Context initialization based on decoder picture buffer

Patent metadata

Field	Value
Publication number	US-9491471-B2
Application number	US-201615084866-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Jun 30, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Technique for initialization of encoders and decoders. In some cases, the decoder receives a slice and identifies if the slice is either a forward predicted B-slice or a backward predicted B-slice, and not both a forward and backward predicted B-slice, and based upon this identification initializes, using a P-slice technique, a context associated with the slice.

First claim

We claim:

1. A method for decoding a video frame, the method comprising:
(a) receiving a slice;
(b) receiving a flag that is used in determining one of three initialization methods; and
(c) initializing a Context-Adaptive Binary Arithmetic Coding (CABAC) context associated with a slice type; wherein
in a case that the slice type indicates a B slice type and a value of the flag is equal to a first value, a CABAC context associated with the B slice type is initialized by a first initialization method of the three initialization methods,
in a case that the slice type indicates the B slice type and the value of the flag is equal to a second value, the CABAC context associated with the B slice type is initialized by a second initialization method of the three initialization methods, wherein the second initialization method being used to initialize a CABAC context associated with a P slice type in a case that the slice type indicates the P slice type and the value of the flag is equal to the first value, and
in a case that the slice type indicates an I slice type, a CABAC context associated with the I slice type is initialized by a third initialization method of the three initialization methods without using the flag.

2. An apparatus for decoding a video frame, the apparatus comprising:
a decoding processor, the decoding processor being implemented with hardware,
wherein:
the decoding processor receives a slice;
the decoding processor receives a flag that is used in determining one of three initialization methods; and
the decoding processor initializes a Context-Adaptive Binary Arithmetic Coding (CABAC) context associated with a slice type; wherein
in a case that the slice type indicates a B slice type and a value of the flag is equal to a first value, a CABAC context associated with the B slice type is initialized by a first initialization method of the three initialization methods,
in a case that the slice type indicates the B slice type and the value of the flag is equal to a second value, the CABAC context associated with the B slice type is initialized by a second initialization method of the three initialization methods, wherein the second initialization method being used to initialize a CABAC context associated with a P slice type in a case that the slice type indicates the P slice type and the value of the flag is equal to the first value, and
in a case that the slice type indicates an I slice type, a CABAC context associated with the I slice type is initialized by a third initialization method of the three initialization methods without using the flag.

Assignees

• Sharp Kk

Inventors

• Misra Kiran
• Segall Christopher Andrew

Classifications

• H04N19/436

  using parallelised computational arrangements · CPC title

• H04N19/159

  Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction · CPC title

• H04N19/577

  Motion compensation with bidirectional frame interpolation, i.e. using B-pictures · CPC title

• H04N19/46

  Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) · CPC title

• H04N19/157

  Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter · CPC title