[M4IF Technotes] Motion vector predictor

[Hao-Chieh Chang]

Dear all,
Motion vector predictor is defined in sec. 7.6.5 of ISO/IEC 14496-2-2001(E) as
Px = Median(MV1x, MV2x, MV3x), Py = Median(MV1y, MV2y, MV3y).
    If the neighbourhood macroblock type is inter, there is no problem.  However, 
if the neighbourhood macroblock type is intra or not_coded = 1, there is no motion
vector in that macroblock.  How to decide its motion vector?  Can we set this
candicate predictor as zero?  Or treat this macroblock not valid as trasparent
block?  These two methods will conduce different results when calculate Px and Py.
    I can not find the answer in standard.  Please tell me if you know the correct
method.  Thank you very much.
Howard Chang
IC/IP Product Division
TEL: +886-2-2226-3630 Ext 513  
FAX: +886-2-2226-7241
Mailto: howardchang   avermedia.com.tw
http://www.avermedia.com
AVerMedia Technologies,Inc.
IC/IP²£«~¨Æ·~³æ¦ì¡G±iµq³Ç
¶ê­è¬ì§Þ(ªÑ)¤½¥q
This message contains information that may be confidential
and privileged. Unless you are the addressee (or authorized
to receive messages for the addressee), you can not use,
copy or disclose to any third party or any information 
contained in the message. If you have received the message
in error, please advise the sender by reply e-mail and 
delete the message. Nothing in this message should be 
interpreted as a digital or electronic signature that can
be used to authenticate a contract or other legal document.
Thank you very much.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/mp4-tech/attachments/20030716/51765f26/attachment.html