DTS Multi-Channel 96 kHz Audio Compression
Yuli You, Zoran Fejzo, Stephen Smyth, Paul D. Smith · 1999
This paper presents DTS multi-channel audio coding technology that operates at a sampling frequency of up to 96 kHz and remains compatible with existing DTS audio coding technology which delivers 5.1 channel audio at a sampling frequency of up to 48 kHz. High-sampling frequency (up to 96 kHz) multi-channel audio is decomposed into core audio (up to 48 kHz) and a residual (difference). The core audio is encoded using existing DTS audio coder to produce a core bit stream which is fully compatible with existing DTS decoders in the market. The residual is encoded using technologies that extend the sampling frequency to up to 96 kHz and can even improve the quality of the core audio. The compressed residual is attached as an extension to the core bit stream. The extension bit stream is ignored by the existing DTS decoders but can be decoded by extended DTS decoders. The encoding algorithm can deliver 96 kHz multi-channel audio at 24 bits per sample with a bit rate of up to 4.5 Mbps. Details of the main processing blocks of the core and extended decoding algorithms, their computational loads and memory requirements are presented. One implementation is described of a 5.1 channel, 96 kHz, 24-bit decoding process operating on dual SHARC 21065L 32-bit floating-point processors. This particular configuration confines all the essential high sampling rate operations to the second processor, allowing a simple hardware upgrade path to be considered for the 96/24 'high definition' audio format.