FFmpeg
transcoding.c
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1 /*
2  * Copyright (c) 2010 Nicolas George
3  * Copyright (c) 2011 Stefano Sabatini
4  * Copyright (c) 2014 Andrey Utkin
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 /**
26  * @file
27  * API example for demuxing, decoding, filtering, encoding and muxing
28  * @example transcoding.c
29  */
30 
31 #include <libavcodec/avcodec.h>
32 #include <libavformat/avformat.h>
33 #include <libavfilter/buffersink.h>
34 #include <libavfilter/buffersrc.h>
36 #include <libavutil/opt.h>
37 #include <libavutil/pixdesc.h>
38 
41 typedef struct FilteringContext {
45 
50 
51 typedef struct StreamContext {
54 
58 
59 static int open_input_file(const char *filename)
60 {
61  int ret;
62  unsigned int i;
63 
64  ifmt_ctx = NULL;
65  if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
66  av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
67  return ret;
68  }
69 
71  av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
72  return ret;
73  }
74 
76  if (!stream_ctx)
77  return AVERROR(ENOMEM);
78 
79  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
80  AVStream *stream = ifmt_ctx->streams[i];
81  const AVCodec *dec = avcodec_find_decoder(stream->codecpar->codec_id);
82  AVCodecContext *codec_ctx;
83  if (!dec) {
84  av_log(NULL, AV_LOG_ERROR, "Failed to find decoder for stream #%u\n", i);
86  }
87  codec_ctx = avcodec_alloc_context3(dec);
88  if (!codec_ctx) {
89  av_log(NULL, AV_LOG_ERROR, "Failed to allocate the decoder context for stream #%u\n", i);
90  return AVERROR(ENOMEM);
91  }
92  ret = avcodec_parameters_to_context(codec_ctx, stream->codecpar);
93  if (ret < 0) {
94  av_log(NULL, AV_LOG_ERROR, "Failed to copy decoder parameters to input decoder context "
95  "for stream #%u\n", i);
96  return ret;
97  }
98  /* Reencode video & audio and remux subtitles etc. */
99  if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
100  || codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
101  if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO)
102  codec_ctx->framerate = av_guess_frame_rate(ifmt_ctx, stream, NULL);
103  /* Open decoder */
104  ret = avcodec_open2(codec_ctx, dec, NULL);
105  if (ret < 0) {
106  av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
107  return ret;
108  }
109  }
110  stream_ctx[i].dec_ctx = codec_ctx;
111 
113  if (!stream_ctx[i].dec_frame)
114  return AVERROR(ENOMEM);
115  }
116 
117  av_dump_format(ifmt_ctx, 0, filename, 0);
118  return 0;
119 }
120 
121 static int open_output_file(const char *filename)
122 {
123  AVStream *out_stream;
124  AVStream *in_stream;
125  AVCodecContext *dec_ctx, *enc_ctx;
126  const AVCodec *encoder;
127  int ret;
128  unsigned int i;
129 
130  ofmt_ctx = NULL;
132  if (!ofmt_ctx) {
133  av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
134  return AVERROR_UNKNOWN;
135  }
136 
137 
138  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
139  out_stream = avformat_new_stream(ofmt_ctx, NULL);
140  if (!out_stream) {
141  av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
142  return AVERROR_UNKNOWN;
143  }
144 
145  in_stream = ifmt_ctx->streams[i];
147 
150  /* in this example, we choose transcoding to same codec */
152  if (!encoder) {
153  av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");
154  return AVERROR_INVALIDDATA;
155  }
156  enc_ctx = avcodec_alloc_context3(encoder);
157  if (!enc_ctx) {
158  av_log(NULL, AV_LOG_FATAL, "Failed to allocate the encoder context\n");
159  return AVERROR(ENOMEM);
160  }
161 
162  /* In this example, we transcode to same properties (picture size,
163  * sample rate etc.). These properties can be changed for output
164  * streams easily using filters */
166  enc_ctx->height = dec_ctx->height;
167  enc_ctx->width = dec_ctx->width;
169  /* take first format from list of supported formats */
170  if (encoder->pix_fmts)
171  enc_ctx->pix_fmt = encoder->pix_fmts[0];
172  else
173  enc_ctx->pix_fmt = dec_ctx->pix_fmt;
174  /* video time_base can be set to whatever is handy and supported by encoder */
175  enc_ctx->time_base = av_inv_q(dec_ctx->framerate);
176  } else {
177  enc_ctx->sample_rate = dec_ctx->sample_rate;
179  if (ret < 0)
180  return ret;
181  /* take first format from list of supported formats */
182  enc_ctx->sample_fmt = encoder->sample_fmts[0];
183  enc_ctx->time_base = (AVRational){1, enc_ctx->sample_rate};
184  }
185 
188 
189  /* Third parameter can be used to pass settings to encoder */
190  ret = avcodec_open2(enc_ctx, encoder, NULL);
191  if (ret < 0) {
192  av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
