Intra prediction of chroma blocks using the same vector

A method of encoding video data, the method comprising:

• determining that a coding unit of a picture of the video data is coded using an intra block copy mode, the coding unit comprising at least a first prediction unit and a second prediction unit and having a plurality of vectors, wherein each prediction unit has an associated vector from the plurality of vectors, wherein a chroma sampling format for the coding unit is 4:2:0;
• locating a first luma reference block using a vector associated with the first prediction unit of the coding unit, wherein the first prediction unit corresponds to a bottom-right block of the coding unit;
• locating a second luma reference block using a vector associated with the second prediction unit of the coding unit, wherein the vector associated with the first prediction unit of the coding unit is different than the vector associated with the second prediction unit of the coding unit;
• determining, from the plurality of vectors associated with the coding unit, a vector for a first chroma block of the coding unit of the picture, wherein determining the vector for the first chroma block of the coding unit comprises obtaining the vector associated with the first prediction unit;
• locating a first chroma reference block for the first chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the first chroma reference block is in the picture, and wherein the first chroma block corresponds to the first prediction unit of the coding unit;
• predicting the first chroma block of the coding unit based on the first chroma reference block;
• locating a second chroma reference block for a second chroma block of the coding unit using the vector associated with the first prediction unit, wherein the second chroma reference block is in the picture and is a different block than the first chroma reference block, wherein the second chroma block corresponds to the second prediction unit of the coding unit;
• predicting a second chroma block of the coding unit based on the second chroma reference block, wherein the second chroma block is a top-right block of the coding unit;
• locating a third chroma reference block using the vector associated with the first prediction unit, wherein the third chroma reference block is in the picture;
• predicting a third chroma block based on the third chroma reference block, wherein the third chroma block is a top-left block of the coding unit;
• locating a fourth chroma reference block using the vector associated with the first prediction unit, wherein the fourth chroma reference block is in the picture;
• and
• predicting a fourth chroma block of the coding unit based on the fourth chroma reference block, wherein the fourth chroma block is a bottom-left block of the coding unit;
• and
• generating, for inclusion in the encoded video data, an indication that the coding unit of the picture is coded using an intra block copy mode and an indication of a vector for each luma block of the coding unit.

A device for coding video data, the device comprising:

• a memory configured to store video data;
• a video coder comprising one or more processors configured to:
• determine a coding unit of a picture of the video data is coded using an intra block copy mode, the coding unit comprising at least a first prediction unit and a second prediction unit and having a plurality of vectors, wherein each prediction unit has an associated vector from the plurality of vectors, wherein a chroma sampling format for the coding unit is 4:2:0;
• locate a first luma reference block using a vector associated with the first prediction unit of the coding unit, wherein the first prediction unit corresponds to a bottom-right block of the coding unit;
• locate a second luma reference block using a vector associated with the second prediction unit of the coding unit, wherein the vector associated with the first prediction unit of the coding unit is different than the vector associated with the second prediction unit of the coding unit;
• determine from the plurality of vectors associated with the coding unit, a vector for a first chroma block of the coding unit, wherein to determine the vector for the first chroma block of the coding unit, the one or more processors are configured to obtain the vector associated with the first prediction unit;
• locate a first chroma reference block for the first chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the first chroma reference block is in the picture, wherein the first chroma block corresponds to the first prediction unit of the coding unit;
• predict the first chroma block of the coding unit based on the first chroma reference block;
• locate a second chroma reference block for a second chroma block of the coding unit using the vector associated with the first prediction unit, wherein the second chroma reference block is in the picture and is a different block than the first chroma reference block, wherein the second chroma block corresponds to the second prediction unit of the coding unit;
• predict the second chroma block of the coding unit based on the second chroma reference block, wherein the second chroma block is a top-right block of the coding unit;
• locate a third chroma reference block using the vector associated with the first prediction unit, wherein the third chroma reference block is in the picture;
• predict a third chroma block based on the third chroma reference block, wherein the third chroma block is a top-left block of the coding unit;
• locate a fourth chroma reference block using the vector associated with the first prediction unit, wherein the fourth chroma reference block is in the picture;
• and
• predict a fourth chroma block of the coding unit based on the fourth chroma reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

