Ideal pipe for streaming live with minimal delay

[Wim Taymans]

On 03/13/2012 06:19 AM, garrett wrote:
> Hello, I came across this thread doing research about gstreamer video
> streaming. Since this thread hasn't developed a definitive answer concerning
> OP's query, it'd like to give it a bump so that it could help others in the
> future.
>
> I am trying to do a similar thing. I'm trying to transmit video, using RTP
> packets but it's over UDP, not TCP. I am getting a constant latency of about
> 4 seconds. I'd like to be able to reduce that latency as much as possible.
>
> Is there any way to possibly drop frames in a receiving pipeline so that
> only the most recent video is displayed? What follows is my current
> gstreamer receiving pipeline.
>
> /gst-launch-0.10 udpsrc multicast-group=224.1.1.1 auto-multicast=true
> port=5000 caps=application/x-rtp ! gstrtpjitterbuffer ! rtph264depay !
> ffdec_h264 ! xvimagesink sync=false/

You need to first remove sync=false, it will result in choppy playback. 
Depending
on the H264 encoding and framerate, you might need to increase the 
gstrtpjitterbuffer
latency property to get smooth playback.

In that pipeline the latency between receiving the packet from the 
network and playing
the decoded frame is determined by gstrtpjitterbuffer, which has a 200ms 
latency by default.
There could also be a 1 frame delay in the H264 decoder. This pipeline 
will certainly not
have a 4 second latency so your problem is either on the network or more 
likely on the sender.

Wim


> If anyone gives me any suggestions: I'd be happy to let you know how they
> turn out.
>
> --
> View this message in context: http://gstreamer-devel.966125.n4.nabble.com/Ideal-pipe-for-streaming-live-with-minimal-delay-tp2314936p4468266.html
> Sent from the GStreamer-devel mailing list archive at Nabble.com.
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