Patent ID: 6252919
Filing Date: 2001-06-26
Classification: G10L,H04J,H04L

Abstract:
A sample-rate converter comprising:an input stream of samples representing audio intensities at points in time, the input stream for playing the samples at an input rate of an input clock;an output stream of samples representing audio intensities at points in time, the output stream for playing the samples at an output rate of an output clock;a buffer for receiving the samples from the input stream in response to the input clock;a derived-clock generator, coupled to the output clock, for generating a derived clock from the output clock, the buffer outputting samples in response to the derived clock to form a buffered stream;a delay register, coupled to the buffer, for delaying samples in the buffered stream by a period of the derived clock, the delay register outputting a delayed stream;a fade-in generator, coupled to the buffer and coupled to the delay register, for fading in the delayed stream by gradually inserting an extra sample into a faded stream of samples by gradually increasing a weighting of samples from the delayed stream and gradually decreasing a weighting of samples from the buffered stream, the fade-in generator outputting the faded stream;a filter stage, coupled to receive samples in the faded stream from the fade-in generator in response to a derived clock, for converting samples read from the buffer at a derived rate of the derived clock to output samples output at the output rate; anda target indicator, coupled to the input clock and coupled to the derived clock, for indicting when the buffer contains a target number of samples, and for indicating when the buffer contains less than the target or more than the target number of samples;wherein the fade-in generator outputs the buffered stream without fading in the delayed stream when the target indicator indicates that the buffer contains the target number of samples, but the fade-in generator fading in the delayed stream when the target indicator indicates that the buffer contains more than the target number of samples,whereby the fade-in generator adds a net sample by fading in the delayed stream in response to a number of samples stored in the buffer.