Techniques are described for determining whether a block in a candidate reference picture is available. A video coder may determine a location of a co-located largest coding unit (CLCU) in the candidate reference picture, where the CLCU is co-located with a LCU in a current picture, and the LCU includes a current block that is to be inter-predicted. The video coder may determine whether a block in the candidate reference picture is available based on a location of the block in the candidate reference picture relative to the location of the CLCU. If the block in the candidate reference picture is unavailable, the video coder may derive a disparity vector for the current block from a block other than the block determined to be unavailable.