output-example.c
Go to the documentation of this file.
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 
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <math.h>
36 
37 #include "libavutil/mathematics.h"
38 #include "libavformat/avformat.h"
39 #include "libswscale/swscale.h"
40 
41 /* 5 seconds stream duration */
42 #define STREAM_DURATION 5.0
43 #define STREAM_FRAME_RATE 25 /* 25 images/s */
44 #define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE))
45 #define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */
46 
47 static int sws_flags = SWS_BICUBIC;
48 
49 /**************************************************************/
50 /* audio output */
51 
52 static float t, tincr, tincr2;
53 static int16_t *samples;
55 
56 /*
57  * add an audio output stream
58  */
60 {
61  AVCodecContext *c;
62  AVStream *st;
63  AVCodec *codec;
64 
65  /* find the audio encoder */
66  codec = avcodec_find_encoder(codec_id);
67  if (!codec) {
68  fprintf(stderr, "codec not found\n");
69  exit(1);
70  }
71 
72  st = avformat_new_stream(oc, codec);
73  if (!st) {
74  fprintf(stderr, "Could not alloc stream\n");
75  exit(1);
76  }
77 
78  c = st->codec;
79 
80  /* put sample parameters */
82  c->bit_rate = 64000;
83  c->sample_rate = 44100;
84  c->channels = 2;
85 
86  // some formats want stream headers to be separate
87  if (oc->oformat->flags & AVFMT_GLOBALHEADER)
89 
90  return st;
91 }
92 
93 static void open_audio(AVFormatContext *oc, AVStream *st)
94 {
95  AVCodecContext *c;
96 
97  c = st->codec;
98 
99  /* open it */
100  if (avcodec_open2(c, NULL, NULL) < 0) {
101  fprintf(stderr, "could not open codec\n");
102  exit(1);
103  }
104 
105  /* init signal generator */
106  t = 0;
107  tincr = 2 * M_PI * 110.0 / c->sample_rate;
108  /* increment frequency by 110 Hz per second */
109  tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
110 
112  audio_input_frame_size = 10000;
113  else
117  c->channels);
118 }
119 
120 /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
121  * 'nb_channels' channels. */
122 static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
123 {
124  int j, i, v;
125  int16_t *q;
126 
127  q = samples;
128  for (j = 0; j < frame_size; j++) {
129  v = (int)(sin(t) * 10000);
130  for (i = 0; i < nb_channels; i++)
131  *q++ = v;
132  t += tincr;
133  tincr += tincr2;
134  }
135 }
136 
138 {
139  AVCodecContext *c;
140  AVPacket pkt = { 0 }; // data and size must be 0;
141  AVFrame *frame = avcodec_alloc_frame();
142  int got_packet;
143 
144  av_init_packet(&pkt);
145  c = st->codec;
146 
150  (uint8_t *)samples,
153  c->channels, 1);
154 
155  avcodec_encode_audio2(c, &pkt, frame, &got_packet);
156  if (!got_packet)
157  return;
158 
159  pkt.stream_index = st->index;
160 
161  /* Write the compressed frame to the media file. */
162  if (av_interleaved_write_frame(oc, &pkt) != 0) {
163  fprintf(stderr, "Error while writing audio frame\n");
164  exit(1);
165  }
166  avcodec_free_frame(&frame);
167 }
168 
169 static void close_audio(AVFormatContext *oc, AVStream *st)
170 {
171  avcodec_close(st->codec);
172 
173  av_free(samples);
174 }
175 
176 /**************************************************************/
177 /* video output */
178 
182 
183 /* Add a video output stream. */
185 {
186  AVCodecContext *c;
187  AVStream *st;
188  AVCodec *codec;
189 
190  /* find the video encoder */
191  codec = avcodec_find_encoder(codec_id);
192  if (!codec) {
193  fprintf(stderr, "codec not found\n");
194  exit(1);
195  }
196 
197  st = avformat_new_stream(oc, codec);
198  if (!st) {
199  fprintf(stderr, "Could not alloc stream\n");
200  exit(1);
201  }
202 
203  c = st->codec;
204 
205  /* Put sample parameters. */
206  c->bit_rate = 400000;
207  /* Resolution must be a multiple of two. */
208  c->width = 352;
209  c->height = 288;
210  /* timebase: This is the fundamental unit of time (in seconds) in terms
211  * of which frame timestamps are represented. For fixed-fps content,
212  * timebase should be 1/framerate and timestamp increments should be
213  * identical to 1. */
215  c->time_base.num = 1;
216  c->gop_size = 12; /* emit one intra frame every twelve frames at most */
217  c->pix_fmt = STREAM_PIX_FMT;
218  if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
219  /* just for testing, we also add B frames */
220  c->max_b_frames = 2;
221  }
222  if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
223  /* Needed to avoid using macroblocks in which some coeffs overflow.
