Xvd Corporation

Boris Trojanovsky

Boris D Kudryashov

Victor D Kolesnik

Sergey Petrov

Andrey Trofimov

Evgeny Ovsyannikov

Eugeny Ovsjannikov

A method and apparatus for audio compression receives an audio signal. Transform coding is applied to the audio signal to generate a sequence of transform frequency coefficients. The sequence of transform frequency coefficients is partitioned into a plurality of non-uniform width frequency ranges and then zero value frequency coefficients are inserted at the boundaries of the non-uniform width frequency ranges. As a result, certain of the transform frequency coefficients that represent high frequencies are dropped.

Method and apparatus for audio compression

According to one embodiment of the invention, a multistage vector list quantizer comprises a first stage quantizer to select candidate first stage codewords from a plurality of first stage codewords, a reference table memory storing a set of second stage codewords for each first stage codeword, and a second stage codebook constructor to generate a reduced complexity second stage codebook that is the union of sets corresponding to the candidate first stage codewords selected by the first stage quantizer.

Vector quantization with a non-structured codebook for audio compression

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St. Petersburg, Russia

Boris Trojanovsky