Texas Instruments Corporation

Jeffrey Scott Hayes

Stephen John Fedigan

Jonathan L Rowlands

Jason Douglas Kridner

Alec C Robinson

Charles D Lueck

Stephen R Handley

Daniel S Jochalson

Rocky Chau-Hsiung Lin

A volume level and crossfade controller with programmable fades and audio stream priority controls saturation for a multiple audio stream mixer. Start of fade and end of fade events trigger updates of relative volume level targets and volume ramps.

Multi-stream audio level controller

A method for converting sample rates includes obtaining coefficients from a sample rate conversion coefficient table. In this method, the table is generated prior to the real-time sample rate conversion using LaGrange Interpolation based on the ratio of the input sample rate to the output sample rate.

High order lagrange sample rate conversion using tables for improved efficiency

According to the present invention, there is developed a proprietary technology for compressing the window tables of audio coders to &frac18; their original size (or less) without any loss of quality. This technology can be applied to all transform based audio coders, or any audio coder that uses a windowing stage. The novel technique for reducing storage requirements for the window tables of audio coders is based on multiple differentiation. Since the difference between any two adjacent samples in the first difference signal is small, so it is more efficient to store this difference. This technique can be carried out several more times, until the returns get smaller, and the computational requirements to &ldquo;undo&rdquo; the compression go up. The optimum number of times to differentiate is dependent on the particular application and the window shape.

TI window compression/expansion method

Growing community of inventors

Houston, TX, United States of America

Jeffrey Scott Hayes