FFmpeg  5.0
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  }
175  if ((*codec)->channel_layouts) {
176  c->channel_layout = (*codec)->channel_layouts[0];
177  for (i = 0; (*codec)->channel_layouts[i]; i++) {
178  if ((*codec)->channel_layouts[i] == AV_CH_LAYOUT_STEREO)
180  }
181  }
183  ost->st->time_base = (AVRational){ 1, c->sample_rate };
184  break;
185 
186  case AVMEDIA_TYPE_VIDEO:
187  c->codec_id = codec_id;
188 
189  c->bit_rate = 400000;
190  /* Resolution must be a multiple of two. */
191  c->width = 352;
192  c->height = 288;
193  /* timebase: This is the fundamental unit of time (in seconds) in terms
194  * of which frame timestamps are represented. For fixed-fps content,
195  * timebase should be 1/framerate and timestamp increments should be
196  * identical to 1. */
197  ost->st->time_base = (AVRational){ 1, STREAM_FRAME_RATE };
198  c->time_base = ost->st->time_base;
199 
200  c->gop_size = 12; /* emit one intra frame every twelve frames at most */
201  c->pix_fmt = STREAM_PIX_FMT;
202  if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
203  /* just for testing, we also add B-frames */
204  c->max_b_frames = 2;
205  }
206  if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
207  /* Needed to avoid using macroblocks in which some coeffs overflow.
208  * This does not happen with normal video, it just happens here as
209  * the motion of the chroma plane does not match the luma plane. */
210  c->mb_decision = 2;
211  }
212  break;
213 
214  default:
215  break;
216  }
217 
218  /* Some formats want stream headers to be separate. */
219  if (oc->oformat->flags & AVFMT_GLOBALHEADER)
221 }
222 
223 /**************************************************************/
224 /* audio output */
225 
226 static AVFrame *alloc_audio_frame(enum AVSampleFormat sample_fmt,
227  uint64_t channel_layout,
228  int sample_rate, int nb_samples)
229 {
231  int ret;
232 
233  if (!frame) {
234  fprintf(stderr, "Error allocating an audio frame\n");
235  exit(1);
236  }
237 
238  frame->format = sample_fmt;
239  frame->channel_layout = channel_layout;
240  frame->sample_rate = sample_rate;
241  frame->nb_samples = nb_samples;
242 
243  if (nb_samples) {
244  ret = av_frame_get_buffer(frame, 0);
245  if (ret < 0) {
246  fprintf(stderr, "Error allocating an audio buffer\n");
247  exit(1);
248  }
249  }
250 
251  return frame;
252 }
253 
254 static void open_audio(AVFormatContext *oc, const AVCodec *codec,
255  OutputStream *ost, AVDictionary *opt_arg)
256 {
257  AVCodecContext *c;
258  int nb_samples;
259  int ret;
260  AVDictionary *opt = NULL;
261 
262  c = ost->enc;
263 
264  /* open it */
265  av_dict_copy(&opt, opt_arg, 0);
266  ret = avcodec_open2(c, codec, &opt);
267  av_dict_free(&opt);
268  if (ret < 0) {
269  fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
270  exit(1);
271  }
272 
273  /* init signal generator */
274  ost->t = 0;
275  ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
276  /* increment frequency by 110 Hz per second */
277  ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
278 
280  nb_samples = 10000;
281  else
282  nb_samples = c->frame_size;
283 
285  c->sample_rate, nb_samples);
287  c->sample_rate, nb_samples);
288 
289  /* copy the stream parameters to the muxer */
291  if (ret < 0) {
292  fprintf(stderr, "Could not copy the stream parameters\n");
293  exit(1);
294  }
295 
296  /* create resampler context */
297  ost->swr_ctx = swr_alloc();
298  if (!ost->swr_ctx) {
299  fprintf(stderr, "Could not allocate resampler context\n");
300  exit(1);
301  }
302 
303  /* set options */
304  av_opt_set_int (ost->swr_ctx, "in_channel_count", c->channels, 0);
305  av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
306  av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
307  av_opt_set_int (ost->swr_ctx, "out_channel_count", c->channels, 0);
308  av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
309  av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
310 
311  /* initialize the resampling context */
312  if ((ret = swr_init(ost->swr_ctx)) < 0) {
313  fprintf(stderr, "Failed to initialize the resampling context\n");
314  exit(1);
315  }
316 }
317 
318 /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
319  * 'nb_channels' channels. */
321 {
322  AVFrame *frame = ost->tmp_frame;
323  int j, i, v;
324  int16_t *q = (int16_t*)frame->data[0];
325 
326  /* check if we want to generate more frames */
327  if (av_compare_ts(ost->next_pts, ost->enc->time_base,
328  STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
329  return NULL;
330 
331  for (j = 0; j <frame->nb_samples; j++) {