An apparatus for coding video data, the apparatus comprising:

• means for determining a coding unit of a picture of the video data is coded using an intra block copy mode, the coding unit comprising at least a first prediction unit and a second prediction unit and having a plurality of vectors, wherein each prediction unit has an associated vector from the plurality of vectors, wherein a chroma sampling format for the coding unit is 4:2:0;
• means for locating a first luma reference block using a vector associated with the first prediction unit of the coding unit, wherein the first prediction unit corresponds to a bottom-right block of the coding unit;
• means for locating a second luma reference block using a vector associated with the second prediction unit of the coding unit, wherein the vector associated with the first prediction unit of the coding unit is different than the vector associated with the second prediction unit of the coding unit;
• means for determining from the plurality of vectors associated with the coding unit, a vector for a first chroma block of the coding unit, wherein the means for determining the vector for the first chroma block of the coding unit comprises means for obtaining the vector associated with the first prediction unit;
• means for locating a first chroma reference block for a first chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the first chroma reference block is in the picture, wherein the first chroma block corresponds to the first prediction unit of the coding unit;
• means for predicting the first chroma block of the coding unit based on the first chroma reference block;
• means for using the vector associated with the first prediction unit of the coding unit, to locate a second chroma reference block for a second chroma block of the coding unit, wherein the second chroma reference block is in the picture and is a different block than the first chroma reference block, wherein the second chroma block corresponds to the second prediction unit of the coding unit;
• means for predicting the second chroma block of the coding unit based on the second chroma reference block, wherein the second chroma block is a top-right block of the coding unit;
• means for locating a third chroma reference block using the vector associated with the first prediction unit, wherein the third chroma reference block is in the picture;
• means for predicting a third chroma block based on the third chroma reference block, wherein the third chroma block is a top-left block of the coding unit;
• means for locating a fourth chroma reference block using the vector associated with the first prediction unit, wherein the fourth chroma reference block is in the picture;
• and
• means for predicting a fourth chroma block of the coding unit based on the fourth chroma reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

A non transitory computer readable storage medium storing instructions that when executed by one or more processors cause the one or more processors to:

• determine a coding unit of a picture of the video data is coded using an intra block copy mode, the coding unit comprising at least a first prediction unit and a second prediction unit and having a plurality of vectors, wherein each prediction unit has an associated vector from the plurality of vectors, wherein a chroma sampling format for the coding unit is 4:2:0;
• locate a first luma reference block using a vector associated with the first prediction unit of the coding unit, wherein the vector associated with the first prediction unit is associated with a bottom-right block of the coding unit;
• locate a second luma reference block using a vector associated with the second prediction unit of the coding unit, wherein the vector associated with the first prediction unit of the coding unit is different than the vector associated with the second prediction unit of the coding unit;
• determine from the plurality of vectors associated with the coding unit, a vector for a first chroma block of the coding unit, wherein determining the vector for the first chroma block of the coding unit comprises obtaining the vector associated with the first prediction unit;
• locate a first chroma reference block for the first chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the first chroma reference block is in the picture, wherein the first chroma block corresponds to the first prediction unit of the coding unit;
• predict the first chroma block of the coding unit based on the first chroma reference block;
• locate a second chroma reference block for a second chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the second chroma reference block is in the picture and is a different block than the first chroma reference block, wherein the second chroma block corresponds to the second prediction unit of the coding unit;
• predict the second chroma block of the coding unit based on the second chroma reference block, wherein the second chroma block is a top-right block of the coding unit;
• locate a third chroma reference block using the vector associated with the first prediction unit, wherein the third chroma reference block is in the picture;
• predict a third chroma block based on the third chroma reference block, wherein the third chroma block is a top-left block of the coding unit;
• locate a fourth chroma reference block using the vector associated with the first prediction unit, wherein the fourth chroma reference block is in the picture;
• and
• predict a fourth chroma block of the coding unit based on the fourth chroma reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

