Classification-Based Frame Loss Concealment for Audio Signals
First Claim
1. A method for performing frame loss concealment (FLC) in an audio decoder, comprising:
- performing a first analysis on a previously-decoded portion of an audio signal;
classifying a lost frame as either speech or music based on the results of the first analysis;
performing a second analysis on the previously-decoded portion of the audio signal; and
selecting either a first FLC technique or a second FLC technique for replacing the lost frame based on the classification and the results of the second analysis.
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Abstract
An audio decoding system performs frame loss concealment (FLC) when portions of a bit stream representing an audio signal are lost within the context of a digital communication system. The audio decoding system employs two different FLC methods: one designed to perform well for music, and the other designed to perform well for speech. When a frame is deemed lost, the audio decoding system analyzes a previously-decoded audio signal corresponding to previously-decoded frames of an audio bit-stream. Based on the results of the analysis, the lost frame is classified as either speech or music. Using this classification, other signal analysis, and knowledge of the employed FLC methods, the audio decoding system selects the appropriate FLC method which then performs FLC on the lost frame.
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Citations
24 Claims
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1. A method for performing frame loss concealment (FLC) in an audio decoder, comprising:
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performing a first analysis on a previously-decoded portion of an audio signal; classifying a lost frame as either speech or music based on the results of the first analysis; performing a second analysis on the previously-decoded portion of the audio signal; and selecting either a first FLC technique or a second FLC technique for replacing the lost frame based on the classification and the results of the second analysis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for performing frame loss concealment (FLC) in an audio decoder, comprising:
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a signal classifier configured to perform a first analysis on a previously-decoded portion of an audio signal and to classify a lost frame as either speech or music based on the results of the first analysis; and decision logic coupled to the signal classifier, the decision logic configured to perform a second analysis on the previously-decoded portion of the audio signal and to select either a first FLC technique or a second FLC technique for replacing the lost frame based on the classification and the results of the second analysis. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for performing frame loss concealment in an audio decoder, comprising:
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(a) generating an extrapolated signal comprising a plurality of audio samples, wherein generating each sample of the extrapolated signal comprises; (i) extrapolating an audio sample based on a previously-received frame of an audio signal and a pitch period; and (ii) simultaneously with the extrapolation, overlap-adding a sample from an audio fade-out signal provided by the decoder; and (b) using the extrapolated signal to produce a replacement frame. - View Dependent Claims (20, 21)
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22. A system for performing frame loss concealment in an audio decoder, comprising:
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(a) first logic configured to generate an extrapolated signal comprising a plurality of audio samples, wherein generating each sample of the extrapolated signal comprises extrapolating an audio sample based on a previously-received frame of an audio signal and a pitch period and simultaneously with the extrapolation, overlap-adding a sample from an audio fade-out signal provided by the decoder; and (b) second logic configured to use the extrapolated signal to produce a replacement frame. - View Dependent Claims (23, 24)
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Specification