ADAPTIVE COEFFICIENT SCANNING FOR VIDEO CODING
First Claim
1. A method of coding video data, the method comprising:
- scanning coefficient values of a first video block using a coefficient scan order;
collecting statistics associated with at least a portion of the coefficient values;
adjusting the coefficient scan order in accordance with the collected statistics;
scanning coefficient values of at least one subsequent video block using the adjusted coefficient scan order when the at least one subsequent video block exists in a coding unit of the first video block; and
entropy coding the coefficient values.
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Accused Products
Abstract
This disclosure describes techniques for scanning coefficients of video blocks. In particular, the techniques of this disclosure adapt a scan order used to scan a two-dimensional block of coefficients into a one-dimensional coefficient vector based on statistics associated with one or more previously coded blocks. For example, statistics that indicate the likelihood that a given coefficient value in each position of a two-dimensional block is zero or non-zero may be collected for one or more previously coded blocks. At some point, an adjustment to the scan order can be made in order to better ensure that non-zero coefficients are grouped together near the front of the one-dimensional coefficient vector, which can improve the effectiveness of entropy coding. The collection of statistics and adjustment of scan order may be made separately for each possible prediction mode.
306 Citations
54 Claims
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1. A method of coding video data, the method comprising:
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scanning coefficient values of a first video block using a coefficient scan order; collecting statistics associated with at least a portion of the coefficient values; adjusting the coefficient scan order in accordance with the collected statistics; scanning coefficient values of at least one subsequent video block using the adjusted coefficient scan order when the at least one subsequent video block exists in a coding unit of the first video block; and entropy coding the coefficient values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A device that codes video data, the device comprising:
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a scanning unit that scans coefficient values of a first video block using a coefficient scan order, collects statistics associated with at least a portion of the coefficient values, adjusts the coefficient scan order in accordance with the collected statistics and scans coefficient values of at least one subsequent video block using the adjusted coefficient scan order when the at least one subsequent video block exists in a coding unit of the first video block; and an entropy coding unit that entropy codes the coefficient values. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A computer-readable medium upon which is stored instructions that upon execution in a video coding device cause the device to code video blocks, wherein the instructions cause the device to:
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scan coefficient values of a first video block using a coefficient scan order; collect statistics associated with at least a portion of the coefficient values; adjust the coefficient scan order in accordance with the collected statistics; scan coefficient values of at least one subsequent video block using the adjusted coefficient scan order when the at least one subsequent video block exists in a coding unit of the first video block; and entropy code the coefficient values. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A device that codes video data, the device comprising:
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means for scanning coefficient values of a first video block using a coefficient scan order; means for collecting statistics associated with at least a portion of the coefficient values; means for adjusting the coefficient scan order in accordance with the collected statistics; wherein the coefficient scanning means scans coefficient values of at least one subsequent video block using the adjusted coefficient scan order when the at least one subsequent video block exists in a coding unit of the first video block; and means for entropy coding the coefficient values. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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Specification