A method of decoding video data, the method comprising:

• determining that a coding unit of a picture of the video data is coded using an intra block copy mode, the coding unit comprising at least a first prediction unit and a second prediction unit and having a plurality of vectors, wherein each prediction unit has an associated vector from the plurality of vectors, wherein a chroma sampling format for the coding unit is 4:2:2;
• locating a first luma reference block using a vector associated with the first prediction unit of the coding unit;
• locating a second luma reference block using a vector associated with the second prediction unit of the coding unit, wherein the vector associated with the first prediction unit of the coding unit is different than the vector associated with the second prediction unit of the coding unit;
• determining, from the plurality of vectors associated with the coding unit, a vector for a first chroma block of the coding unit, wherein determining the vector for the first chroma block of the coding unit comprises obtaining the vector associated with the first prediction unit, wherein the first chroma block is a top-right block;
• locating a first chroma reference block for the first chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the first chroma reference block is in the picture, and wherein the first chroma block corresponds to the first prediction unit of the coding unit;
• predicting the first chroma block of the coding unit based on the first chroma reference block;
• locating a second chroma reference block for a second chroma block of the coding unit using the vector associated with the second prediction unit of the coding unit, wherein the second chroma reference block is in the picture and is a different block than the first chroma reference block, wherein the second chroma block corresponds to the second prediction unit of the coding unit;
• predicting the second chroma block based on the second chroma reference block, wherein the second chroma block is a bottom-right block of the coding unit;
• locating a third chroma reference block using the vector associated with the first prediction unit, wherein the third chroma reference block is in the picture;
• predicting a third chroma block based on the third chroma reference block, wherein the third chroma block is a top-left block of the coding unit;
• locating a fourth chroma reference block using the vector associated with the second prediction unit, wherein the fourth chroma reference block is in the picture;
• and
• predicting a fourth chroma block of the coding unit based on the fourth chroma reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

A device for coding video data, the device comprising:

• a memory configured to store video data;
• a video coder comprising one or more processors configured to:
• determine that a coding unit of a picture of the video data is coded using an intra block copy mode, the coding unit comprising at least a first prediction unit and a second prediction unit and having a plurality of vectors, wherein each prediction unit has an associated vector from the plurality of vectors, wherein a chroma sampling format for the coding unit is 4:2:2;
• locate a first luma reference block using a vector associated with the first prediction unit of the coding unit;
• locate a second luma reference block using a vector associated with the second prediction unit of the coding unit, wherein the vector associated with the first prediction unit of the coding unit is different than the vector associated with the second prediction unit of the coding unit;
• determine, from the plurality of vectors associated with the coding unit, a vector for a first chroma block of the coding unit, wherein to determine the vector for the first chroma block of the coding unit, the one or more processors are configured to obtain the vector associated with the first prediction unit, wherein the first chroma block is a top-right block;
• locate a first chroma reference block for the first chroma block of the coding unit using the vector associated with the first prediction unit of the coding unit, wherein the first chroma reference block is in the picture, and wherein the first chroma block corresponds to the first prediction unit of the coding unit;
• predict the first chroma block of the coding unit based on the first chroma reference block;
• locate a second chroma reference block for a second chroma block of the coding unit using the vector associated with the second prediction unit of the coding unit, wherein the second chroma reference block is in the picture and is a different block than the first chroma reference block, wherein the second chroma block corresponds to the second prediction unit of the coding unit;
• predict the second chroma block based on the second chroma reference block, wherein the second chroma block is a bottom-right block of the coding unit;
• locate a third chroma reference block using the vector associated with the first prediction unit, wherein the third chroma reference block is in the picture;
• predict a third chroma block based on the third chroma reference block, wherein the third chroma block is a top-left block of the coding unit;
• locate a fourth chroma reference block using the vector associated with the second prediction unit, wherein the fourth chroma reference block is in the picture;
• and
• predict a fourth chroma block of the coding unit based on the fourth chroma reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.