Transform coding of speech and audio signals
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsManuel Briand, Anisse Taleb
Life of this patent
Estimating the term…
Abstract
In a method of perceptual transform coding of audio signals in a telecommunication system, performing the steps of determining transform coefficients representative of a time to frequency transformation of a time segmented input audio signal; determining a spectrum of perceptual sub-bands for said input audio signal based on said determined transform coefficients; determining masking thresholds for each said sub-band based on said determined spectrum; computing scale factors for each said sub-band based on said determined masking thresholds, and finally adapting said computed scale factors for each said sub-band to prevent energy loss for perceptually relevant sub-bands.
Claims12
A method of perceptual transform coding of audio signals in a telecommunication system, characterized by the steps of:
- determining transform coefficients representative of a time to frequency transformation of a time segmented input audio signal;
- determining a spectrum of perceptual sub-bands for said input audio signal based on said determined transform coefficients;
- determining masking thresholds for each said sub-band based on said determined spectrum;
- computing scale factors for each said sub-band based on said determined masking thresholds;
- adapting said computed scale factors for each said sub-band to prevent energy loss due to encoding for the perceptually relevant sub-bands.
An arrangement for perceptual transform coding of audio signals in a telecommunication system, characterized by:
- transform determining means for determining transform coefficients representative of a time to frequency transformation of a time segmented input audio signal;
- spectrum means for determining a spectrum of perceptual sub-bands for said input audio signal based on said determined transform coefficients;
- masking means for determining masking thresholds for each said sub-band based on said determined spectrum;
- scale factor means for computing scale factors for each said sub-band based on said determined masking thresholds;
- adapting means for adapting said computed scale factors for each said sub-band to prevent energy loss for perceptually relevant sub-bands.
Dependencies are inferred from the claim text.