VARIABLE LENGTH CODING TECHNIQUES FOR CODED BLOCK PATTERNS

Variable length coding (VLC) techniques are described for coded block patterns (CBPs) used in block-based video coding. In VLC of CBPs, patterns of transform coefficients that are more likely to occur are coded with shorter codes, while patterns of coefficients that are less likely to occur are coded with longer codes. According to the techniques of this disclosure, several different VLC tables are stored in the coding devices. During the encoding and decoding processes, one of the VLC tables is selected and used to perform the coding of CBPs for a given video block. The table may be selected based on a number of neighboring video blocks to the current video block that include non-zero transform coefficients. The techniques may be particularly useful in the coding of video blocks of enhancement layers in scalable video coding (SVC).