332  v = (int)(sin(ost->t) * 10000);
333  for (i = 0; i < ost->enc->channels; i++)
334  *q++ = v;
335  ost->t += ost->tincr;
336  ost->tincr += ost->tincr2;
337  }
338 
339  frame->pts = ost->next_pts;
340  ost->next_pts += frame->nb_samples;
341 
342  return frame;
343 }
344 
345 /*
346  * encode one audio frame and send it to the muxer
347  * return 1 when encoding is finished, 0 otherwise
348  */
350 {
351  AVCodecContext *c;
352  AVFrame *frame;
353  int ret;
354  int dst_nb_samples;
355 
356  c = ost->enc;
357 
359 
360  if (frame) {
361  /* convert samples from native format to destination codec format, using the resampler */
362  /* compute destination number of samples */
363  dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
365  av_assert0(dst_nb_samples == frame->nb_samples);
366 
367  /* when we pass a frame to the encoder, it may keep a reference to it
368  * internally;
369  * make sure we do not overwrite it here
370  */
371  ret = av_frame_make_writable(ost->frame);
372  if (ret < 0)
373  exit(1);
374 
375  /* convert to destination format */
376  ret = swr_convert(ost->swr_ctx,
377  ost->frame->data, dst_nb_samples,
378  (const uint8_t **)frame->data, frame->nb_samples);
379  if (ret < 0) {
380  fprintf(stderr, "Error while converting\n");
381  exit(1);
382  }
383  frame = ost->frame;
384 
385  frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
386  ost->samples_count += dst_nb_samples;
387  }
388 
389  return write_frame(oc, c, ost->st, frame, ost->tmp_pkt);
390 }
391 
392 /**************************************************************/
393 /* video output */
394 
396 {
397  AVFrame *picture;
398  int ret;
399 
400  picture = av_frame_alloc();
401  if (!picture)
402  return NULL;
403 
404  picture->format = pix_fmt;
405  picture->width = width;
406  picture->height = height;
407 
408  /* allocate the buffers for the frame data */
409  ret = av_frame_get_buffer(picture, 0);
410  if (ret < 0) {
411  fprintf(stderr, "Could not allocate frame data.\n");
412  exit(1);
413  }
414 
415  return picture;
416 }
417 
418 static void open_video(AVFormatContext *oc, const AVCodec *codec,
419  OutputStream *ost, AVDictionary *opt_arg)
420 {
421  int ret;
422  AVCodecContext *c = ost->enc;
423  AVDictionary *opt = NULL;
424 
425  av_dict_copy(&opt, opt_arg, 0);
426 
427  /* open the codec */
428  ret = avcodec_open2(c, codec, &opt);
429  av_dict_free(&opt);
430  if (ret < 0) {
431  fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
432  exit(1);
433  }
434 
435  /* allocate and init a re-usable frame */
436  ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
437  if (!ost->frame) {
438  fprintf(stderr, "Could not allocate video frame\n");
439  exit(1);
440  }
441 
442  /* If the output format is not YUV420P, then a temporary YUV420P
443  * picture is needed too. It is then converted to the required
444  * output format. */
445  ost->tmp_frame = NULL;
446  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
447  ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
448  if (!ost->tmp_frame) {
449  fprintf(stderr, "Could not allocate temporary picture\n");
450  exit(1);
451  }
452  }
453 
454  /* copy the stream parameters to the muxer */
456  if (ret < 0) {
457  fprintf(stderr, "Could not copy the stream parameters\n");
458  exit(1);
459  }
460 }
461 
462 /* Prepare a dummy image. */
463 static void fill_yuv_image(AVFrame *pict, int frame_index,
464  int width, int height)
465 {
466  int x, y, i;
467 
468  i = frame_index;
469 
470  /* Y */
471  for (y = 0; y < height; y++)
472  for (x = 0; x < width; x++)
473  pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
474 
475  /* Cb and Cr */
476  for (y = 0; y < height / 2; y++) {
477  for (x = 0; x < width / 2; x++) {
478  pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
479  pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
480  }
481  }
482 }
483 
485 {
486  AVCodecContext *c = ost->enc;
487 
488  /* check if we want to generate more frames */
489  if (av_compare_ts(ost->next_pts, c->time_base,
490  STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
491  return NULL;
492 
493  /* when we pass a frame to the encoder, it may keep a reference to it
494  * internally; make sure we do not overwrite it here */
495  if (av_frame_make_writable(ost->frame) < 0)
496  exit(1);
497 
498  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
499  /* as we only generate a YUV420P picture, we must convert it
500  * to the codec pixel format if needed */
501  if (!ost->sws_ctx) {
502  ost->sws_ctx = sws_getContext(c->width, c->height,
504  c->width, c->height,
505  c->pix_fmt,
