Probability initialization and signaling for adaptive arithmetic coding in video coding

A device for decoding video data, the device comprising:

• one or more storage media;
• and
• one or more processors configured to:
• receive a video bitstream including encoded representations of one or more syntax elements of a coded unit;
• initialize a respective probability state for each bin of a plurality of bins for the one or more syntax elements based on a comparison of a parameter associated with the coded unit and a respective threshold of a plurality of thresholds;
• perform inverse binary arithmetic coding on the encoded representations of the one or more syntax elements to obtain each bin of the plurality of bins using a respective probability state for the bin;
• inverse binarize the plurality of bins to obtain the one or more syntax elements;
• and
• decode the video data based on the one or more syntax elements.

A computer-readable storage medium storing instructions that, when executed, cause one or more processors to:

• receive a video bitstream including encoded representations of one or more syntax elements of a coded unit;
• initialize a respective probability state for each bin of a plurality of bins for the one or more syntax elements based on a comparison of a parameter associated with the coded unit and a respective threshold of a plurality of thresholds;
• perform inverse binary arithmetic coding on the encoded representations of the one or more syntax elements to obtain each bin of the plurality of bins using a respective probability state for the bin;
• inverse binarize the plurality of bins to obtain the one or more syntax elements;
• and
• decode the video data based on the one or more syntax elements.

An apparatus comprising:

• means receiving a video bitstream including encoded representations of one or more syntax elements of a coded unit;
• means for initializing a respective probability state for each bin of a plurality of bins for the one or more syntax elements based on a comparison of a parameter associated with the coded unit and a respective threshold of a plurality of thresholds;
• means for performing inverse binary arithmetic coding on the encoded representations of the one or more syntax elements to obtain each bin of the plurality of bins using a respective probability state for the bin;
• means for inverse binarizing the plurality of bins to obtain the one or more syntax elements;
• and
• means for decoding the video data based on the one or more syntax elements.

A method of encoding video data, the method comprising:

• encoding, by processing circuitry, the video data to generate one or more syntax elements of a coded unit;
• binarizing, by the processing circuitry, the one or more syntax elements to obtain a plurality of bins;
• initializing, by the processing circuitry, a respective probability state for each bin of the plurality of bins for the one or more syntax elements based on a comparison of a parameter associated with the coded unit and a respective threshold of a plurality of thresholds;
• performing, by the processing circuitry, binary arithmetic coding on the plurality of bins of the one or more syntax elements to obtain encoded representations of the one or more syntax elements using a respective probability state for the bin;
• and
• outputting, by the processing circuitry, a video bitstream including the encoded representations of the one or more syntax elements.

A device for encoding video data, the device comprising:

• one or more storage media configured to store video data;
• and
• one or more processors configured to:
• encode the video data to generate one or more syntax elements of a coded unit;
• binarize the one or more syntax elements to obtain a plurality of bins;
• initialize a respective probability state for each bin of the plurality of bins for the one or more syntax elements based on a comparison of a parameter associated with the coded unit and a respective threshold of a plurality of thresholds;
• perform binary arithmetic coding on the plurality of bins of the one or more syntax elements to obtain encoded representations of the one or more syntax elements using a respective probability state for the bin;
• and
• output a video bitstream including the encoded representations of the one or more syntax elements.