FFmpeg
demux_decode.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 libavformat and libavcodec demuxing and decoding API usage example
25  * @example demux_decode.c
26  *
27  * Show how to use the libavformat and libavcodec API to demux and decode audio
28  * and video data. Write the output as raw audio and input files to be played by
29  * ffplay.
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\n",
78 
79  /* copy decoded frame to destination buffer:
80  * this is required since rawvideo expects non aligned data */
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  }
142 
143  return ret;
144 }
145 
146 static int open_codec_context(int *stream_idx,
148 {
149  int ret, stream_index;
150  AVStream *st;
151  const AVCodec *dec = NULL;
152 
153  ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
154  if (ret < 0) {
155  fprintf(stderr, "Could not find %s stream in input file '%s'\n",
157  return ret;
158  } else {
159  stream_index = ret;
160  st = fmt_ctx->streams[stream_index];
161 
162  /* find decoder for the stream */
164  if (!dec) {
165  fprintf(stderr, "Failed to find %s codec\n",
167  return AVERROR(EINVAL);
168  }
169 
170  /* Allocate a codec context for the decoder */
172  if (!*dec_ctx) {
173  fprintf(stderr, "Failed to allocate the %s codec context\n",
175  return AVERROR(ENOMEM);
176  }
177 
178  /* Copy codec parameters from input stream to output codec context */
179  if ((ret = avcodec_parameters_to_context(*dec_ctx, st->codecpar)) < 0) {
180  fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",
182  return ret;
183  }
184 
185  /* Init the decoders */
186  if ((ret = avcodec_open2(*dec_ctx, dec, NULL)) < 0) {
187  fprintf(stderr, "Failed to open %s codec\n",
189  return ret;
190  }
191  *stream_idx = stream_index;
192  }
193 
194  return 0;
195 }
196 
197 static int get_format_from_sample_fmt(const char **fmt,
198  enum AVSampleFormat sample_fmt)
199 {
200  int i;
201  struct sample_fmt_entry {
202  enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;
203  } sample_fmt_entries[] = {
204  { AV_SAMPLE_FMT_U8, "u8", "u8" },
205  { AV_SAMPLE_FMT_S16, "s16be", "s16le" },
206  { AV_SAMPLE_FMT_S32, "s32be", "s32le" },
207  { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },
208  { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },
209  };
210  *fmt = NULL;
211 
212  for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {
213  struct sample_fmt_entry *entry = &sample_fmt_entries[i];
214  if (sample_fmt == entry->sample_fmt) {
215  *fmt = AV_NE(entry->fmt_be, entry->fmt_le);
216  return 0;
217  }
218  }
219 
220  fprintf(stderr,
221  "sample format %s is not supported as output format\n",
222  av_get_sample_fmt_name(sample_fmt));
223  return -1;
224 }
225 
226 int main (int argc, char **argv)
227 {
228  int ret = 0;
229 
230  if (argc != 4) {
231  fprintf(stderr, "usage: %s input_file video_output_file audio_output_file\n"
232  "API example program to show how to read frames from an input file.\n"
233  "This program reads frames from a file, decodes them, and writes decoded\n"
234  "video frames to a rawvideo file named video_output_file, and decoded\n"
235  "audio frames to a rawaudio file named audio_output_file.\n",
236  argv[0]);
