FFmpeg  5.1.1
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>
40 #include <libavutil/mathematics.h>
41 #include <libavutil/timestamp.h>
42 #include <libavcodec/avcodec.h>
43 #include <libavformat/avformat.h>
44 #include <libswscale/swscale.h>
46 
47 #define STREAM_DURATION 10.0
48 #define STREAM_FRAME_RATE 25 /* 25 images/s */
49 #define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */
50 
51 #define SCALE_FLAGS SWS_BICUBIC
52 
53 // a wrapper around a single output AVStream
54 typedef struct OutputStream {
57 
58  /* pts of the next frame that will be generated */
59  int64_t next_pts;
61 
64 
66 
67  float t, tincr, tincr2;
68 
69  struct SwsContext *sws_ctx;
71 } OutputStream;
72 
73 static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
74 {
76 
77  printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
78  av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
79  av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
81  pkt->stream_index);
82 }
83 
86 {
87  int ret;
88 
89  // send the frame to the encoder
90  ret = avcodec_send_frame(c, frame);
91  if (ret < 0) {
92  fprintf(stderr, "Error sending a frame to the encoder: %s\n",
93  av_err2str(ret));
94  exit(1);
95  }
96 
97  while (ret >= 0) {
98  ret = avcodec_receive_packet(c, pkt);
99  if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
100  break;
101  else if (ret < 0) {
102  fprintf(stderr, "Error encoding a frame: %s\n", av_err2str(ret));
103  exit(1);
104  }
105 
106  /* rescale output packet timestamp values from codec to stream timebase */
108  pkt->stream_index = st->index;
109 
110  /* Write the compressed frame to the media file. */
113  /* pkt is now blank (av_interleaved_write_frame() takes ownership of
114  * its contents and resets pkt), so that no unreferencing is necessary.
115  * This would be different if one used av_write_frame(). */
116  if (ret < 0) {
117  fprintf(stderr, "Error while writing output packet: %s\n", av_err2str(ret));
118  exit(1);
119  }
120  }
121 
122  return ret == AVERROR_EOF ? 1 : 0;
123 }
124 
125 /* Add an output stream. */
127  const AVCodec **codec,
128  enum AVCodecID codec_id)
129 {
130  AVCodecContext *c;
131  int i;
132 
133  /* find the encoder */
134  *codec = avcodec_find_encoder(codec_id);
135  if (!(*codec)) {
136  fprintf(stderr, "Could not find encoder for '%s'\n",
137  avcodec_get_name(codec_id));
138  exit(1);
139  }
140 
141  ost->tmp_pkt = av_packet_alloc();
142  if (!ost->tmp_pkt) {
143  fprintf(stderr, "Could not allocate AVPacket\n");
144  exit(1);
145  }
146 
147  ost->st = avformat_new_stream(oc, NULL);
148  if (!ost->st) {
149  fprintf(stderr, "Could not allocate stream\n");
150  exit(1);
151  }
152  ost->st->id = oc->nb_streams-1;
153  c = avcodec_alloc_context3(*codec);
154  if (!c) {
155  fprintf(stderr, "Could not alloc an encoding context\n");
156  exit(1);
157  }
158  ost->enc = c;
159 
160  switch ((*codec)->type) {
161  case AVMEDIA_TYPE_AUDIO:
162  c->sample_fmt = (*codec)->sample_fmts ?
