public extern static void CallResulOfFunction(int a, int b, CBFunction callback);
public static extern void DFCSetCallBack(int channelID, CBFunction func);
public VideoStreamDecoder(string url, bool forceTCP = false, int tcpTimeout = 100, CBFunction callBack = null)
{
_pFormatContext = ffmpeg.avformat_alloc_context();
var pFormatContext = _pFormatContext;
AVDictionary *dic = null;
pFormatContext->max_delay = 0;
///https://ffmpeg.org/ffmpeg-protocols.html
if (forceTCP)
{
ffmpeg.av_dict_set(&dic, "rtsp_transport", "tcp", 0);
ffmpeg.av_dict_set(&dic, "stimeout", $"{tcpTimeout}", 0);
}
else
{
pFormatContext->max_delay = 0;
}
if (callBack != null)
{
_pFormatContext->interrupt_callback = new AVIOInterruptCB()
{
callback = new AVIOInterruptCB_callback_func()
{
Pointer = Marshal.GetFunctionPointerForDelegate(callBack)
}, opaque = pFormatContext
}
}
;
ffmpeg.avformat_open_input(&pFormatContext, url, null, &dic).ThrowExceptionIfError();
ffmpeg.avformat_find_stream_info(_pFormatContext, null).ThrowExceptionIfError();
// find the first video stream
AVStream *pStream = null;
for (var i = 0; i < _pFormatContext->nb_streams; i++)
{
if (_pFormatContext->streams[i]->codec->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO)
{
pStream = _pFormatContext->streams[i];
break;
}
}
if (pStream == null)
{
throw new InvalidOperationException("Could not found video stream.");
}
_streamIndex = pStream->index;
_pCodecContext = pStream->codec;
var codecId = _pCodecContext->codec_id;
var pCodec = ffmpeg.avcodec_find_decoder(codecId);
if (pCodec == null)
{
throw new InvalidOperationException("Unsupported codec.");
}
ffmpeg.avcodec_open2(_pCodecContext, pCodec, &dic).ThrowExceptionIfError();
CodecName = ffmpeg.avcodec_get_name(codecId);
FrameSize = new Size(_pCodecContext->width, _pCodecContext->height);
PixelFormat = _pCodecContext->pix_fmt;
_pPacket = ffmpeg.av_packet_alloc();
_pFrame = ffmpeg.av_frame_alloc();
}