[M4IF Technotes] About definition of skipped macroblock!

[Peter Haighton]

MessageYes, S(GMC)-VOPs  handle skipped (not_coded) macroblocks by treating
them as macroblocks with not MC and not DCT co-efficients. Also B-VOPs do
skipping differently, and I-VOPs cannot have not_coded macroblocks.
Peter
-----Original Message-----
From: technotes-admin   lists.m4if.org
[mailto:technotes-admin   lists.m4if.org]On Behalf Of Gary Sullivan
Sent: Tuesday, January 21, 2024 2:05 PM
To: Peter Haighton; gaodd; technotes   lists.m4if.org
Subject: RE: [M4IF Technotes] About definition of skipped macroblock!
I think that's a correct statement P VOPs for simple profile.  I think it is
not a correct definition for S(GMC)-VOPs.
See the semantics of not_coded - subclause 6.3.6.
It may also not be correct for B VOPs.  In a B VOP, I think skipped
macroblocks use direct prediction (but I don't know for certain whether the
term "skipped" is used in that context).
I don't think a macroblock can be skipped in an I VOP.
-Gary
-----Original Message-----
From: Peter Haighton [mailto:Peter.Haighton   m4if.org]
Sent: Tuesday, January 21, 2024 4:58 AM
To: gaodd; technotes   lists.m4if.org
Subject: RE: [M4IF Technotes] About definition of skipped macroblock!
  A skipped macroblock is one that information about the macroblock is not
transmitted and the image for that macroblock is taken directly from the
same position of the previously displayed frame.
  Peter
  -----Original Message-----
  From: technotes-admin   lists.m4if.org
[mailto:technotes-admin   lists.m4if.org]On Behalf Of gaodd
  Sent: Tuesday, January 21, 2024 2:01 AM
  To: technotes   lists.m4if.org
  Subject: [M4IF Technotes] About definition of skipped macroblock!
  hello!
  now, i have encountered a question:
  In w3056, "skipped macroblock" is often mentioned in many places.it seems
that in P-VOP,I-VOP,S-VOP,this phrase is defined differently.now,i want to
know its precise definition,how can i find it?
  thanks for help!
  Regards,
  Gao DD
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