Patent ID: 8467891

Claim:
A controller for outputting audio having a predetermined output sample rate, said controller comprising a hardware based first converter, a hardware based second converter, and a hardware based third converter, said controller programmed to: receive an audio signal having a first sample rate, wherein the first sample rate of the received audio signal includes a sample rate that is less than the predetermined output sample rate; identify the first sample rate of the audio signal; select one of the first converter, the second converter, and the third converter based on identification of the first sample rate, whereby a selected converter is identified; and convert the first sample rate of the received audio signal to the predetermined output sample rate using the selected converter; wherein the first converter is programmed to convert the first sample rate of the audio signal to the predetermined output sample rate by increasing the first sample rate by a factor equal to a ratio of the predetermined output sample rate to the first sample rate, and subsequently applying a first low-pass filter; wherein the second converter is programmed to convert the first sample rate of the audio signal to a second sample rate by increasing the first sample rate by a factor equal to a ratio of one-half of the predetermined output sample rate to the first sample rate, and subsequently applying a first low-pass filter; and convert the second sample rate of the audio signal to the predetermined output sample rate by increasing the second sample rate by the factor, and subsequently applying a second low-pass filter: and wherein the third controller is programmed to convert the first sample rate of the audio signal to the predetermined output sample rate by: converting the first sample rate to a second sample rate by increasing he first sample rate by a first factor equal to a least common numerator of a ratio of the predetermined output sample rate to the first sample rate and applying a first low-pass filter; and converting the second sample rate to the predetermined output sample rate by decreasing the second sample rate by a second factor equal to a least common denominator of the ratio; and filter the audio signal at the predetermined output sample rate by applying a first fast-Fourier transform (FFT) to the audio signal at the predetermined output sample rate; multiplying a result of the FFT application with a second fast-Fourier transform of a second low-pass filter; and applying an inverse fast-Fourier transform to the product.