# US 2013/0156103 A1 · Mode searching and early termination of a video picture and fast compression of variable length symbols

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- Number: US 2013/0156103 A1
- Document ID: US20130156103A1
- Status: Published application
- Kind: A1
- Application number: 13/769,735
- Filed: 2013-02-18
- Published: 2013-06-20
- Earliest claimed: 2009-09-02
- Assignees: Sony Computer Entertainment Inc.
- Inventors: Jason N. Wang; Rathish Krishnan; Michael Kutner; Milan Mehta; Cheng Huang; Yi Luo; Jon Brelin
- Web page: https://patentgrep.com/patent/US20130156103A1

## CPC

- H04N 19/50: using predictive coding (H04N19/61 takes precedence)
- H04N 19/103: Selection of coding mode or of prediction mode
- H04N 19/109: among a plurality of temporal predictive coding modes
- H04N 19/11: among a plurality of spatial predictive coding modes
- H04N 19/147: according to rate distortion criteria (rate-distortion as a criterion for motion estimation H04N19/567)
- H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/436: using parallelised computational arrangements
- H04N 19/61: in combination with predictive coding
- H04N 19/86: involving reduction of coding artifacts, e.g. of blockiness
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Mode searching and early termination of a video picture may include determining the cost value of a simple intra-mode prediction of the video picture; determining the cost value of an inter-mode prediction of the video picture; determining a threshold value based on a given quantization parameter (QP); comparing the cost value of the simple intra-mode prediction to the sum of the cost value of the inter-mode prediction and the threshold value; and performing a mode-prediction of the video picture in accordance with the result obtained. Fast compression of variable length symbols may include receiving a variable length symbol with one or more tokens; combining the one or more tokens in the variable length symbol to form a token combination; and determining a bit representation of the token combination in correspondence to a probability threshold associated with the token combination.

## Claims

### Claim 1

A method for mode searching and early termination of a video picture, comprising:
a) determining the cost value of a simple intra-mode prediction of the video picture;
b) determining the cost value of an inter-mode prediction of the video picture;
c) determining a threshold value based on a given quantization parameter (QP);
d) comparing the cost value of the simple intra-mode prediction to the sum of the cost value of the inter-mode prediction and the threshold value; and
e) performing a mode-prediction of the video picture in accordance with the result obtained in d).

### Claim 2 (depends on 1)

The method of claim 1, wherein e) includes performing an inter-mode prediction if the cost value of the simple intra-mode prediction is greater than the sum of the cost value of the inter-mode prediction and the threshold value.

### Claim 3 (depends on 1)

The method of claim 1, wherein e) includes performing an intra-mode prediction if the cost value of the simple intra-mode prediction is lower than the sum of the cost value of the inter-mode prediction and the threshold value.

### Claim 4 (depends on 1)

The method of claim 1, wherein the simple intra-mode prediction for a given section does not wait for an intra prediction result of neighbor section

### Claim 5 (depends on 1)

The method of claim 1, wherein the simple intra-mode search uses a simplified 16-bit quantization process.

### Claim 6 (depends on 1)

The method of claim 1, wherein the simplified intra-mode search includes a search for the best intra prediction for input pixels of a given macroblock in a section,
using the best intra prediction to calculate a prediction error,
converting the prediction error into residual DCT coefficients using DCT transforms,
constructing a locally decoded macroblock
using the locally decoded macroblock to do intra prediction for one or more neighbor macroblocks of the given macroblock.

### Claim 7 (depends on 6)

The method of claim 6 wherein a simplified 16 bit quantization is used to obtain quantized DCT coefficients.

### Claim 8 (depends on 7)

The method of claim 7 wherein the locally decoded macroblock is constructed from pixel predictors and the quantized DCT coefficients.

### Claim 9 (depends on 7)

The method of claim 7, wherein the quantized DCT coefficients are not for entropy encoding.

### Claim 10 (depends on 6)

The method of claim 6 wherein locally decoded macroblock is used to do intra prediction for its right and lower neighbor macroblocks.

### Claim 11

A method for fast compression of variable length symbols, comprising:
a) receiving the variable length symbol with one or more tokens;
b) combining the one or more tokens in the variable length symbol to form a token combination; and
c) determining a bit representation of the token combination in correspondence to a probability threshold associated with the token combination.

### Claim 12 (depends on 11)

The method of claim 11, wherein c) includes using a lookup table to determine the bit representation of the token combination, where a single entry of the lookup table may include a combination of one or more tokens.

### Claim 13 (depends on 12)

The method of claim 12, wherein c) includes calculating the bit representation of a token combination if the token combination is not in the lookup table.

### Claim 14 (depends on 11)

The method of claim 11 wherein each variable length symbol represents a discrete cosine transform of a residual pixel from an entropy coding process.

### Claim 15 (depends on 11)

The method of claim 11 wherein the entropy coding process is an entropy coding process used in encoding a digital picture.