Video coding using adaptive motion vector resolution

Patent metadata

Field	Value
Publication number	US-10536701-B2
Application number	US-201213536218-A
Country	US
Kind code	B2
Filing date	Jun 28, 2012
Priority date	Jul 1, 2011
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

In one example, a device for coding video data includes a video coder configured to configured to code information representative of whether an absolute value of an x-component of a motion vector difference value for a current block of video data is greater than zero, code information representative of whether an absolute value of a y-component of the motion vector difference value is greater than zero, when the absolute value of the x-component is greater than zero, code information representative of the absolute value of the x-component, when the absolute value of the y-component is greater than zero, code information representative of the absolute value of the y-component, when the absolute value of the x-component is greater than zero, code a sign of the x-component, and when the absolute value of the y-component is greater than zero, code a sign of the y-component.

First claim

What is claimed is:

1. A method of entropy coding video data, the method comprising:
when an absolute value of an x-component of a first motion vector difference value for a current block of video data is greater than zero, and when an absolute value of a y-component of the first motion vector difference value for the current block of video data is greater than zero, entropy coding, by a video coder, information representative of the first motion vector difference value, wherein entropy coding the information representative of the first motion vector difference value comprises:
coding, by the video coder, interleaved information from or into an encoded video bitstream, wherein the interleaved information includes information associated with the x-component of the first motion vector difference value and information associated with the y-component of the first motion vector difference value such that at least a first portion of the information associated with the y-component of the first motion vector difference value is coded before at least a first portion of the information associated with the x-component of the first motion vector difference value, and at least a second portion of the information associated with the x-component of the first motion vector difference value is coded before at least a second portion of the information associated with the y-component of the first motion vector difference value,
wherein the information associated with the x-component of the first motion vector difference value includes information indicative that the absolute value of the x-component of the first motion vector difference value for the current block of video data is greater than zero, information representative of the absolute value of the x-component of the first motion vector difference value, and a sign of the x-component of the first motion vector difference value, and
wherein the information associated with the y-component of the first motion vector difference value includes information indicative that the absolute value of the y-component of the first motion vector difference value is greater than zero, information representative of the absolute value of the y-component of the first motion vector difference value, and a sign of the y-component of the first motion vector difference value.

2. The method of claim, 1 , wherein entropy coding comprises context-adaptive binary arithmetic coding (CABAC) encoding, the method further comprising:
calculating a motion vector for the current block of video data; and
calculating the first motion vector difference value as a difference between the motion vector for the current block of video data and a motion vector predictor determined for the current block of video data.

3. The method of claim 1 , wherein entropy coding comprises context-adaptive binary arithmetic coding (CABAC) decoding, the method further comprising:
determining a motion vector predictor for the current block of video data; and
calculating a motion vector for the current block of video data as a sum of the first motion vector difference value and the motion vector predictor.

4. The method of claim 1 , further comprising:
coding a value representative of whether a motion vector of the current block of video data has a first sub-pixel precision or a second sub-pixel precision, wherein the second sub-pixel precision is greater than the first sub-pixel precision; and
coding a jointly coded value representative of both the x-component of the first motion vector difference value and the y-component of the first motion vector difference value when the motion vector has the second sub-pixel precision, when the x-component of the first motion vector difference value is not equal to zero, and when the y-component of the first motion vector difference value is not equal to zero.

5. The method of claim 4 , further comprising:
determining whether the motion vector has the first sub-pixel precision or the second sub-pixel precision based on a threshold value associated with the motion vector; and
determining that the motion vector has the first sub-pixel precision when both the x-component of the first motion vector difference value and the y-component of the first motion vector difference value are greater than the threshold value.

6. The method of claim 4 , further comprising:
determining whether the motion vector has the first sub-pixel precision or the second sub-pixel precision based on a value of a motion vector resolution flag when at least one of the x-component of the first motion vector difference value and the y-component of the first motion vector difference value is less than or equal to a threshold value associated with the motion vector.

7. The method of claim 4 , wherein coding the value representative of whether the motion vector has the first sub-pixel precision or the second sub-pixel precision comprises coding a value for a motion vector resolution flag.

8. The method of claim 1 , further comprising:
coding, from or into the encoded video bitstream, the absolute value of the x-component of the first motion vector difference value as mvd_x/2−1, wherein mvd_x comprises the x-component of the first motion vector difference value; and
coding, from or into the encoded video bitstream, the absolute value of the y-component of the first motion vector difference value as mvd_y/2−1, wherein mvd_y comprises the y-component of the first motion vector difference value.

9. An apparatus for entropy coding video data, the apparatus comprising:
a memory configured to store at least one reference picture; and
a video entropy coder configured to:
entropy code information representative of a first motion vector difference value for a motion vector of a current block relative to a predictive block of the at least one reference picture when an absolute value of an x-component of a first motion vector difference value is greater than zero and when an absolute value of a y-component of the first motion vector difference is greater than zero, wherein to entropy code the information representative of the first motion vector difference value, the apparatus for entropy coding is configured to:
code interleaved information from or into an encoded video bitstream, wherein the interleaved information includes information associated with the x-component of the first motion vector difference value and information associated with the y-component of the first motion vector difference value such that at least a first portion of the information associated with the y-component of the first motion vector difference value is coded before at least a first portion of the information associated with the x-component of the first motion vector difference value, and at least a second portion of the information associated with the x-component of the first motion vector difference value is coded before at least a second portion of the information associated with the y-component of the first motion vector difference value,
wherein the information associated with the x-component of the first motion vector difference value includes information indicative that the absolute value of the x-component of the first motion vector difference value for the current block is greater than zero, information representative of the absolute value of the x-component of the first motion vector difference value, and a sign of the x-component of the first motion vector difference value, and
wherein the information associated with the y-component of the first motion vector difference value includes information indicative that the absolute value of the y-component of the first motion vector difference value is greater than zero, information representative of the absolute value of

Assignees

• Chien Wei Jung
• Chen Peisong
• Karczewicz Marta
• Qualcomm Inc

Inventors

• Chien Wei-Jung
• Chen Peisong
• Karczewicz Marta

Classifications

• H04N19/523

  with sub-pixel accuracy · CPC title

• H04N19/517

  by encoding · CPC title

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/13 Primary

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

• H04N19/91

  Entropy coding, e.g. variable length coding [VLC] or arithmetic coding · CPC title