FFmpeg  4.3.1
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 <libavformat/avformat.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
53 typedef struct OutputStream {
56 
57  /* pts of the next frame that will be generated */
58  int64_t next_pts;
60 
63 
64  float t, tincr, tincr2;
65 
66  struct SwsContext *sws_ctx;
68 } OutputStream;
69 
70 static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
71 {
73 
74  printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
75  av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
76  av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
78  pkt->stream_index);
79 }
80 
82  AVStream *st, AVFrame *frame)
83 {
84  int ret;
85 
86  // send the frame to the encoder
87  ret = avcodec_send_frame(c, frame);
88  if (ret < 0) {
89  fprintf(stderr, "Error sending a frame to the encoder: %s\n",
90  av_err2str(ret));
91  exit(1);
92  }
93 
94  while (ret >= 0) {
95  AVPacket pkt = { 0 };
96 
97  ret = avcodec_receive_packet(c, &pkt);
98  if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
99  break;
100  else if (ret < 0) {
101  fprintf(stderr, "Error encoding a frame: %s\n", av_err2str(ret));
102  exit(1);
103  }
104 
105  /* rescale output packet timestamp values from codec to stream timebase */
107  pkt.stream_index = st->index;
108 
109  /* Write the compressed frame to the media file. */
113  if (ret < 0) {
114  fprintf(stderr, "Error while writing output packet: %s\n", av_err2str(ret));
115  exit(1);
116  }
117  }
118 
119  return ret == AVERROR_EOF ? 1 : 0;
120 }
121 
122 /* Add an output stream. */
124  AVCodec **codec,
125  enum AVCodecID codec_id)
126 {
127  AVCodecContext *c;
128  int i;
129 
130  /* find the encoder */
131  *codec = avcodec_find_encoder(codec_id);
132  if (!(*codec)) {
133  fprintf(stderr, "Could not find encoder for '%s'\n",
134  avcodec_get_name(codec_id));
135  exit(1);
136  }
137 
138  ost->st = avformat_new_stream(oc, NULL);
139  if (!ost->st) {
140  fprintf(stderr, "Could not allocate stream\n");
141  exit(1);
142  }
143  ost->st->id = oc->nb_streams-1;
144  c = avcodec_alloc_context3(*codec);
145  if (!c) {
146  fprintf(stderr, "Could not alloc an encoding context\n");
147  exit(1);
148  }
149  ost->enc = c;
150 
151  switch ((*codec)->type) {
152  case AVMEDIA_TYPE_AUDIO:
153  c->sample_fmt = (*codec)->sample_fmts ?
154  (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
155  c->bit_rate = 64000;
156  c->sample_rate = 44100;
157  if ((*codec)->supported_samplerates) {
158  c->sample_rate = (*codec)->supported_samplerates[0];
159  for (i = 0; (*codec)->supported_samplerates[i]; i++) {
160  if ((*codec)->supported_samplerates[i] == 44100)
161  c->sample_rate = 44100;
162  }
163  }
166  if ((*codec)->channel_layouts) {
167  c->channel_layout = (*codec)->channel_layouts[0];
168  for (i = 0; (*codec)->channel_layouts[i]; i++) {
169  if ((*codec)->channel_layouts[i] == AV_CH_LAYOUT_STEREO)
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  uint64_t 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  frame->channel_layout = channel_layout;
231  frame->sample_rate = sample_rate;
232  frame->nb_samples = nb_samples;
233 
234  if (nb_samples) {
235  ret = av_frame_get_buffer(frame, 0);
236  if (ret < 0) {
237  fprintf(stderr, "Error allocating an audio buffer\n");
238  exit(1);
239  }
240  }
241 
242  return frame;
243 }
244 
245 static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
246 {
247  AVCodecContext *c;
248  int nb_samples;
249  int ret;
250  AVDictionary *opt = NULL;
251 
252  c = ost->enc;
253 
254  /* open it */
255  av_dict_copy(&opt, opt_arg, 0);
256  ret = avcodec_open2(c, codec, &opt);
257  av_dict_free(&opt);
258  if (ret < 0) {
259  fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
260  exit(1);
261  }
262 
263  /* init signal generator */
264  ost->t = 0;
