| 摘要 |
<p>Apparatus and method for quantizing and entropy encoding transform coefficients in the encoding of multimedia data, for example video and audio data. Pixel value data is input into a decorrelator (302). The decorrelator generates reduced transform coefficients. A quantizer (304), for example a bit plane slicer, is used to remove irrelevant data from the reduced coefficients. Statistical dependencies in the bit planes are exploited by the application of a context selection means (308), which in turn generates multilevel context paths. The multilevel context paths are input into an entropy encoding mechanism (310). In one embodiment, the entropy encoding mechanism comprises: a run-length pre-coder (312), for receiving input data at each context level and outputs run-length symbols; and an analytical entropy coder (314), which receives the symbols and generates a compressed data stream. The above stages are reversed in decoding.</p> |
