M11956: Memory Management Control Operation for picture duplication

1
M11956 Memory Management Control Operation for
picture duplication

• Panasonic Singapore Laboratories
• ChinPhek Ong

2
MCTF

• Lowpass picture of the current GOP is used as
  reference picture for the next GOP.
• In the decoder, this lowpass picture needs to be
  duplicated and stored in the memory.
• Otherwise, the contents will be overwritten when
  inverse MCTF is performed.

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MCTF
Inverse MCTF will overwrite content
Use as reference for next GOP
Picture is duplicated before it is overwritten
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Low Delay Mode

• Referring to M11616, in real low delay situation,
  encoding and decoding is performed partition by
  partition.
• Inter-partition reference pictures need to be
  duplicated and stored in memory

5
Low Delay Mode
Need to be duplicated during decoding
6
WD Editorial Note 8

• To some extent, this problem is mentioned in the
  WD, editorial note 8.
• For key pictures (identified by the variable
  KeyPicture) for which progressive refinement NAL
  units are present, we need to store a second
  representation, which is needed for enabling the
  closed loop coding between successive key
  pictures. These representations shall be marked
  as base representation and shall be chosen in
  the reference picture selection process, when
  KeyPicture is equal to 1 and such a
  representation exists. It need to be specified
  when such a representation needs to be stored in
  addition to the normal picture, and when it is
  used for motion-compensated prediction.

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MMCO for duplication

• To ensure conformance between encoded bitstream
  and a decoder having finite amount of memory,
  MMCO is used.
• A new MMCO command for frame duplication is
  proposed.

8
Semantics Proposed change

• Table 7-9 subclause S.7.4.3.3

9
Syntaxes Proposed change
10
Decoding Process Proposed change
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Conclusion

• Picture duplication is required for inverse MCTF.
• We proposed using a newly defined MMCO command to
  perform duplication.

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Q A

• Thank You!