[vlc] Re: Videoconference solutions

[Sigmund Augdal Helberg]

On Mon, 2006-10-23 at 17:55 +0200, Rubén Lagar wrote:
> Great, setting all parameters to 20, and setting those parameters you 
> told me, I got a delay of about 1 second. It is better now.
> 
> But now the video quality is horrible, I will try to adjust these 
> parameters.
> 
> vlc.exe -vvv -I rc --rc-quiet --sout-ffmpeg-bframes 0 
> --sout-ffmpeg-keyint 3 --sout-ts-shaping 100 --sout-ts-dts-delay 100 
> --sout-udp-caching 20 --realrtsp-caching 20 --rtsp-caching 20 
> --udp-caching 20 --dshow-caching 400 dshow:// vdev="" adev="" 
> --sout=#transcode{vcodec=H263,width=176,height=144,vb=256,scale=1,acodec=mp3,ab=96,channels=2}:duplicate{dst=std{access=rtp,mux=ts,dst=193.147.53.32:1234}}
I think it's possible to reduce shaping and delay a bit more. Also the
real delay here (if you were down to 1s) is the 400ms dshow caching.
Increasing keyint will improve quality.

Sigmund
> 
> 
> 
> 
> Sigmund Augdal Helberg escribió:
> > On Mon, 2006-10-23 at 14:28 +0200, Rubén Lagar wrote:
> >   
> >> Hello,
> >>
> >> I am working for a French company, and we want to include a 
> >> videoconference application in our web site (it is a collaborative 
> >> site). For this, we have been testing VLC as solution. It works fine, we 
> >> get a better sound and video quality than Skype.
> >>
> >> The way we have done this is including a VLC activeX in the web page 
> >> that shows the remote WebCam. For streaming we use a java applet that 
> >> runs VLC from command line, and stream the local webcam to the remote 
> >> site. We have solved also NAT issues, so anyone can videoconference. As 
> >> I say, it is really good quality, and video and audio are fluid (we are 
> >> using H263 and MP3 codifications).
> >>
> >> We have just one problem, that may cause that we drop VLC as solution, 
> >> and this would make me really upset. We can not remove a 2 seconds delay 
> >> from the system, what makes conversation a pain. I have set to 0 almost 
> >> every cache paremeter that I know, and the 2 seconds dealy is still there.
> >>     
> > I think 0 is an invalid value for most caching options, and vlc will
> > reset them to default if they are set to 0. I'd try to set the caching
> > options to something like 20. 
> >
> > Other options that may, or may not affect the delay:
> > --sout-ts-shaping and --sout-ts-dts-delay (if you use mux=ts)
> > --sout-ffmpeg-bframes and --sout-ffmpeg-keyint (if you use ffmpeg for
> > encoding (which I guess you do)). Try setting bframes to 0 and keyint to
> > 1 to get the lowest possible delay, then try increasing keyint and see
> > if that improves quality without increasing delay (too much).
> >
> > Regards
> >
> > Sigmund
> >   
> >> I was wondering if any of the VLC developers could help me in locating 
> >> where is this delay located, to try to remove it.
> >>
> >> Thank you in advance,
> >> Rubén.
> >>
> >>     
> >
> >   
> 

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