Intra-coding for 4:2:2 sample format in video coding

Patent metadata

Field	Value
Publication number	US-9667994-B2
Application number	US-201314038536-A
Country	US
Kind code	B2
Filing date	Sep 26, 2013
Priority date	Oct 1, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

Systems, methods, and devices for video coding that may receive a rectangular chroma block are disclosed. The rectangular chroma block may be divided into a first square sub-block and a second square sub-block. The systems, methods, and devices may reconstruct the first square sub-block and intra-predict the second square sub-block using reference samples from the reconstructed first square sub-block.

First claim

What is claimed is:

1. A method of decoding video data, the method comprising:
based on a chroma sampling format of a coding unit, determining, for a leaf node of the coding unit, that a non-square rectangular chroma block comprises a first square sub-block and a second square sub-block, wherein the leaf node of the coding unit corresponds to a node of a quadtree with no child nodes;
obtaining a first block of intra-predicted chroma data associated with the first square sub-block:
inverse quantizing transform coefficients associated with the first square sub-block;
inverse transforming the inverse quantized transform coefficients to generate first residual data
adding the first residual data to the first block of intra-predicted chroma data to reconstruct the first square sub-block;
intra-predicting the second square sub-block using reference samples from the reconstructed first square sub-block, wherein intra-predicting the second square sub-block comprises generating a second block of intra-predicted chroma data using reference samples from the reconstructed first square sub-block; and
reconstructing the second square sub-block using the second block of intra-predicted chroma data and second residual data for the second square sub-block.

2. The method of claim 1 , further comprising generating the second block of intra-predicted chroma data using intra-prediction samples of a neighboring block that is in addition to the reconstructed first square sub-block.

3. The method of claim 2 , wherein the first square sub-block is a top block of the non-square rectangular chroma block and the second square sub-block is a bottom block of the non-square rectangular chroma block.

4. A method of encoding video data, the method comprising:
based on a chroma sampling format of a coding unit, determining that a leaf node of the coding unit comprises a non-square rectangular chroma block comprising a first square sub-block and a second square sub-block, wherein the leaf node of the coding unit corresponds to a node of a quadtree with no child nodes;
quantizing transform coefficients associated with the first square sub-block;
transforming the inverse quantized transform coefficients to generate first residual data; reconstructing reference samples for the first square sub-block based on the first residual data; and
intra-predicting the second square sub-block using the reference samples for the reconstructed first square sub-block, wherein intra-predicting the second square sub-block comprises:
generating a second block of intra-predicted chroma data based on intra-prediction samples in the first square sub-block; and

encoding, for the second square sub-block, second residual data.

5. The method of claim 4 , further comprising encoding the second block of intra-predicted chroma data using other reference samples in addition to the reference sample of the reconstructed first square sub-block.

6. The method of claim 5 , wherein the first square sub-block is a top block of the non-square rectangular chroma block and the second square sub-block is a bottom block of the non-square rectangular chroma block.

7. An apparatus for decoding video data comprising:
a memory configured to store video data; and
one or more processors configured to:
based on a chroma sampling format of a coding unit of the video data, determine, for a leaf node of the coding unit, that a non-square rectangular chroma block comprises a first square sub-block and a second square sub-block, wherein the leaf node of the coding unit corresponds to a node of a quadtree with no child nodes;
obtain a first block of intra predicted chroma data associated with the first square sub-block;
inverse quantize transform coefficients associated with the first square sub-block;
inverse transform the inverse quantized transform coefficients to generate first residual data
add the first residual data to the first block of intra-predicted chroma data to reconstruct the first square sub-block;
intra-predict the second square sub-block using reference samples from the reconstructed first square sub-block, wherein to intra-predict the second square sub-block the one or more processors are configured to generate a second block of intra-predicted chroma data using reference samples from the reconstructed first square sub-block; and
reconstruct the second square sub-block using the second block of intra-predicted chroma data and second residual data for the second square sub-block.

8. The apparatus of claim 7 , wherein the one or more processors are further configured to encode the second block of intra-predicted chroma data using other reference samples in addition to the reference samples of the reconstructed first square sub-block.

9. The apparatus of claim 8 , wherein the first square sub-block is a top block of the non-square rectangular chroma block and the second square sub-block is a bottom block of the non-square rectangular chroma block.

10. An apparatus for decoding video data comprising:
means for determining, for a leaf node of the coding unit based on a chroma sampling format of a coding unit, that a non-square rectangular chroma block comprises a first square sub-block and a second square sub-block, wherein the leaf node of the coding unit corresponds to a node of a quadtree with no child nodes;
means for obtaining a first block of intra predicted chroma data associated with the first square sub-block;
means for inverse quantizing transform coefficients associated with the first square sub-block;
means for inverse transforming the inverse quantized transform coefficients to generate first residual data;
means for adding the first residual data to the first block of intra-predicted chroma data to reconstruct the first square sub-block;
means for intra-predicting the second square sub-block using reference samples from the reconstructed first square sub-block, wherein the means for intra-predicting the second square sub-block comprises means for generating a second block of intra-predicted chroma data using reference samples from the reconstructed first square sub-block; and
means for reconstructing the second square sub-block using the second block of intra-predicted chroma data and second residual data for the second square sub-block.

11. The apparatus of claim 10 , further comprising means for generating the second block of intra-predicted chroma data using other reference samples in addition to the reference samples from the reconstructed first square sub-block.

12. The apparatus of claim 11 , wherein the first square sub-block is a top block of the non-square rectangular chroma block and the second square sub-block is a bottom block of the non-square rectangular chroma block.

13. A non-transitory computer readable storage medium storing instructions that upon execution by one or more processors cause the one or more processors to:
based on a chroma sampling format of a coding unit, determine, for a leaf node of the coding unit, that a non-square rectangular chroma block comprising a first square sub-block and a second square sub-block, wherein the leaf node of the coding unit corresponds to a node of a quadtree with no child nodes;
obtain a first block of intra predicted chroma data associated with the first square sub-block;
inverse quantize transform coefficients associated with the first square sub-block;
inverse transform the inverse quantized transform coefficients to generate first residual data;
add the first residual data to the first block of intra-predicted chroma data to reconstruct the first square sub-block;
intra-predict the second square sub-block using refere

Assignees

• Qualcomm Inc

Inventors

• Joshi Rajan Laxman
• Guo Liwei
• Karczewicz Marta

Classifications

• H04N19/593 Primary

  involving spatial prediction techniques · CPC title

• H04N19/176 Primary

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

• H04N19/70

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04N19/645

  by grouping of coefficients into blocks after the transform · CPC title

• H04N19/11

  among a plurality of spatial predictive coding modes · CPC title