163  (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
164  c->bit_rate = 64000;
165  c->sample_rate = 44100;
166  if ((*codec)->supported_samplerates) {
167  c->sample_rate = (*codec)->supported_samplerates[0];
168  for (i = 0; (*codec)->supported_samplerates[i]; i++) {
169  if ((*codec)->supported_samplerates[i] == 44100)
170  c->sample_rate = 44100;
171  }
172  }
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)
212 }
213 
214 /**************************************************************/
215 /* audio output */
216 
217 static AVFrame *alloc_audio_frame(enum AVSampleFormat sample_fmt,
218  const AVChannelLayout *channel_layout,
219  int sample_rate, int nb_samples)
220 {
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  av_channel_layout_copy(&frame->ch_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 
245 static void open_audio(AVFormatContext *oc, const AVCodec *codec,
246  OutputStream *ost, AVDictionary *opt_arg)
247 {
248  AVCodecContext *c;
249  int nb_samples;
250  int ret;
251  AVDictionary *opt = NULL;
252 
253  c = ost->enc;
254 
255  /* open it */
256  av_dict_copy(&opt, opt_arg, 0);
257  ret = avcodec_open2(c, codec, &opt);
258  av_dict_free(&opt);
259  if (ret < 0) {
260  fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
261  exit(1);
262  }
263 
264  /* init signal generator */
265  ost->t = 0;
266  ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
267  /* increment frequency by 110 Hz per second */
268  ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
269 
271  nb_samples = 10000;
272  else
273  nb_samples = c->frame_size;
274 
275  ost->frame = alloc_audio_frame(c->sample_fmt, &c->ch_layout,
276  c->sample_rate, nb_samples);
278  c->sample_rate, nb_samples);
279 
280  /* copy the stream parameters to the muxer */
282  if (ret < 0) {
283  fprintf(stderr, "Could not copy the stream parameters\n");
284  exit(1);
285  }
286 
287  /* create resampler context */
288  ost->swr_ctx = swr_alloc();
289  if (!ost->swr_ctx) {
290  fprintf(stderr, "Could not allocate resampler context\n");
291  exit(1);
292  }
293 
294  /* set options */
295  av_opt_set_chlayout (ost->swr_ctx, "in_chlayout", &c->ch_layout, 0);
296  av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
297  av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
298  av_opt_set_chlayout (ost->swr_ctx, "out_chlayout", &c->ch_layout, 0);
299  av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
300  av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
301 
302  /* initialize the resampling context */
303  if ((ret = swr_init(ost->swr_ctx)) < 0) {
304  fprintf(stderr, "Failed to initialize the resampling context\n");
305  exit(1);
306  }
307 }
308 
309 /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
310  * 'nb_channels' channels. */
312 {
313  AVFrame *frame = ost->tmp_frame;
314  int j, i, v;
315  int16_t *q = (int16_t*)frame->data[0];
316 
317  /* check if we want to generate more frames */
318  if (av_compare_ts(ost->next_pts, ost->enc->time_base,
319  STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
320  return NULL;
321 
322  for (j = 0; j <frame->nb_samples; j++) {
323  v = (int)(sin(ost->t) * 10000);
324  for (i = 0; i < ost->enc->ch_layout.nb_channels; i++)
325  *q++ = v;
326  ost->t += ost->tincr;
327  ost->tincr += ost->tincr2;
328  }
329 
330  frame->pts = ost->next_pts;
331  ost->next_pts += frame->nb_samples;
332 
333  return frame;
334 }
335 
336 /*
337  * encode one audio frame and send it to the muxer
338  * return 1 when encoding is finished, 0 otherwise
339  */
341 {
342  AVCodecContext *c;
343  AVFrame *frame;
344  int ret;
345  int dst_nb_samples;
346 
347  c = ost->enc;
348 
350 
351  if (frame) {
352  /* convert samples from native format to destination codec format, using the resampler */
353  /* compute destination number of samples */
354  dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
356  av_assert0(dst_nb_samples == frame->nb_samples);
357 
358  /* when we pass a frame to the encoder, it may keep a reference to it
359  * internally;
360  * make sure we do not overwrite it here
361  */
362  ret = av_frame_make_writable(ost->frame);
363  if (ret < 0)
364  exit(1);
365 
366  /* convert to destination format */
