FFmpeg
demuxing_decoding.c
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1 /*
2  * Copyright (c) 2012 Stefano Sabatini
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  * Demuxing and decoding example.
26  *
27  * Show how to use the libavformat and libavcodec API to demux and
28  * decode audio and video data.
29  * @example demuxing_decoding.c
30  */
31 
32 #include <libavutil/imgutils.h>
33 #include <libavutil/samplefmt.h>
34 #include <libavutil/timestamp.h>
35 #include <libavcodec/avcodec.h>
36 #include <libavformat/avformat.h>
37 
40 static int width, height;
41 static enum AVPixelFormat pix_fmt;
43 static const char *src_filename = NULL;
44 static const char *video_dst_filename = NULL;
45 static const char *audio_dst_filename = NULL;
46 static FILE *video_dst_file = NULL;
47 static FILE *audio_dst_file = NULL;
48 
49 static uint8_t *video_dst_data[4] = {NULL};
50 static int video_dst_linesize[4];
51 static int video_dst_bufsize;
52 
53 static int video_stream_idx = -1, audio_stream_idx = -1;
54 static AVFrame *frame = NULL;
55 static AVPacket *pkt = NULL;
56 static int video_frame_count = 0;
57 static int audio_frame_count = 0;
58 
60 {
61  if (frame->width != width || frame->height != height ||
62  frame->format != pix_fmt) {
63  /* To handle this change, one could call av_image_alloc again and
64  * decode the following frames into another rawvideo file. */
65  fprintf(stderr, "Error: Width, height and pixel format have to be "
66  "constant in a rawvideo file, but the width, height or "
67  "pixel format of the input video changed:\n"
68  "old: width = %d, height = %d, format = %s\n"
69  "new: width = %d, height = %d, format = %s\n",
73  return -1;
74  }
75 
76  printf("video_frame n:%d coded_n:%d\n",
78 
79  /* copy decoded frame to destination buffer:
80  * this is required since rawvideo expects non aligned data */
82  (const uint8_t **)(frame->data), frame->linesize,
83  pix_fmt, width, height);
84 
85  /* write to rawvideo file */
87  return 0;
88 }
89 
91 {
92  size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);
93  printf("audio_frame n:%d nb_samples:%d pts:%s\n",
96 
97  /* Write the raw audio data samples of the first plane. This works
98  * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,
99  * most audio decoders output planar audio, which uses a separate
100  * plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).
101  * In other words, this code will write only the first audio channel
102  * in these cases.
103  * You should use libswresample or libavfilter to convert the frame
104  * to packed data. */
105  fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);
106 
107  return 0;
108 }
109 
110 static int decode_packet(AVCodecContext *dec, const AVPacket *pkt)
111 {
112  int ret = 0;
113 
114  // submit the packet to the decoder
115  ret = avcodec_send_packet(dec, pkt);
116  if (ret < 0) {
117  fprintf(stderr, "Error submitting a packet for decoding (%s)\n", av_err2str(ret));
118  return ret;
119  }
120 
121  // get all the available frames from the decoder
122  while (ret >= 0) {
124  if (ret < 0) {
125  // those two return values are special and mean there is no output
126  // frame available, but there were no errors during decoding
127  if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN))
128  return 0;
129 
130  fprintf(stderr, "Error during decoding (%s)\n", av_err2str(ret));
131  return ret;
132  }
133 
134  // write the frame data to output file
135  if (dec->codec->type == AVMEDIA_TYPE_VIDEO)
137  else
139 
141  if (ret < 0)
142  return ret;
143  }
144 
145  return 0;
146 }
147 
148 static int open_codec_context(int *stream_idx,
150 {
151  int ret, stream_index;
152  AVStream *st;
153  const AVCodec *dec = NULL;
154 
155  ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
156  if (ret < 0) {
157  fprintf(stderr, "Could not find %s stream in input file '%s'\n",
159  return ret;
160  } else {
161  stream_index = ret;
162  st = fmt_ctx->streams[stream_index];
163 
164  /* find decoder for the stream */
166  if (!dec) {
167  fprintf(stderr, "Failed to find %s codec\n",
