static void show_stream(AVFormatContext *fmt_ctx, int stream_idx)
{
    AVStream *stream = fmt_ctx->streams[stream_idx];
    AVCodecContext *dec_ctx;
    AVCodec *dec;
    char val_str[128];
    AVDictionaryEntry *tag = NULL;
    AVRational display_aspect_ratio;

    printf("[STREAM]\n");

    printf("index=%d\n", stream->index);

    if ((dec_ctx = stream->codec)) {
        if ((dec = dec_ctx->codec)) {
            printf("codec_name=%s\n", dec->name);
            printf("codec_long_name=%s\n", dec->long_name);
        } else {
            printf("codec_name=unknown\n");
        }

        printf("codec_type=%s\n", media_type_string(dec_ctx->codec_type));
        printf("codec_time_base=%d/%d\n",
               dec_ctx->time_base.num, dec_ctx->time_base.den);

        /* print AVI/FourCC tag */
        av_get_codec_tag_string(val_str, sizeof(val_str), dec_ctx->codec_tag);
        printf("codec_tag_string=%s\n", val_str);
        printf("codec_tag=0x%04x\n", dec_ctx->codec_tag);

        switch (dec_ctx->codec_type) {
        case AVMEDIA_TYPE_VIDEO:
            printf("width=%d\n", dec_ctx->width);
            printf("height=%d\n", dec_ctx->height);
            printf("has_b_frames=%d\n", dec_ctx->has_b_frames);
            if (dec_ctx->sample_aspect_ratio.num) {
                printf("sample_aspect_ratio=%d:%d\n",
                       dec_ctx->sample_aspect_ratio.num,
                       dec_ctx->sample_aspect_ratio.den);
                av_reduce(&display_aspect_ratio.num, &display_aspect_ratio.den,
                          dec_ctx->width  * dec_ctx->sample_aspect_ratio.num,
                          dec_ctx->height * dec_ctx->sample_aspect_ratio.den,
                          1024*1024);
                printf("display_aspect_ratio=%d:%d\n",
                       display_aspect_ratio.num, display_aspect_ratio.den);
            }
            printf("pix_fmt=%s\n",
                   dec_ctx->pix_fmt != PIX_FMT_NONE ? av_pix_fmt_descriptors[dec_ctx->pix_fmt].name
                                                    : "unknown");
            printf("level=%d\n", dec_ctx->level);
            break;

        case AVMEDIA_TYPE_AUDIO:
            printf("sample_rate=%s\n", value_string(val_str, sizeof(val_str),
                                                    dec_ctx->sample_rate,
                                                    unit_hertz_str));
            printf("channels=%d\n", dec_ctx->channels);
            printf("bits_per_sample=%d\n",
                   av_get_bits_per_sample(dec_ctx->codec_id));
            break;
        }
    } else {
        printf("codec_type=unknown\n");
    }

    if (fmt_ctx->iformat->flags & AVFMT_SHOW_IDS)
        printf("id=0x%x\n", stream->id);
    printf("r_frame_rate=%d/%d\n",
           stream->r_frame_rate.num, stream->r_frame_rate.den);
    printf("avg_frame_rate=%d/%d\n",
           stream->avg_frame_rate.num, stream->avg_frame_rate.den);
    printf("time_base=%d/%d\n",
           stream->time_base.num, stream->time_base.den);
    printf("start_time=%s\n",
           time_value_string(val_str, sizeof(val_str),
                             stream->start_time, &stream->time_base));
    printf("duration=%s\n",
           time_value_string(val_str, sizeof(val_str),
                             stream->duration, &stream->time_base));
    if (stream->nb_frames)
        printf("nb_frames=%"PRId64"\n", stream->nb_frames);

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

    printf("[/STREAM]\n");
}