367  ret = swr_convert(ost->swr_ctx,
368  ost->frame->data, dst_nb_samples,
369  (const uint8_t **)frame->data, frame->nb_samples);
370  if (ret < 0) {
371  fprintf(stderr, "Error while converting\n");
372  exit(1);
373  }
374  frame = ost->frame;
375 
376  frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
377  ost->samples_count += dst_nb_samples;
378  }
379 
380  return write_frame(oc, c, ost->st, frame, ost->tmp_pkt);
381 }
382 
383 /**************************************************************/
384 /* video output */
385 
387 {
388  AVFrame *picture;
389  int ret;
390 
391  picture = av_frame_alloc();
392  if (!picture)
393  return NULL;
394 
395  picture->format = pix_fmt;
396  picture->width = width;
397  picture->height = height;
398 
399  /* allocate the buffers for the frame data */
400  ret = av_frame_get_buffer(picture, 0);
401  if (ret < 0) {
402  fprintf(stderr, "Could not allocate frame data.\n");
403  exit(1);
404  }
405 
406  return picture;
407 }
408 
409 static void open_video(AVFormatContext *oc, const AVCodec *codec,
410  OutputStream *ost, AVDictionary *opt_arg)
411 {
412  int ret;
413  AVCodecContext *c = ost->enc;
414  AVDictionary *opt = NULL;
415 
416  av_dict_copy(&opt, opt_arg, 0);
417 
418  /* open the codec */
419  ret = avcodec_open2(c, codec, &opt);
420  av_dict_free(&opt);
421  if (ret < 0) {
422  fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
423  exit(1);
424  }
425 
426  /* allocate and init a re-usable frame */
427  ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
428  if (!ost->frame) {
429  fprintf(stderr, "Could not allocate video frame\n");
430  exit(1);
431  }
432 
433  /* If the output format is not YUV420P, then a temporary YUV420P
434  * picture is needed too. It is then converted to the required
435  * output format. */
436  ost->tmp_frame = NULL;
437  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
438  ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
439  if (!ost->tmp_frame) {
440  fprintf(stderr, "Could not allocate temporary picture\n");
441  exit(1);
442  }
443  }
444 
445  /* copy the stream parameters to the muxer */
447  if (ret < 0) {
448  fprintf(stderr, "Could not copy the stream parameters\n");
449  exit(1);
450  }
451 }
452 
453 /* Prepare a dummy image. */
454 static void fill_yuv_image(AVFrame *pict, int frame_index,
455  int width, int height)
456 {
457  int x, y, i;
458 
459  i = frame_index;
460 
461  /* Y */
462  for (y = 0; y < height; y++)
463  for (x = 0; x < width; x++)
464  pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
465 
466  /* Cb and Cr */
467  for (y = 0; y < height / 2; y++) {
468  for (x = 0; x < width / 2; x++) {
469  pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
470  pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
471  }
472  }
473 }
474 
476 {
477  AVCodecContext *c = ost->enc;
478 
479  /* check if we want to generate more frames */
480  if (av_compare_ts(ost->next_pts, c->time_base,
481  STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
482  return NULL;
483 
484  /* when we pass a frame to the encoder, it may keep a reference to it
485  * internally; make sure we do not overwrite it here */
486  if (av_frame_make_writable(ost->frame) < 0)
487  exit(1);
488 
489  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
490  /* as we only generate a YUV420P picture, we must convert it
491  * to the codec pixel format if needed */
492  if (!ost->sws_ctx) {
493  ost->sws_ctx = sws_getContext(c->width, c->height,
495  c->width, c->height,
496  c->pix_fmt,
497  SCALE_FLAGS, NULL, NULL, NULL);
498  if (!ost->sws_ctx) {
499  fprintf(stderr,
500  "Could not initialize the conversion context\n");
501  exit(1);
502  }
503  }
504  fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
505  sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
506  ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
507  ost->frame->linesize);
508  } else {
509  fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
510  }
511 
512  ost->frame->pts = ost->next_pts++;
513 
514  return ost->frame;
515 }
516 
517 /*
518  * encode one video frame and send it to the muxer
519  * return 1 when encoding is finished, 0 otherwise
520  */
522 {