237  exit(1);
238  }
239  src_filename = argv[1];
240  video_dst_filename = argv[2];
241  audio_dst_filename = argv[3];
242 
243  /* open input file, and allocate format context */
245  fprintf(stderr, "Could not open source file %s\n", src_filename);
246  exit(1);
247  }
248 
249  /* retrieve stream information */
251  fprintf(stderr, "Could not find stream information\n");
252  exit(1);
253  }
254 
257 
258  video_dst_file = fopen(video_dst_filename, "wb");
259  if (!video_dst_file) {
260  fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);
261  ret = 1;
262  goto end;
263  }
264 
265  /* allocate image where the decoded image will be put */
270  width, height, pix_fmt, 1);
271  if (ret < 0) {
272  fprintf(stderr, "Could not allocate raw video buffer\n");
273  goto end;
274  }
276  }
277 
280  audio_dst_file = fopen(audio_dst_filename, "wb");
281  if (!audio_dst_file) {
282  fprintf(stderr, "Could not open destination file %s\n", audio_dst_filename);
283  ret = 1;
284  goto end;
285  }
286  }
287 
288  /* dump input information to stderr */
290 
291  if (!audio_stream && !video_stream) {
292  fprintf(stderr, "Could not find audio or video stream in the input, aborting\n");
293  ret = 1;
294  goto end;
295  }
296 
297  frame = av_frame_alloc();
298  if (!frame) {
299  fprintf(stderr, "Could not allocate frame\n");
300  ret = AVERROR(ENOMEM);
301  goto end;
302  }
303 
304  pkt = av_packet_alloc();
305  if (!pkt) {
306  fprintf(stderr, "Could not allocate packet\n");
307  ret = AVERROR(ENOMEM);
308  goto end;
309  }
310 
311  if (video_stream)
312  printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);
313  if (audio_stream)
314  printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);
315 
316  /* read frames from the file */
317  while (av_read_frame(fmt_ctx, pkt) >= 0) {
318  // check if the packet belongs to a stream we are interested in, otherwise
319  // skip it
322  else if (pkt->stream_index == audio_stream_idx)
325  if (ret < 0)
326  break;
327  }
328 
329  /* flush the decoders */
330  if (video_dec_ctx)
332  if (audio_dec_ctx)
334 
335  printf("Demuxing succeeded.\n");
336 
337  if (video_stream) {
338  printf("Play the output video file with the command:\n"
339  "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
342  }
343 
344  if (audio_stream) {
346  int n_channels = audio_dec_ctx->ch_layout.nb_channels;
347  const char *fmt;
348 
349  if (av_sample_fmt_is_planar(sfmt)) {
350  const char *packed = av_get_sample_fmt_name(sfmt);
351  printf("Warning: the sample format the decoder produced is planar "
352  "(%s). This example will output the first channel only.\n",
353  packed ? packed : "?");
354  sfmt = av_get_packed_sample_fmt(sfmt);
355  n_channels = 1;
356  }
357 
358  if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) < 0)
359  goto end;
360 
361  printf("Play the output audio file with the command:\n"
362  "ffplay -f %s -ac %d -ar %d %s\n",
363  fmt, n_channels, audio_dec_ctx->sample_rate,
365  }
366 
367 end:
371  if (video_dst_file)
372  fclose(video_dst_file);
373  if (audio_dst_file)
374  fclose(audio_dst_file);
378 
379  return ret < 0;
380 }
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: packet.c:427
AVCodec
AVCodec.