193  return ret;
194  }
195  ret = avcodec_parameters_from_context(out_stream->codecpar, enc_ctx);
196  if (ret < 0) {
197  av_log(NULL, AV_LOG_ERROR, "Failed to copy encoder parameters to output stream #%u\n", i);
198  return ret;
199  }
200 
201  out_stream->time_base = enc_ctx->time_base;
202  stream_ctx[i].enc_ctx = enc_ctx;
203  } else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
204  av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
205  return AVERROR_INVALIDDATA;
206  } else {
207  /* if this stream must be remuxed */
208  ret = avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar);
209  if (ret < 0) {
210  av_log(NULL, AV_LOG_ERROR, "Copying parameters for stream #%u failed\n", i);
211  return ret;
212  }
213  out_stream->time_base = in_stream->time_base;
214  }
215 
216  }
217  av_dump_format(ofmt_ctx, 0, filename, 1);
218 
219  if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
220  ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
221  if (ret < 0) {
222  av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
223  return ret;
224  }
225  }
226 
227  /* init muxer, write output file header */
229  if (ret < 0) {
230  av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
231  return ret;
232  }
233 
234  return 0;
235 }
236 
238  AVCodecContext *enc_ctx, const char *filter_spec)
239 {
240  char args[512];
241  int ret = 0;
242  const AVFilter *buffersrc = NULL;
243  const AVFilter *buffersink = NULL;
249 
250  if (!outputs || !inputs || !filter_graph) {
251  ret = AVERROR(ENOMEM);
252  goto end;
253  }
254 
256  buffersrc = avfilter_get_by_name("buffer");
257  buffersink = avfilter_get_by_name("buffersink");
258  if (!buffersrc || !buffersink) {
259  av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
261  goto end;
262  }
263 
264  snprintf(args, sizeof(args),
265  "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
270 
271  ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
272  args, NULL, filter_graph);
273  if (ret < 0) {
274  av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
275  goto end;
276  }
277 
278  ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
280  if (ret < 0) {
281  av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
282  goto end;
283  }
284 
285  ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
286  (uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
288  if (ret < 0) {
289  av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
290  goto end;
291  }
292  } else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
293  char buf[64];
294  buffersrc = avfilter_get_by_name("abuffer");
295  buffersink = avfilter_get_by_name("abuffersink");
296  if (!buffersrc || !buffersink) {
297  av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
299  goto end;
300  }
301 
304  av_channel_layout_describe(&dec_ctx->ch_layout, buf, sizeof(buf));
305  snprintf(args, sizeof(args),
306  "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=%s",
309  buf);
310  ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
311  args, NULL, filter_graph);
312  if (ret < 0) {
313  av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
314  goto end;
315  }
316 
317  ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
319  if (ret < 0) {
320  av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
321  goto end;
322  }
323 
324  ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
325  (uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
327  if (ret < 0) {
328  av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
329  goto end;
330  }
331 
332  av_channel_layout_describe(&enc_ctx->ch_layout, buf, sizeof(buf));
333  ret = av_opt_set(buffersink_ctx, "ch_layouts",
335  if (ret < 0) {
336  av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
337  goto end;
338  }
339 
340  ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
341  (uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
343  if (ret < 0) {
344  av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
345  goto end;
346  }
347  } else {
349  goto end;
350  }
351 
352  /* Endpoints for the filter graph. */
353  outputs->name = av_strdup("in");
354  outputs->filter_ctx = buffersrc_ctx;
355  outputs->pad_idx = 0;
356  outputs->next = NULL;
357 
358  inputs->name = av_strdup("out");
359  inputs->filter_ctx = buffersink_ctx;
360  inputs->pad_idx = 0;
361  inputs->next = NULL;
362 
363  if (!outputs->name || !inputs->name) {
364  ret = AVERROR(ENOMEM);
365  goto end;
366  }
367 
368  if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
369  &inputs, &outputs, NULL)) < 0)
370  goto end;
371 
