[Mp4-tech] PSNR of Full Search

[Gary Sullivan]

That is probably the main reason.  Here are a couple of more possibilities:
1) "full search" often has a seriously-limited search range (e.g. plus or minus 16 samples) -- the "fast search" may not be limiting its search to the same range.
2) "full search" often only refers to an integer-MV value search, with a limited number of fractional sample grid positions being checked as a next stage MV refinement operation -- the "fast search" may generate more sensible motion vectors that work better as a seed for the next stage of fractional position refinement search.
Best Regards,
Gary Sullivan
________________________________
From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Daniel, Ilan
Sent: Wednesday, May 21, 2024 2:51 AM
To: Peace; mp4-tech lists.mpegif.org
Subject: RE: [Mp4-tech] PSNR of Full Search
Hi,
Any ME implementation (Fast or Full) is usually trying to minimize a metrics target function (usually involves SAD calculation),
but the real function that need to be minimized is number of encoded bits for certain quality/PSNR.
therefore it is possible that Fast search will get MV's that give better result.
Regards,
Ilan Daniel
________________________________
From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Peace
Sent: Wednesday, May 21, 2024 12:21 PM
To: mp4-tech lists.mpegif.org
Subject: [Mp4-tech] PSNR of Full Search
Hi,
Sometimes the PSNR of Fast search ME algorithms is better than that of Full Search.
How this can be explained?
Thanks
Humaira
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/mp4-tech/attachments/20080521/cdb0ba81/attachment.html