Patent ID: 8897359

Claim:
A computing device comprising a processing unit, memory and a storage medium storing computer-executable instructions which, when executed, cause the computing device to perform a method comprising: encoding enhancement layer video for a picture organized in plural color channels, including selectively varying quantization spatially and between the plural color channels of the enhancement layer video for the picture, and further including, when spatial quantization variation is used, for a current macroblock of the enhancement layer video for the picture, predicting a macroblock-level quantization parameter for the current macroblock using one or more macroblock-level quantization parameters for spatially neighboring macroblocks; and outputting the encoded enhancement layer video for the picture in a bitstream, including: signaling in the bitstream information that indicates an on/off decision for spatial quantization variation; signaling in the bitstream information that indicates an on/off decision for quantization variation between channels; and signaling in the bitstream quantization parameter information that indicates plural quantization parameters that at least in part parameterize the varied quantization of the enhancement layer video for the picture, the quantization parameter information including, when spatial quantization variation is used, the macroblock-level quantization parameter for the current macroblock signaled in the bitstream as a differential quantization parameter relative to the predicted macroblock-level quantization parameter for the current macroblock, thereby facilitating combination by a video decoder of the differential quantization parameter with a prediction of the macroblock-level quantization parameter computed by the video decoder for the current macroblock.