Merge candidates with multiple hypothesis
A video decoder receives to-be-decoded data from a bitstream for a block of pixels to be decoded as a current block of a current picture of the video. The video decoder generates a first prediction of the current block based on a first prediction mode that is selected from a first candidate list. The video decoder generates a second prediction of the current block based on a second prediction mode that is selected from a second candidate list. The video decoder generates a combined prediction for the current block based on the first prediction and the second prediction. The video decoder reconstructs the current block by using the combined prediction.
1. A video decoding method, comprising:
receiving to-be-decoded data from a bitstream for a block of pixels to be decoded as a current block of a current picture of a video;
generating a first prediction of the current block according to an inter-prediction mode and a selected motion candidate selected from a candidate list, the candidate list including one or more motion candidates;
generating a second prediction of the current block according to a selected intra-prediction mode selected from one or more candidate intra-prediction modes that include a directional intra-prediction mode, a DC mode, or a Planar mode;
generating a combined prediction for the current block based on the first prediction and the second prediction; and
reconstructing the current block according to the combined prediction.
2. The method of claim 1 , wherein the candidate list is identical to a merge candidate list of the current block.
3. The method of claim 1 , wherein the candidate list is a subset of a merge candidate list of the current block.
4. The method of claim 1 , further comprising determining whether to generate the second prediction based on an explicit flag in the bitstream.
5. The method of claim 4 , further comprising determining whether to parse the explicit flag from the bitstream based on a width, a height, or a size of the current block.
6. The method of claim 1 , further comprising determining whether to generate the second prediction based on a width, a height, or a size of the current block.
7. The method of claim 1 , wherein the second prediction mode is selected based on an ordering of the one or more candidate intra-prediction modes that is determined based on a width, a height, or a size of the current block.
8. The method of claim 1 , wherein the intra-prediction mode is selected based on the selected inter-prediction mode.
9. The method of claim 1 , wherein selection information for the selected motion candidate or the selected intra-prediction mode is signaled by using a shortest code word.
10. The method of claim 1 , wherein a number of the one or more candidate intra-prediction modes for the current block is determined based on a width, a height, or a size of the current block.
11. The method of claim 1 , wherein the one or more candidate intra-prediction modes include only one candidate intra-prediction mode.
12. The method of claim 11 , wherein the only one candidate intra-prediction mode is identified based on a ratio between a width of the current block and a height of the current block.
13. The method of claim 1 , wherein the candidate list is a subset of a merge candidate list of the current block that comprises spatial candidates but not temporal candidates.
14. The method of claim 1 , wherein the combined prediction is applicable to a sub-region of the current block and not outside of the sub-region of the current block, and wherein a size of the sub-region is determined based on a width, height, or size of the current block.
15. A video encoding method, comprising:
receiving raw pixel data for a block of pixels to be encoded as a current block of a current picture of a video into a bitstream;
generating a first prediction of the current block according to an inter-prediction mode and a selected motion candidate selected from a candidate list, the candidate list including one or more motion candidates;
generating a second prediction of the current block according to a selected intra-prediction mode selected from one or more candidate intra-prediction modes that include a directional intra-prediction mode, a DC mode, or a Planar mode;
generating a combined prediction for the current block based on the first prediction and the second prediction; and
encoding the current block into the bitstream according to the combined prediction.
16. An electronic apparatus, comprising:
a processing circuit configured to:
receive data to be encoded or decoded as a current block of a current picture of a video;
generate a first prediction of the current block according to an inter-prediction mode and a selected motion candidate selected from a candidate list, the candidate list including one or more motion candidates;
generate a second prediction of the current block according to a selected intra-prediction mode selected from one or more candidate intra-prediction modes that include a directional intra-prediction mode, a DC mode, or a Planar mode;
generate a combined prediction for the current block based on the first prediction and the second prediction; and
encode the current block into a bitstream or reconstruct the current block according to the combined prediction.