224  * This does not happen with normal video, it just happens here as
225  * the motion of the chroma plane does not match the luma plane. */
226  c->mb_decision = 2;
227  }
228  /* Some formats want stream headers to be separate. */
229  if (oc->oformat->flags & AVFMT_GLOBALHEADER)
231 
232  return st;
233 }
234 
236 {
237  AVFrame *picture;
238  uint8_t *picture_buf;
239  int size;
240 
241  picture = avcodec_alloc_frame();
242  if (!picture)
243  return NULL;
244  size = avpicture_get_size(pix_fmt, width, height);
245  picture_buf = av_malloc(size);
246  if (!picture_buf) {
247  av_free(picture);
248  return NULL;
249  }
250  avpicture_fill((AVPicture *)picture, picture_buf,
251  pix_fmt, width, height);
252  return picture;
253 }
254 
255 static void open_video(AVFormatContext *oc, AVStream *st)
256 {
257  AVCodecContext *c;
258 
259  c = st->codec;
260 
261  /* open the codec */
262  if (avcodec_open2(c, NULL, NULL) < 0) {
263  fprintf(stderr, "could not open codec\n");
264  exit(1);
265  }
266 
267  video_outbuf = NULL;
268  if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
269  /* Allocate output buffer. */
270  /* XXX: API change will be done. */
271  /* Buffers passed into lav* can be allocated any way you prefer,
272  * as long as they're aligned enough for the architecture, and
273  * they're freed appropriately (such as using av_free for buffers
274  * allocated with av_malloc). */
275  video_outbuf_size = 200000;
277  }
278 
279  /* Allocate the encoded raw picture. */
280  picture = alloc_picture(c->pix_fmt, c->width, c->height);
281  if (!picture) {
282  fprintf(stderr, "Could not allocate picture\n");
283  exit(1);
284  }
285 
286  /* If the output format is not YUV420P, then a temporary YUV420P
287  * picture is needed too. It is then converted to the required
288  * output format. */
289  tmp_picture = NULL;
290  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
291  tmp_picture = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
292  if (!tmp_picture) {
293  fprintf(stderr, "Could not allocate temporary picture\n");
294  exit(1);
295  }
296  }
297 }
298 
299 /* Prepare a dummy image. */
300 static void fill_yuv_image(AVFrame *pict, int frame_index,
301  int width, int height)
302 {
303  int x, y, i;
304 
305  i = frame_index;
306 
307  /* Y */
308  for (y = 0; y < height; y++)
309  for (x = 0; x < width; x++)
310  pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
311 
312  /* Cb and Cr */
313  for (y = 0; y < height / 2; y++) {
314  for (x = 0; x < width / 2; x++) {
315  pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
316  pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
317  }
318  }
319 }
320 
322 {
323  int out_size, ret;
324  AVCodecContext *c;
325  static struct SwsContext *img_convert_ctx;
326 
327  c = st->codec;
328 
329  if (frame_count >= STREAM_NB_FRAMES) {
330  /* No more frames to compress. The codec has a latency of a few
331  * frames if using B-frames, so we get the last frames by
332  * passing the same picture again. */
333  } else {
334  if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
335  /* as we only generate a YUV420P picture, we must convert it
336  * to the codec pixel format if needed */
337  if (img_convert_ctx == NULL) {
338  img_convert_ctx = sws_getContext(c->width, c->height,
340  c->width, c->height,
341  c->pix_fmt,
342  sws_flags, NULL, NULL, NULL);
343  if (img_convert_ctx == NULL) {
344  fprintf(stderr,
345  "Cannot initialize the conversion context\n");
346  exit(1);
347  }
348  }
349  fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
350  sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize,
351  0, c->height, picture->data, picture->linesize);
352  } else {
353  fill_yuv_image(picture, frame_count, c->width, c->height);