265  ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
266  /* increment frequency by 110 Hz per second */
267  ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
268 
270  nb_samples = 10000;
271  else
272  nb_samples = c->frame_size;
273 
275  c->sample_rate, nb_samples);
277  c->sample_rate, nb_samples);
278 
279  /* copy the stream parameters to the muxer */
281  if (ret < 0) {
282  fprintf(stderr, "Could not copy the stream parameters\n");
283  exit(1);
284  }
285 
286  /* create resampler context */
287  ost->swr_ctx = swr_alloc();
288  if (!ost->swr_ctx) {
289  fprintf(stderr, "Could not allocate resampler context\n");
290  exit(1);
291  }
292 
293  /* set options */
294  av_opt_set_int (ost->swr_ctx, "in_channel_count", c->channels, 0);
295  av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
296  av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
297  av_opt_set_int (ost->swr_ctx, "out_channel_count", c->channels, 0);
298  av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
299  av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
300 
301  /* initialize the resampling context */
302  if ((ret = swr_init(ost->swr_ctx)) < 0) {
303  fprintf(stderr, "Failed to initialize the resampling context\n");
304  exit(1);
305  }
306 }
307 
308 /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
309  * 'nb_channels' channels. */
311 {
312  AVFrame *frame = ost->tmp_frame;
313  int j, i, v;
314  int16_t *q = (int16_t*)frame->data[0];
315 
316  /* check if we want to generate more frames */
317  if (av_compare_ts(ost->next_pts, ost->enc->time_base,
318  STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
319  return NULL;
320 
321  for (j = 0; j <frame->nb_samples; j++) {
322  v = (int)(sin(ost->t) * 10000);
323  for (i = 0; i < ost->enc->channels; i++)
324  *q++ = v;
325  ost->t += ost->tincr;
326  ost->tincr += ost->tincr2;
327  }
328 
329  frame->pts = ost->next_pts;
330  ost->next_pts += frame->nb_samples;
331 
332  return frame;
333 }
334 
335 /*
336  * encode one audio frame and send it to the muxer
337  * return 1 when encoding is finished, 0 otherwise
338  */
340 {
341  AVCodecContext *c;
342  AVFrame *frame;
343  int ret;
344  int dst_nb_samples;
345 
346  c = ost->enc;
347 
349 
350  if (frame) {
351  /* convert samples from native format to destination codec format, using the resampler */
352  /* compute destination number of samples */
353  dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
355  av_assert0(dst_nb_samples == frame->nb_samples);
356 
357  /* when we pass a frame to the encoder, it may keep a reference to it
358  * internally;
359  * make sure we do not overwrite it here
360  */
361  ret = av_frame_make_writable(ost->frame);
362  if (ret < 0)
363  exit(1);
364 
365  /* convert to destination format */
366  ret = swr_convert(ost->swr_ctx,
367  ost->frame->data, dst_nb_samples,
368  (const uint8_t **)frame->data, frame->nb_samples);
369  if (ret < 0) {
370  fprintf(stderr, "Error while converting\n");
371  exit(1);
372  }
373  frame = ost->frame;
374 
375  frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
376  ost->samples_count += dst_nb_samples;
377  }
378 
379  return write_frame(oc, c, ost->st, frame);
380 }
381 
382 /**************************************************************/
383 /* video output */
384 
386 {
387  AVFrame *picture;
388  int ret;
389 
390  picture = av_frame_alloc();
391  if (!picture)
392  return NULL;
393 
394  picture->format = pix_fmt;
395  picture->width = width;
396  picture->height = height;
397 
398  /* allocate the buffers for the frame data */
399  ret = av_frame_get_buffer(picture, 0);
400  if (ret < 0) {
401  fprintf(stderr, "Could not allocate frame data.\n");
402  exit(1);
403  }
404 
405  return picture;
406 }
407 
408 static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
409 {
