Sample rate converter having distributed filtering

A computer-readable storage medium embodying computer executable instructions for converting a digital audio signal at an initial sample rate to a different intended sample rate, the instructions comprising:

• code for receiving a plurality of data points, associated with an audio signal, at an initial sample rate;
• code for halfband filtering said plurality of data points with a halfband filter to provide intermediate data points, said halfband filter having a first transition band with an image corresponding thereto;
• code for interpolating the intermediate data points with an interpolator utilizing an interpolation equation and having independently programmable parameters and a second transition band, with a width associated with the second transition band being a function of the spectral separation of said first transition band and said image, and wherein the different sample rate is provided by interpolating at least a subset of the intermediate data points based on the independently programmable parameters, and wherein said different sample rate is controllably varied at any output data sample by interpolation;
• and
• code for producing an output signal at the different sample rate.

A sample rate converter to convert an input signal at an input sample rate to one of a plurality of differing intended output sample rates, the sample rate converter comprising:

• circuitry to receive a plurality of data points, associated with the input signal, at the input sample rate;
• a filter to operate on said plurality of data points to associate said input signal with a predetermined set of parameters, with said set of parameters including a first transition band having a first width;
• an interpolator to, for said plurality of data points, controllably convert said input sample rate to any one of said plurality of differing output sample rates for any output data sample in response to a variation in an intended rational sample rate conversion ratio by converting said input sample rate associated with said signal to any one of the plurality of differing intended output sample rates by interpolating a subset of data points of said plurality of data points with an interpolator implementing an interpolation equation and having associated therewith a second transition band, with the width associated with said second transition band being a function of a spectral separation of said first transition band and said image;
• and
• circuitry to produce an output signal having a sequence of data samples approximating the input signal.

A sample rate converter to convert a digital audio signal at an initial sample rate to a different intended sample rate, the sample rate converter comprising:

• circuitry to receive a plurality of data points, associated with an audio signal, at an initial sample rate;
• a halfband filter to halfband filter said plurality of data points to provide intermediate data points, said halfband filter having a first transition band with an image corresponding thereto;
• an interpolator to interpolate the intermediate data points utilizing an interpolation equation and having independently programmable parameters and a second transition band, with a width associated with the second transition band being a function of the spectral separation of said first transition band and said image, and wherein the different sample rate is provided by interpolating at least a subset of the intermediate data points based on the independently programmable parameters, and wherein said different sample rate is controllably varied at any output data sample by interpolation;
• and
• circuitry to produce an output signal at the different sample rate.