US 12,192,463 B2
Control and use of chroma quantization parameter values
Gary J. Sullivan, Bellevue, WA (US); and Sandeep Kanumuri, Redmond, WA (US)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on Sep. 23, 2022, as Appl. No. 17/951,409.
Application 15/202,933 is a division of application No. 13/732,356, filed on Dec. 31, 2012, granted, now 9,414,054, issued on Aug. 9, 2016.
Application 17/951,409 is a continuation of application No. 17/145,535, filed on Jan. 11, 2021, granted, now 11,457,212.
Application 17/145,535 is a continuation of application No. 16/600,287, filed on Oct. 11, 2019, granted, now 10,924,740, issued on Feb. 16, 2021.
Application 16/600,287 is a continuation of application No. 16/277,704, filed on Feb. 15, 2019, granted, now 10,491,898, issued on Nov. 26, 2019.
Application 16/277,704 is a continuation of application No. 15/202,933, filed on Jul. 6, 2016, granted, now 10,250,882, issued on Apr. 2, 2019.
Claims priority of provisional application 61/667,381, filed on Jul. 2, 2012.
Prior Publication US 2023/0023086 A1, Jan. 26, 2023
Int. Cl. H04N 19/124 (2014.01); H04N 19/126 (2014.01); H04N 19/174 (2014.01); H04N 19/186 (2014.01); H04N 19/44 (2014.01); H04N 19/70 (2014.01); H04N 19/146 (2014.01)
CPC H04N 19/124 (2014.11) [H04N 19/126 (2014.11); H04N 19/174 (2014.11); H04N 19/186 (2014.11); H04N 19/44 (2014.11); H04N 19/70 (2014.11); H04N 19/146 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A computer system comprising one or more processing units and memory, wherein the computer system implements a video decoder configured to perform operations comprising:
receiving encoded data in a bitstream for which values of quantization parameter (QP) vary according to a relationship between a luma component and chroma components, wherein the encoded data in the bitstream includes:
a flag in a picture parameter set that indicates presence of slice-level chroma QP offsets in slice headers;
syntax elements that indicate picture-level chroma QP offsets; and
syntax elements that indicate the slice-level chroma QP offsets; and
decoding at least some of the encoded data to reconstruct one or more pictures, including, for a portion of a given picture among the one or more pictures:
determining a QP index from a luma component QP and a chroma component QP offset, wherein the chroma component QP offset incorporates one of the picture-level chroma QP offsets and one of the slice-level chroma QP offsets, the QP index being determined according to:
qPI=Clip3(a,b,QPY+qp_offset+slice_qp_delta),
where qPI represents the QP index, QPY represents the luma component QP, qp_offset represents the one of the picture-level chroma QP offsets, slice_qp_delta represents the one of the slice-level chroma QP offsets, and Clip3(a, b, c) represents a function that clips the value of c to the range of a to b; and
mapping the QP index to a chroma component QP.