static void show_packets(AVFormatContext *fmt_ctx)
{
    AVPacket pkt;

    av_init_packet(&pkt);
    probe_array_header("packets", 0);
    while (!av_read_frame(fmt_ctx, &pkt)) {
        show_packet(fmt_ctx, &pkt);
        av_packet_unref(&pkt);
    }
    probe_array_footer("packets", 0);
}