR(e)
Definition: error.h:45
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:134
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
@ AV_SAMPLE_FMT_FLTP
float, planar
Definition: samplefmt.h:66
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:58
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:189
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_chlayout(void *obj, const char *name, const AVChannelLayout *layout, 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:67
static void open_video(AVFormatContext *oc, const AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: mux.c:405
static AVFrame * get_video_frame(OutputStream *ost)
Definition: mux.c:471
static void add_stream(OutputStream *ost, AVFormatContext *oc, const AVCodec **codec, enum AVCodecID codec_id)
Definition: mux.c:125
int main(int argc, char **argv)
Definition: mux.c:535
static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
Definition: mux.c:517
static void open_audio(AVFormatContext *oc, const AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: mux.c:241
static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
Definition: mux.c:336
static int write_frame(AVFormatContext *fmt_ctx, AVCodecContext *c, AVStream *st, AVFrame *frame, AVPacket *pkt)
Definition: mux.c:83
static AVFrame * alloc_frame(enum AVPixelFormat pix_fmt, int width, int height)
Definition: mux.c:382
static void close_stream(AVFormatContext *oc, OutputStream *ost)
Definition: mux.c:522
static AVFrame * get_audio_frame(OutputStream *ost)
Definition: mux.c:307
#define SCALE_FLAGS
Definition: mux.c:50
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
Definition: mux.c:72
static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
Definition: mux.c:450
#define STREAM_DURATION
Definition: mux.c:46
static AVFrame * alloc_audio_frame(enum AVSampleFormat sample_fmt, const AVChannelLayout *channel_layout, int sample_rate, int nb_samples)
Definition: mux.c:216
#define STREAM_FRAME_RATE
Definition: mux.c:47
#define STREAM_PIX_FMT
Definition: mux.c:48
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
An AVChannelLayout holds information about the channel layout of audio data.
main external API structure.
Definition: avcodec.h:441
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:658
int width
picture width / height.
Definition: avcodec.h:621
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2107
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1080
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:720
int mb_decision
macroblock decision mode
Definition: avcodec.h:925
int64_t bit_rate
the average bitrate
Definition: avcodec.h:491
const struct AVCodec * codec
Definition: avcodec.h:450
int sample_rate
samples per second
Definition: avcodec.h:1064
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:643
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:563
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:521
enum AVCodecID codec_id
Definition: avcodec.h:451
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1092
AVCodec.
Definition: codec.h:187
int capabilities
Codec capabilities.
Definition: codec.h:206
Format I/O context.
Definition: avformat.h:1115
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1171
AVIOContext * pb
I/O context.
Definition: avformat.h:1157
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1134
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1183
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:420
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:452
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
int width
Definition: frame.h:412
int height
Definition: frame.h:412
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:385
int sample_rate
Sample rate of the audio data.
Definition: frame.h:567
AVChannelLayout ch_layout
Channel layout of the audio data.
Definition: frame.h:802
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:427
enum AVCodecID video_codec
default video codec
Definition: avformat.h:522
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:521
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:530
This structure stores compressed data.
Definition: packet.h:468
int stream_index
Definition: packet.h:493
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:509
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:484
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:490
Rational number (pair of numerator and denominator).
Definition: rational.h:58
Stream structure.
Definition: avformat.h:841
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
int id
Format-specific stream ID.
Definition: avformat.h:853
int index
stream index in AVFormatContext
Definition: avformat.h:847
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:880
float tincr2
Definition: mux.c:66
AVFrame * frame
Definition: mux.c:61
int samples_count
Definition: mux.c:59
struct SwrContext * swr_ctx
Definition: mux.c:69
AVFrame * tmp_frame
Definition: mux.c:62
AVPacket * tmp_pkt
Definition: mux.c:64
struct SwsContext * sws_ctx
Definition: mux.c:68
int64_t next_pts
Definition: mux.c:58
float t
Definition: mux.c:66
AVStream * st
Definition: mux.c:54
AVCodecContext * enc
Definition: mux.c:55
float tincr
Definition: mux.c:66
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