169  return AVERROR(EINVAL);
170  }
171 
172  /* Allocate a codec context for the decoder */
174  if (!*dec_ctx) {
175  fprintf(stderr, "Failed to allocate the %s codec context\n",
177  return AVERROR(ENOMEM);
178  }
179 
180  /* Copy codec parameters from input stream to output codec context */
181  if ((ret = avcodec_parameters_to_context(*dec_ctx, st->codecpar)) < 0) {
182  fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",
184  return ret;
185  }
186 
187  /* Init the decoders */
188  if ((ret = avcodec_open2(*dec_ctx, dec, NULL)) < 0) {
189  fprintf(stderr, "Failed to open %s codec\n",
191  return ret;
192  }
193  *stream_idx = stream_index;
194  }
195 
196  return 0;
197 }
198 
199 static int get_format_from_sample_fmt(const char **fmt,
200  enum AVSampleFormat sample_fmt)
201 {
202  int i;
203  struct sample_fmt_entry {
204  enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;
205  } sample_fmt_entries[] = {
206  { AV_SAMPLE_FMT_U8, "u8", "u8" },
207  { AV_SAMPLE_FMT_S16, "s16be", "s16le" },
208  { AV_SAMPLE_FMT_S32, "s32be", "s32le" },
209  { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },
210  { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },
211  };
212  *fmt = NULL;
213 
214  for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {
215  struct sample_fmt_entry *entry = &sample_fmt_entries[i];
216  if (sample_fmt == entry->sample_fmt) {
217  *fmt = AV_NE(entry->fmt_be, entry->fmt_le);
218  return 0;
219  }
220  }
221 
222  fprintf(stderr,
223  "sample format %s is not supported as output format\n",
224  av_get_sample_fmt_name(sample_fmt));
225  return -1;
226 }
227 
228 int main (int argc, char **argv)
229 {
230  int ret = 0;
231 
232  if (argc != 4) {
233  fprintf(stderr, "usage: %s input_file video_output_file audio_output_file\n"
234  "API example program to show how to read frames from an input file.\n"
235  "This program reads frames from a file, decodes them, and writes decoded\n"
236  "video frames to a rawvideo file named video_output_file, and decoded\n"
237  "audio frames to a rawaudio file named audio_output_file.\n",
238  argv[0]);
239  exit(1);
240  }
241  src_filename = argv[1];
242  video_dst_filename = argv[2];
243  audio_dst_filename = argv[3];
244 
245  /* open input file, and allocate format context */
247  fprintf(stderr, "Could not open source file %s\n", src_filename);
248  exit(1);
249  }
250 
251  /* retrieve stream information */
253  fprintf(stderr, "Could not find stream information\n");
254  exit(1);
255  }
256 
259 
260  video_dst_file = fopen(video_dst_filename, "wb");
261  if (!video_dst_file) {
262  fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);
263  ret = 1;
264  goto end;
265  }
266 
267  /* allocate image where the decoded image will be put */
272  width, height, pix_fmt, 1);
273  if (ret < 0) {
274  fprintf(stderr, "Could not allocate raw video buffer\n");
275  goto end;
276  }
278  }
279 
282  audio_dst_file = fopen(audio_dst_filename, "wb");
283  if (!audio_dst_file) {
284  fprintf(stderr, "Could not open destination file %s\n", audio_dst_filename);
285  ret = 1;
286  goto end;
287  }
288  }
289 
290  /* dump input information to stderr */
292 
293  if (!audio_stream && !video_stream) {
294  fprintf(stderr, "Could not find audio or video stream in the input, aborting\n");
295  ret = 1;
296  goto end;
297  }
298 
299  frame = av_frame_alloc();
300  if (!frame) {
301  fprintf(stderr, "Could not allocate frame\n");
302  ret = AVERROR(ENOMEM);
303  goto end;
304  }
305 
306  pkt = av_packet_alloc();
307  if (!pkt) {
308  fprintf(stderr, "Could not allocate packet\n");
309  ret = AVERROR(ENOMEM);
310  goto end;
311  }
312 
313  if (video_stream)
314  printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);
315  if (audio_stream)
316  printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);
317 
318  /* read frames from the file */
319  while (av_read_frame(fmt_ctx, pkt) >= 0) {
320  // check if the packet belongs to a stream we are interested in, otherwise
321  // skip it
324  else if (pkt->stream_index == audio_stream_idx)