354  }
355  }
356 
357  if (oc->oformat->flags & AVFMT_RAWPICTURE) {
358  /* Raw video case - the API will change slightly in the near
359  * future for that. */
360  AVPacket pkt;
361  av_init_packet(&pkt);
362 
363  pkt.flags |= AV_PKT_FLAG_KEY;
364  pkt.stream_index = st->index;
365  pkt.data = (uint8_t *)picture;
366  pkt.size = sizeof(AVPicture);
367 
368  ret = av_interleaved_write_frame(oc, &pkt);
369  } else {
370  /* encode the image */
371  out_size = avcodec_encode_video(c, video_outbuf,
372  video_outbuf_size, picture);
373  /* If size is zero, it means the image was buffered. */
374  if (out_size > 0) {
375  AVPacket pkt;
376  av_init_packet(&pkt);
377 
378  if (c->coded_frame->pts != AV_NOPTS_VALUE)
379  pkt.pts = av_rescale_q(c->coded_frame->pts,
380  c->time_base, st->time_base);
381  if (c->coded_frame->key_frame)
382  pkt.flags |= AV_PKT_FLAG_KEY;
383  pkt.stream_index = st->index;
384  pkt.data = video_outbuf;
385  pkt.size = out_size;
386 
387  /* Write the compressed frame to the media file. */
388  ret = av_interleaved_write_frame(oc, &pkt);
389  } else {
390  ret = 0;
391  }
392  }
393  if (ret != 0) {
394  fprintf(stderr, "Error while writing video frame\n");
395  exit(1);
396  }
397  frame_count++;
398 }
399 
400 static void close_video(AVFormatContext *oc, AVStream *st)
401 {
402  avcodec_close(st->codec);
403  av_free(picture->data[0]);
404  av_free(picture);
405  if (tmp_picture) {
406  av_free(tmp_picture->data[0]);
407  av_free(tmp_picture);
408  }
410 }
411 
412 /**************************************************************/
413 /* media file output */
414 
415 int main(int argc, char **argv)
416 {
417  const char *filename;
418  AVOutputFormat *fmt;
419  AVFormatContext *oc;
420  AVStream *audio_st, *video_st;
421  double audio_pts, video_pts;
422  int i;
423 
424  /* Initialize libavcodec, and register all codecs and formats. */
425  av_register_all();
426 
427  if (argc != 2) {
428  printf("usage: %s output_file\n"
429  "API example program to output a media file with libavformat.\n"
430  "The output format is automatically guessed according to the file extension.\n"
431  "Raw images can also be output by using '%%d' in the filename\n"
432  "\n", argv[0]);
433  return 1;
434  }
435 
436  filename = argv[1];
437 
438  /* Autodetect the output format from the name. default is MPEG. */
439  fmt = av_guess_format(NULL, filename, NULL);
440  if (!fmt) {
441  printf("Could not deduce output format from file extension: using MPEG.\n");
442  fmt = av_guess_format("mpeg", NULL, NULL);
443  }
444  if (!fmt) {
445  fprintf(stderr, "Could not find suitable output format\n");
446  return 1;
447  }
448 
449  /* Allocate the output media context. */
450  oc = avformat_alloc_context();
451  if (!oc) {
452  fprintf(stderr, "Memory error\n");
453  return 1;
454  }
455  oc->oformat = fmt;
456  snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
457 
458  /* Add the audio and video streams using the default format codecs
459  * and initialize the codecs. */
460  video_st = NULL;
461  audio_st = NULL;
462  if (fmt->video_codec != AV_CODEC_ID_NONE) {
463  video_st = add_video_stream(oc, fmt->video_codec);
464  }
465  if (fmt->audio_codec != AV_CODEC_ID_NONE) {
466  audio_st = add_audio_stream(oc, fmt->audio_codec);
467  }
468 
469  /* Now that all the parameters are set, we can open the audio and
470  * video codecs and allocate the necessary encode buffers. */
471  if (video_st)
472  open_video(oc, video_st);
473  if (audio_st)
474  open_audio(oc, audio_st);
475 
476  av_dump_format(oc, 0, filename, 1);
477 
478  /* open the output file, if needed */
479  if (!(fmt->flags & AVFMT_NOFILE)) {
480  if (avio_open(&oc->pb, filename, AVIO_FLAG_WRITE) < 0) {
481  fprintf(stderr, "Could not open '%s'\n", filename);