523  return write_frame(oc, ost->enc, ost->st, get_video_frame(ost), ost->tmp_pkt);
524 }
525 
527 {
528  avcodec_free_context(&ost->enc);
529  av_frame_free(&ost->frame);
530  av_frame_free(&ost->tmp_frame);
531  av_packet_free(&ost->tmp_pkt);
532  sws_freeContext(ost->sws_ctx);
533  swr_free(&ost->swr_ctx);
534 }
535 
536 /**************************************************************/
537 /* media file output */
538 
539 int main(int argc, char **argv)
540 {
541  OutputStream video_st = { 0 }, audio_st = { 0 };
542  const AVOutputFormat *fmt;
543  const char *filename;
544  AVFormatContext *oc;
545  const AVCodec *audio_codec, *video_codec;
546  int ret;
547  int have_video = 0, have_audio = 0;
548  int encode_video = 0, encode_audio = 0;
549  AVDictionary *opt = NULL;
550  int i;
551 
552  if (argc < 2) {
553  printf("usage: %s output_file\n"
554  "API example program to output a media file with libavformat.\n"
555  "This program generates a synthetic audio and video stream, encodes and\n"
556  "muxes them into a file named output_file.\n"
557  "The output format is automatically guessed according to the file extension.\n"
558  "Raw images can also be output by using '%%d' in the filename.\n"
559  "\n", argv[0]);
560  return 1;
561  }
562 
563  filename = argv[1];
564  for (i = 2; i+1 < argc; i+=2) {
565  if (!strcmp(argv[i], "-flags") || !strcmp(argv[i], "-fflags"))
566  av_dict_set(&opt, argv[i]+1, argv[i+1], 0);
567  }
568 
569  /* allocate the output media context */
570  avformat_alloc_output_context2(&oc, NULL, NULL, filename);
571  if (!oc) {
572  printf("Could not deduce output format from file extension: using MPEG.\n");
573  avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
574  }
575  if (!oc)
576  return 1;
577 
578  fmt = oc->oformat;
579 
580  /* Add the audio and video streams using the default format codecs
581  * and initialize the codecs. */
582  if (fmt->video_codec != AV_CODEC_ID_NONE) {
583  add_stream(&video_st, oc, &video_codec, fmt->video_codec);
584  have_video = 1;
585  encode_video = 1;
586  }
587  if (fmt->audio_codec != AV_CODEC_ID_NONE) {
588  add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
589  have_audio = 1;
590  encode_audio = 1;
591  }
592 
593  /* Now that all the parameters are set, we can open the audio and
594  * video codecs and allocate the necessary encode buffers. */
595  if (have_video)
596  open_video(oc, video_codec, &video_st, opt);
597 
598  if (have_audio)
599  open_audio(oc, audio_codec, &audio_st, opt);
600 
601  av_dump_format(oc, 0, filename, 1);
602 
603  /* open the output file, if needed */
604  if (!(fmt->flags & AVFMT_NOFILE)) {
605  ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
606  if (ret < 0) {
607  fprintf(stderr, "Could not open '%s': %s\n", filename,
608  av_err2str(ret));
609  return 1;
610  }
611  }
612 
613  /* Write the stream header, if any. */
614  ret = avformat_write_header(oc, &opt);
615  if (ret < 0) {
616  fprintf(stderr, "Error occurred when opening output file: %s\n",
617  av_err2str(ret));
618  return 1;
619  }
620 
621  while (encode_video || encode_audio) {
622  /* select the stream to encode */
623  if (encode_video &&
624  (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
625  audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
626  encode_video = !write_video_frame(oc, &video_st);
627  } else {
628  encode_audio = !write_audio_frame(oc, &audio_st);
629  }
630  }
631 
632  av_write_trailer(oc);
633 
634  /* Close each codec. */
635  if (have_video)
636  close_stream(oc, &video_st);
637  if (have_audio)
638  close_stream(oc, &audio_st);
639 
640  if (!(fmt->flags & AVFMT_NOFILE))
641  /* Close the output file. */
642  avio_closep(&oc->pb);
643 
644  /* free the stream */
646 
647  return 0;
648 }
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
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:470
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:480
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:629
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
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.
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
#define AV_CODEC_CAP_VARIABLE_FRAME_SIZE
Audio encoder supports receiving a different number of samples in each call.
