Template matching based advanced motion vector predictor (AMVP) candidate list construction with non-adjacent candidates and AMVP index signaling

A device for coding video data, the device comprising:

• memory configured to store the video data;
• and
• one or more processors implemented in circuitry and communicatively coupled to the memory, the one or more processors being configured to:
• determine at least one of a temporal candidate or a history-based candidate;
• determine at least one non-adjacent candidate from at least one non-adjacent candidate unit, wherein the at least one non-adjacent candidate unit is not adjacent to a current prediction unit (PU), and wherein as part of determining the at least one non-adjacent candidate, the one or more processors are configured to:
• determine a horizontal offset relative to a top-left luma sample of the current PU and a vertical offset relative to the top-left luma sample of the current PU in accordance with a first syntax element indicative of a level index and a second syntax element indicative of the horizontal offset and the vertical offset;
• select one of offsetX=−iNADistanceHor−1 and offsetY=height+iNADistanceVer−1, offsetX=width+iNADistanceHor−1 and offsetY=−iNADistanceVer−1, offsetX=width>>1 and offsetY=−iNADistanceVer−1, offsetX=−iNADistanceHor−1 and offsetY=height>>1, or offsetX=−iNADistanceHor−1 and offsetY=−iNADistanceVer−1, wherein offsetX is the horizontal offset, offsetY is the vertical offset, width is a width of the current PU in a number of luma samples, height is a height of the current PU in a number of luma samples, and iNA represents an i-th non-adjacent candidate unit and iNADistanceHor=width*(the level index+1) and iNADistanceVer=height*(the level index+1);
• and
• add the horizontal offset and the vertical offset to a top-left luma sample coordinate of the current PU;
• determine an advanced motion vector predictor (AMVP) candidate list comprising the at least one of the temporal candidate or the history-based candidate and the at least one non-adjacent candidate, wherein the at least one non-adjacent candidate is added to the AMVP candidate list at least one of after the temporal candidate or before the history-based candidate;
• and
• code the current PU based on the AMVP candidate list.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors to:

• determine at least one of a temporal candidate or a history-based candidate;
• determine at least one non-adjacent candidate from at least one non-adjacent candidate unit, wherein the at least one non-adjacent candidate unit is not adjacent to a current prediction unit (PU), and wherein as part of determining the at least one non-adjacent candidate, the instructions cause the one or more processors to:
• determine a horizontal offset relative to a top-left luma sample of the current PU and a vertical offset relative to the top-left luma sample of the current PU in accordance with a first syntax element indicative of a level index and a second syntax element indicative of the horizontal offset and the vertical offset;
• select one of offsetX=−iNADistanceHor−1 and offsetY=height+iNADistanceVer−1, offsetX=width+iNADistanceHor−1 and offsetY=−iNADistanceVer−1, offsetX=width>>1 and offsetY=−iNADistanceVer−1, offsetX=−iNADistanceHor−1 and offsetY=height>>1, or offsetX=−iNADistanceHor−1 and offsetY=−iNADistanceVer−1, wherein offsetX is the horizontal offset, offsetY is the vertical offset, width is a width of the current PU in a number of luma samples, height is a height of the current PU in a number of luma samples, and iNA represents an i-th non-adjacent candidate unit and iNADistanceHor=width*(the level index+1) and iNADistanceVer=height*(the level index+1);
• and
• add the horizontal offset and the vertical offset to a top-left luma sample coordinate of the current PU;
• determine an advanced motion vector predictor (AMVP) candidate list comprising the at least one of the temporal candidate or the history-based candidate and the at least one non-adjacent candidate, wherein the at least one non-adjacent candidate is added to the AMVP candidate list at least one of after the temporal candidate or before the history-based candidate;
• and
• code the current PU based on the AMVP candidate list.

A device for coding video data, the device comprising:

• means for determining at least one of a temporal candidate or a history-based candidate;
• means for determining at least one non-adjacent candidate from at least one non-adjacent candidate unit, wherein the at least one non-adjacent candidate unit is not adjacent to a current prediction unit (PU) and wherein the means for determining the at least one non-adjacent candidate comprises:
• means for determining a horizontal offset relative to a top-left luma sample of the current PU and a vertical offset relative to the top-left luma sample of the current PU in accordance with a first syntax element indicative of a level index and a second syntax element indicative of the horizontal offset and the vertical offset;
• means for selecting one of offsetX=−iNADistanceHor−1 and offsetY=height+iNADistanceVer−1, offsetX=width+iNADistanceHor−1 and offsetY=−iNADistanceVer−1, offsetX=width>>1 and offsetY=−iNADistanceVer−1, offsetX=−iNADistanceHor−1 and offsetY=height>>1, or offsetX=−iNADistanceHor−1 and offsetY=−iNADistanceVer−1, wherein offsetX is the horizontal offset, offsetY is the vertical offset, width is a width of the current PU in a number of luma samples, height is a height of the current PU in a number of luma samples, and iNA represents an i-th non-adjacent candidate unit and iNADistanceHor=width*(the level index+1) and iNADistanceVer=height*(the level index+1);
• and
• means for adding the horizontal offset and the vertical offset to a top-left luma sample coordinate of the current PU;
• means for determining an advanced motion vector predictor (AMVP) candidate list comprising the at least one of the temporal candidate or the history-based candidate and the at least one non-adjacent candidate, wherein the at least one non-adjacent candidate is added to the AMVP candidate list at least one of after the temporal candidate or before the history-based candidate;
• and
• means for coding the current PU based on the AMVP candidate list.