SYNTHESIS OF LOST DIGITAL AUDIO SIGNAL BLOCKS WITH PITCH PERIOD CORRECTION

摘要

1. A method for synthesizing a digital audio signal, presented in the form of successive blocks of samples, in which, after receiving such a signal to replace at least one defective block, a replacement block is generated based on samples of at least one normal block, the method contains the following steps:! a) determine (402) the repetition period of the signal in at least one normal block, and! b) samples of the repetition period are copied (403) into at least one replacement block, characterized in that in step a) the last repetition period (Tj) is determined in at least one normal block immediately preceding the defective block, and in step b), the samples (e (3)) of the last indicated repetition period (Tj) are adjusted depending on the samples (e (2-T0), e (3-T0), e (4-T0)) of the repetition period (Tj- 1) preceding the indicated last repetition period in such a way as to limit the amplitude of a possible transition signal in the decree SG last repetition period, and adjusted so that the sample is copied into said replacement block (Tj + 1, Tj + 2). ! 2. The method according to claim 1, in which the signal is tonal, characterized in that the repetition period is a pitch period corresponding to the opposite of the fundamental frequency of the signal. ! 3. The method according to claim 1, characterized in that in step b) the current sample (e (3)) of the last repetition period is adjusted by comparing the amplitude of this current sample in absolute value with the amplitude in absolute value of at least one sample ( e (2-T0)), temporarily positioned, essentially, in one repetition period before the current selection, and the current selection comes