US 12,309,372 B2
Method and apparatus for signaling of mapping function of chroma quantization parameter
Sergey Yurievich Ikonin, Moscow (RU); Roman Igorevich Chernyak, Moscow (RU); Timofey Mikhailovich Solovyev, Moscow (RU); Alexander Alexandrovich Karabutov, Moscow (RU); Elena Alexandrovna Alshina, Munich (DE); and Jianle Chen, San Diego, CA (US)
Assigned to HUAWEI TECHNOLOGIES CO., LTD., Shenzhen (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed on Feb. 12, 2024, as Appl. No. 18/439,264.
Application 18/439,264 is a continuation of application No. 17/452,137, filed on Oct. 25, 2021, granted, now 12,052,419.
Application 17/452,137 is a continuation of application No. PCT/CN2020/086933, filed on Apr. 26, 2020.
Claims priority of provisional application 62/872,238, filed on Jul. 9, 2019.
Claims priority of provisional application 62/871,197, filed on Jul. 7, 2019.
Claims priority of provisional application 62/839,607, filed on Apr. 26, 2019.
Claims priority of application No. PCT/RU2019/000444 (WO), filed on Jun. 21, 2019.
Prior Publication US 2024/0205406 A1, Jun. 20, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/126 (2014.01); H04N 19/124 (2014.01); H04N 19/132 (2014.01); H04N 19/172 (2014.01); H04N 19/174 (2014.01); H04N 19/184 (2014.01); H04N 19/186 (2014.01); H04N 19/44 (2014.01)
CPC H04N 19/126 (2014.11) [H04N 19/124 (2014.11); H04N 19/132 (2014.11); H04N 19/172 (2014.11); H04N 19/174 (2014.11); H04N 19/184 (2014.11); H04N 19/186 (2014.11); H04N 19/44 (2014.11)] 3 Claims
OG exemplary drawing
 
1. A method comprising:
receiving a bitstream comprising a sequence parameter set (SPS);
parsing the bitstream to obtain a luminance quantization parameter (QP) and information of a chroma QP mapping table which associates a QP index (QPi) to a chrominance QP (QPc), wherein the chroma QP mapping table is signaled in the SPS;
obtaining a QPi based at least in part on the obtained luminance QP;
obtaining the chroma QP mapping table based on the obtained information of the chroma QP mapping table;
obtaining a first QPc based on the obtained chroma QP mapping table and the obtained QPi; and
obtaining a second QPc based on the first QPc, wherein
qPChroma=Clip3(−QpBdOffset,63,QpY);
qPCb=ChromaQpTable[0][qPChroma];
qPCr=ChromaOpTable[1][qPChroma]; or
qPCbCr=ChromaQpTable[2][qPChroma];
wherein the QpY represents the luminance QPY;
wherein the ChromaOpTable represents the chroma QP mapping table;
wherein the qPChroma represents the obtained QPi;
wherein the qPCb, qPCr or qPCbCr represents the first QPc;
wherein the QpBdOffset represents a bit depth offset calculated based on a bit depth of samples of luma and chroma arrays using the following:
QpBdOffset=6*bit_depth_minus8,
wherein the bit_depth_minus8 is in a range of 0 to 8, inclusive.