Delaying analog sourced audio in a radio simulcast

摘要

A method and apparatus is disclosed in which delay is applied to analog-sourced audio in a radio simulcast when the analog signal initially leads the digital signal. A radio receiver is configured to receive a simulcast radio program broadcast with an analog signal and a digital signal. The program content can be extracted from either the analog or digital signals, with the audio source eventually being blended to the digital signal. Audio is initially provided based on the analog signal. If the analog signal is initially leading the digital signal, delay is applied a data stream corresponding to the analog signal relative to a data stream corresponding to the digital signal. Delay applied to the data stream corresponding to the analog signal is increased at a rate that avoids audio artifacts of the output audio. The blend is performed when the data streams are aligned in time.

主权项

1. An apparatus comprising:
a delay unit implemented in a radio receiver, wherein the delay unit is configured to receive a first data stream and a second data stream corresponding respectively to analog-transmitted and digitally-transmitted portions of a simulcast radio program, wherein the delay unit is further configured to determine an amount of an initial time lag between corresponding points of the first data stream and the second data stream; wherein the delay unit, in response to determining that the second data stream lags the first data stream, is configured to increase an amount of delay applied to the first data stream until the first and second data streams reach a target time alignment, and wherein the delay unit is configured to increase the amount of delay at a rate that avoids audible artifacts in an audio output signal generated from the analog-transmitted portion of the radio program, and wherein the delay unit is further configured to store information indicative of the amount of the initial time lag between the first data stream and the second data stream and further configured to use the recorded initial time lag to re-tune the radio receiver to a source of the simulcast radio program.