482  return 1;
483  }
484  }
485 
486  /* Write the stream header, if any. */
488 
489  for (;;) {
490  /* Compute current audio and video time. */
491  if (audio_st)
492  audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
493  else
494  audio_pts = 0.0;
495 
496  if (video_st)
497  video_pts = (double)video_st->pts.val * video_st->time_base.num /
498  video_st->time_base.den;
499  else
500  video_pts = 0.0;
501 
502  if ((!audio_st || audio_pts >= STREAM_DURATION) &&
503  (!video_st || video_pts >= STREAM_DURATION))
504  break;
505 
506  /* write interleaved audio and video frames */
507  if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
508  write_audio_frame(oc, audio_st);
509  } else {
510  write_video_frame(oc, video_st);
511  }
512  }
513 
514  /* Write the trailer, if any. The trailer must be written before you
515  * close the CodecContexts open when you wrote the header; otherwise
516  * av_write_trailer() may try to use memory that was freed on
517  * av_codec_close(). */
518  av_write_trailer(oc);
519 
520  /* Close each codec. */
521  if (video_st)
522  close_video(oc, video_st);
523  if (audio_st)
524  close_audio(oc, audio_st);
525 
526  /* Free the streams. */
527  for (i = 0; i < oc->nb_streams; i++) {
528  av_freep(&oc->streams[i]->codec);
529  av_freep(&oc->streams[i]);
530  }
531 
532  if (!(fmt->flags & AVFMT_NOFILE))
533  /* Close the output file. */
534  avio_close(oc->pb);
535 
536  /* free the stream */
537  av_free(oc);
538 
539  return 0;
540 }
#define STREAM_NB_FRAMES
int avio_open(AVIOContext **s, const char *url, int flags)
Create and initialize a AVIOContext for accessing the resource indicated by url.
Definition: aviobuf.c:760
const struct AVCodec * codec
Definition: avcodec.h:1348
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:61
static int16_t * samples
int size
This structure describes decoded (raw) audio or video data.
Definition: avcodec.h:989
AVCodec * avcodec_find_encoder(enum AVCodecID id)
Find a registered encoder with a matching codec ID.
Definition: utils.c:1494
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:524
int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:295
int avpicture_fill(AVPicture *picture, uint8_t *ptr, enum AVPixelFormat pix_fmt, int width, int height)
Fill in the AVPicture fields.
Definition: avpicture.c:34
static AVStream * add_audio_stream(AVFormatContext *oc, enum AVCodecID codec_id)
static float tincr
AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2725
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:1588
enum AVCodecID video_codec
default video codec
Definition: avformat.h:387
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...
int num
numerator
Definition: rational.h:44
int index
stream index in AVFormatContext
Definition: avformat.h:623
int size
Definition: avcodec.h:916
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1533
int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Encode a frame of audio.
Definition: utils.c:944
signed 16 bits
Definition: samplefmt.h:52
four components are given, that's all.
Definition: avcodec.h:3153
AVCodec.
Definition: avcodec.h:2960
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avcodec.h:1465
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:151
Format I/O context.
Definition: avformat.h:828
int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels, enum AVSampleFormat sample_fmt, const uint8_t *buf, int buf_size, int align)
Fill audio frame data and linesize.
Definition: utils.c:264
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2112
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, AVFMT_TS_NONSTRICT
Definition: avformat.h:395
uint8_t
int64_t pts
presentation timestamp in time_base units (time when frame should be shown to user) If AV_NOPTS_VALUE...
