[vlc] Re: Videoconference solutions

[Mark Moriarty]

It sounds like people are doing well with this :)
For me, what I've been using:
I use a server command line like:
c:\vlc\vlc.exe dshow:// :dshow-adev="none":dshow-vdev="Osprey-210 Video
Device 1" :dshow-adev="none" :dshow-size="640x480" :dshow-amtuner-mode=1
:sout=#transcode{vcodec=mp4v,vb=1536,scale=1}:duplicate{dst=std{access=rtp,m
ux=ts,dst=239.20.30.40:1234}} :sout-transcode-fps=25.0 :sout-udp-ttl=4
:sout-rtp-ttl=4

And for the client is then:
c:\vlc\vlc.exe rtp://@239.20.30.40:1234

with:
dshow-caching=40
rtsp-caching=30
realrtsp-caching=30
sout-udp-caching=30
udp-caching=30
rtp-late=30
sout-display-delay=30

set for both sides (some of the delay values are for the TX end, others for
the RX, but I'm lazy and just set them in VLCRC; likewise I know some of
these aren't needed) 

If anyone gets what they believe is the very best quality and low latency,
please post :)

-----Original Message-----
From: vlc-bounce at videolan.org [mailto:vlc-bounce at videolan.org] On Behalf Of
Rubén Lagar
Sent: Monday, October 23, 2006 12:34 PM
To: vlc at videolan.org
Subject: [vlc] Re: Videoconference solutions


You are right, now it is about half a second. With --sout-ffmpeg-keyint set
to 4 or 5 it is not so bad quality.

I would invite you to some beers for your help, but I think it is going to
be difficult.

Thank you very much!! :)



Sigmund Augdal Helberg escribió:
> 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,aco
>> dec=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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