Subject: Re: A/V Congestion Control

From: Orion Hodson <[email-masked]>
Date: Mon, 04 Sep 2000 00:46:38 +0100

Orion Hodson wrote:
> With the addition of the congestion control to the RTP draft I was
> wondering if anyone in the group has references or pointers on work
> examining subjective and/or objective performance of adaptive coding
> schemes?  i.e. the effects, real or simulated, from an end-user
> perspective.  Any pointers would be welcome.

It's been bought to my attention that this question is a too vague,
that was the intention, but I clearly went too far.  I'm interested in
work assessing the subjective, or objective, quality at the receiver
when the encoder has multiple operational modes (and/or bit-rates)
with a modulation mechanism that controls the encoder.

As an example, consider MPEG-4 audio.  It includes several distinct
families of audio encoder operating at different data rates and over
different signal bandwidths.  An application might adapt the mean data
rate in response to a congestion indicator.  You might (reasonably)
expect transitions between encoder family to be harder to conceal than
small differences in mean data rate by the encoder.  This type of
information might influence an adaptation algorithm.

Is there work that other members of the group are aware of that
quantifies those types of transitions by subjective or objective
assessment?

- Orion.

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From: Orion Hodson <[email-masked]>
Date: Sun, 03 Sep 2000 22:47:03 +0100

cheers
- Orion.