410  int ret;
411  AVCodecContext *c = ost->enc;
412  AVDictionary *opt = NULL;
413 
414  av_dict_copy(&opt, opt_arg, 0);
415 
416  /* open the codec */
417  ret = avcodec_open2(c, codec, &opt);
418  av_dict_free(&opt);
419  if (ret < 0) {
420  fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
421  exit(1);
422  }
423 
424  /* allocate and init a re-usable frame */
425  ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
426  if (!ost->frame) {
427  fprintf(stderr, "Could not allocate video frame\n");
428  exit(1);
429  }
430 
431  /* If the output format is not YUV420P, then a temporary YUV420P
432  * picture is needed too. It is then converted to the required
433  * output format. */
434  ost->tmp_frame = NULL;
435  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
436  ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
437  if (!ost->tmp_frame) {
438  fprintf(stderr, "Could not allocate temporary picture\n");
439  exit(1);
440  }
441  }
442 
443  /* copy the stream parameters to the muxer */
445  if (ret < 0) {
446  fprintf(stderr, "Could not copy the stream parameters\n");
447  exit(1);
448  }
449 }
450 
451 /* Prepare a dummy image. */
452 static void fill_yuv_image(AVFrame *pict, int frame_index,
453  int width, int height)
454 {
455  int x, y, i;
456 
457  i = frame_index;
458 
459  /* Y */
460  for (y = 0; y < height; y++)
461  for (x = 0; x < width; x++)
462  pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
463 
464  /* Cb and Cr */
465  for (y = 0; y < height / 2; y++) {
466  for (x = 0; x < width / 2; x++) {
467  pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
468  pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
469  }
470  }
471 }
472 
474 {
475  AVCodecContext *c = ost->enc;
476 
477  /* check if we want to generate more frames */
478  if (av_compare_ts(ost->next_pts, c->time_base,
479  STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
480  return NULL;
481 
482  /* when we pass a frame to the encoder, it may keep a reference to it
483  * internally; make sure we do not overwrite it here */
484  if (av_frame_make_writable(ost->frame) < 0)
485  exit(1);
486 
487  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
488  /* as we only generate a YUV420P picture, we must convert it
489  * to the codec pixel format if needed */
490  if (!ost->sws_ctx) {
491  ost->sws_ctx = sws_getContext(c->width, c->height,
493  c->width, c->height,
494  c->pix_fmt,
495  SCALE_FLAGS, NULL, NULL, NULL);
496  if (!ost->sws_ctx) {
497  fprintf(stderr,
498  "Could not initialize the conversion context\n");
499  exit(1);
500  }
501  }
502  fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
503  sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
504  ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
505  ost->frame->linesize);
506  } else {
507  fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
508  }
509 
510  ost->frame->pts = ost->next_pts++;
511 
512  return ost->frame;
513 }
514 
515 /*
516  * encode one video frame and send it to the muxer
517  * return 1 when encoding is finished, 0 otherwise
518  */
520 {
521  return write_frame(oc, ost->enc, ost->st, get_video_frame(ost));
522 
523 }
524 
526 {
527  avcodec_free_context(&ost->enc);
528  av_frame_free(&ost->frame);
529  av_frame_free(&ost->tmp_frame);
530  sws_freeContext(ost->sws_ctx);
531  swr_free(&ost->swr_ctx);
532 }
533 
534 /**************************************************************/
535 /* media file output */
536 
537 int main(int argc, char **argv)
538 {
539  OutputStream video_st = { 0 }, audio_st = { 0 };
540  const char *filename;
541  AVOutputFormat *fmt;
542  AVFormatContext *oc;
543  AVCodec *audio_codec, *video_codec;
544  int ret;
545  int have_video = 0, have_audio = 0;
546  int encode_video = 0, encode_audio = 0;
547  AVDictionary *opt = NULL;
548  int i;