Definition: codec.h:134
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:274
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
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:48
@ AV_CODEC_ID_MPEG1VIDEO
Definition: codec_id.h:51
@ AV_CODEC_ID_MPEG2VIDEO
preferred ID for MPEG-1/2 video decoding
Definition: codec_id.h:52
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.
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
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:84
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:83
@ 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
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 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.
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.
struct SwrContext * swr_alloc(void)
Allocate SwrContext.
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:52
static AVFrame * alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
Definition: muxing.c:386
static void open_video(AVFormatContext *oc, const AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:409
static void add_stream(OutputStream *ost, AVFormatContext *oc, const AVCodec **codec, enum AVCodecID codec_id)
Definition: muxing.c:126
static AVFrame * get_video_frame(OutputStream *ost)
Definition: muxing.c:475
int main(int argc, char **argv)
Definition: muxing.c:539
static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:521
static AVFrame * get_audio_frame(OutputStream *ost)
Definition: muxing.c:311
static void open_audio(AVFormatContext *oc, const AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:245
static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:340
static int write_frame(AVFormatContext *fmt_ctx, AVCodecContext *c, AVStream *st, AVFrame *frame, AVPacket *pkt)
Definition: muxing.c:84
static AVFrame * alloc_audio_frame(enum AVSampleFormat sample_fmt, const AVChannelLayout *channel_layout, int sample_rate, int nb_samples)
Definition: muxing.c:217
static void close_stream(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:526
#define SCALE_FLAGS
Definition: muxing.c:51
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
Definition: muxing.c:73
static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
Definition: muxing.c:454
#define STREAM_DURATION
Definition: muxing.c:47
#define STREAM_FRAME_RATE
Definition: muxing.c:48
#define STREAM_PIX_FMT
Definition: muxing.c:49
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:389
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:599
int width
picture width / height.
Definition: avcodec.h:562
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2056
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1014
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:661
int mb_decision
macroblock decision mode
Definition: avcodec.h:862
int64_t bit_rate
the average bitrate
Definition: avcodec.h:439
const struct AVCodec * codec
Definition: avcodec.h:398
int sample_rate
samples per second
Definition: avcodec.h:998
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:584
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:512
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:469
enum AVCodecID codec_id
Definition: avcodec.h:399
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1026
AVCodec.
Definition: codec.h:196
int capabilities
Codec capabilities.
Definition: codec.h:215
Format I/O context.
Definition: avformat.h:1213
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1269
AVIOContext * pb
I/O context.
Definition: avformat.h:1255
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1232
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1281
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:405
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:432
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
int width
Definition: frame.h:397
int height
Definition: frame.h:397
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:370
int sample_rate
Sample rate of the audio data.
Definition: frame.h:502
AVChannelLayout ch_layout
Channel layout of the audio data.
Definition: frame.h:704
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:412
enum AVCodecID video_codec
default video codec
Definition: avformat.h:521
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:520
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:529
This structure stores compressed data.
Definition: packet.h:351
int stream_index
Definition: packet.h:376
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:392
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:367
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:373
Rational number (pair of numerator and denominator).
Definition: rational.h:58
Stream structure.
Definition: avformat.h:948
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
int id
Format-specific stream ID.
Definition: avformat.h:962
int index
stream index in AVFormatContext
Definition: avformat.h:956
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:978
float tincr2
Definition: muxing.c:67
AVFrame * frame
Definition: muxing.c:62
int samples_count
Definition: muxing.c:60
struct SwrContext * swr_ctx
Definition: muxing.c:70
AVFrame * tmp_frame
Definition: muxing.c:63
AVPacket * tmp_pkt
Definition: muxing.c:65
struct SwsContext * sws_ctx
Definition: muxing.c:69
int64_t next_pts
Definition: muxing.c:59
float t
Definition: muxing.c:67
AVStream * st
Definition: muxing.c:55
AVCodecContext * enc
Definition: muxing.c:56
float tincr
Definition: muxing.c:67
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