373  goto end;
374 
375  /* Fill FilteringContext */
378  fctx->filter_graph = filter_graph;
379 
380 end:
383 
384  return ret;
385 }
386 
387 static int init_filters(void)
388 {
389  const char *filter_spec;
390  unsigned int i;
391  int ret;
393  if (!filter_ctx)
394  return AVERROR(ENOMEM);
395 
396  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
402  continue;
403 
404 
406  filter_spec = "null"; /* passthrough (dummy) filter for video */
407  else
408  filter_spec = "anull"; /* passthrough (dummy) filter for audio */
410  stream_ctx[i].enc_ctx, filter_spec);
411  if (ret)
412  return ret;
413 
415  if (!filter_ctx[i].enc_pkt)
416  return AVERROR(ENOMEM);
417 
419  if (!filter_ctx[i].filtered_frame)
420  return AVERROR(ENOMEM);
421  }
422  return 0;
423 }
424 
425 static int encode_write_frame(unsigned int stream_index, int flush)
426 {
427  StreamContext *stream = &stream_ctx[stream_index];
428  FilteringContext *filter = &filter_ctx[stream_index];
429  AVFrame *filt_frame = flush ? NULL : filter->filtered_frame;
430  AVPacket *enc_pkt = filter->enc_pkt;
431  int ret;
432 
433  av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
434  /* encode filtered frame */
435  av_packet_unref(enc_pkt);
436 
437  ret = avcodec_send_frame(stream->enc_ctx, filt_frame);
438 
439  if (ret < 0)
440  return ret;
441 
442  while (ret >= 0) {
443  ret = avcodec_receive_packet(stream->enc_ctx, enc_pkt);
444 
445  if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
446  return 0;
447 
448  /* prepare packet for muxing */
449  enc_pkt->stream_index = stream_index;
450  av_packet_rescale_ts(enc_pkt,
451  stream->enc_ctx->time_base,
452  ofmt_ctx->streams[stream_index]->time_base);
453 
454  av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
455  /* mux encoded frame */
457  }
458 
459  return ret;
460 }
461 
462 static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
463 {
464  FilteringContext *filter = &filter_ctx[stream_index];
465  int ret;
466 
467  av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
468  /* push the decoded frame into the filtergraph */
469  ret = av_buffersrc_add_frame_flags(filter->buffersrc_ctx,
470  frame, 0);
471  if (ret < 0) {
472  av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
473  return ret;
474  }
475 
476  /* pull filtered frames from the filtergraph */
477  while (1) {
478  av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
479  ret = av_buffersink_get_frame(filter->buffersink_ctx,
480  filter->filtered_frame);
481  if (ret < 0) {
482  /* if no more frames for output - returns AVERROR(EAGAIN)
483  * if flushed and no more frames for output - returns AVERROR_EOF
484  * rewrite retcode to 0 to show it as normal procedure completion
485  */
486  if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
487  ret = 0;
488  break;
489  }
490 
491  filter->filtered_frame->pict_type = AV_PICTURE_TYPE_NONE;
492  ret = encode_write_frame(stream_index, 0);
493  av_frame_unref(filter->filtered_frame);
494  if (ret < 0)
495  break;
496  }
497 
498  return ret;
499 }
500 
501 static int flush_encoder(unsigned int stream_index)
502 {
503  if (!(stream_ctx[stream_index].enc_ctx->codec->capabilities &
505  return 0;
506 
507  av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
508  return encode_write_frame(stream_index, 1);
509 }
510 
511 int main(int argc, char **argv)
512 {
513  int ret;
514  AVPacket *packet = NULL;
515  unsigned int stream_index;
516  unsigned int i;
517 
518  if (argc != 3) {
519  av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
520  return 1;
521  }
522 
523  if ((ret = open_input_file(argv[1])) < 0)
524  goto end;
525  if ((ret = open_output_file(argv[2])) < 0)
526  goto end;
527  if ((ret = init_filters()) < 0)
528  goto end;
529  if (!(packet = av_packet_alloc()))
530  goto end;
531 
532  /* read all packets */
533  while (1) {
534  if ((ret = av_read_frame(ifmt_ctx, packet)) < 0)
535  break;
536  stream_index = packet->stream_index;
537  av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
538  stream_index);
539 
540  if (filter_ctx[stream_index].filter_graph) {
541  StreamContext *stream = &stream_ctx[stream_index];
542 
543  av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
544 
545  av_packet_rescale_ts(packet,
546  ifmt_ctx->streams[stream_index]->time_base,
547  stream->dec_ctx->time_base);
548  ret = avcodec_send_packet(stream->dec_ctx, packet);
549  if (ret < 0) {
550  av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
551  break;
552  }
553 
554  while (ret >= 0) {
555  ret = avcodec_receive_frame(stream->dec_ctx, stream->dec_frame);
