jetson.utils.videoSource() and RTSP with low latency on Nano - is it possible?

dusty_nv · September 10, 2020, 1:24pm

Hi @martin2wu0d, please see this line from jetson-inference/utils/codec/gstDecoder.cpp:

dusty-nv/jetson-utils/blob/cae2730a09edd955631fcbdfc8c4c38556a93600/codec/gstDecoder.cpp#L521


      
          		else if( mOptions.codec == videoOptions::CODEC_MPEG4 )

          			ss << "MP4V-ES\" ! rtpmp4vdepay ! ";	// MPEG4-GENERIC\" ! rtpmp4gdepay

          		else if( mOptions.codec == videoOptions::CODEC_MJPEG )

          			ss << "JPEG\" ! rtpjpegdepay ! ";

          

          		mOptions.deviceType = videoOptions::DEVICE_IP;

          	}

          	else if( uri.protocol == "rtsp" )

          	{

          		ss << "rtspsrc location=" << uri.string;

          		//ss << " latency=200 drop-on-latency=true";

          		ss << " ! queue ! ";

          		

          		if( mOptions.codec == videoOptions::CODEC_H264 )

          			ss << "rtph264depay ! h264parse ! ";

          		else if( mOptions.codec == videoOptions::CODEC_H265 )

          			ss << "rtph265depay ! h265parse ! ";

          		else if( mOptions.codec == videoOptions::CODEC_VP8 )

          			ss << "rtpvp8depay ! ";

          		else if( mOptions.codec == videoOptions::CODEC_VP9 )

          			ss << "rtpvp9depay ! ";

Uncomment it and change it to latency=0. Then you want to re-run make and sudo make install.

If this improves the latency for you, let me know, and I will enable it in master. On my RTSP test sources I was unable to test it myself.