Noise filling without side information for celp-like coders

An audio decoder for providing a decoded audio information on the basis of an encoded audio information comprising linear prediction coefficients (LPC),

• the audio decoder comprising:
• a noise level estimator configured to estimate a noise level for a current frame using a plurality of linear prediction coefficients of at least one previous frame to acquire a noise level information;
• and
• a noise inserter configured to add a noise to the current frame in dependence on the noise level information provided by the noise level estimator;
• wherein the audio decoder is adapted to decode an excitation signal of the current frame and to compute its root mean square erms;
• wherein the audio decoder is adapted to compute a peak level p of a transfer function of an LPC filter of the current frame;
• wherein the audio decoder is adapted to compute a spectral minimum mf of the current audio frame by computing the quotient of the root mean square erms and the peak level p to acquire the noise level information;
• wherein the noise level estimator is adapted to estimate the noise level on the basis of two or more quotients of different audio frames;
• wherein the audio decoder comprises a decoder core configured to decode an audio information of the current frame using linear prediction coefficients of the current frame to acquire a decoded core coder output signal and wherein the noise inserter adds the noise depending on linear prediction coefficients used in decoding the audio information of the current frame and used in decoding the audio information of one or more previous frames.

A method for providing a decoded audio information on the basis of an encoded audio information comprising linear prediction coefficients (LPC),

• the method comprising:
• estimating a noise level;
• adjusting a tilt of a background noise, wherein linear prediction coefficients of a current frame are used to acquire a tilt information;
• and
• decoding an audio information of the current frame using the linear prediction coefficients of the current frame to acquire a decoded core coder output signal;
• and
• adding the adjusted background noise to the current frame, to perform a noise filling.

A method for providing a decoded audio information on the basis of an encoded audio information comprising linear prediction coefficients (LPC), the method comprising:

• estimating a noise level for a current frame using a plurality of linear prediction coefficients of at least one previous frame to acquire a noise level information;
• and
• adding a noise to the current frame in dependence on the noise level information provided by the noise level estimation;
• wherein an excitation signal of the current frame is decoded and wherein its root mean square erms is computed;
• wherein a peak level p of a transfer function of an LPC filter of the current frame is computed;
• wherein a spectral minimum mf of the current audio frame is computed by computing the quotient of the root mean square erms and the peak level p to acquire the noise level information;
• wherein the noise level is estimated on the basis of two or more quotients of different audio frames;
• wherein the method comprises decoding an audio information of the current frame using linear prediction coefficients of the current frame to acquire a decoded core coder output signal and
• wherein the method comprises adding the noise depending on linear prediction coefficients used in decoding the audio information of the current frame and used in decoding the audio information of one or more previous frames.