Palette mode coding

Patent metadata

Field	Value
Publication number	US-9961351-B2
Application number	US-201514952438-A
Country	US
Kind code	B2
Filing date	Nov 25, 2015
Priority date	Nov 26, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A device for decoding video data may be configured to determine a block of the video data is coded using a palette-based coding mode; determine a sample of the block of video data is coded using a copy from top mode or an index mode; and decode a greater than zero flag to indicate whether a run value is greater than zero, wherein the run value specifies a number of samples subsequent to the sample that have a same mode as the sample.

First claim

What is claimed is:

1. A method of decoding video data, the method comprising:
determining a block of the video data is coded using a palette-based coding mode;
determining a sample of the block of video data is coded using a copy from top mode or an index mode;
decoding a greater than zero flag to indicate whether a run value is greater than zero, wherein the run value specifies a number of samples subsequent to the sample that have a same mode as the sample;
in response to the greater than zero flag indicating the run value is greater than zero, decoding a greater than one flag to indicate whether the run value is greater than one;
in response to the greater than one flag indicating the run value is greater than one, decoding an indication of the run value minus 2;
based on the indication of the run value minus 2, decoding the run value for the block of the video data; and
outputting a decoded picture comprising the block of the video data.

2. The method of claim 1 , further comprising:
decoding the greater than zero flag and the greater than one flag using one or more contexts for a context-adaptive binary arithmetic coding (CABAC) decoding operation.

3. The method of claim 1 , wherein determining the sample of the block of video data is coded using the copy from top mode or the index mode comprises determining the sample of the block of video data is coded using the index mode, and wherein the run value further specifies the number of samples subsequent to the sample that have a same palette entry index value as the sample.

4. The method of claim 1 , wherein determining the sample of the block of video data is coded using the copy from top mode or the index mode comprises determining the sample of the block of video data is coded using the copy from top mode, and wherein the run value further specifies the number of samples subsequent to the sample that have a same palette entry index value as a corresponding sample from a line of other samples above a line comprising the sample.

5. The method of claim 1 , further comprising:
based on whether the sample of the block of video data is coded using the copy from top mode or the index mode, selecting a context for a context-adaptive binary arithmetic coding (CABAC) decoding operation for decoding the run value, wherein the copy from top mode and the index mode have different associated contexts.

6. The method claim 1 , wherein determining the sample of the block of video data is coded using the copy from top mode or the index mode comprises:
receiving a flag, wherein a value of the flag indicates one of the copy from top mode or the index mode.

7. The method of claim 6 , wherein the flag is coded using context-adaptive binary arithmetic coding (CABAC).

8. The method of claim 6 , wherein determining the sample of the block of video data is coded using the copy from top mode or the index mode comprises:
receiving an escape mode flag indicating the sample is not coded in an escape mode.

9. The method of claim 1 , further comprising:
decoding the block of video data based on the mode for the sample and the run value; and
outputting a picture of decoded video data that includes the decoded block.

10. The method of claim 1 , further comprising:
receiving the video data at a receiver of a wireless communication device;
storing the video data in a memory of the wireless communication device; and
processing the video data on one or more processors of the wireless communication device.

11. The method of claim 10 , wherein the wireless communication device comprises a telephone handset and wherein receiving the video data at the receiver of the wireless communication device comprises demodulating, according to a wireless communication standard, a signal comprising the video data.

12. A method of encoding video data, the method comprising:
determining a block of the video data is coded using a palette-based coding mode;
determining a sample of the block of video data is coded using a copy from top mode or an index mode;
determining a number of samples subsequent to the sample that have a same mode as the sample; and
generating, for inclusion in an encoded bitstream, a greater than zero flag to indicate whether a run value is greater than zero, wherein the run value indicates the number of samples subsequent to the sample that have the same mode as the sample;
in response to the greater than zero flag indicating the run value is greater than zero, generating, for inclusion in the encoded bitstream, a greater than one flag to indicate whether the run value is greater than one; and
in response to the greater than one flag indicating the run value is greater than one, generating, for inclusion in the encoded bitstream, an indication of the run value minus 2; and
outputting the encoded bitstream comprising the greater than zero flag, the greater than one flag, and the indication of the run value minus 2.

13. The method of claim 12 , further comprising:
encoding the greater than zero flag and the greater than one flag using one or more contexts for a context-adaptive binary arithmetic coding (CABAC) operation.

14. The method of claim 12 , wherein determining the sample of the block of video data is coded using the copy from top mode or the index mode comprises determining the sample of the block of video data is coded using the index mode, and wherein the run value further specifies the number of samples subsequent to the sample that have a same palette entry index value as the sample.

15. The method of claim 12 , wherein determining the sample of the block of video data is coded using the copy from top mode or the index mode comprises determining the sample of the block of video data is coded using the copy from top mode, and wherein the run value further specifies the number of samples subsequent to the sample that have a same palette entry index value as a corresponding sample from a line above.

16. The method of claim 12 , further comprising:
based on whether the sample of the block of video data is encoded using the copy from top mode or the index mode, selecting a context for a context-adaptive binary arithmetic coding (CABAC) decoding operation for decoding the run value, wherein the copy from top mode and the index mode have different associated contexts.

17. The method of claim 12 , further comprising:
generating, for inclusion in the encoded bitstream, a flag to indicate one of the copy from top mode or the index mode.

18. The method of claim 17 , further comprising:
encoding the flag using context-adaptive binary arithmetic coding (CABAC).

19. The method of claim 17 , further comprising:
generating, for inclusion in the encoded bitstream, an escape mode flag indicating the sample is not coded in an escape mode.

20. The method of claim 12 , further comprising:
storing the video data in a memory of a wireless communication device;
processing the video data on one or more processors of the wireless communication device; and
transmitting the video data from a transmitter of the wireless communication device.

21. The method of claim 20 , wherein the wireless communication device comprises a telephone handset and wherein transmitting the video data at the transmitter of the wireless communication device comprises modulating, according to a wireless communication standard, a signal comprising the video data.

22. A device for decoding video data, the device comprising:
a memory configured to st

Assignees

• Qualcomm Inc

Inventors

• Joshi Rajan Laxman
• Guo Liwei
• Karczewicz Marta
• Pu Wei
• Sole Rojals Joel

Classifications

• H04N19/176 Primary

  the region being a block, e.g. a macroblock · CPC title

• H04N19/13

  Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] · 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

• H04N19/593

  involving spatial prediction techniques · CPC title