speech codec

Pepijn van den Berkhof vandenberkhof.pepijn at gmail.com
Tue Jul 26 19:08:08 UTC 2011


> Thank you Harald for the response.
> 
> It seems to be working now although the only sounds we hear are "digital sounding" clicks and pops.
> 
> Thanks again.
> 
> - Pepijn
> 
> Op 25 jul 2011, om 09:39 heeft Harald Welte het volgende geschreven:
> 
>> On Sun, Jul 24, 2011 at 01:02:40PM +0100, Graham Palmer wrote:
>> 
>>> I too was wondering how the u-plane data was passed to the codec.
>>> 300-395-2 states that acelp-codec requires 2 * (137+1) 16bit samples per frame
>>> and not 216 + 216 bits indicated in the tch reordering file comments.
>> 
>> This is the input to the codec, i.e the PCM audio data.
>> 
>> the 216 + 216 bits are the encoded data, i.e. the codec output (which is
>> the decoder input).
>> 
>> The re-ordering code in osmo-tetra is untested.  You can feed the raw
>> burst bits into the ETSI reference codec, as it includes the error
>> correction / viterbi decoder.
>> 
>> -- 
>> - Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
>> ============================================================================
>> "Privacy in residential applications is a desirable marketing option."
>>                                                 (ETSI EN 300 175-7 Ch. A6)
>> 
> 





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