Multiple coding mode signal classification

摘要

Improved audio classification is provided for encoding applications. An initial classification is performed, followed by a finer classification, to produce speech classifications and music classifications with higher accuracy and less complexity than previously available. Audio is classified as speech or music on a frame by frame basis. If the frame is classified as music by the initial classification, that frame undergoes a second, finer classification to confirm that the frame is music and not speech (e.g., speech that is tonal and/or structured that may not have been classified as speech by the initial classification). Depending on the implementation, one or more parameters may be used in the finer classification. Example parameters include voicing, modified correlation, signal activity, and long term pitch gain.

主权项

1. A method comprising:
receiving a portion of an audio signal at a first classifier in a digital audio device; classifying, by the digital audio device, the portion of the audio signal at the first classifier as speech or as music; and processing the portion of the audio signal, wherein processing the portion of the audio signal comprises:
if the portion is classified by the first classifier as speech, then encoding, by the digital audio device, the speech using a first coding mode; orif the portion is classified by the first classifier as music, then:
providing the portion to a second classifier in the digital audio device;classifying, by the digital audio device, the portion at the second classifier as speech or as music; andencoding the portion of the audio signal, wherein encoding the portion of the audio signal comprises:
if the portion is classified at the second classifier as speech, then encoding, by the digital audio device, the portion using a second coding mode; orif the portion is classified at the second classifier as music, then encoding, by the digital audio device, the portion using a third coding mode.