Systems and methods for video encoding and decoding

A method is described for forming output video frames by a decoder device, comprising: receiving a bitstream comprising bitstream parts representing encoded media data of video tiles and tile positioning information associated with the encoded video tiles; extracting tile positioning information from the bitstream, the tile positioning information comprising tile identifiers for identifying encoded video tiles, a tile identifier being associated with one or more boundary identifiers, each identifying a boundary of a video tile identified by a tile identifier; determining a tile map based on the boundary identifiers, the tile map representing a spatial layout of video tiles in an output video frame; and forming an output video frame, including identifying parts of the bitstream representing encoded media data of video tiles identified in the tile map, decoding the identified encoded media data and copying the decoded media data in the output video frame buffer according to spatial layout.