Granted Patent B2

US 9,055,290 · App. 14/448,936 · Granted Jun 9, 2015

Abstract

Claims (41)

1. A method of coding a block of coefficients associated with a block of video data during a video coding process, the method comprising:

determining contexts for performing context adaptive entropy coding of the x- and y-coordinates indicating a horizontal position and a vertical position, respectively, of a last non-zero coefficient within the block of coefficients, wherein the contexts indicate a probability of each of the x- and y-coordinates comprising a given value when the coefficients of the block of video data are scanned in a first scanning order;

in the case that the coefficients are scanned in the first scanning order, entropy coding the x-coordinate and the y-coordinate using the determined contexts such that the x-coordinate is entropy coded based on the probability of the x-coordinate having a given value and the y-coordinate is entropy coded based on the probability of the y-coordinate having a given value; and

in the case that the coefficients are scanned in the second scanning order, interchanging the x- and y-coordinates and entropy coding the interchanged x-coordinate and the interchanged y-coordinate using the determined contexts such that the interchanged x-coordinate is entropy coded based on the probability of the y-coordinate having a given value and the interchanged y-coordinate is entropy coded based on the probability of the x-coordinate having a given value.

2. The method of claim 1 , wherein the first scanning order comprises a horizontal scanning order and the second scanning order comprises a vertical scanning order.

3. The method of claim 1 , wherein entropy coding the x- and y-coordinates and the interchanged x- and y-coordinates comprises coding a sequence of one or more bins, wherein the contexts indicate probabilities of each of the bins having a given value.

4. The method of claim 1 , wherein coding comprises decoding, the method further comprising:

receiving entropy encoded values indicative of the x-coordinate and y-coordinate in the video bitstream, wherein entropy coding the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates comprises entropy decoding the received entropy encoded values so as to obtain the respective ones of x- and y-coordinates or the interchanged x- and y-coordinates;

receiving encoded values of non-zero coefficients associated with the block of video data in a bitstream; and

decoding the encoded values of the non-zero coefficients based on the respective ones of the x- and y-coordinates and the interchanged x- and y-coordinates.

5. The method of claim 1 , wherein coding comprises encoding, and wherein entropy coding the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates comprises entropy encoding the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinate so as to obtain the entropy encoded values indicative of the x-coordinate and y-coordinate; the method further comprising:

encoding values of non-zero coefficients associated with the block of video data based on the respective ones of the x- and y-coordinates and the interchanged x- and y-coordinates; and

outputting entropy encoded values indicative of the x-coordinate and y-coordinate and the encoded values of the non-zero coefficients in a video bitstream.

6. An apparatus for coding a block of coefficients associated with a block of video data during a video coding process, the apparatus comprising:

a memory configured to store video data; and

a processor in communication with the memory and configured to:

determine contexts for performing context adaptive entropy coding of the x- and y-coordinates indicating a horizontal position and a vertical position, respectively, of a last non-zero coefficient within the block of coefficients, wherein the contexts indicate a probability of each of the x- and y-coordinates comprising a given value when the coefficients of the block of video data are scanned in a first scanning order;

in the case that the coefficients are scanned in the first scanning order, entropy code the x-coordinate and the y-coordinate using the determined contexts such that the x-coordinate is entropy coded based on the probability of the x-coordinate having a given value and the y-coordinate is entropy coded based on the probability of the y-coordinate having a given value; and

in the case that the coefficients are scanned in the second scanning order, interchange the x- and y-coordinates and entropy code the interchanged x-coordinate and the interchanged y-coordinate using the determined contexts such that the interchanged x-coordinate is entropy coded based on the probability of the y-coordinate having a given value and the interchanged y-coordinate is entropy coded based on the probability of the x-coordinate having a given value.

7. The apparatus of claim 6 , wherein the first scanning order comprises a horizontal scanning order and the second scanning order comprises a vertical scanning order.

