Video decoding implementations for a graphics processing unit

One or more non-transitory computer-readable media having stored therein computer-executable instructions for causing a computer system, when programmed thereby, to perform video processing operations comprising:

• receiving encoded data for a picture that includes plural portions;
• and
• decoding the encoded data to reconstruct the picture, wherein the decoding the encoded data includes performing decoding operations, including context-adaptive binary arithmetic decoding operations, for the plural portions of the picture, the context-adaptive binary arithmetic decoding operations including, for one of the plural portions not having dependencies on other portions of the plural portions, initialization of variables, and wherein the decoding the encoded data is otherwise subject to dependencies between the plural portions that allow performing at least some of the decoding operations for the plural portions of the picture, on a wave-by-wave basis, as plural waves, the plural portions of the picture having variable size, each of the plural waves including one or more of the plural portions of the picture, wherein, for at least one of the plural waves, the dependencies between the plural portions allow at least some of the one or more portions within the wave to be processed in parallel such that the plural waves ripple from a top-left corner of the picture toward a bottom-right corner of the picture, such that each of the plural waves depends on results of the at least some of the decoding operations for any preceding waves among the plural waves, and such that, for each of the plural waves, for each given portion of the wave the at least some of the decoding operations have completed for (1) the portion, if any, left of the given portion, (2) the portion, if any, above-left of the given portion, (3) the portion, if any, above the given portion, and (4) the portion, if any, above-right of the given portion.

A computer system comprising:

• a buffer, implemented with memory, configured to receive encoded data for a picture that includes plural portions;
• and
• a video decoder, implemented with one or more processing units, configured to decode the encoded data to reconstruct the picture, wherein the video decoder is configured to perform decoding operations, including context-adaptive binary arithmetic decoding operations, for the plural portions of the picture, the context-adaptive binary arithmetic decoding operations including, for one of the plural portions not having dependencies on other portions of the plural portions, initialization of variables, and wherein dependencies between the plural portions otherwise allow the video decoder is to perform at least some of the decoding operations for the plural portions of the picture, on a wave-by-wave basis, as plural waves, the plural portions of the picture having variable size, each of the plural waves including one or more of the plural portions of the picture, wherein, for at least one of the plural waves, the dependencies between the plural portions allow at least some of the one or more portions within the wave to be processed in parallel such that the plural waves ripple from a top-left corner of the picture toward a bottom-right corner of the picture, such that each of the plural waves depends on results of the at least some of the decoding operations for any preceding waves among the plural waves, and such that, for each of the plural waves, for each given portion of the wave the at least some of the decoding operations have completed for (1) the portion, if any, left of the given portion, (2) the portion, if any, above-left of the given portion, (3) the portion, if any, above the given portion, and (4) the portion, if any, above-right of the given portion.