556  if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN))
557  break;
558  else if (ret < 0)
559  goto end;
560 
561  stream->dec_frame->pts = stream->dec_frame->best_effort_timestamp;
562  ret = filter_encode_write_frame(stream->dec_frame, stream_index);
563  if (ret < 0)
564  goto end;
565  }
566  } else {
567  /* remux this frame without reencoding */
568  av_packet_rescale_ts(packet,
569  ifmt_ctx->streams[stream_index]->time_base,
570  ofmt_ctx->streams[stream_index]->time_base);
571 
573  if (ret < 0)
574  goto end;
575  }
576  av_packet_unref(packet);
577  }
578 
579  /* flush filters and encoders */
580  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
581  /* flush filter */
582  if (!filter_ctx[i].filter_graph)
583  continue;
585  if (ret < 0) {
586  av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
587  goto end;
588  }
589 
590  /* flush encoder */
591  ret = flush_encoder(i);
592  if (ret < 0) {
593  av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
594  goto end;
595  }
596  }
597 
599 end:
600  av_packet_free(&packet);
601  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
604  avcodec_free_context(&stream_ctx[i].enc_ctx);
607  av_packet_free(&filter_ctx[i].enc_pkt);
608  av_frame_free(&filter_ctx[i].filtered_frame);
609  }
610 
611  av_frame_free(&stream_ctx[i].dec_frame);
612  }
619 
620  if (ret < 0)
621  av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));
622 
623  return ret ? 1 : 0;
624 }
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:422
AVCodec
AVCodec.
Definition: codec.h:204
avcodec_receive_packet
int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
Read encoded data from the encoder.
Definition: encode.c:452
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: options.c:237
filter_ctx
static FilteringContext * filter_ctx
Definition: transcoding.c:49
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:57
AVCodecContext::sample_rate
int sample_rate
samples per second
Definition: avcodec.h:1007
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
buffersink_ctx
AVFilterContext * buffersink_ctx
Definition: filtering_audio.c:45
FilteringContext::filtered_frame
AVFrame * filtered_frame
Definition: transcoding.c:47
avcodec_parameters_from_context
int avcodec_parameters_from_context(AVCodecParameters *par, const AVCodecContext *codec)
Fill the parameters struct based on the values from the supplied codec context.
Definition: codec_par.c:99
main
int main(int argc, char **argv)
Definition: transcoding.c:511
AVCodec::pix_fmts
enum AVPixelFormat * pix_fmts
array of supported pixel formats, or NULL if unknown, array is terminated by -1
Definition: codec.h:226
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:116
avcodec_find_encoder
const AVCodec * avcodec_find_encoder(enum AVCodecID id)
Find a registered encoder with a matching codec ID.
Definition: allcodecs.c:934
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
pixdesc.h
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1281
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:432
ofmt_ctx
static AVFormatContext * ofmt_ctx
Definition: transcoding.c:40
encode_write_frame
static int encode_write_frame(unsigned int stream_index, int flush)
Definition: transcoding.c:425
filter
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
Definition: filter_design.txt:228
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:295
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: demux.c:1438
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:300
StreamContext::dec_frame
AVFrame * dec_frame
Definition: transcoding.c:55
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:73
AV_CODEC_FLAG_GLOBAL_HEADER
#define AV_CODEC_FLAG_GLOBAL_HEADER
Place global headers in extradata instead of every keyframe.
Definition: avcodec.h:284
avfilter_graph_free
void avfilter_graph_free(AVFilterGraph **graph)
Free a graph, destroy its links, and set *graph to NULL.
Definition: avfiltergraph.c:119
av_channel_layout_copy
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
Make a copy of a channel layout.
Definition: channel_layout.c:637
AVCodecContext::framerate
AVRational framerate
Definition: avcodec.h:1741
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: demux.c:368
flush_encoder
static int flush_encoder(unsigned int stream_index)
Definition: transcoding.c:501
FilteringContext
Definition: transcoding.c:41
avfilter_graph_create_filter
int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt, const char *name, const char *args, void *opaque, AVFilterGraph *graph_ctx)
Create and add a filter instance into an existing graph.
