[M4IF Technotes] Lack of audio-priority in MPEG4 streaming? Ref: Steve Jobs Apple MPEG4 webcast

[StreamingMP4 aol.com]

The current Steve Jobs webcast from this week's Apple Developers conference 
is well worth watching and includes discussion of their new 
post-production-oriented wavelet codec developed with Pixar for high-resolution collaboration and 
distribution, called Pixlet, as well as their impressive new software 
platform Panther that integrates web video/audio conferencing: 
http://www.apple.com/quicktime/qtv/wwdc03/ 
The 2 hour webcast itself reveals a serious audio flaw in that MPEG4 video 
will be maintained, but the audio drops out for very long periods of time when 
there is a measure of network congestion. For example in playback the first day 
I watched the entire first hour and could see it acceptably, but there was 
only perhaps one or two words audible every 10 minutes!   During the hour there 
was only two 10-15 second periods where the audio came through. Video showed 
some congestion but was OK.
I assume there's a standardized parameter in MPEG4 that allows for 
audio-priority in streaming but I don't how this would be invoked?   Are there decoder 
compatibility issues that might account for such a major speech having this 
lack of audio-priority vulnerability (I'm sure thousands experienced the same 
problem.)   Is it related to a flaw in the Quicktime wrapper? Is there a known 
timeframe for this to be fixed (Q to Apple list participants.)   Could those of 
you familiar with this issue shed some light on this? Thank you.
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