Prioritized decoding and output of parts of a picture in video coding

Abstract

Methods and apparatus for processing an encoded representation of a sequence of pictures are disclosed, wherein the method includes: allocating memory for a current picture of the sequence of pictures in a decoded picture buffer, DPB; receiving a bitstream comprising an encoded representation of the current picture, and storing the encoded representation as a plurality of decoding units DUs, in a coded picture buffer, CPB, each of the plurality of DUs comprising an encoded set of pixels, wherein no coding dependency exists between coded pixels of different DUs of the current picture; receiving prioritization information associated with each of the plurality of DUs stored in the CPB, the prioritization information defining a decoding order in which the DUs of the current picture are being decoded; decoding one or more of said plurality of DU's into one or more decoded DU's, in accordance with said decoding order, each decoded DU comprising a set of pixels, each set of pixels being associated with a different area in the current picture; storing the sets of pixels in the DPB, a set of pixels being stored at a location in the allocated memory of the DPB that corresponds to a position of the area in the current picture; and, outputting as a partial output, one or more sets of pixels of decoded DUs of the current picture in accordance with the decoding order, while other DUs of the current picture are being decoded or received by the decoding apparatus.