Method and system for scalable representation, storage, transmission and reconstruction of media streams

1. Method for defining a compression scheme of a media stream, the method comprising the steps of:

determining a plurality of compression levels for the media stream and a relationship between valid values of compressed representations of the media stream, each compressed representation of the media stream associated with one of the compression levels;

defining the highest level of compression of the compression levels as a base level; and

defining enhancement data for representing a relationship between valid values of the compressed representations of the media stream.

2. The method according to claim 1 wherein the enhancement data reflects a relationship between valid values of two successive compressed representations of the media stream.

3. The method according to claim 1 wherein the step of defining enhancement data comprises defining enhancement data if a valid value of a compressed representation of a media stream is associated with at least two valid values of a successive compressed representation of the media stream.

4. The method according to claim 1 wherein the media stream is defined as an original media stream; and wherein a relationship between valid values of distinct compressed representations of the media stream reflect a relationship between valid values of the original media stream mapped to the valid values of distinct compressed representations of the media stream.

5. The method according to claim 1 wherein the step of defining enhancement data relating to valid values of a pair of compressed representations of the media stream comprises checking a relationship between valid values of lower compressed representations of the media stream, lower compressed representations of the media stream being characterized by a higher compression level.

6. The method according to claim 1 wherein the step of defining enhancement data comprises defining a p th layer enhancement data for valid values of pair of a (p−1) th and a p th compressed representations of the media stream, if the reconstruction of the valid values of the p th compressed representation of the media stream requires the p th layer enhancement data, whereas p ranges between 2 and k, k reflects the number of compression levels.

7. The method according to claim 1 wherein the compressed representations of the media streams are generated by applying a compression function selected from the group consisting of:

sampling functions;

quantizing functions;

linear quantizing functions;

non-linear quantizing functions; and

uniform quantizing functions.

8. The method according to claim 1 further comprising a step of compressing the enhancement data.

9. The method according to claim 1 wherein enhancement data includes enhancement data symbols; and wherein the method further comprising a step of variable length encoding the enhancement data symbols to provide enhancement data code words.

10. The method according to claim 1 , wherein said media stream comprises one of the list consisting of:

MPEG compliant media stream;

original media stream;

JPEG media stream;

video stream;

audio stream;

data stream;

H.261 compliant media stream;

H.263 compliant stream;

streaming media stream;

JPEG stream;

AC-3 audio stream;

AAC audio stream; and

a stream containing a plurality of streams.

11. The method according to claim 1 further comprising a step of:

compressing the media stream according to the compression levels, thereby producing a plurality of compressed representations of the media stream;

defining a selected one of said compressed representations of the media stream a base media layer, the selected compressed version being compressed according to the base level;

determining if enhancement data is required for reconstructing a compressed representation of the media stream; and

generating enhancement data, in response to the determination.

12. A method for generating a compressed representation of a media stream, the media stream comprising a plurality of media stream symbols, the method comprising the steps of:

determining a plurality of compression functions of statistically distinct compression levels, wherein applying a compression function on the media stream produces a compressed representation of the media stream; determining a relationship between valid values of compressed representations of the media stream;

defining the statistically most compressed representation of the media stream as a base layer media stream;

defining enhancement data for representing a relationship between valid values of the compressed representations of the media stream;

compressing the media stream by applying the compression functions, thereby producing a plurality of compressed representations of the media stream;

determining if enhancement data is required for reconstructing a compressed representation of the media stream; and

generating enhancement data, in response to the determination.

13. The method according to claim 12 wherein the p th compressed representation is characterized by a p th statistically compression level, p ranges between 1 to k, k reflecting the amount of compression functions; and wherein the p th compressed representation of the media stream is defined as a p th layer media stream.

14. The method according to claim 12 wherein the step of determining starts from the second media layer and ends at the original media stream, the original media stream is defined as the media stream.

15. The method according to claim 12 wherein determining a necessity of enhancement data relating to symbols of a pair of compressed representations of the media stream comprises checking a relationship between symbols of lower compressed representations of the media stream, lower compressed representations of the media stream being characterized by a higher compression level.

16. The method according to claim 12 further comprising a step of compressing the enhancement data.

17. The method according to claim 12 wherein enhancement data includes enhancement data symbols; and wherein the method further comprising a step of variable length encoding the enhancement data symbols to provide enhancement data code words.

18. The method according to claim 17 wherein defining an enhancement data code word reflecting a relationship between a (p−1) th media layer symbol and a p th media layer symbol in response to the complexity of reconstructing an original media layer symbol from the p th media layer symbol.

19. The method according to claim 12 , wherein said media stream comprises one of the list consisting of:

MPEG compliant media stream;

original media stream;

JPEG media stream;

video stream;

audio stream;

data stream;

H.261 compliant media stream;

H.263 compliant stream;

streaming media stream;

JPEG stream;

AC-3 audio stream;

AAC audio stream; and

a stream containing a plurality of streams.

20. The method of claim 12 further comprising a step of encrypting the base media layer, whereas the base media layer and the enhancement data defining an encrypted representation of the media stream.