327  if (ret < 0)
328  break;
329  }
330 
331  /* flush the decoders */
332  if (video_dec_ctx)
334  if (audio_dec_ctx)
336 
337  printf("Demuxing succeeded.\n");
338 
339  if (video_stream) {
340  printf("Play the output video file with the command:\n"
341  "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
344  }
345 
346  if (audio_stream) {
348  int n_channels = audio_dec_ctx->channels;
349  const char *fmt;
350 
351  if (av_sample_fmt_is_planar(sfmt)) {
352  const char *packed = av_get_sample_fmt_name(sfmt);
353  printf("Warning: the sample format the decoder produced is planar "
354  "(%s). This example will output the first channel only.\n",
355  packed ? packed : "?");
356  sfmt = av_get_packed_sample_fmt(sfmt);
357  n_channels = 1;
358  }
359 
360  if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) < 0)
361  goto end;
362 
363  printf("Play the output audio file with the command:\n"
364  "ffplay -f %s -ac %d -ar %d %s\n",
365  fmt, n_channels, audio_dec_ctx->sample_rate,
367  }
368 
369 end:
373  if (video_dst_file)
374  fclose(video_dst_file);
375  if (audio_dst_file)
376  fclose(audio_dst_file);
380 
381  return ret < 0;
382 }
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:403
AVCodec
AVCodec.
Definition: codec.h:197
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
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
AVCodecContext::sample_rate
int sample_rate
samples per second
Definition: avcodec.h:981
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
AVFrame::coded_picture_number
int coded_picture_number
picture number in bitstream order
Definition: frame.h:408
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:111
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1165
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:396
AVFrame::width
int width
Definition: frame.h:361
video_dst_filename
static const char * video_dst_filename
Definition: demuxing_decoding.c:44
get_format_from_sample_fmt
static int get_format_from_sample_fmt(const char **fmt, enum AVSampleFormat sample_fmt)
Definition: demuxing_decoding.c:199
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1667
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:70
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:317
av_find_best_stream
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, const AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
Definition: utils.c:4122
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4348
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:393
samplefmt.h
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
pkt
static AVPacket * pkt
Definition: demuxing_decoding.c:55
video_dst_bufsize
static int video_dst_bufsize
Definition: demuxing_decoding.c:51
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:98
main
int main(int argc, char **argv)
Definition: demuxing_decoding.c:228
decode_packet
static int decode_packet(AVCodecContext *dec, const AVPacket *pkt)
Definition: demuxing_decoding.c:110
FF_ARRAY_ELEMS
#define FF_ARRAY_ELEMS(a)
Definition: sinewin_tablegen.c:29
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:620
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: utils.c:481
avcodec_alloc_context3
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:141
output_audio_frame
static int output_audio_frame(AVFrame *frame)
Definition: demuxing_decoding.c:90
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
src_filename
static const char * src_filename
Definition: demuxing_decoding.c:43
avcodec_receive_frame
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder.
Definition: decode.c:637
av_sample_fmt_is_planar
int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt)
Check if the sample format is planar.
Definition: samplefmt.c:112
pix_fmt
static enum AVPixelFormat pix_fmt
Definition: demuxing_decoding.c:41
audio_dec_ctx
static AVCodecContext * audio_dec_ctx
Definition: demuxing_decoding.c:39
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:49
video_frame_count
static int video_frame_count
Definition: demuxing_decoding.c:56
AVFormatContext
Format I/O context.
