Intra block copy (IntraBC) cost estimation

A method for encoding video data, the method comprising:

• determining that a parent coding unit of a coding unit of the video data was not predicted in an intra-prediction block copy (IntraBC) mode;
• and
• in response to the determining that the parent coding unit was not predicted in IntraBC mode:
• computing activity of the coding unit;
• when the activity of the coding unit is not less than an activity threshold:
• determining an IntraBC coding cost of the coding unit using a two dimensional (2D) search;
• selecting an encoding mode as one of the IntraBC mode, an intra-prediction mode, and an inter-prediction mode based on a coding cost of each of these encoding modes;
• and
• encoding the coding unit using the selected encoding mode;
• and
• when the activity of the coding unit is less than the activity threshold:
• selecting an encoding mode as one of the intra-prediction mode and the inter-prediction mode based on a coding cost of each of these encoding modes;
• and
• encoding the coding unit using the selected encoding mode.

A method for selecting a best mode for encoding a coding unit (CU) of video data in a video stream, the method comprising:

• computing an inter-prediction coding cost for the CU;
• computing an intra-prediction coding cost for the CU;
• determining whether or not a minimum of the inter-prediction coding cost and the intra-prediction coding cost is less than a cost threshold;
• when the minimum of the inter-prediction coding cost and the intra-prediction coding cost is less than a cost threshold:
• computing an intra block copy (IntraBC) coding cost of the CU using a one dimensional (1D) search;
• and
• selecting a best mode for encoding the CU based the inter-prediction coding cost, the intra-prediction coding cost, and the IntraBC coding cost computed with the 1D search;
• and
• when the minimum of the inter-prediction coding cost and the intra-prediction coding cost is not less than a cost threshold:
• determining whether or not a parent CU of the CU was predicted in IntraBC mode;
• when the parent CU was predicted in IntraBC mode:
• computing an IntraBC coding cost of the CU using a two dimensional (2D) search;
• and
• selecting the best mode for encoding the CU based the inter-prediction coding cost, the intra-prediction coding cost, and the IntraBC coding cost computed with the 2D search;
• and
• when the parent CU was not predicted in IntraBC mode:
• computing activity of the CU;
• determining whether the activity of the CU is less than an activity threshold;
• when the activity is not less than the activity threshold:
• computing an IntraBC coding cost of the CU using a 2D search;
• and
• selecting the best mode for encoding the CU based the inter-prediction coding cost, the intra-prediction coding cost, and the IntraBC coding cost computed with the 2D search;
• and
• when the activity is less than the activity threshold:
• computing an IntraBC coding cost of the CU using a 1D search;
• and
• selecting the best mode for encoding the CU based the inter-prediction coding cost, the intra-prediction coding cost, and the IntraBC coding cost computed with the 1D search.