[Mp4-tech] Effect of losing only partition B or both partition A and B

[Gary Sullivan]

Ashfiqua Tahseen et al,
The only reason that I can think of to explain why the first case would be likely to produce a worse result than the second one is poor decoder design.
Three things to keep in mind:
1) All aspects of how a decoder responds to missing or corrupted data are outside the scope of the standard.  Some decoders may "gracefully degrade" while others might produce complete garbage or halt entirely.  The standard simply does not specify what a decoder should do under such circumstances.
2) Error resilience behavior depends just as much or more on good encoder design as on good decoder design.  If you are not optimizing the encoder behavior for error resilience performance, then you should probably not attempt to draw any conclusions about the degree of rubustness of a decoder design, the degree of robustness of the syntax design, or the likely quality that will be obtained under realistic conditions in a well-designed system implementation.  Analysis of codec behavior under loss/error-prone conditions is a tricky thing. If you're not going to do a good job of it, it may be better not to try.  Reading a significant amount of literature on what other people have already done should be an essential component of any such work.
3) Few implementations of the standard support data partitioned operation.  That may even be an understatement.  As a result, you should not expect the experiments for study of that feature to resemble "smooth sailing on a sunny day".
Best Regards,
Gary Sullivan
________________________________
From: mp4-tech-bounces lists.mpegif.org [mp4-tech-bounces lists.mpegif.org] On Behalf Of ashfiqua tahseen [ashfiqua03 yahoo.com]
Sent: Friday, May 16, 2024 6:30 PM
To: mp4-tech lists.mpegif.org
Subject: [Mp4-tech] Effect of losing only partition B or both partition A and B
Hi,
I am working on data partitioned H.264. If I have a lossy environemnt where:
case1: Partition B of an I frame is lost.
case2: Both partition A and B of an I frame are lost.
What will be the PSNR value of that particular I frame? I found that for the first case the PSNR is very low (around 15 dB) and in the second case the PSNR is around 26dB. I am using frame copy error concealment and JM 13.1.
Why does case 1 provide lower PSNR than case 2?
Any suggestion will be highly appreciated.
Thanking you,
Ashfiqua
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