Methods and apparatuses for hierarchically encoding and decoding a bytestream

A method of encoding information to be compressed into an encoded data set, the method comprising:

• encoding a plurality of subsets of the data set, comprising:
• retrieving encoding parameters for each subset;
• and,
• encoding each subset according to the retrieved encoding parameters for each subset;
• and,
• generating a set of attribute indicators, each indicator of the set of indicators being associated with a subset of the data set according to the retrieved encoding parameters for each subset.

A method of processing metadata associated with a stream of video data, the method comprising the steps of, for a first frame of video data:

• subdividing the first frame of video data into a plurality of tiles;
• calculating a first statistical attribute for each of a plurality of tiles;
• identifying tiles having a first instance of identical, or similar statistical, attributes, and grouping said identified tiles together as a tile set;
• for each tile set defining metadata for the tile set, said metadata indicative of the statistical attribute of the tiles defining the tile set;
• and
• encoding data indicative of the metadata for the tiles of the first frame of video data based on the metadata defined for each of the tile set to which said tile belongs.

A system for encoding metadata associated with a stream of video data, the system comprising a processor, the processor configured to, for a first frame of video data:

• subdivide the first frame of video data into a plurality of tiles;
• for each of a plurality of tiles calculate a first statistical attributes of the tile;
• identify tiles having a first instance of identical, or similar statistical, attributes, and group said identified tiles together as a tile set;
• for each tile set define metadata for the tile set, said metadata indicative of the statistical attribute of the tiles defining the tile set;
• and
• encode data indicative of the metadata for the tiles of the first frame of video data based on the metadata defined for each of the tile set to which said tile belongs.

A method of decoding metadata associated with a stream of video data, the method comprising the steps of, for a first frame of video data, at a decoder:

• obtaining information to enable the decoder to subdivide the first frame of video data into a plurality of tiles;
• receiving an encoded stream of metadata, said encoded stream of metadata comprising information identifying tiles having a first instance of identical, or similar statistical, attributes, and information grouping said identified tiles together as a tile set;
• obtaining information regarding the identical, or similar statistical, attributes;
• and
• decoding the metadata for each of the tiles forming the tile set with the obtained information regarding the identical, or similar statistical, attributes.

A method of decoding an encoded data set comprising a header and a payload, the payload comprising a plurality of encoded data symbols representing information that has been compressed, wherein a decoder is configured to decode subsets of the payload according to a predetermined decoding process, the method comprising:

• decoding the header to derive a set of metadata elements;
• retrieving from the set of metadata elements, a variation parameter which indicates how the predetermined decoding process should be varied;
• decoding the payload according to a modified decoding process based on the variation parameter, such that the decoding process is optimised for the plurality of encoded data symbols;
• and,
• reconstructing the information that has been compressed from the decoded payload.