[vlc] Re: Videoconference solutions

[Rubén Lagar]

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,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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