Methods and apparatus for unified significance map coding

A method, comprising:

• encoding transform coefficients obtained using a plurality of transforms and converted from a two dimensional to a one-dimensional array, wherein one or more context sharing maps are generated for the transform coefficients based on a unified rule for generating the context sharing maps, the one or more context sharing maps for providing at least one context that is shared among at least some of the transform coefficients obtained from at least two different ones of the plurality of transforms, wherein a context is assigned based on transform coefficient position (800, 1000).

An apparatus, comprising:

• a video decoder (500) for decoding transform coefficients obtained using a plurality of transforms and converted from a two dimensional to a one-dimensional array, wherein one or more context sharing maps are generated for the transform coefficients based on a unified rule for generating the context sharing maps, the one or more context sharing maps for providing at least one context that is shared among at least some of the transform coefficients obtained from at least two different ones of the plurality of transforms, wherein a context is assigned based on transform coefficient position.

A method, comprising:

• decoding transform coefficients for at least a portion of a picture, the transform coefficients obtained using a plurality of transforms and converted from a two dimensional to a one-dimensional array, wherein one or more context sharing maps are generated for the transform coefficients based on a unified rule for generating the context sharing maps, the one or more context sharing maps for providing at least one context that is shared among at least some of the transform coefficients obtained from at least two different ones of the plurality of transforms, wherein a context is assigned based on transform coefficient position (900, 1100).

A non-transitory computer readable storage media having video signal data encoded thereupon, comprising:

• transform coefficients obtained using a plurality of transforms and converted from a two dimensional to a one-dimensional array, wherein one or more context sharing maps are generated for the transform coefficients based on a unified rule for generating the context sharing maps, the one or more context sharing maps for providing at least one context that is shared among at least some of the transform coefficients obtained from at least two different ones of the plurality of transforms, wherein a context is assigned based on transform coefficient position.