Definition: avfiltergraph.c:138
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2065
filter_graph
AVFilterGraph * filter_graph
Definition: filtering_audio.c:47
AVCodec::sample_fmts
enum AVSampleFormat * sample_fmts
array of supported sample formats, or NULL if unknown, array is terminated by -1
Definition: codec.h:228
avfilter_graph_alloc
AVFilterGraph * avfilter_graph_alloc(void)
Allocate a filter graph.
Definition: avfiltergraph.c:82
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:478
av_opt_set
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:487
AVRational::num
int num
Numerator.
Definition: rational.h:59
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:104
avfilter_inout_free
void avfilter_inout_free(AVFilterInOut **inout)
Free the supplied list of AVFilterInOut and set *inout to NULL.
Definition: graphparser.c:212
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_dump_format
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,...
Definition: dump.c:630
avformat_open_input
int avformat_open_input(AVFormatContext **ps, const char *url, const AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: demux.c:220
avcodec_alloc_context3
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:149
AV_CHANNEL_ORDER_UNSPEC
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
Definition: channel_layout.h:106
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
av_buffersink_get_frame
int attribute_align_arg av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame)
Get a frame with filtered data from sink and put it in frame.
Definition: buffersink.c:94
avcodec_receive_frame
int attribute_align_arg avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder or encoder (when the AV_CODEC_FLAG_RECON_FRAME flag is used...
Definition: avcodec.c:718
outputs
static const AVFilterPad outputs[]
Definition: af_acontrast.c:172
AVIO_FLAG_WRITE
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:629
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
av_get_sample_fmt_name
const char * av_get_sample_fmt_name(enum AVSampleFormat sample_fmt)
Return the name of sample_fmt, or NULL if sample_fmt is not recognized.
Definition: samplefmt.c:51
buffersrc_ctx
AVFilterContext * buffersrc_ctx
Definition: filtering_audio.c:46
avformat_write_header
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.
Definition: mux.c:449
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:408
FilteringContext::buffersrc_ctx
AVFilterContext * buffersrc_ctx
Definition: transcoding.c:43
AVFormatContext
Format I/O context.
Definition: avformat.h:1213
avfilter_get_by_name
const AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
Definition: allfilters.c:596
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
avfilter_graph_config
int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
Check validity and configure all the links and formats in the graph.
Definition: avfiltergraph.c:1167
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:978
flush
static void flush(AVCodecContext *avctx)
Definition: aacdec_template.c:606
NULL
#define NULL
Definition: coverity.c:32
av_opt_set_bin
int av_opt_set_bin(void *obj, const char *name, const uint8_t *val, int len, int search_flags)
Definition: opt.c:639
init_filters
static int init_filters(void)
Definition: transcoding.c:387
avcodec_free_context
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer.
Definition: options.c:164
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1255
av_channel_layout_default
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
Get the default channel layout for a given number of channels.
Definition: channel_layout.c:960
avfilter_inout_alloc
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
Definition: graphparser.c:207
avcodec_open2
int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
Definition: avcodec.c:115
AVFilterGraph
Definition: avfilter.h:871
inputs
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
Definition: filter_design.txt:243
stream_ctx
static StreamContext * stream_ctx
Definition: transcoding.c:57
avcodec_find_decoder
const AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
Definition: allcodecs.c:939
AVFrame::best_effort_timestamp
int64_t best_effort_timestamp
frame timestamp estimated using various heuristics, in stream time base
Definition: frame.h:598
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1269
StreamContext
Definition: transcoding.c:51
AVOutputFormat::flags
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:529
AVCodecContext::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:521
avformat_find_stream_info
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: demux.c:2415
open_output_file
static int open_output_file(const char *filename)
Definition: transcoding.c:121
av_err2str
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:121
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1023
av_guess_frame_rate
AVRational av_guess_frame_rate(AVFormatContext *format, AVStream *st, AVFrame *frame)
Guess the frame rate, based on both the container and codec information.
Definition: avformat.c:678
AVFMT_NOFILE
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:470
AVMEDIA_TYPE_UNKNOWN
@ AVMEDIA_TYPE_UNKNOWN
Usually treated as AVMEDIA_TYPE_DATA.
Definition: avutil.h:200
AV_PICTURE_TYPE_NONE
@ AV_PICTURE_TYPE_NONE
Undefined.
Definition: avutil.h:273
AV_OPT_SEARCH_CHILDREN
#define AV_OPT_SEARCH_CHILDREN
Search in possible children of the given object first.
