| 摘要 |
The invention concerns a method and a device for coding an audio signal by "forward" and "backward" LPC analysis, the coding being produced by "forward" LPC filtering for non-stationary zones and on a synthetic signal based on "backward" LPC filtering for stationary zones. For each current LPC block (Bn) (10), the degree of stationarity of the digital audio signal is determined (11), and a "forward" or "backward" LPC analysis selection value is established (12) based on a decision function, according to the stationarity parameter. A "forward" or "backward" LPC analysis criterion is applied (13) to the analysis selection value to produce the audio signal coding before proceeding to the next LPC block. The invention is applicable to mobile radiotelephony, to the production, memorisation of audio recordings, to the transmission by satellite and wideband telephony.
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