Granted Patent B2

US 12,335,509 · App. 18/593,515 · Granted Jun 17, 2025

Inventors: Kiran Misra (Vancouver, WA); Sachin G. Deshpande (Camas, WA); Christopher A. Segall (Camas, WA)

Assignee: DOLBY INTERNATIONAL AB

H04N19/503H04N19/423H04N19/44H04N19/573H04N19/58H04N19/587H04N19/70

Abstract

Claims (28)

1. A method for decoding a video bitstream comprising:

receiving a bitstream comprising quantized transform coefficients;

receiving a reference description for decoded reference pictures from said bitstream;

determining a picture order count (POC) of a current picture for decoding, wherein each of the decoded reference pictures is associated with a picture order count (POC), and the picture order counts (POCs) of the decoded reference pictures are ordered in a plurality of sets each having a range [0 . . . MaxPOC−1] of POC values, wherein a particular value of MaxPOCSetIndex corresponds to a particular set of [0 . . . MaxPOC−1] of POC values,

wherein said reference description includes a modification parameter for a long term reference picture,

wherein the modification parameter for the long term reference picture is a difference between a value of MaxPOCSetIndex of a decoded reference picture of the current picture and a value of MaxPOCSetIndex of the current picture;

identifying said decoded reference picture of said current picture from a decoded picture buffer based on said picture order count (POC) of the current picture and said modification parameter;

decoding said current picture using inter-frame prediction based on said decoded reference picture; and

buffering said decoded picture in said decoded picture buffer for future prediction.

2. The method of claim 1 , wherein said modification parameter is a POC cycle parameter.

3. The method of claim 2 , wherein said POC cycle parameter is in a slice header.

4. The method of claim 1 , wherein said modification parameter is an indicator to start another POC cycle.

5. The method of claim 1 , wherein said reference description includes a picture order count for said decoded reference pictures.

6. A method for encoding a video stream comprising:

determining a picture order count (POC) of a current picture being encoded;

identifying a reference picture of said current picture from reference pictures in a decoded picture buffer;

encoding the current picture using inter-frame prediction based on the reference picture, wherein each of the reference pictures is associated with a picture order count (POC), and the picture order counts (POCs) of the reference pictures are ordered in a plurality of sets each having a range [0 . . . MaxPOC−1] of POC values, wherein a particular value of MaxPOCSetIndex corresponds to a particular set of [0 . . . MaxPOC−1] of POC values;

determining a reference description for reference pictures;

transmitting a bitstream including the encoded picture and the reference description for reference pictures;

wherein said bitstream includes quantized transform coefficients,

wherein said reference description includes a modification parameter for a long term reference picture,

wherein the modification parameter for the long term reference picture is a difference between a value of MaxPOCSetIndex of the reference picture used for encoding the current picture and a value of MaxPOCSetIndex of the current picture,

wherein identifying the reference picture of said current picture from the decoded picture buffer is based on a picture order count of the current picture and the modification parameter;

decoding said current picture using inter-frame prediction based on the reference picture used for encoding the current picture; and

buffering said decoded picture in said decoded picture buffer for future prediction.

7. An apparatus for encoding a video stream, comprising:

a processor;

a data storage storing instructions executable by the processor to perform the method of claim 6 .

Assignments (2)

Continuity (6)

References Cited (106)