NESTED ENTROPY ENCODING

1 . A decoding system for decoding received encoded data, said system comprising:

(a) a syntax modeler for associating a sequence of first symbols with syntax elements from said data;

(b) at least one buffer for storing a plurality of tables, each nested within a respective one of said sequence of first symbols, and each used to associate a respective one of a sequence of second symbols with encoded data; and

(c) a decoder that decodes said data into a bitstream using a selected respective one of said sequence of second symbols retrieved from a respective one of plurality of tables, where said bitstream is free from including any of said sequence of first symbols.

2 . The decoding system of claim 1 where said sequence of first symbols is an entropy code.

3 . The decoding system of claim 2 where said sequence of first symbols is a selected one of a Huffman code or an arithmetic code.

4 . The decoding system of claim 1 where said sequence of first symbols is a fixed-length code.

5 . The decoding system of claim 1 where said sequence of second symbols is an entropy code.

6 . The decoding system of claim 1 where said decoded data is a set of candidate motion vectors.

7 . The decoding system of claim 1 where said decoder rearranges the association of data with said sequence of second symbols in a respective one of said plurality of tables.

8 . The decoding system of claim 7 where the rearrangement improves coding efficiency by associating lower bit-length symbols with data coded more frequently in said bitstream.

9 . The decoding system of claim 1 where the decoded said data is at least one of spatially independent and temporally independent.

10 . The decoding system of claim 1 where the decoded said data is both spatially independent and temporally independent.

11 . A method for decoding data, said method comprising:

(a) receiving a candidate set of motion vectors used to decode a block of video, one of said candidate set being encoded in said data;

(b) receiving a value for a flag characterizing said one as belonging to a subset within said candidate set;

(c) using said value to trim said candidate set; and

(e) identifying said one of said candidate motion vectors based on the number of motion vectors remaining in said candidate set.

12 . The method of claim 11 where said flag is a temporal_mvp_flag.

13 . The method of claim 12 where said value is used to trim from said candidate set duplicate motion vectors in said subset.

14 . The method of claim 12 where said value is used to trim from said candidate set motion vectors not belonging to said subset

15 . The method of claim 11 where said flag preserves at least one of spatial independence and temporal independence in said data.

16 . The method of claim 11 where said flag is decoded using an entropy coded table nested in a symbol identified from a syntax element of said data.

17 . The method of claim 11 where said flag is used as a syntax element to decode said one using an entropy coded table nested in a symbol identified from said syntax element.

18 . The method of claim 11 where said value is selectively set to that of a constrained_intra_pred_flag.

19 . The method of claim 11 where said flag is nested within a symbol indicating the number of unique motion vectors in said candidate set.

20 . The method of claim 11 where said subset is a maximized collection of motion vectors for which each member of the subset has an identical motion vector not included in the subset.