1. A method of decoding video data, the method comprising: decoding a base layer picture having a first aspect ratio; decoding data representative of whether a tile of an enhancement layer picture, corresponding to the base layer picture, can be predicted using inter-layer prediction, wherein the tile comprises an integer number of coding tree blocks co-occurring in one column and one row, ordered consecutively in coding tree block raster scan of the tile, wherein the enhancement layer picture has a second aspect ratio, wherein the second aspect ratio is larger than the first aspect ratio such that the enhancement layer picture includes a first portion that corresponds to the base layer picture and a second portion that is outside of the base layer picture, and wherein when the tile of the enhancement layer picture is in the second portion, decoding the data representative of whether the tile can be predicted using inter-layer prediction comprises decoding data indicating that the tile cannot be predicted using inter-layer prediction; predicting data of the tile using inter-layer prediction only when the data indicates that the tile can be predicted using inter-layer prediction; and decoding, in parallel with the base layer picture, the enhancement layer picture.