Sign coding for blocks with transform skipped

摘要

Methods of encoding and decoding sign information for non-zero coefficients in a block of video with transform skipped. The methods include context-based coding of a flag that signals if all signs are the same in the block; using a finite state machine to determine contexts for coding of sign information, some of which may be context-based coded and some of which may be non-context-based coded; context-based coding of sign information wherein the context is based upon the signs of neighbouring coefficients; context-based coding of sign information, where the sign information is a prediction of the sign; and using a dedicated context to code signs with a sign flag indicating whether signs in a transform skipping block have been inverted to preserve a dominant sign bias.

主权项

1. A method of decoding a bitstream of data in a video decoder to reconstruct non-zero coefficients of a block in a video, the method comprising:
determining that the block was encoded with transform skipped and, based on that determination, for each non-zero coefficient in the block in a scan order,
decoding sign information for that non-zero coefficient; andsetting that non-zero coefficient to positive or negative based on that sign information,wherein the decoding comprises non-context-based decoding of sign information for at least one non-zero coefficient and context-based decoding of sign information for at least one other non-zero coefficient.