[Live-devel] [live-devel] Too long delay for JPEG live image.

[Ross Finlayson]

>Hello,
>
>I'm trying to developpe a MJPEG live streamer server.
>I work with a camera and our specific driver (that I've wrote too) 
>for our frame grabber.
>To do this I've learned about Elphel example.
>I've wrote a JPEGVideoSource derivated class then I've overload the 
>doGetNextFrame function.
>
>Now I can see remotely live JPEG video from camera with a VLC client program.
>But I've observe a delay of 2 sec between images received by the 
>driver and those received by VLC client.
>It seem there is a too big fifo buffer for live image between them.
>I've disable our fifo buffer to see what's happened.
>Now I copy directly image (30 kB) to FramedSource::fTo data members.
>But the problem is always present.
>
>How can I reduce this delay?

There's no signifcant delay in the "LIVE555 Streaming Media" code - 
at either the sending end or the receiving (VLC) end.

However, VLC does have a separate jitter buffer that - by default - 
adds 1.2 seconds (1200 ms) at the receiving end.  You can reduce this 
by changing VLC's
	Preferences->Input/Codecs->Demuxers->RTP/RTSP->Advanced->Caching 
value (ms)

Don't forget also that JPEG encoding (even in hardware) and decoding 
also add some delay, which you are unlikely to be able to reduce.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/