Telediffusion De France

Alexandre Joly

The invention relates to a method of qualitatively evaluating a digital audio signal. It calculates a quality indicator consisting of a vector associated with each time window in real time, in continuous time, and in successive time windows. For example, the generation of a quality indicator vector calculates, for a reference audio signal and for an audio signal to be evaluated, the spectral power density of the audio signal, the coefficients of a prediction filter, using an autoregressive method, a temporal activity of the signal or the minimum value of the spectrum in successive blocks of the signal. To evaluate the deterioration of the audio signal, the method may calculate a distance between the vectors of the reference audio signal and the audio signal to be evaluated associated with each time window.

Method for qualitative evaluation of a digital audio signal

The invention relates to a method of synchronizing two digital data streams with the same content, the method comprising the steps of: a) generating at given intervals for each of the two digital data streams Sand Sat least two characteristic numbers expressing at least one parameter characteristic of their content; b) generating from said numbers points Dand Dfor each of the two streams Sand Srepresenting at least one of said characteristic parameters in a space of at least two dimensions, the points Dcorresponding to the stream Sand the points Dcorresponding to the stream Sthat are situated in a time period T defining trajectories representative of the data streams Sand Sto be synchronized; c) shifting the time periods of duration T assigned to the digital data streams Sand Srelative to each other by calculating a criterion of superposition of said trajectories having an optimum value representing the required synchronization; d) choosing the shift between the time periods corresponding to said optimum value as a value representative of the synchronization.

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La Notte-Sercolex, France

Alexandre Joly