Re: [AVT] RE: Suggestion for how to handle derived/computedmetricindraft-avt-rtcpxr-*

[Colin Perkins <csp at csperkins.org>]

Hi,

On 26 Jul 2007, at 21:07, Ingemar Johansson S (LU/EAB) wrote:
> Coming from the area to speech and audio compression I can only  
> second the opinion that you really must specify what algrithm you  
> are using. Lots of work has been done to try to pair subjective  
> quality measurements against objective measurements and the results  
> are not always straightforward. One typical problem is impact of  
> longer packet loss where the models and what people actually  
> perceive differs.
>
> Another big problem is that I cannot see how you account for  
> jitterbuffer adaptation in this case, especially if you use  
> adaptive jitterbuffering. My fear is that you only get to a point  
> where you compare apples and oranges. But I wont argue more about  
> the applications and the reliability.
>
> Besides all this I find it a bit too static to specify binary RTCP  
> report blocks for every kind of computed metric that one can come  
> up with. A better solution would be some kind of an XML structure  
> that allows for more dynamics. I know it is probably/maybe not  
> doable for bandwidth reasons but extensibility would be alot easier  
> then.

I'm not sure we want this to be too easily extensible. A limited set  
of well defined metrics probably makes analysis easier than a very  
extensible and flexible system, filled with "metric of the day"  
parameters.

--
Colin Perkins
http://csperkins.org/



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