Low complexity history usage for Rice parameter derivation for high bit-depth video coding

A device for decoding video data, the device comprising:

• a memory configured to store video data;
• one or more processors implemented in circuitry and configured to:
• determine a default history value based on a bit depth of a slice of a picture that includes a first transform block (TB) and a second TB;
• and
• reset a coefficient statistic value to the default history value at a start of a partitioning of the picture;
• update the coefficient statistic value based on one or more transform coefficients of the first TB, wherein to update the coefficient statistic value, the one or more processors are further configured to, for each respective transform coefficient of the one or more transform coefficients of the first TB:
• perform a derivation process to determine a temporary value, wherein the derivation process is determined based at least in part on which encoding process of a plurality of encoding processes is used to encode the respective transform coefficient, the plurality of encoding processes including a context-based process for encoding the respective transform coefficient and encoding the respective transform coefficient as an absolute value;
• and
• set the coefficient statistic value as an average of the coefficient statistic value and the temporary value;
• determine a history value based on the coefficient statistic value;
• determine a Rice parameter for a specific transform coefficient of the second TB based on the history value;
• determine a level of the specific transform coefficient based on the Rice parameter for the specific transform coefficient and one or more syntax elements encoded in a bitstream;
• and
• decode a block of the video data based on the level of the specific transform coefficient.

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

• determine a default history value based on a bit depth of a slice of a picture that includes a first transform block (TB) and a second TB;
• and
• reset a coefficient statistic value to the default history value at a start of a partitioning of the picture;
• update the coefficient statistic value based on one or more transform coefficients of the first TB, wherein to update the coefficient statistic value, the instructions cause the one or more processors to, for each respective transform coefficient of the one or more transform coefficients of the first TB:
• perform a derivation process to determine a temporary value, wherein the derivation process is determined based at least in part on which encoding process of a plurality of encoding processes is used to encode the respective transform coefficient, the plurality of encoding processes including a context-based process for encoding the respective transform coefficient and encoding the respective transform coefficient as an absolute value;
• and
• set the coefficient statistic value as an average of the coefficient statistic value and the temporary value;
• determine a history value based on the coefficient statistic value;
• determine a Rice parameter for a specific transform coefficient of the second TB based on the history value;
• determine a level of the specific transform coefficient based on the Rice parameter for the specific transform coefficient and one or more syntax elements encoded in a bitstream;
• and
• decode a block of video data based on the level of the specific transform coefficient.