Method and apparatus for video coding
Aspects of the disclosure provide a method and an apparatus for video coding. In some examples, an apparatus includes processing circuitry that receives a bitstream that includes coded information representing a current bin of a current syntax element of a first syntax element type for a block in a picture. The processing circuitry determines, for the current bin of the current syntax element, a current context model associated with both the first syntax element type and a second syntax element type different from the first syntax element type. The processing circuitry also decodes the coded information according to the current context model to obtain the current bin of the current syntax element, and reconstructs the current block according to a characteristic indicated by the current bin of the current syntax element.
1. A method of video decoding, comprising:
receiving a bitstream that includes coded information representing a current bin of a current syntax element of a first syntax element type for a block in a picture;
determining, by processing circuitry for the current bin of the current syntax element, a current context model associated with both the first syntax element type and a second syntax element type different from the first syntax element type, wherein
each syntax element of the first syntax element type specifies a first mode flag indicating whether a combined inter and intra prediction is used, and
each syntax element of the second syntax element type specifies a second mode flag indicating whether a regular merge mode is used;
determining an initial context state associated with the current context model for a coding region that includes the block according to a type of the coding region;
decoding, by the processing circuitry, the coded information according to the current context model to obtain the current bin of the current syntax element; and
reconstructing the block according to a characteristic indicated by the current bin of the current syntax element,
wherein the decoding the coded information according to the current context model includes:
determining a current context state according to one or more of (i) the initial context state, (ii) a previous context state, or (iii) a bin of a previously coded syntax element of the first syntax element type or the second syntax element type within the coding region, and
updating the current context model according to the current context state.
2. The method of claim 1 , wherein
multiple context models identifiable by respective context increment index values are associated with the second syntax element type, and
the current context model corresponds to one of the multiple context models identifiable by a context increment index value.
3. The method of claim 2 , wherein
the context increment index value is 0 or 1.
4. The method of claim 1 , wherein the coding region corresponds to a tile or a slice in the picture.
5. An apparatus, comprising:
processing circuitry configured to:
receive a bitstream that includes coded information representing a current bin of a current syntax element of a first syntax element type for a block in a picture;
determine, for the current bin of the current syntax element, a current context model associated with both the first syntax element type and a second syntax element type different from the first syntax element type, wherein
each syntax element of the first syntax element type specifies a first mode flag indicating whether a combined inter and intra prediction is used, and
each syntax element of the second syntax element type specifies a second mode flag indicating whether a regular merge mode is used;
determine an initial context state associated with the current context model for a coding region that includes the block according to a type of the coding region;
decode the coded information according to the current context model to obtain the current bin of the current syntax element; and
reconstruct the block according to a characteristic indicated by the current bin of the current syntax element, wherein the processing circuitry is further configured to:
determine a current context state according to one or more of (i) the initial context state, (ii) a previous context state, or (iii) a bin of a previously coded syntax element of the first syntax element type or the second syntax element type within the coding region, and
update the current context model according to the current context state.
6. The apparatus of claim 5 , wherein
multiple context models identifiable by respective context increment index values are associated with the second syntax element type, and
the current context model corresponds to one of the multiple context models identifiable by a context increment index value.
7. The apparatus of claim 6 , wherein
the context increment index value is 0 or 1.
8. The apparatus of claim 5 , wherein the coding region corresponds to a tile or a slice in the picture.
9. A non-transitory computer-readable medium storing instructions which, when executed by a computer for video decoding, cause the computer to perform:
receiving a bitstream that includes coded information representing a current bin of a current syntax element of a first syntax element type for a block in a picture;
determining, for the current bin of the current syntax element, a current context model associated with both the first syntax element type and a second syntax element type different from the first syntax element type, wherein
each syntax element of the first syntax element type specifies a first mode flag indicating whether a combined inter and intra prediction is used, and
each syntax element of the second syntax element type specifies a second mode flag indicating whether a regular merge mode is used;
determining an initial context state associated with the current context model for a coding region that includes the block according to a type of the coding region;
decoding the coded information according to the current context model to obtain the current bin of the current syntax element; and
reconstructing the block according to a characteristic indicated by the current bin of the current syntax element,
wherein the decoding the coded information according to the current context model includes:
determining a current context state according to one or more of (i) the initial context state, (ii) a previous context state, or (iii) a bin of a previously coded syntax element of the first syntax element type or the second syntax element type within the coding region, and
updating the current context model according to the current context state.
10. The non-transitory computer-readable medium of claim 9 , wherein
multiple context models identifiable by respective context increment index values are associated with the second syntax element type, and
the current context model corresponds to one of the multiple context models identifiable by a context increment index value.
11. The non-transitory computer-readable medium of claim 10 , wherein
the context increment index value is 0 or 1.