Method and Apparatus for Analog and Digital Audio Blend for HD Radio Receivers

摘要

A method and apparatus are provided for blending analog and digital portions of a composite digital radio broadcast signal by processing compressed audio packets to compute corresponding digital audio quality indicator values, storing the compressed audio packets in an audio blend buffer, processing audio information from each compressed audio packet stored in the audio blend buffer with an audio decoder to generate decompressed digital audio signal samples, and using the digital audio quality indicator values to guide a blending process for combining analog audio signal samples with the digital audio signal samples to produce an audio output by preventing unnecessary blending back and forth between analog and digital if the digital audio quality indicator values indicate that the compressed audio packets are degraded or impaired.

主权项

1. A method for processing a composite digital radio broadcast signal to smooth signal blending, comprising:
separating a received composite digital radio broadcast signal into an analog audio portion and a digital audio portion; demodulating the analog audio portion of the composite digital radio broadcast signal to produce analog audio signal samples; demodulating the digital audio portion of the composite digital radio broadcast signal to produce digital audio signal samples by:
demodulating the digital audio portion of the composite digital radio broadcast signal to produce a digital audio signal,decoding the digital audio signal using an upper layer decoding process to compute a plurality of compressed audio packets,processing each compressed audio packet to compute a corresponding digital audio quality indicator value,storing each compressed audio packet in an audio blend buffer for storing a plurality of compressed audio packets, andprocessing audio information from each compressed audio packet stored in the audio blend buffer with an audio decoder which generates decompressed digital audio signal samples; and digitally combining the analog audio signal samples with the digital audio signal samples to produce an audio output by preventing or delaying blending from analog to digital when indicated by one or more corresponding digital audio quality indicator values.