Telefonaktiebolaget Lm Ericsson (publ)

Gustaf Ullberg

Anisse Taleb

Manuel Briand

A transient detector analyzes a given frame n of the input audio signal to determine, based on audio signal characteristics of the given frame n, a transient hangover indicator for a following frame n+1, and signals the determined transient hangover indicator to an associated audio encoder to enable proper encoding of the following frame n+1.

Transient detection with hangover indicator for encoding an audio signal

A method for spectrum recovery in spectral decoding of an audio signal, comprises obtaining of an initial set of spectral coefficients representing the audio signal, and determining a transition frequency. The transition frequency is adapted to a spectral content of the audio signal. Spectral holes in the initial set of spectral coefficients below the transition frequency are noise filled and the initial set of spectral coefficients are bandwidth extended above the transition frequency. Decoders and encoders being arranged for performing part of or the entire method are also illustrated.

Adaptive transition frequency between noise fill and bandwidth extension

A transient detector () analyzes () a given frame n of the input audio signal to determine, based on audio signal characteristics of the given frame n, a transient hangover indicator for a following frame n+1, and signals () the determined transient hangover indicator to an associated audio encoder () to enable proper encoding of the following frame n+1.

Transient detector and method for supporting encoding of an audio signal

A method for spectrum recovery in spectral decoding of an audio signal, comprises obtaining () of an initial set of spectral coefficients representing the audio signal, and determining () a transition frequency. The transition frequency is adapted to a spectral content of the audio signal. Spectral holes in the initial set of spectral coefficients below the transition frequency are noise filled () and the initial set of spectral coefficients are bandwidth extended () above the transition frequency. Decoders and encoders being arranged for performing part of or the entire method are also illustrated.

A method for perceptual spectral decoding includes decoding of spectral coefficients recovered from a binary flux into decoded spectral coefficients of an initial set of spectral coefficients. The initial set of spectral coefficients are spectrum filled. The spectrum filling includes noise filling of spectral holes by setting spectral coefficients in the initial set of spectral coefficients not being decoded from the binary flux equal to elements derived from the decoded spectral coefficients. The set of reconstructed spectral coefficients of a frequency domain formed by the spectrum filling is converted into an audio signal of a time domain.

Methods and systems for perceptual spectral decoding

A method for perceptual spectral decoding comprises decoding of spectral coefficients recovered from a binary flux into decoded spectral coefficients of an initial set of spectral coefficients. The initial set of spectral coefficients are spectrum filled. The spectrum filling comprises noise filling of spectral holes by setting spectral coefficients in the initial set of spectral coefficients not being decoded from the binary flux equal to elements derived from the decoded spectral coefficients. The set of reconstructed spectral coefficients of a frequency domain formed by the spectrum filling is converted into an audio signal of a time domain. A perceptual spectral decoder comprises a noise filler, operating according to the method for perceptual spectral decoding.

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Stockholm, Sweden

Gustaf Ullberg