Definition: avcodec.h:1088
static AVFrame * tmp_picture
static uint8_t * video_outbuf
static void close_video(AVFormatContext *oc, AVStream *st)
AVStream ** streams
Definition: avformat.h:876
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:97
uint8_t * data
Definition: avcodec.h:915
external api for the swscale stuff
static void write_video_frame(AVFormatContext *oc, AVStream *st)
static float t
static void write_audio_frame(AVFormatContext *oc, AVStream *st)
struct AVOutputFormat * oformat
Definition: avformat.h:842
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:122
static const uint8_t frame_size[4]
Definition: g723_1_data.h:47
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Definition: utils.c:2952
int avcodec_close(AVCodecContext *avctx)
Close a given AVCodecContext and free all the data associated with it (but not the AVCodecContext its...
Definition: utils.c:1435
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.
Definition: utils.c:1282
static int sws_flags
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:95
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:139
static float tincr2
static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
#define SWS_BICUBIC
Definition: swscale.h:55
int avio_close(AVIOContext *s)
Close the resource accessed by the AVIOContext s and free it.
Definition: aviobuf.c:782
int capabilities
Codec capabilities.
Definition: avcodec.h:2979
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1434
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2736
enum AVCodecID codec_id
Definition: mov_chan.c:432
struct AVPicture AVPicture
four components are given, that's all.
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:921
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:641
AVFrame * avcodec_alloc_frame(void)
Allocate an AVFrame and set its fields to default values.
Definition: utils.c:616
unsigned int nb_streams
A list of all streams in the file.
Definition: avformat.h:875
int bit_rate
the average bitrate
Definition: avcodec.h:1404
static AVFrame * picture
char filename[1024]
input or output filename
Definition: avformat.h:878
int width
picture width / height.
Definition: avcodec.h:1508
static int audio_input_frame_size
static void close_audio(AVFormatContext *oc, AVStream *st)
#define STREAM_FRAME_RATE
static int frame_count
static AVFrame * alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: utils.c:151
int mb_decision
macroblock decision mode
Definition: avcodec.h:1882
enum AVPixelFormat pix_fmt
Definition: movenc.c:801
static int video_outbuf_size
int main(int argc, char **argv)
preferred ID for MPEG-1/2 video decoding
Definition: avcodec.h:100
#define STREAM_DURATION
int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt)
Return number of bytes per sample.
Definition: samplefmt.c:95
Stream structure.
Definition: avformat.h:622
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:2124
NULL
Definition: eval.c:52
static int width
Definition: utils.c:156
static void open_audio(AVFormatContext *oc, AVStream *st)
enum AVCodecID codec_id
Definition: avcodec.h:1350
int sample_rate
samples per second
Definition: avcodec.h:2104
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
AVIOContext * pb
I/O context.
Definition: avformat.h:861
static void open_video(AVFormatContext *oc, AVStream *st)
main external API structure.
Definition: avcodec.h:1339
#define STREAM_PIX_FMT
static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
static AVStream * add_video_stream(AVFormatContext *oc, enum AVCodecID codec_id)
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
Definition: utils.c:643
int64_t val
Definition: avformat.h:327
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
int height
Definition: gxfenc.c:72
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:1524
Main libavformat public API header.
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:65
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
Definition: avpacket.c:42
int den
denominator
Definition: rational.h:45
struct AVFrac pts
encoding: pts generation when outputting stream
Definition: avformat.h:658
int channels
number of audio channels
Definition: avcodec.h:2105
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:386
int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height)
Calculate the size in bytes that a picture of the given width and height would occupy if stored in th...
Definition: avpicture.c:85
int key_frame
1 -> keyframe, 0-> not
Definition: avcodec.h:1058
void avcodec_free_frame(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: utils.c:628
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:565
int nb_channels
int stream_index
Definition: avcodec.h:917
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:669
AVPixelFormat
Pixel format.
Definition: pixfmt.h:63
This structure stores compressed data.
Definition: avcodec.h:898
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
Definition: allformats.c:52
int nb_samples
number of audio samples (per channel) described by this frame
Definition: avcodec.h:1042
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:908
for(j=16;j >0;--j)
if(!(ptr_align%ac->ptr_align)&&samples_align >=aligned_len)