Definition: opt.h:563
FilteringContext::enc_pkt
AVPacket * enc_pkt
Definition: transcoding.c:46
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:62
av_packet_rescale_ts
void av_packet_rescale_ts(AVPacket *pkt, AVRational src_tb, AVRational dst_tb)
Convert valid timing fields (timestamps / durations) in a packet from one timebase to another.
Definition: avpacket.c:526
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:191
buffersink.h
avcodec_parameters_copy
int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src)
Copy the contents of src to dst.
Definition: codec_par.c:74
avcodec_send_packet
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
Definition: decode.c:637
avio_closep
int avio_closep(AVIOContext **s)
Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL...
Definition: aviobuf.c:1288
av_write_trailer
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1250
open_input_file
static int open_input_file(const char *filename)
Definition: transcoding.c:59
StreamContext::dec_ctx
AVCodecContext * dec_ctx
Definition: transcoding.c:52
AVFMT_GLOBALHEADER
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:480
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
avfilter_graph_parse_ptr
int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters, AVFilterInOut **inputs, AVFilterInOut **outputs, void *log_ctx)
Add a graph described by a string to a graph.
Definition: graphparser.c:549
avcodec_parameters_to_context
int avcodec_parameters_to_context(AVCodecContext *codec, const AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
Definition: codec_par.c:182
av_buffersrc_add_frame_flags
int attribute_align_arg av_buffersrc_add_frame_flags(AVFilterContext *ctx, AVFrame *frame, int flags)
Add a frame to the buffer source.
Definition: buffersrc.c:178
av_malloc_array
#define av_malloc_array(a, b)
Definition: tableprint_vlc.h:31
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:487
av_inv_q
static av_always_inline AVRational av_inv_q(AVRational q)
Invert a rational.
Definition: rational.h:159
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
AVCodecContext::height
int height
Definition: avcodec.h:571
avcodec_send_frame
int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame)
Supply a raw video or audio frame to the encoder.
Definition: encode.c:419
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:272
avcodec.h
AVFilter
Filter definition.
Definition: avfilter.h:171
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:948
AV_LOG_FATAL
#define AV_LOG_FATAL
Something went wrong and recovery is not possible.
Definition: log.h:174
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
AVFormatContext::oformat
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1232
avformat.h
StreamContext::enc_ctx
AVCodecContext * enc_ctx
Definition: transcoding.c:53
AVCodecContext
main external API structure.
Definition: avcodec.h:398
channel_layout.h
AVRational::den
int den
Denominator.
Definition: rational.h:60
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: avformat.c:95
AV_CODEC_CAP_DELAY
#define AV_CODEC_CAP_DELAY
Encoder or decoder requires flushing with NULL input at the end in order to give the complete and cor...
Definition: codec.h:82
av_channel_layout_describe
int av_channel_layout_describe(const AVChannelLayout *channel_layout, char *buf, size_t buf_size)
Get a human-readable string describing the channel layout properties.
Definition: channel_layout.c:776
avio_open
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:1223
AVPacket::stream_index
int stream_index
Definition: packet.h:376
ifmt_ctx
static AVFormatContext * ifmt_ctx
Definition: transcoding.c:39
AVFilterContext
An instance of a filter.
Definition: avfilter.h:408
AVERROR_DECODER_NOT_FOUND
#define AVERROR_DECODER_NOT_FOUND
Decoder not found.
Definition: error.h:54
AVCodecContext::codec_type
enum AVMediaType codec_type
Definition: avcodec.h:406
av_strdup
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:280
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:61
AVPacket
This structure stores compressed data.
Definition: packet.h:351
av_interleaved_write_frame
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1235
FilteringContext::buffersink_ctx
AVFilterContext * buffersink_ctx
Definition: transcoding.c:42
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
avformat_alloc_output_context2
int avformat_alloc_output_context2(AVFormatContext **ctx, const AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:91
AVFilterInOut
A linked-list of the inputs/outputs of the filter chain.
Definition: avfilter.h:1031
snprintf
#define snprintf
Definition: snprintf.h:34
FilteringContext::filter_graph
AVFilterGraph * filter_graph
Definition: transcoding.c:44
buffersrc.h
init_filter
static int init_filter(FilteringContext *fctx, AVCodecContext *dec_ctx, AVCodecContext *enc_ctx, const char *filter_spec)
Definition: transcoding.c:237
AVCodecContext::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel.
Definition: avcodec.h:768
dec_ctx
static AVCodecContext * dec_ctx
Definition: filtering_audio.c:44
filter_encode_write_frame
static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
Definition: transcoding.c:462