Sixth European Conference on Speech Communication and Technology
This paper gives the description of the multi-rate speech codec family which was the basis of the candidate developed by France Telecom and Nortel Networks for the ETSI GSM AMR normalization. This codec family is built on the ACELP technology. For each type of parameters derived from CELP analysis like LP filter coefficients, adaptive and fixed codebooks and gains, a set of vector quantizers has been designed. This allows to select the bit-rate for any parameter and consequently to vary the global speech coder bit-rate gradually in the range of 4.7 – 12.2 kbit/s. Formal subjective listening test results of the GSM AMR candidate codec performed by two world wide recognized listening laboratories in two languages (English and French) are also given.
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Bibliographic reference. Kövesi, Balázs / Lamblin, Claude / Quinquis, Catherine / Thiérion, Philippe / Navarro, William (1999): "A multi-rate codec family based on GSM EFR and ITU-t g.729", In EUROSPEECH'99, 1743-1746.