read_file_meta.c

#include <stdio.h>

#include <libavformat/avformat.h>
#include <libavutil/dict.h>

int main (int argc, char **argv)
{
    AVFormatContext *fmt_ctx = NULL;
    AVDictionaryEntry *tag = NULL;
    int ret;

    if (argc != 2) {
        printf("usage: %s <input_file>\n"
               "example program to demonstrate the use of the libavformat metadata API.\n"
               "\n", argv[0]);
        return 1;
    }

    av_register_all();
    if ((ret = avformat_open_input(&fmt_ctx, argv[1], NULL, NULL)))
        return ret;

    while ((tag = av_dict_get(fmt_ctx->metadata, "", tag, AV_DICT_IGNORE_SUFFIX)))
        printf("%s=%s\n", tag->key, tag->value);

    avformat_close_input(&fmt_ctx);
    return 0;
}