[M4IF Technotes] Is OBMC implementation different from Momusys and 14496-2??

[dsearles]

CC_Ju   mtk.com.tw wrote:
>Dear all:
>    I don't know if I misunderstand the OBMC implementation in Momusys
>software. It seems to use only up, left, right, and current macroblock's
>motion vector to do OBMC operation. The motion vector in bottom macroblock
>seems don't used in OBMC operation. This differs from 14496-2
>specification. Anybody can help?
>
>Thanks in advance.
>
>---
>Chi-Cheng
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>  
>
I didn't look at the Momusys code, so this may not be the answer to your 
question,
but the spec has a line in it that implies that you will never actually 
have to have
a motion vector from the macroblock under the one being processed:
"if the current
block is at the bottom of the macroblock, the remote motion vector 
corresponding with an 8*8 luminance block in
the macroblock below the current macroblock is replaced by the motion 
vector for the current block."
Dan Searles
-- 
Dan Searles
Atmel Multimedia & Communications
3800 Gateway Centre, Suite 311
Morrisville, NC 27560
phone: (919)462-6553 fax: (919)462-0300