549 
550  if (argc < 2) {
551  printf("usage: %s output_file\n"
552  "API example program to output a media file with libavformat.\n"
553  "This program generates a synthetic audio and video stream, encodes and\n"
554  "muxes them into a file named output_file.\n"
555  "The output format is automatically guessed according to the file extension.\n"
556  "Raw images can also be output by using '%%d' in the filename.\n"
557  "\n", argv[0]);
558  return 1;
559  }
560 
561  filename = argv[1];
562  for (i = 2; i+1 < argc; i+=2) {
563  if (!strcmp(argv[i], "-flags") || !strcmp(argv[i], "-fflags"))
564  av_dict_set(&opt, argv[i]+1, argv[i+1], 0);
565  }
566 
567  /* allocate the output media context */
568  avformat_alloc_output_context2(&oc, NULL, NULL, filename);
569  if (!oc) {
570  printf("Could not deduce output format from file extension: using MPEG.\n");
571  avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
572  }
573  if (!oc)
574  return 1;
575 
576  fmt = oc->oformat;
577 
578  /* Add the audio and video streams using the default format codecs
579  * and initialize the codecs. */
580  if (fmt->video_codec != AV_CODEC_ID_NONE) {
581  add_stream(&video_st, oc, &video_codec, fmt->video_codec);
582  have_video = 1;
583  encode_video = 1;
584  }
585  if (fmt->audio_codec != AV_CODEC_ID_NONE) {
586  add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
587  have_audio = 1;
588  encode_audio = 1;
589  }
590 
591  /* Now that all the parameters are set, we can open the audio and
592  * video codecs and allocate the necessary encode buffers. */
593  if (have_video)
594  open_video(oc, video_codec, &video_st, opt);
595 
596  if (have_audio)
597  open_audio(oc, audio_codec, &audio_st, opt);
598 
599  av_dump_format(oc, 0, filename, 1);
600 
601  /* open the output file, if needed */
602  if (!(fmt->flags & AVFMT_NOFILE)) {
603  ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
604  if (ret < 0) {
605  fprintf(stderr, "Could not open '%s': %s\n", filename,
606  av_err2str(ret));
607  return 1;
608  }
609  }
610 
611  /* Write the stream header, if any. */
612  ret = avformat_write_header(oc, &opt);
613  if (ret < 0) {
614  fprintf(stderr, "Error occurred when opening output file: %s\n",
615  av_err2str(ret));
616  return 1;
617  }
618 
619  while (encode_video || encode_audio) {
620  /* select the stream to encode */
621  if (encode_video &&
622  (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
623  audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
624  encode_video = !write_video_frame(oc, &video_st);
625  } else {
626  encode_audio = !write_audio_frame(oc, &audio_st);
627  }
628  }
629 
630  /* Write the trailer, if any. The trailer must be written before you
631  * close the CodecContexts open when you wrote the header; otherwise
632  * av_write_trailer() may try to use memory that was freed on
633  * av_codec_close(). */
634  av_write_trailer(oc);
635 
636  /* Close each codec. */
637  if (have_video)
638  close_stream(oc, &video_st);
639  if (have_audio)
640  close_stream(oc, &audio_st);
641 
642  if (!(fmt->flags & AVFMT_NOFILE))
643  /* Close the output file. */
644  avio_closep(&oc->pb);
645 
646  /* free the stream */
648 
649  return 0;
650 }
simple assert() macros that are a bit more flexible than ISO C assert().
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
Main libavformat public API header.
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:458
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:461
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:675
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:122
#define AV_CODEC_FLAG_GLOBAL_HEADER
Place global headers in extradata instead of every keyframe.
Definition: avcodec.h:329
AVCodec * avcodec_find_encoder(enum AVCodecID id)
Find a registered encoder with a matching codec ID.
