Enhanced audio frame loss concealment

摘要

A method is provided for concealing a lost audio frame of a received audio signal by performing a sinusoidal analysis of a part of a previously received or reconstructed audio signal. The sinusoidal analysis involves identifying frequencies of sinusoidal components of the audio signal, and applying a sinusoidal model on a segment of the previously received or reconstructed audio signal. The segment is used as a prototype frame in order to create a substitution frame for a lost audio frame. The method includes creating the substitution frame for the lost audio frame by time-evolving sinusoidal components of the prototype frame, up to the time instance of the lost audio frame, in response to the corresponding identified frequencies. The method further includes performing at least one of an enhanced frequency estimation and an adaptation of the creating of the substitution frame in response to the tonality of the audio signal.

主权项

1. A method of concealing a lost audio frame of a received audio signal, the method comprising:
performing a sinusoidal analysis of a previously received or reconstructed part of the received audio signal, wherein the sinusoidal analysis comprises identifying frequencies of sinusoidal components of the previously received or reconstructed part by performing an enhanced frequency estimation comprising determining whether the previously received or reconstructed part is harmonic by performing at least one of an autocorrelation analysis of the received audio signal and using a result of a closed-loop pitch prediction; applying a sinusoidal model on a segment of the previously received or reconstructed part of the received audio signal, wherein the segment is used as a prototype frame in order to create a substitution frame for a lost audio frame; and creating the substitution frame for the lost audio frame, wherein the creating comprises time-evolving sinusoidal components of the prototype frame, up to a time instance of the lost audio frame, based at least in part on the frequencies of the sinusoidal components, wherein the time-evolving comprises changing a spectral coefficient of the prototype frame included in an interval located in a vicinity of a sinusoid by a phase shift proportional to a sinusoidal frequency and a time difference between the lost audio fame and the prototype frame, while retaining a magnitude of the spectral coefficient, and wherein the creating is based on a tonality of the received audio signal.