US Patent 11683476 Size restriction for intra-block copy virtual buffer

A method for video processing is described. The method comprises: making a decision, for a conversion between a current video block of a video picture of a video and a coded representation of the video, regarding a size of a reference region of the video picture from which reference samples are used for predicting the current video block, based on a size of a virtual pipeline data unit (VPDU), a size of a coding tree block (CTB), or a size of a coding tree unit (CTU); and performing the conversion based on the decision.