Methods and apparatuses for hierarchically encoding and decoding a bytestream

1. A method of decoding a received set of encoded data representing a two-dimensional array of information that has been compressed, the method comprising:

obtaining a set of attribute indicators from the data set, each indicator of the set of attribute indicators being associated with a corresponding subset of the data set, wherein each indicator is an index value referencing a set of parameters useable for decoding, and wherein each indicator is difference encoded such that each indicator represents a difference between a current set of parameters and a previous set of parameters; and

decoding a plurality of subsets of the data set, wherein each subset in the plurality of subsets is to be decoded separately, the decoding comprising:

retrieving decoding parameters for each subset in the plurality of subsets according to the corresponding attribute indicator that is associated with each subset; and

decoding each subset in the plurality of subsets according to the retrieved decoding parameters for each subset,

wherein retrieving the decoding parameters comprises retrieving a plurality of decoding parameters according to each attribute indicator, the plurality of decoding parameters corresponding to different functions of a decoding process.

2. The method of claim 1 , wherein each indicator of the set of attribute indicators is associated with a respective subset of the plurality of subsets of the data set.

3. The method of claim 1 , wherein the attribute indicators of subsets containing data values rather than metadata values are obtained by separately decoding an attribute metadata subset of the data set, wherein the attribute metadata subset is a subset of the dataset comprising the decoding parameters pointed to by the attribute indicators.

4. The method of claim 1 , further comprising:

obtaining an initial attribute indicator associated with an initial subset of the data set, wherein the initial attribute indicator is an index value pointing to decoding parameters to be used to decode the initial subset;

retrieving initial decoding parameters of the initial subset according to the initial attribute indicator;

decoding the initial subset according to the initial decoding parameters, wherein the initial subset contains the attribute indicators of the plurality of subsets of the data set.

5. The method of claim 1 , wherein the decoding parameters include quantization parameters or entropy decoding probability metadata or both.

6. An apparatus for decoding a received set of encoded data representing information that has been compressed, said apparatus comprising a processor configured to:

obtain a set of attribute indicators from the data set, each indicator of the set of attribute indicators being associated with a corresponding subset of the data set, wherein each indicator is an index value referencing a set of parameters useable for decoding, and wherein each indicator is difference encoded such that each indicator is calculated based on a difference between a current set of parameters and a previous set of parameters; and

decode a plurality of subsets of the data set, wherein each subset in the plurality of subsets is to be decoded separately, said decoding comprising:

retrieving decoding parameters for each subset in the plurality of subsets according to the corresponding attribute indicator that is associated with each subset; and

decoding each subset in the plurality of subsets according to the retrieved decoding parameters for each subset,

wherein retrieving the decoding parameters includes retrieving a plurality of decoding parameters according to each attribute indicator, the plurality of decoding parameters corresponding to different functions of a decoding process.

7. The apparatus of claim 6 , wherein each indicator of the set of attribute indicators is associated with a respective subset of the plurality of subsets of the data set.

8. The apparatus of claim 6 , wherein the attribute indicators of subsets containing data values rather than metadata values are obtained by separately decoding an attribute metadata subset of the data set, wherein the attribute metadata subset is a subset of the dataset comprising the decoding parameters pointed to by the attribute indicators.

9. The apparatus of claim 6 , wherein the processor is further configured to:

obtain an initial attribute indicator associated with an initial subset of the data set, wherein the initial attribute indicator is an index value pointing to decoding parameters to be used to decode the initial subset;

retrieve initial decoding parameters of the initial subset according to the initial attribute indicator; and

decode the initial subset according to the initial decoding parameters, wherein the initial subset contains the attribute indicators of the plurality of subsets of the data set.

10. The apparatus of claim 6 , wherein the decoding parameters include quantization parameters or entropy decoding probability metadata or both.

11. A method of encoding a two-dimensional array of information to be compressed into an encoded data set, the method comprising:

encoding a plurality of subsets of a data set, wherein each subset in the plurality of subsets is encoded separately, the encoding comprising:

retrieving encoding parameters for each subset in the plurality of subsets, and

encoding each subset in the plurality of subsets according to the retrieved encoding parameters for each subset; and

generating a set of attribute indicators, each indicator of the set of attribute indicators being associated with a corresponding subset of the data set according to the retrieved encoding parameters for each subset, wherein:

each indicator is an index value referencing a set of parameters that are useable for decoding,

each indicator is difference encoded such that each indicator represents a difference between a current set of parameters and a previous set of parameters, and

retrieving the encoding parameters comprises retrieving a plurality of encoding parameters, where the plurality of decoding parameters correspond to different functions of an encoding process.

12. The method of claim 11 , wherein each indicator of the set of attribute indicators is associated with a respective subset of the plurality of subsets of the data set.

13. The method of claim 11 , wherein the attribute indicators for subsets containing data values rather than metadata values are separately encoded as an attribute metadata subset of the data set, wherein the attribute metadata subset is a subset of the dataset comprising the encoding parameters pointed to by the attribute indicators.

14. The method of claim 11 , further comprising:

encoding an initial subset according to retrieved initial encoding parameters, and

generating an initial attribute indicator associated with an initial subset of the data set, wherein the initial attribute indicator is an index value pointing to decoding parameters to be used to decode the initial subset; wherein the encoded initial subset contains the attribute indicators of the plurality of subsets of the data set.

15. The method of claim 11 , wherein the encoding parameters include quantization parameters or entropy coding probability metadata or both.

16. An apparatus for encoding information to be compressed into an encoded data set, said apparatus comprising a processor configured to:

encode a plurality of subsets of a data set, wherein each subset in the plurality of subsets is encoded separately, wherein the encoding includes:

retrieving encoding parameters for each subset in the plurality of subsets, and

encoding each subset in the plurality of subsets according to the retrieved encoding parameters for each subset; and

generate a set of attribute indicators, each indicator of the set of attribute indicators being associated with a corresponding subset of the data set according to the retrieved encoding parameters for each subset, wherein:

each indicator is an index value referencing a set of parameters that are useable for decoding,

each indicator is difference encoded such that each indicator is calculated based on a difference between a current set of parameters and a previous set of parameters, and

retrieving the encoding parameters comprises retrieving a plurality of encoding parameters, where the plurality of decoding parameters correspond to different functions of an encoding process.

17. The apparatus of claim 16 , wherein each indicator of the set of attribute indicators is associated with a respective subset of the plurality of subsets of the data set.

18. The apparatus of claim 16 , wherein the attribute indicators for subsets containing data values rather than metadata values are separately encoded as an attribute metadata subset of the data set, wherein the attribute metadata subset is a subset of the dataset comprising the encoding parameters pointed to by the attribute indicators.

19. The apparatus of claim 16 , where the processor is further configured to:

encode an initial subset according to retrieved initial encoding parameters, and

generate an initial attribute indicator associated with an initial subset of the data set, wherein the initial attribute indicator is an index value pointing to decoding parameters to be used to decode the initial subset,

wherein the encoded initial subset contains the attribute indicators of the plurality of subsets of the data set.

20. The apparatus of claim 16 , wherein the encoding parameters include quantization parameters or entropy coding probability metadata or both.