506  SCALE_FLAGS, NULL, NULL, NULL);
507  if (!ost->sws_ctx) {
508  fprintf(stderr,
509  "Could not initialize the conversion context\n");
510  exit(1);
511  }
512  }
513  fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
514  sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
515  ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
516  ost->frame->linesize);
517  } else {
518  fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
519  }
520 
521  ost->frame->pts = ost->next_pts++;
522 
523  return ost->frame;
524 }
525 
526 /*
527  * encode one video frame and send it to the muxer
528  * return 1 when encoding is finished, 0 otherwise
529  */
531 {
532  return write_frame(oc, ost->enc, ost->st, get_video_frame(ost), ost->tmp_pkt);
533 }
534 
536 {
537  avcodec_free_context(&ost->enc);
538  av_frame_free(&ost->frame);
539  av_frame_free(&ost->tmp_frame);
540  av_packet_free(&ost->tmp_pkt);
541  sws_freeContext(ost->sws_ctx);
542  swr_free(&ost->swr_ctx);
543 }
544 
545 /**************************************************************/
546 /* media file output */
547 
548 int main(int argc, char **argv)
549 {
550  OutputStream video_st = { 0 }, audio_st = { 0 };
551  const AVOutputFormat *fmt;
552  const char *filename;
553  AVFormatContext *oc;
554  const AVCodec *audio_codec, *video_codec;
555  int ret;
556  int have_video = 0, have_audio = 0;
557  int encode_video = 0, encode_audio = 0;
558  AVDictionary *opt = NULL;
559  int i;
560 
561  if (argc < 2) {
562  printf("usage: %s output_file\n"
563  "API example program to output a media file with libavformat.\n"
564  "This program generates a synthetic audio and video stream, encodes and\n"
565  "muxes them into a file named output_file.\n"
566  "The output format is automatically guessed according to the file extension.\n"
567  "Raw images can also be output by using '%%d' in the filename.\n"
568  "\n", argv[0]);
569  return 1;
570  }
571 
572  filename = argv[1];
573  for (i = 2; i+1 < argc; i+=2) {
574  if (!strcmp(argv[i], "-flags") || !strcmp(argv[i], "-fflags"))
575  av_dict_set(&opt, argv[i]+1, argv[i+1], 0);
576  }
577 
578  /* allocate the output media context */
579  avformat_alloc_output_context2(&oc, NULL, NULL, filename);
580  if (!oc) {
581  printf("Could not deduce output format from file extension: using MPEG.\n");
582  avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
583  }
584  if (!oc)
585  return 1;
586 
587  fmt = oc->oformat;
588 
589  /* Add the audio and video streams using the default format codecs
590  * and initialize the codecs. */
591  if (fmt->video_codec != AV_CODEC_ID_NONE) {
592  add_stream(&video_st, oc, &video_codec, fmt->video_codec);
593  have_video = 1;
594  encode_video = 1;
595  }
596  if (fmt->audio_codec != AV_CODEC_ID_NONE) {
597  add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
598  have_audio = 1;
599  encode_audio = 1;
600  }
601 
602  /* Now that all the parameters are set, we can open the audio and
603  * video codecs and allocate the necessary encode buffers. */
604  if (have_video)
605  open_video(oc, video_codec, &video_st, opt);
606 
607  if (have_audio)
608  open_audio(oc, audio_codec, &audio_st, opt);
609 
610  av_dump_format(oc, 0, filename, 1);
611 
612  /* open the output file, if needed */
613  if (!(fmt->flags & AVFMT_NOFILE)) {
614  ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
615  if (ret < 0) {
616  fprintf(stderr, "Could not open '%s': %s\n", filename,
617  av_err2str(ret));
618  return 1;
619  }
620  }
621 
622  /* Write the stream header, if any. */
623  ret = avformat_write_header(oc, &opt);
624  if (ret < 0) {
625  fprintf(stderr, "Error occurred when opening output file: %s\n",
626  av_err2str(ret));
627  return 1;
628  }
629 
630  while (encode_video || encode_audio) {
631  /* select the stream to encode */
632  if (encode_video &&
633  (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
634  audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
635  encode_video = !write_video_frame(oc, &video_st);
636  } else {
637  encode_audio = !write_audio_frame(oc, &audio_st);
638  }
639  }
640 
641  /* Write the trailer, if any. The trailer must be written before you
642  * close the CodecContexts open when you wrote the header; otherwise
643  * av_write_trailer() may try to use memory that was freed on
644  * av_codec_close(). */
645  av_write_trailer(oc);
646 
647  /* Close each codec. */
648  if (have_video)
649  close_stream(oc, &video_st);
650  if (have_audio)
651  close_stream(oc, &audio_st);
652 
653  if (!(fmt->flags & AVFMT_NOFILE))
654  /* Close the output file. */
655  avio_closep(&oc->pb);
