Method and apparatus for real time compression and decompression of a digital motion video signal using a fixed Huffman table

DETAILED DESCRIPTION A method and apparatus for real time compression and decompression of a digital motion video signal is disclosed.
According to the present invention, a bitstream representative of at least one digital video image is decoded in real time by first providing a code-book index from the bitstream.
The code-book index is applied to an index table to determine an index value which is compared to a first predetermined threshold.
A single fixed table is used for any number of different frames.
If the index value is greater than the predetermined threshold, then at least one current pixel is determined by copying a corresponding previous pixel into the location of at least one current pixel; otherwise, the index value is applied to a vector table to determine at least one vector value and at least one current pixel is determined from the vector value and a corresponding previous pixel.
In accordance with the present invention, at least one digital video image is encoded in real time by selecting at least one pixel for encoding and determining at least one difference value between the selected pixel and at least one corresponding previous pixel.
An index value corresponding to the location in a first table of the difference value is calculated.
If the index value is equal to a first predetermined value then a run-length counter is incremented by a second predetermined value and the process is repeated until the index value is not equal to the first predetermined value.
The run-length counter is then encoded.
If the index value is not equal to the first predetermined value then the index value is encoded.