Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Nokia Technologies Oy

Emma Jokinen

Tom Baeckstroem

Ville Mikael Myllyla

Hannu Juhani Pulakka

Johannes Fischer

Jari Petteri Sjoberg

Tom Bäckström

Paavo Ilmari Alku

Tom Backstrom

Tom BÄCKSTRÖM

It is shown an encoder for encoding an audio signal with reduced background noise using linear predictive coding. The encoder includes a background noise estimator configured to estimate background noise of the audio signal, a background noise reducer configured to generate background noise reduced audio signal by subtracting the estimated background noise of the audio signal from the audio signal, and a predictor configured to subject the audio signal to linear prediction analysis to obtain a first set of linear prediction filter (LPC) coefficients and to subject the background noise reduced audio signal to linear prediction analysis to obtain a second set of linear prediction filter (LPC) coefficients. Furthermore, the encoder includes an analysis filter composed of a cascade of time-domain filters controlled by the obtained first set of LPC coefficients and the obtained second set of LPC coefficients.

Encoder and method for encoding an audio signal with reduced background noise using linear predictive coding

An audio encoder for providing an encoded representation on the basis of an audio signal, wherein the audio encoder is configured to obtain a noise information describing a noise included in the audio signal, and wherein the audio encoder is configured to adaptively encode the audio signal in dependence on the noise information, such that encoding accuracy is higher for parts of the audio signal that are less affected by the noise included in the audio signal than for parts of the audio signal that are more affected by the noise included in the audio signal.

Method for adaptively encoding an audio signal in dependence on noise information for higher encoding accuracy

An apparatus comprising at least one processor and at least one memory including computer code for one or more programs, the at least one memory and the computer code configured to with the at least one processor to cause the apparatus to at least perform: estimating a signal to noise ratio value for an audio signal; generating a post-filter comprising at least one of: a first formant frequency filter and a second formant frequency filter, wherein the post-filter is dependent on the signal to noise ratio value for the audio signal.

Noise adaptive post filtering

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Helsinki, Finland

Emma Jokinen