Patent ID: 7263481

Claim:
An apparatus for a voice transcoder that produces a destination code bitstream in a destination codec format from a source code bitstream in a source codec format, the apparatus comprising: an unpacking module operative to unpack the source codec bitstream and decode the information into at least one parameter of a common codec for which a common codec parameter space is defined; a linear prediction parameters generation module operative to generate destination codec linear prediction parameters by mapping from source codec linear prediction parameters or by linear prediction analysis; a perceptual weighting filter module operative to use weighting factors that have been optimized for transcoding between a specific source codec and destination codec pair; an excitation parameter generation module for determining at least one common codec excitation parameter in the destination codec format, said parameter generation module operative to provide direct mapping processes and searching processes for each said common codec excitation parameter; a packing module operative to pack the destination codec common codec parameters to the bitstream; and a control module for selecting a transcoding strategy and to provide additional control information.