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sylvain, 02/19/2016 10:50 PM

= Speech Codec =

The speech codec is a proprietary AMBE variant from [ DVSI]. The official spec only contain a very rough overview and no technical information about the format and how to encode or decode it.


The ETSI lists patents relevant to GMR. (See [ here]).

This list is not really complete or accurate though. In particular it's missing the patent that has the most in common with the actual codec is (US&EU versions) :


Osmocom-GMR contains a basic implementation of a voice decoder. Its quality is not as good as the official decoder but it does produce perfectly intelligible voice. You can find the implementation in the src/codec directory of the git.

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