FFmpeg
show_metadata.c
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1 /*
2  * Copyright (c) 2011 Reinhard Tartler
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 metadata extraction API usage example
25  * @example show_metadata.c
26  *
27  * Show metadata from an input file.
28  */
29 
30 #include <stdio.h>
31 
32 #include <libavformat/avformat.h>
33 #include <libavutil/dict.h>
34 
35 int main (int argc, char **argv)
36 {
38  const AVDictionaryEntry *tag = NULL;
39  int ret;
40 
41  if (argc != 2) {
42  printf("usage: %s <input_file>\n"
43  "example program to demonstrate the use of the libavformat metadata API.\n"
44  "\n", argv[0]);
45  return 1;
46  }
47 
48  if ((ret = avformat_open_input(&fmt_ctx, argv[1], NULL, NULL)))
49  return ret;
50 
51  if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) {
52  av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
53  return ret;
54  }
55 
56  while ((tag = av_dict_iterate(fmt_ctx->metadata, tag)))
57  printf("%s=%s\n", tag->key, tag->value);
58 
60  return 0;
61 }
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: demux.c:374
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AVFormatContext::metadata
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1430
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:226
AVFormatContext
Format I/O context.
Definition: avformat.h:1202
NULL
#define NULL
Definition: coverity.c:32
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:2532
fmt_ctx
static AVFormatContext * fmt_ctx
Definition: decode_filter_audio.c:45
printf
printf("static const uint8_t my_array[100] = {\n")
main
int main(int argc, char **argv)
Definition: show_metadata.c:35
tag
uint32_t tag
Definition: movenc.c:1786
ret
ret
Definition: filter_design.txt:187
avformat.h
dict.h
AVDictionaryEntry
Definition: dict.h:89
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
av_dict_iterate
const AVDictionaryEntry * av_dict_iterate(const AVDictionary *m, const AVDictionaryEntry *prev)
Iterate over a dictionary.
Definition: dict.c:44