656 
657  /* free the stream */
659 
660  return 0;
661 }
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:464
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:474
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:622
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.
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:268
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,...
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:58
@ AV_SAMPLE_FMT_FLTP
float, planar
Definition: samplefmt.h:69
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:61
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: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.
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_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:395
static void open_video(AVFormatContext *oc, const AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:418
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:484
static AVFrame * alloc_audio_frame(enum AVSampleFormat sample_fmt, uint64_t channel_layout, int sample_rate, int nb_samples)
Definition: muxing.c:226
int main(int argc, char **argv)
Definition: muxing.c:548
static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:530
static AVFrame * get_audio_frame(OutputStream *ost)
Definition: muxing.c:320
static void open_audio(AVFormatContext *oc, const AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:254
static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:349
static int write_frame(AVFormatContext *fmt_ctx, AVCodecContext *c, AVStream *st, AVFrame *frame, AVPacket *pkt)
Definition: muxing.c:84
static void close_stream(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:535
#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:463
#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
main external API structure.
Definition: avcodec.h:383
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
int width
picture width / height.
Definition: avcodec.h:556
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1000
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:655
int mb_decision
macroblock decision mode
Definition: avcodec.h:856
int64_t bit_rate
the average bitrate
Definition: avcodec.h:433
const struct AVCodec * codec
Definition: avcodec.h:392
int sample_rate
samples per second
Definition: avcodec.h:992
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:578
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:506
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:463
int channels
number of audio channels
Definition: avcodec.h:993
enum AVCodecID codec_id
Definition: avcodec.h:393
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1043
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1012
AVCodec.
Definition: codec.h:202
int capabilities
Codec capabilities.
Definition: codec.h:221
Format I/O context.
Definition: avformat.h:1200
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1256
AVIOContext * pb
I/O context.
Definition: avformat.h:1242
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1219
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1268
This structure describes decoded (raw) audio or video data.
Definition: frame.h:317
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:397
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:424
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:338
int width
Definition: frame.h:389
int height
Definition: frame.h:389
uint64_t channel_layout
Channel layout of the audio data.
Definition: frame.h:499
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:362
int sample_rate
Sample rate of the audio data.
Definition: frame.h:494
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:404
enum AVCodecID video_codec
default video codec
Definition: avformat.h:515
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:514
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:523
This structure stores compressed data.
Definition: packet.h:350
int stream_index
Definition: packet.h:375
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:391
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:366
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:372
Rational number (pair of numerator and denominator).
Definition: rational.h:58
Stream structure.
Definition: avformat.h:935
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1095
int id
Format-specific stream ID.
Definition: avformat.h:949
int index
stream index in AVFormatContext
Definition: avformat.h:943
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:965
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