SEARCH STRATEGIES FOR INTRA-PICTURE PREDICTION MODES

摘要

Innovations are presented that reduce the computational complexity of video encoding by selectively skipping certain evaluation stages during intra-picture prediction. A video encoder receives and encodes a current picture. As part of the encoding, for a current block of the current picture, the video encoder evaluates at least some intra-picture prediction modes (“IPPMs”). According to a search strategy, the video encoder selectively skips time-consuming evaluation of certain IPPMs for the current block when those IPPMs are not expected to improve rate-distortion performance, which can dramatically speed up the encoding process. For example, the video encoder conditionally performs a gradient search among angular IPPMs. Or, as another example, the video encoder selectively skips evaluation of IPPMs depending on a cost of encoding the current block using motion compensation. Or, as another example, the video encoder prioritizes IPPMs evaluated for a block of chroma sample values.

主权项

1. A computer system comprising a processor and memory, wherein the computer system implements a video encoder system comprising:
a buffer configured to store a current picture of a video sequence; and a video encoder configured to encode the current picture, including, for a current block of the current picture, evaluating at least some of multiple intra-picture prediction modes (“IPPMs”) according to a search strategy, the search strategy including:
checking one or more conditions; andupon satisfaction of the one or more conditions, performing a gradient search among angular IPPMs of the multiple IPPMs.