Definition: avformat.h:1097
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:984
NULL
#define NULL
Definition: coverity.c:32
fmt_ctx
static AVFormatContext * fmt_ctx
Definition: demuxing_decoding.c:38
AVCodec::type
enum AVMediaType type
Definition: codec.h:210
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:156
audio_frame_count
static int audio_frame_count
Definition: demuxing_decoding.c:57
video_dst_file
static FILE * video_dst_file
Definition: demuxing_decoding.c:46
open_codec_context
static int open_codec_context(int *stream_idx, AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type)
Definition: demuxing_decoding.c:148
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:135
avcodec_find_decoder
const AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
Definition: allcodecs.c:911
av_image_alloc
int av_image_alloc(uint8_t *pointers[4], int linesizes[4], int w, int h, enum AVPixelFormat pix_fmt, int align)
Allocate an image with size w and h and pixel format pix_fmt, and fill pointers and linesizes accordi...
Definition: imgutils.c:218
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:507
avformat_find_stream_info
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3545
av_ts2timestr
#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
AVMediaType
AVMediaType
Definition: avutil.h:199
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:119
height
static int height
Definition: demuxing_decoding.c:40
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:989
printf
printf("static const uint8_t my_array[100] = {\n")
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:376
AV_NE
#define AV_NE(be, le)
Definition: common.h:50
width
static int width
Definition: demuxing_decoding.c:40
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:59
frame
static AVFrame * frame
Definition: demuxing_decoding.c:54
AVCodecContext::channels
int channels
number of audio channels
Definition: avcodec.h:982
avcodec_send_packet
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
Definition: decode.c:574
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:369
i
int i
Definition: input.c:407
av_get_bytes_per_sample
int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt)
Return number of bytes per sample.
Definition: samplefmt.c:106
AV_SAMPLE_FMT_U8
@ AV_SAMPLE_FMT_U8
unsigned 8 bits
Definition: samplefmt.h:60
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:147
output_video_frame
static int output_video_frame(AVFrame *frame)
Definition: demuxing_decoding.c:59
AVFrame::extended_data
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:350
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:436
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:61
AVCodecContext::height
int height
Definition: avcodec.h:557
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:594
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:837
video_stream
static AVStream * video_stream
Definition: demuxing_decoding.c:42
avformat.h
video_stream_idx
static int video_stream_idx
Definition: demuxing_decoding.c:53
av_get_media_type_string
const char * av_get_media_type_string(enum AVMediaType media_type)
Return a string describing the media_type enum, NULL if media_type is unknown.
Definition: utils.c:76
AVCodecContext
main external API structure.
Definition: avcodec.h:384
AVFrame::height
int height
Definition: frame.h:361
audio_stream_idx
static int audio_stream_idx
Definition: demuxing_decoding.c:53
av_image_copy
void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4], const uint8_t *src_data[4], const int src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)
Copy image in src_data to dst_data.
Definition: imgutils.c:422
av_get_packed_sample_fmt
enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt)
Get the packed alternative form of the given sample format.
Definition: samplefmt.c:75
audio_dst_filename
static const char * audio_dst_filename
Definition: demuxing_decoding.c:45
AVPacket::stream_index
int stream_index
Definition: packet.h:367
video_dec_ctx
static AVCodecContext * video_dec_ctx
Definition: demuxing_decoding.c:39
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
audio_dst_file
static FILE * audio_dst_file
Definition: demuxing_decoding.c:47
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:342
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:557
imgutils.h
timestamp.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:334
video_dst_linesize
static int video_dst_linesize[4]
Definition: demuxing_decoding.c:50
AV_SAMPLE_FMT_DBL
@ AV_SAMPLE_FMT_DBL
double
Definition: samplefmt.h:64
audio_stream
static AVStream * audio_stream
Definition: demuxing_decoding.c:42
video_dst_data
static uint8_t * video_dst_data[4]
Definition: demuxing_decoding.c:49
AV_SAMPLE_FMT_S32
@ AV_SAMPLE_FMT_S32
signed 32 bits
Definition: samplefmt.h:62
AV_SAMPLE_FMT_FLT
@ AV_SAMPLE_FMT_FLT
float
Definition: samplefmt.h:63
dec_ctx
static AVCodecContext * dec_ctx
Definition: filtering_audio.c:43
av_get_pix_fmt_name
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2461