Intra block copy prediction restrictions for parallel processing

A method of encoding video data, the method comprising:

• determining a coding tree block (CTB) delay for one or more blocks coded with wavefront parallel processing enabled, wherein the CTB delay identifies a delay between when a first row of CTBs starts being decoded and when a second row of CTBs below the first row of CTBs starts being decoded;
• for a first block of video data coded in an intra-block copy (IBC) mode and coded with wavefront parallel processing disabled, determining an IBC prediction region for the first block based on the CTB delay;
• identifying, from within the IBC prediction region for the first block, a predictive block for the first block;
• and
• generating syntax to indicate a block vector for locating the predictive block.

A device for performing video decoding, the device comprising:

• a memory to store video data;
• one or more processors configured to:
• determine a coding tree block (CTB) delay for one or more blocks coded with wavefront parallel processing enabled, wherein the CTB delay identifies a delay between when a first row of CTBs starts being decoded and when a second row of CTBs below the first row of CTBs starts being decoded;
• for a current block of video data coded in an intra-block copy (IBC) mode and coded with wavefront parallel processing disabled, determine an IBC prediction region for the current block within a picture that includes the current block based on the CTB delay that was determined for the one or more blocks coded with wavefront parallel processing enabled;
• identify a predictive block for the current block from within the determined IBC prediction region for the current block;
• and
• IBC decode the current block based on the predictive block.

A device for performing video encoding, the device comprising:

• a memory to store video data;
• one or more processors configured to:
• determine a coding tree block (CTB) delay for one or more blocks coded with wavefront parallel processing enabled, wherein the CTB delay identifies a delay between when a first row of CTBs starts being decoded and when a second row of CTBs below the first row of CTBs starts being decoded;
• for a first block of video data coded in an intra-block copy (IBC) mode and coded with wavefront parallel processing disabled, determine an IBC prediction region for the first block based on the CTB delay;
• identify, from within the IBC prediction region for the first block, a predictive block for the first block;
• and
• generate syntax to indicate a block vector for locating the predictive block.

An apparatus for decoding video data, the apparatus comprising:

• means for determining a coding tree block (CTB) delay for one or more blocks coded with wavefront parallel processing enabled, wherein the CTB delay identifies a delay between when a first row of CTBs starts being decoded and when a second row of CTBs below the first row of CTBs starts being decoded;
• for a current block of video data coded in an intra-block copy (IBC) mode and coded with wavefront parallel processing disabled, means for determining an IBC prediction region for the current block within a picture that includes the current block based on the CTB delay that was determined for the one or more blocks coded with wavefront parallel processing enabled;
• means for identifying, from within the determined IBC prediction region for the current block, a predictive block for the current block;
• and
• means for IBC decoding the current block based on the predictive block.

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

• determine a coding tree block (CTB) delay for one or more blocks coded with wavefront parallel processing enabled, wherein the CTB delay identifies a delay between when a first row of CTBs starts being decoded and when a second row of CTBs below the first row of CTBs starts being decoded;
• for a current block of video data coded in an intra-block copy (IBC) mode and coded with wavefront parallel processing disabled, determine an IBC prediction region for the current block within a picture that includes the current block based on the CTB delay that was determined for the one or more blocks coded with wavefront parallel processing enabled;
• identify a predictive block for the current block from within the determined IBC prediction region for the current block;
• and
• IBC decode the current block based on the predictive block.