Digital Theater Systems, Inc.

Stephen M Smyth

William Paul Smith

William P Smith

Zoran Fejzo

Yu-Li You

Ming Yan

The present invention provides a method of decoding two-channel matrix encoded audio to reconstruct multichannel audio that more closely approximates a discrete surround-sound presentation. This is accomplished by subband filtering the two-channel matrix encoded audio, mapping each of the subband signals into an expanded sound field to produce multichannel subband signals, and synthesizing those subband signals to reconstruct multichannel audio. By steering the subbands separately about an expanded sound field, various sounds can be simultaneously positioned about the sound field at different points allowing for more accurate placement and more distinct definition of each sound element.

Method of decoding two-channel matrix encoded audio to reconstruct multichannel audio

A multi-channel audio compression technology is presented that extends the range of sampling frequencies compared to existing technologies and/or lowers the noise floor while remaining compatible with those earlier generation technologies. The high-sampling frequency multi-channel audio is decomposed into core audio up to the existing sampling frequencies and a difference signal up to the sampling frequencies of the next generation technologies. The core audio is encoded using a first generation technology such as DTS, Dolby AC-3 or MPEG I or II such that the encoded core bit stream is fully compatible with a comparable decoder in the market. The difference signal is encoded using technologies that extend the sampling frequency and/or improve the quality of the core audio. The compressed difference signal is attached as an extension to the core bit stream. The extension data will be ignored by the first generation decoders but can be decoded by the second generation decoders. By summing the decoded core and extension audio signals together, a second generation decoder can effectively extend the audio signal bandwidth and/or improve the signal to noise ratio beyond that available through the core decoder alone.

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Newtownards, Ireland

Stephen M Smyth