Entropy coding supporting mode switching

An encoder for encoding data of a video into a data stream, the encoder comprising:

• a constructor configured to encode the data of the video into a sequence of syntax elements;
• a symbolizer configured to symbolize the sequence of syntax elements into a sequence of symbols;
• an entropy encoding engine configured to encode the sequence of symbols based on an entropy encoding scheme, wherein, with respect to at least one symbol of the sequence of symbols, the entropy encoding engine is configured to:
• select a context corresponding to the at least one symbol, and
• encode the at least one symbol using the selected context based on the entropy encoding scheme, wherein the entropy decoding includes updating a probability model associated with the selected context at one of a first update rate under a high-efficiency mode of entropy encoding and a second update rate, that is lower than the first update rate, under a low-complexity mode of entropy encoding;
• and
• a data inserter configured to insert the encoded sequence of symbols into the data stream.

A non-transitory computer-readable medium for storing data associated with a video, comprising:

• a data stream stored in the non-transitory computer-readable medium, the data stream comprising an encoded sequence of symbols corresponding to a sequence of syntax elements representing a video, wherein the sequence of symbols is encoded into the data stream based on a plurality of operations comprising:
• entropy encoding the sequence of symbols based on an entropy encoding scheme, wherein, with respect to at least one symbol of the sequence of symbols, the entropy encoding includes:
• selecting a context corresponding to the at least one symbol, and
• encoding the at least one symbol using the selected context based on the entropy encoding scheme, which includes updating a probability model associated with the selected context at one of a first update rate under a high-efficiency mode of entropy encoding and a second update rate, that is lower than the first update rate, under a low-complexity mode of entropy encoding.

A method for decoding a data stream including encoded data of a video, the method comprising:

• decoding data from the data stream based on an entropy decoding scheme to obtain a sequence of symbols, wherein, with respect to at least one symbol of the sequence of symbols, the decoding includes:
• selecting a context corresponding to the at least one symbol, and
• decoding the at least one symbol using the selected context based on the entropy decoding scheme, wherein the entropy decoding includes updating a probability model associated with the selected context at one of a first update rate under a high-efficiency mode of entropy decoding and a second update rate, that is lower than the first update rate, under a low-complexity mode of entropy decoding;
• desymbolizing the sequence of symbols to obtain a sequence of syntax elements;
• and
• a reconstructing configured to reconstruct at least a portion of the video based on the sequence of syntax elements.