US 12,316,847 B2
Efficient coding of transform coefficients using or suitable for a combination with dependent scalar quantization
Heiko Schwarz, Berlin (DE); Thomas Wiegand, Berlin (DE); Phan Hoang Tung Nguyen, Berlin (DE); and Detlev Marpe, Berlin (DE)
Assigned to FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V., Munich (DE)
Filed by FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V., Munich (DE)
Filed on Apr. 13, 2023, as Appl. No. 18/134,252.
Application 18/134,252 is a continuation of application No. 17/207,396, filed on Mar. 19, 2021, granted, now 11,677,950.
Application 17/207,396 is a continuation of application No. PCT/EP2019/075732, filed on Sep. 24, 2019.
Claims priority of application No. 18196399 (EP), filed on Sep. 24, 2018.
Prior Publication US 2023/0379471 A1, Nov. 23, 2023
Int. Cl. H04N 19/13 (2014.01); H04N 19/169 (2014.01); H04N 19/18 (2014.01); H04N 19/46 (2014.01); H04N 19/91 (2014.01)
CPC H04N 19/13 (2014.11) [H04N 19/18 (2014.11); H04N 19/1887 (2014.11); H04N 19/46 (2014.11); H04N 19/91 (2014.11)] 33 Claims
OG exemplary drawing
 
1. A method for decoding a picture from a data stream, the method comprising:
identifying a number of available context coded bins for decoding a transform block representing a portion of the picture;
during a decoding pass for at least one position, each position corresponding to a transform coefficient in a subblock of the transform block, starting at a starting position and progressing along a scan order that sequentially traverses the at least one position:
decoding at least one context coded flag at a current position within the subblock,
in response to decoding each of the at least one context coded flag, updating the number of available context coded bins,
after decoding all context coded flags associated with the current position and prior to progressing to a subsequent position immediately following the current position in the scan order, comparing the updated number of available context coded bins to a predefined value, and
terminating the decoding pass, based on the comparison indicating that the updated number of available context coded bins is less than the predefined value; and
after terminating the decoding pass and during at least one additional decoding pass, for each position along the scan order starting from the subsequent position to an ending position within the subblock:
deriving a Rice parameter based on a sum of absolute levels associated with at least one transform coefficient that neighbors a current transform coefficient at a respective position,
decoding a value using Golomb Rice code with the Rice parameter,
deriving a parameter zPos based at least in part on the sum of absolute levels, and
determining an absolute level associated with the current transform coefficient at the respective position based in part on the parameter zPos and the decoded value.