[WinForms(unsafe)] USBカメラの列挙

public unsafe void ListDevices()
{
    AVFormatContext* camera;
    AVDictionary* option = null;

    ffmpeg.av_log_set_level(ffmpeg.AV_LOG_VERBOSE);
    av_log_set_callback_callback logCallback = (p0, level, format, vl) =>
    {
        if (level > ffmpeg.av_log_get_level()) return;

        var lineSize = 1024;
        var lineBuffer = stackalloc byte[lineSize];
        var printPrefix = 1;
        ffmpeg.av_log_format_line(p0, level, format, vl, lineBuffer, lineSize, &printPrefix);
        var line = Marshal.PtrToStringAnsi((IntPtr)lineBuffer);
        Console.Write(line);
    };
    ffmpeg.av_log_set_callback(logCallback);

    ffmpeg.avdevice_register_all();
    ffmpeg.av_dict_set(&option, "list_devices", "true", 0);
    ffmpeg.avformat_open_input(&camera, null, ffmpeg.av_find_input_format("dshow"), &option);
}

FFmpeg.AutoGen @Ruslan-B