Block vector predictor for intra block copying

A method for encoding video data using Intra Block Copy (BC), the method comprising:

• constructing a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein constructing the block vector candidate list for the current block further comprises:
• including, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, including, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• determining, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, including the block vector of the first previously decoded block in the block vector candidate list for the current block;
• determining, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, determining whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, including the block vector of the second previously decoded block in the block vector candidate list for the current block;
• determining, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, including a first predefined default block vector in the block vector candidate list for the current block;
• determining, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, including a second predefined default block vector in the block vector candidate list for the current block;
• and
• determining that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• selecting a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• generating a syntax element that indicates the particular block vector predictor candidate;
• and
• including, in an encoded video bitstream, the syntax element.

A device for decoding video data, the device comprising:

• a memory configured to store data associated with a current block of video data;
• and
• one or more processors configured to:
• construct a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein, to construct the block vector candidate list for the current block, the one or more processors are configured to:
• include, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, include, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• determine, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the first previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, determine whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the second previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a first predefined default block vector in the block vector candidate list for the current block;
• determine, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a second predefined default block vector in the block vector candidate list for the current block;
• and
• determine that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• determine, based on a syntax element obtained from an encoded video bitstream, a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• determine, based on the particular block vector predictor candidate, a value of a block vector that represents a displacement between the current block of video data and a predictor block of video data in a picture in which the current block resides;
• determine, based on the value the block vector, the predictor block of video data;
• and
• reconstruct the current block based on the predictor block.

A device for encoding video data, the device comprising:

• a memory configured to store data associated with a current block of video data;
• and
• one or more processors configured to:
• construct a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein, to construct the block vector candidate list for the current block, the one or more processors are configured to:
• include, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, include, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• determine, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the first previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, determine whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the
• second previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the second previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a first predefined default block vector in the block vector candidate list for the current block;
• determine, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold:
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a second predefined default block vector in the block vector candidate list for the current block;
• and
• determine that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• select a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• generate a syntax element that indicates the particular block vector predictor candidate;
• and
• include, in an encoded video bitstream, the syntax element.

A device for decoding video data using Intra Block Copy (BC), the device comprising:

• means for constructing a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein the means for constructing the block vector candidate list for the current block comprise:
• means for including, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• means for including, responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• means for determining, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• means for including, responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, the block vector of the first previously decoded block in the block vector candidate list for the current block;
• means for determining, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• means for determining, responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block;
• means for including, responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, the block vector of the second previously decoded block in the block vector candidate list for the current block;
• means for determining, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• means for including, responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, a first predefined default block vector in the block vector candidate list for the current block;
• means for determining, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• means for including, responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, a second predefined default block vector in the block vector candidate list for the current block;
• and
• means for determining that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• means for determining, based on a syntax element obtained from an encoded video bitstream, a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• means for determining, based on the particular block vector predictor candidate, a value of a block vector that represents a displacement between the current block of video data and a predictor block of video data in a picture in which the current block resides;
• means for determining, based on the value the block vector, the predictor block of video data;
• and
• means for reconstructing the current block based on the predictor block.

A device for encoding video data using Intra Block Copy (BC), the device comprising:

• means for constructing a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein the means for constructing the block vector candidate list for the current block comprise:
• means for including, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• means for including, responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• means for determining, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• means for including, responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, the block vector of the first previously decoded block in the block vector candidate list for the current block;
• means for determining, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• means for determining, responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block;
• means for including, responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, the block vector of the second previously decoded block in the block vector candidate list for the current block;
• means for determining, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• means for including, responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, a first predefined default block vector in the block vector candidate list for the current block;
• means for determining, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• means for including, responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, a second predefined default block vector in the block vector candidate list for the current block;
• and
• means for determining that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• means for selecting a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• means for generating a syntax element that indicates the particular block vector predictor candidate;
• and
• means for including, in an encoded video bitstream, the syntax element.

A computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device to decode video data using Intra Block Copy (BC) by at least causing the one or more processors to:

• construct a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein the instructions that cause the one or more processors to construct the block vector candidate list for the current block, comprise instructions that cause the one or more processors to:
• include, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, include, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• determine, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the first previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, determine whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the second previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a first predefined default block vector in the block vector candidate list for the current block;
• determine, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a second predefined default block vector in the block vector candidate list for the current block;
• and
• determine that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• determine, based on a syntax element obtained from an encoded video bitstream, a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• determine, based on the particular block vector predictor candidate, a value of a block vector that represents a displacement between the current block of video data and a predictor block of video data in a picture in which the current block resides;
• determine, based on the value the block vector, the predictor block of video data;
• and
• reconstruct the current block based on the predictor block.

A computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device to encode video data using Intra Block Copy (BC) by at least causing the one or more processors to:

• construct a block vector candidate list for a current block of the video data, the block vector candidate list comprising a plurality of block vector predictor candidates, wherein each respective block vector predictor candidate of the plurality of block vector predictor candidates is one of:
• a block vector of a neighboring block, a block vector of a previously coded block, and a predefined default block vector, wherein at least one block vector predictor candidate in the plurality of block vector predictor candidates included in the constructed block vector candidate list is a default block vector, wherein the instructions that cause the one or more processors to construct the block vector candidate list for the current block, comprise instructions that cause the one or more processors to:
• include, based on a left neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the left neighboring block in the block vector candidate list for the current block;
• responsive to determining that the left neighboring block of the current block does not include a block vector that is available for use as a block vector predictor candidate for the current block or that the block vector of the left neighboring block is the same as the predefined default block vector, include, based on an above neighboring block of the current block including a block vector that is available for use as a block vector predictor candidate for the current block, the block vector of the above neighboring block in the block vector candidate list for the current block;
• determine, based on one or both of the left neighboring block of the current block or the above neighboring block of the current block not including a block vector that is available for use as a block vector predictor candidate for the current block, whether to include a block vector of a first previously decoded block in the block vector candidate list for the current block based on whether the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the first previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the first previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the first previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than a threshold, wherein the threshold is two;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, determine whether to include a block vector of a second previously decoded block in the block vector candidate list for the current block based on whether the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block;
• responsive to determining that the block vector of the second previously decoded block is available for use as a block vector predictor candidate for the current block, include the block vector of the second previously decoded block in the block vector candidate list for the current block;
• determine, based on including the block vector of the second previously decoded block in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a first predefined default block vector in the block vector candidate list for the current block;
• determine, based on including the first predefined default block vector in the block vector candidate list for the current block, whether the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold;
• responsive to determining that the block vector candidate list for the current block includes a number of block vector predictor candidates that is less than the threshold, include a second predefined default block vector in the block vector candidate list for the current block;
• and
• determine that a block vector is not available for use as a block vector predictor candidate for the current block where the block vector is identical to a block vector predictor candidate already included in the block vector candidate list for the current block;
• select a particular block vector predictor candidate from the plurality of block vector predictor candidates;
• generate a syntax element that indicates the particular block vector predictor candidate;
• and
• include, in an encoded video bitstream, the syntax element.