Chroma Quantization Parameter Extension
AssigneeVelos Media, LLC
InventorsJun Xu, Kazushi Sato, Ehsan Maani
Life of this patent
Estimating the term…
Abstract
The quantization parameters (QP) for Chroma are extended up to and more preferably to the same range as Luma QP (e.g., 0 to 51). Previous, values of Chroma QP only extended up to 39. Techniques are provided for determining extended Chroma QP values (e.g., for Cr and Cb) based on the Luma QP and picture level chroma offsets. In one preferred embodiment, slice level offsets are added making the method particularly well-suited for slice level parallel processing. The extension of Chroma QP enhances functionality, flexibility and friendliness of the High Efficiency Video Coding (HEVC) standard for various applications.
Claims15
A decoding apparatus, comprising:
- circuitry configured to:
- decode a bit stream that includes a slice level chroma quantization parameter (QP) offset;
- obtain the slice level chroma QP offset from the bit stream;
- set a chroma QP in a chroma QP range from 0 to 51 equal to a luma QP range from 0 to 51, based on a parameter including a picture level chroma QP offset and the slice level chroma QP offset added to a luma QP;
- obtain quantization data from the bit stream;
- and
- inverse quantize the quantization data, based on the chroma QP.
A decoding method, comprising:
- decoding a bit stream that includes a slice level chroma quantization parameter (QP) offset;
- obtaining the slice level chroma QP offset from the bit stream;
- setting a chroma QP in a chroma QP range from 0 to 51 equal to a luma QP range from 0 to 51, based on a parameter including a picture level chroma QP offset and the slice level chroma QP offset added to a luma QP;
- obtaining quantization data from the bit stream;
- and
- inverse quantizing the quantization data based on the chroma QP.
At least one computer-readable medium encoded with instructions that, when executed by a processor, causes the processor to perform:
- decoding a bit stream that includes a slice level chroma quantization parameter (QP) offset;
- obtaining the slice level chroma QP offset from the bit stream;
- setting a chroma QP in a chroma QP range from 0 to 51 equal to a luma QP range from 0 to 51, based on a parameter including a picture level chroma QP offset and the slice level chroma QP offset added to a luma QP;
- obtaining quantization data from the bit stream;
- and
- inverse quantizing the quantization data based on the chroma QP.
Dependencies are inferred from the claim text.