Patent ID: 11863749
Assignee: MICROSOFT TECHNOLOGY LICENSING, LLC
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A computer system comprising one or more processing units and memory, wherein the computer system implements a video encoder configured to perform operations comprising:
encoding a frame of pixel values, the pixel values of the frame being organized spatially into multiple areas within the frame, the multiple areas being further organized spatially into groups, the pixel values of the frame also being organized by first, second, and third color channels, wherein the encoding includes:
for blocks of at least some of the multiple areas of the frame, performing frequency transform operations, thereby producing transform coefficients;
for the blocks of at least some of the multiple areas of the frame, quantizing the transform coefficients; and
setting one or more syntax elements that control variation of quantization parameters along a spatial dimension within the frame, one or more syntax elements that control variation of the quantization parameters along a color channel dimension, and, for a given group of the groups, syntax elements that indicate how to vary the quantization parameters for the second and third color channels, respectively, for the given group; and

outputting encoded data as part of a bitstream, wherein the encoded data includes:
the one or more syntax elements that control variation of the quantization parameters along the spatial dimension, including at least one syntax element that indicates whether variation of the quantization parameters is possible between the multiple areas within the respective groups;
the one or more syntax elements that control variation of the quantization parameters along the color channel dimension, including a syntax element that indicates whether, for the given group, the encoded data includes the syntax elements that indicate how to vary the quantization parameters for the second and third colors channels, respectively, for the given group; and
for the given group, the syntax elements that indicate how to vary the quantization parameters for the second and third color channels, respectively, for the given group.