Component dependent intra and inter prediction signaling
Coded information of a first color component and a second color component associated with a current block is determined. A first prediction mode is determined to be selected from an intra prediction mode, an inter prediction mode, or a combined intra-inter prediction mode for the first color component associated with the current block. A second prediction mode is determined to be selected from the intra prediction mode, the inter prediction mode, or the combined intra-inter prediction mode for the second color component associated with the current block. The second prediction mode is different from the first prediction mode. The current block is reconstructed based on predicting the first color component of the current block in the first prediction mode and predicting the second color component of the current block in the second prediction mode.
1. A method of decoding performed in a decoder, the method comprising:
receiving a coded video bitstream comprising a current block, the current block being associated with at least a first color component and a second color component;
obtaining coded information of the first color component and the second color component associated with the current block;
when a first prediction mode for the first color component associated with the current block is one of (i) an intra prediction mode, (ii) an inter prediction mode, or (iii) a combined intra-inter prediction mode,
determining a second prediction mode for the second color component associated with the current block based on the first prediction mode being selected from (i), (ii), or (iii), wherein when the first prediction mode for the first color component is the inter prediction mode, the second prediction mode for the second color component is determined based on a template matching (TM) cost of a template of the second color component, the template including adjacent samples of the second color component; and
reconstructing the current block based on predicting the first color component of the current block in the first prediction mode and predicting the second color component of the current block in the second prediction mode.
2. The method of claim 1 , wherein the inter prediction mode includes one of an inter prediction mode without a motion vector difference, an inter prediction mode with a motion vector difference, and an inter prediction mode with a motion vector displacement.
3. The method of claim 2 , wherein:
the inter prediction mode without the motion vector difference includes one of a merge mode and a near mode,
the inter prediction mode with the motion vector difference includes one of an advanced motion vector prediction (AMVP) mode and a new motion vector (NEWMV) mode, and
the inter prediction mode with the motion vector displacement includes a merge motion vector difference (MMVD) mode.
4. The method of claim 1 , wherein:
the first color component is a luma component and the second color component is a chroma component.
5. The method of claim 1 , wherein:
the first color component is one of a red component, a green component, and a blue component, and
the second color component is another one of the red component, the green component, and the blue component.
6. The method of claim 1 , wherein
when the first prediction mode for the first color component is selected as the one of (i) the intra prediction mode, (ii) the inter prediction mode, and (iii) the combined intra-inter prediction mode, whether the second prediction mode is the intra prediction mode is determined based on signaling information that is included in the coded information.
7. The method of claim 6 , wherein:
the signaling information includes a flag that is entropy coded using a context, and
the context is derived from the coded information based on at least one of a block size of the current block, the first prediction mode, or a value of the flag that is signaled for a neighboring block of the current block.
8. The method of claim 1 , wherein
when the first color component is selected as the one of (i) the intra prediction mode, (ii) the inter prediction mode, and (iii) the combined intra-inter prediction mode, whether the second prediction mode is a cross-component prediction mode is determined based on signaling information that is included in the coded information.
9. The method of claim 8 , wherein the cross-component prediction mode includes one of a cross-component linear mode (CCLM), a chroma from luma mode (CfL), a multi-model CCLM mode, a multiple filter CCLM mode, and a convolutional cross-component model (CCCM).
10. The method of claim 1 , wherein the determining the second prediction mode further comprises:
generating a plurality of prediction sample values of the template of the current block based on a plurality of candidate prediction modes, each of the plurality of prediction sample values being generated based on a respective candidate prediction mode of the plurality of candidate prediction modes;
generating a plurality of TM costs based on the plurality of prediction sample values of the template, each of the plurality of TM costs being associated with a difference between a respective prediction sample value of the plurality of prediction sample values and a reconstructed sample value of the template; and
determining the second prediction mode as a candidate prediction mode of the plurality of candidate prediction modes that corresponds to a minimum TM cost of the plurality of TM costs.
11. The method of claim 10 , wherein
when the reconstructed sample value of the template is unavailable, the second prediction mode is determined as the first prediction mode.
12. A method of encoding, the method comprising:
determining a first prediction mode for a first color component associated with a current block;
when the first prediction mode for the first color component associated with the current block is determined as one of (i) an intra prediction mode, (ii) an inter prediction mode, or (iii) a combined intra-inter prediction mode, determining a second prediction mode for a second color component associated with the current block based on the first prediction mode being determined from (i), (ii), or (iii), wherein when the first prediction mode for the first color component is the inter prediction mode, the second prediction mode for the second color component is determined based on a template matching (TM) cost of a template of the second color component, the template including adjacent samples of the second color component; and
encoding the current block into a bitstream, the first color component of the current block being encoded with the first prediction mode and the second color component of the current block being encoded with the second prediction mode.
13. The method of claim 12 , wherein the inter prediction mode includes one of an inter prediction mode without a motion vector difference, an inter prediction mode with a motion vector difference, and an inter prediction mode with a motion vector displacement.
14. The method of claim 13 , wherein:
the inter prediction mode without the motion vector difference includes one of a merge mode and a near mode,
the inter prediction mode with the motion vector difference includes one of an advanced motion vector prediction (AMVP) mode and a new motion vector (NEWMV) mode, and
the inter prediction mode with the motion vector displacement includes a merge motion vector difference (MMVD) mode.
15. The method of claim 12 , wherein:
the first color component is a luma component and the second color component is a chroma component.
16. The method of claim 12 , wherein:
the first color component is one of a red component, a green component, and a blue component, and
the second color component is another one of the red component, the green component, and the blue component.
17. The method of claim 12 , further comprising:
signaling prediction mode information into the bitstream, the prediction mode information indicating whether the second prediction mode is the intra prediction mode when the first color component is determined as the one of (i) the intra prediction mode, (ii) the inter prediction mode, and (iii) the combined intra-inter prediction mode.
18. The method of claim 12 , further comprising:
signaling prediction mode information into the bitstream, the prediction mode information indicating whether the second prediction mode is a cross-component prediction mode when the first color component is determined as the one of (i) the intra prediction mode, (ii) the inter prediction mode, (iii) the combined intra-inter prediction mode.
19. The method of claim 18 , wherein the cross-component prediction mode includes one of a cross-component linear mode (CCLM), a chroma from luma mode (CfL), a multi-model CCLM mode, a multiple filter CCLM mode, and a convolutional cross-component model (CCCM).
20. A method of processing visual media data, the method comprising:
processing a bitstream of the visual media data according to a format rule, wherein:
the bitstream includes coded information of a first color component and a second color component associated with a current block; and
the format rule specifies that:
when a first prediction mode for the first color component associated with the current block is one of (i) an intra prediction mode, (ii) an inter prediction mode, or (iii) a combined intra-inter prediction mode,
a second prediction mode is determined for the second color component associated with the current block based on the first prediction mode being selected from (i), (ii), or (iii), wherein when the first prediction mode for the first color component is the inter prediction mode, the second prediction mode for the second color component is determined based on a template matching (TM) cost of a template of the second color component, the template including adjacent samples of the second color component; and
the current block is processed based on predicting the first color component of the current block in the first prediction mode and predicting the second color component of the current block in the second prediction mode.