8. The apparatus of claim 6 , wherein to entropy code the x- and y-coordinates and the interchanged x- and y-coordinates, the processor is configured to code a sequence of one or more bins, wherein the contexts indicate probabilities of each of the bins having a given value.

9. The apparatus of claim 6 , wherein the processor is further configured to:

receive entropy encoded values indicative of the x-coordinate and y-coordinate in the video bitstream, wherein to entropy code the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates, the processor is configured to entropy decode the received entropy encoded values so as to obtain the respective ones of x- and y-coordinates or the interchanged x- and y-coordinates;

receive encoded values of non-zero coefficients associated with the block of video data in a bitstream; and

decode the encoded values of the non-zero coefficients based on the respective ones of the x- and y-coordinates and the interchanged x- and y-coordinates.

10. The apparatus of claim 6 , wherein to entropy code the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates, the processor is configured to entropy encode the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates so as to obtain the entropy encoded values indicative of the x-coordinate and y-coordinate and wherein the processor is further configured to:

decode values of non-zero coefficients associated with the block of video data based on the respective ones of the x- and y-coordinates and the interchanged x- and y-coordinates; and

output entropy encoded values indicative of the x-coordinate and y-coordinate and the encoded values of the non-zero coefficients in a video bitstream.

11. A non-transitory computer-readable medium having stored thereon instructions that, when executed, cause a processor to code coefficients associated with a block of video data during a video coding process, wherein the instructions cause the processor to:

determine contexts for performing context adaptive entropy coding of the x- and y-coordinates indicating a horizontal position and a vertical position, respectively, of a last non-zero coefficient within the block, wherein the contexts indicate a probability of each of the x- and y-coordinates comprising a given value when the coefficients of the block of video data are scanned in a first scanning order;

when the coefficients of the block of video data are scanned in the first scanning order, code the x-coordinate and the y-coordinate using the determined contexts such that the x-coordinate is coded based on the probability of the x-coordinate comprising a given value and the y-coordinate is coded based on the probability of the y-coordinate comprising a given value; and

interchange the x- and y-coordinates when the coefficients of the block of video data are scanned in the second scanning order and code the interchanged x-coordinate and the interchanged y-coordinate using the determined contexts such that the interchanged x-coordinate is coded based on the probability of the y-coordinate comprising a given value and the interchanged y-coordinate is coded based on the probability of the x-coordinate comprising a given value.

12. The computer-readable medium of claim 11 , wherein the first scanning order comprises a horizontal scanning order and the second scanning order comprises a vertical scanning order.

13. The computer-readable medium of claim 11 , wherein to entropy code the x- and y-coordinates and the interchanged x- and y-coordinates, the instructions cause the processor to code a sequence of one or more bins, wherein the contexts indicate probabilities of each of the bins having a given value.

14. The computer-readable medium of claim 11 , wherein the instructions further cause the processor to:

receive entropy encoded values indicative of the x-coordinate and y-coordinate in the video bitstream, wherein to entropy code the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates, the processor is configured to entropy decode the received entropy encoded values so as to obtain the respective ones of x- and y-coordinates or the interchanged x- and y-coordinates;

receive encoded values of non-zero coefficients associated with the block of video data in a bitstream; and

decode the encoded values of the non-zero coefficients based on the respective ones of the x- and y-coordinates and the interchanged x- and y-coordinates.

15. The computer-readable medium of claim 11 , wherein to entropy code the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates, the instructions cause the processor to entropy encode the respective ones of the x- and y-coordinates or the interchanged x- and y-coordinates so as to obtain the entropy encoded values indicative of the x-coordinate and y-coordinate and wherein the instructions further cause the processor:

decode values of non-zero coefficients associated with the block of video data based on the respective ones of the x- and y-coordinates and the interchanged x- and y-coordinates; and

output entropy encoded values indicative of the x-coordinate and y-coordinate and the encoded values of the non-zero coefficients in a video bitstream.

Assignments (6)