CONTEXT INITIALIZATION BASED ON DECODER PICTURE BUFFER

• US 20130003830A1
• Filed: 11/10/2011
• Published: 01/03/2013
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Velos Media, LLC (Inception Holdings, LLC)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: SEGALL, Christopher A., MISRA, Kiran
• Granted Patent: US 9,338,465 B2
• Time in Patent Office: Days
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/157 Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/174 the region being a slice, e.g. a line of blocks or a group of blocks
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures

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.

Claims

1. A method for decoding a video frame of a video sequence comprising:

(a) receiving a slice in a video decoder;

(b) identifying if said slice is either a forward predicted B-slice or a backward predicted B-slice, and not both a forward and backward predicted B-slice;

(c) initializing, using a P-slice technique, a context associated with said slice.

2. The method of claim 1 wherein said identifying comprises only said backward predicted B-slice.

3. The method of claim 1 wherein said identifying is based upon:

(1) a first list identifying reference pictures has at least one entry, (2) said first list and a second list identifying reference pictures contain the same set of said pictures, (3) all pictures in said first list and said second list are to be displayed prior to a current slice.

4. The method of claim 1 wherein said identifying is based upon:

(1) a first list identifying reference pictures has at least one entry, (2) said first list and a second list identifying reference pictures contain the same set of picture, (3) all pictures in said first list and said second list are to be displayed after a current slice.

5. The method of claim 1 wherein said identifying is based upon:

(1) a first list identifying reference pictures has at least one entry, (2) said first list and a second list identifying reference pictures contain a non-coextensive set of pictures, and said non-coextensive set of pictures are to be displayed prior to a current slice.

6. The method of claim 1 wherein said identifying is based upon:

(1) a first list identifying reference pictures has at least one entry, (2) said first list and a second list identifying reference pictures contain a non-coextensive set of pictures, and said non-coextensive set of pictures are to be displayed after a current slice.

7. The method of claim 1 wherein said identifying is based upon:

(1) a first list identifying reference pictures has at least one entry, (2) a first reference picture in said first list is the same as a second reference picture in a second list, (3) a first reference picture in said second list is the same as a second reference picture in said first list, (4) said first list and a second list identifying reference pictures contain a non-coextensive set of pictures, and said non-coextensive set of pictures are to be displayed prior to a current slice.

8. A method for decoding a video frame in a video sequence comprising:

(a) receiving a slice in a video decoder;

(b) identifying if said slice is a forward predicted B-slice;

(c) initializing, using a technique different than used for any of a B-slice, a P-slice, and an I-slice, a context associated with said slice.