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:46
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:47
@ AV_CODEC_ID_MPEG1VIDEO
Definition: codec_id.h:50
@ AV_CODEC_ID_MPEG2VIDEO
preferred ID for MPEG-1/2 video decoding
Definition: codec_id.h:51
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_unref(AVPacket *pkt)
Wipe the packet.
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:86
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
#define AVERROR(e)
Definition: error.h:43
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 int write_frame(AVFormatContext *fmt_ctx, AVCodecContext *c, AVStream *st, AVFrame *frame)
Definition: muxing.c:81
static AVFrame * alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
Definition: muxing.c:385
static AVFrame * get_video_frame(OutputStream *ost)
Definition: muxing.c:473
static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:408
static AVFrame * alloc_audio_frame(enum AVSampleFormat sample_fmt, uint64_t channel_layout, int sample_rate, int nb_samples)
Definition: muxing.c:217
int main(int argc, char **argv)
Definition: muxing.c:537
static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:519
static AVFrame * get_audio_frame(OutputStream *ost)
Definition: muxing.c:310
static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:339
static void close_stream(AVFormatContext *oc, OutputStream *ost)
Definition: muxing.c:525
#define SCALE_FLAGS
Definition: muxing.c:50
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
Definition: muxing.c:70
static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
Definition: muxing.c:452
#define STREAM_DURATION
Definition: muxing.c:46
#define STREAM_FRAME_RATE
Definition: muxing.c:47
#define STREAM_PIX_FMT
Definition: muxing.c:48
static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
Definition: muxing.c:245
static void add_stream(OutputStream *ost, AVFormatContext *oc, AVCodec **codec, enum AVCodecID codec_id)
Definition: muxing.c:123
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:526
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:736
int width
picture width / height.
Definition: avcodec.h:699
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1194
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:786
int mb_decision
macroblock decision mode
Definition: avcodec.h:1014
int64_t bit_rate
the average bitrate
Definition: avcodec.h:576
const struct AVCodec * codec
Definition: avcodec.h:535
int sample_rate
samples per second
Definition: avcodec.h:1186
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:721
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:649
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:606
int channels
number of audio channels
Definition: avcodec.h:1187
enum AVCodecID codec_id
Definition: avcodec.h:536
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1237
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1206
AVCodec.
Definition: codec.h:190
int capabilities
Codec capabilities.
Definition: codec.h:209
Format I/O context.
Definition: avformat.h:1335
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1391
AVIOContext * pb
I/O context.
Definition: avformat.h:1377
ff_const59 struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1354
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1403
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:366
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:393
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:314
int width
Definition: frame.h:358
int height
Definition: frame.h:358
uint64_t channel_layout
Channel layout of the audio data.
Definition: frame.h:477
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:331
int sample_rate
Sample rate of the audio data.
Definition: frame.h:472
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:373
enum AVCodecID video_codec
default video codec
Definition: avformat.h:502
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:501
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:510
This structure stores compressed data.
Definition: packet.h:332
int stream_index
Definition: packet.h:357
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:373
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:348
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:354
Rational number (pair of numerator and denominator).
Definition: rational.h:58
Stream structure.
Definition: avformat.h:865
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1012
int id
Format-specific stream ID.
Definition: avformat.h:872
int index
stream index in AVFormatContext
Definition: avformat.h:866
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:894
float tincr2
Definition: muxing.c:64
AVFrame * frame
Definition: muxing.c:61
int samples_count
Definition: muxing.c:59
struct SwrContext * swr_ctx
Definition: muxing.c:67
AVFrame * tmp_frame
Definition: muxing.c:62
struct SwsContext * sws_ctx
Definition: muxing.c:66
int64_t next_pts
Definition: muxing.c:58
float t
Definition: muxing.c:64
AVStream * st
Definition: muxing.c:54
AVCodecContext * enc
Definition: muxing.c:55
float tincr
Definition: muxing.c:64
libswresample public header
external API header
timestamp utils, mostly useful for debugging/logging purposes
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:76
static AVStream * ost