Definition: codec.h:187
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:71
entry
#define entry
Definition: aom_film_grain_template.c:66
dec_ctx
static AVCodecContext * dec_ctx
Definition: decode_filter_audio.c:47
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
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)
Definition: avformat.c:443
AVCodecContext::sample_rate
int sample_rate
samples per second
Definition: avcodec.h:1050
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:160
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1323
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:486
AVFrame::width
int width
Definition: frame.h:446
output_video_frame
static int output_video_frame(AVFrame *frame)
Definition: demux_decode.c:59
get_format_from_sample_fmt
static int get_format_from_sample_fmt(const char **fmt, enum AVSampleFormat sample_fmt)
Definition: demux_decode.c:197
decode_packet
static int decode_packet(AVCodecContext *dec, const AVPacket *pkt)
Definition: demux_decode.c:110
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: demux.c:1538
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:313
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: packet.c:74
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:395
video_dst_filename
static const char * video_dst_filename
Definition: demux_decode.c:44
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: demux.c:363
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:454
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:1065
audio_stream_idx
static int audio_stream_idx
Definition: demux_decode.c:53
samplefmt.h
audio_dst_file
static FILE * audio_dst_file
Definition: demux_decode.c:47
src_filename
static const char * src_filename
Definition: demux_decode.c:43
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
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:148
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:761
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:215
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_NE
#define AV_NE(be, le)
Definition: macros.h:33
pix_fmt
static enum AVPixelFormat pix_fmt
Definition: demux_decode.c:41
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
video_stream
static AVStream * video_stream
Definition: demux_decode.c:42
video_dst_file
static FILE * video_dst_file
Definition: demux_decode.c:46
audio_frame_count
static int audio_frame_count
Definition: demux_decode.c:57
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:698
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:114
audio_dec_ctx
static AVCodecContext * audio_dec_ctx
Definition: demux_decode.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:51
frame
static AVFrame * frame
Definition: demux_decode.c:54
video_stream_idx
static int video_stream_idx
Definition: demux_decode.c:53
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:766
avcodec_parameters_to_context
int avcodec_parameters_to_context(AVCodecContext *codec, const struct AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
NULL
#define NULL
Definition: coverity.c:32
AVCodec::type
enum AVMediaType type
Definition: codec.h:200
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
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:142
avcodec_find_decoder
const AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
Definition: allcodecs.c:964
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:544
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:2516
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:83
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:122
audio_dst_filename
static const char * audio_dst_filename
Definition: demux_decode.c:45
audio_stream
static AVStream * audio_stream
Definition: demux_decode.c:42
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1057
video_dst_linesize
static int video_dst_linesize[4]
Definition: demux_decode.c:50
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:461
fmt_ctx
static AVFormatContext * fmt_ctx
Definition: demux_decode.c:38
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: packet.c:63
avcodec_send_packet
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
Definition: decode.c:696
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:454
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
av_get_bytes_per_sample
int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt)
Return number of bytes per sample.
Definition: samplefmt.c:108
AV_SAMPLE_FMT_U8
@ AV_SAMPLE_FMT_U8
unsigned 8 bits
Definition: samplefmt.h:57
AVFrame::extended_data
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:435
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:606
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:58
video_dst_data
static uint8_t * video_dst_data[4]
Definition: demux_decode.c:49
open_codec_context
static int open_codec_context(int *stream_idx, AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type)
Definition: demux_decode.c:146
AVCodecContext::height
int height
Definition: avcodec.h:618
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:743
avformat.h
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:28
AVCodecContext
main external API structure.
Definition: avcodec.h:445
AVFrame::height
int height
Definition: frame.h:446
av_image_copy2
static void av_image_copy2(uint8_t *const dst_data[4], const int dst_linesizes[4], uint8_t *const src_data[4], const int src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)
Wrapper around av_image_copy() to workaround the limitation that the conversion from uint8_t * const ...
Definition: imgutils.h:184
width
static int width
Definition: demux_decode.c:40
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:77
AVPacket::stream_index
int stream_index
Definition: packet.h:526
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
main
int main(int argc, char **argv)
Definition: demux_decode.c:226
video_frame_count
static int video_frame_count
Definition: demux_decode.c:56
video_dst_bufsize
static int video_dst_bufsize
Definition: demux_decode.c:51
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
height
static int height
Definition: demux_decode.c:40
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:501
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:618
imgutils.h
timestamp.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:419
AV_SAMPLE_FMT_DBL
@ AV_SAMPLE_FMT_DBL
double
Definition: samplefmt.h:61
video_dec_ctx
static AVCodecContext * video_dec_ctx
Definition: demux_decode.c:39
pkt
static AVPacket * pkt
Definition: demux_decode.c:55
output_audio_frame
static int output_audio_frame(AVFrame *frame)
Definition: demux_decode.c:90
AV_SAMPLE_FMT_S32
@ AV_SAMPLE_FMT_S32
signed 32 bits
Definition: samplefmt.h:59
AV_SAMPLE_FMT_FLT
@ AV_SAMPLE_FMT_FLT
float
Definition: samplefmt.h:60
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:2885