[M4IF Technotes] MS mpeg4 decoder

[Nitin Gupta--DSP, Noida]

Hi all,
	I also have few lines to add to this ..
though i fully support that the response of
various decoders to errors in the bitstreams 
can vary from one to the other .. but at least
every decoder should be able to decode all the
conformance streams provided by ISO .. the conformance 
streams i m talking of are described in the table 
4-5, 4-6, 4-7, 4-8, & 4-9 of ISO/IEC 14496-4:2000(E).
But the MS decoder explicitly fails to decode some 
streams flagging an error that actually is not present
in those bitstreams. Those bitstreams are on page 57
of ISO/IEC 14496-4:2000(E) in the table 4-8. These are
extracted from the ISO CD from the following file:
 \Visual\Natural\Simple\short.zip. They are
1. short\mit021.m4v
2. short\mit022.m4v
3. short\mit023.m4v
4. short\mit024.m4v
As these bitstreams are provided by ISO, i presume them
to be totally error free. Moreover i myself have deocoded
them by some other deocoder that decodes these bitstreams
without flagging any error, thus conforming that they are
totally correct. That is all i have to say.
Thanx for the time of all.
Regards,
Nitin.
-----Original Message-----
From: Rob Koenen [mailto:rkoenen   intertrust.com]
Sent: Saturday, July 20, 2023 9:28 AM
To: 'yrenjie'; Technotes   lists.m4if.org
Subject: RE: [M4IF Technotes] MS mpeg4 decoder
Response of the decoder to errors is not normatively defined in
the standard. Therefore it is not in ther reference sw either.
Please do not expect ISO participants (including microsoft) to 
provide you with optimized software (and hence, with their 
trade secrets). THe reference SW is a non-optimal example 
implementation of the standard, nothing less, but also nothing
more.
There is a lot of literature around on error resilience;
I kindl suggest that you check that out.
Best,
Rob
> -----Original Message-----
> From: yrenjie [mailto:yrenjie   sina.com]
> Sent: Friday, July 19, 2023 19:18
> To: Technotes   lists.m4if.org
> Subject: [M4IF Technotes] MS mpeg4 decoder
> 
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