23 Sep
2011
23 Sep
'11
1:49 p.m.
hi,
I am using "fcdp-tetra_demod.py" with my funcube dongle and i can decode
datas. The networks in my place are unencrypted.
I saw on the "Dieter Spaar's blog" :
"I also implemented some proof of concept code which allows decoding
speech traffic and converting it to raw audio using the TETRA reference
codec. Please note that this cannot be used to listen to encrypted TETRA
traffic, it only works if no encryption is used. "
Is it possible to release some part of the code necessary to decode
Tetra voice or give some explaination of Gsmtap usage ?
thanks for answer
24 Sep
24 Sep
4:28 p.m.
Hello,
Regarding questions how to use the ETSI codec: It consists of two steps,
"cdecoder" and "sdecoder". The ouput of "sdecoder" is raw
sound in signed
16-Bit PCM format with 8000 samples/second. For example Audacity can play
it without problems.
(And no, its no "magic", it just requires to read a few comment lines in
the source code of the codec).
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
3:49 p.m.
Hello,
I have tried this and ran the sdecoder and cdecoder whitout any problems. But when I open
the result in Audacity (8000Hz / 16-bit PCM) I just hear clicks and pops and a long beep
every now and then.
I have read the ETSI document regarding the codec, so no magics :)
But do you actually hear output from a real life network? Because I tried the examples
attached to the ETSI document regarding the testing of the codec. They work very nicely,
but no luck on real life networks so far. (yes, no encryption)
Regards,
Pepijn
Op 24 sep. 2011, om 14:28 heeft Dieter Spaar het volgende geschreven:
Hello,
Regarding questions how to use the ETSI codec: It consists of two steps,
"cdecoder" and "sdecoder". The ouput of "sdecoder" is raw
sound in signed
16-Bit PCM format with 8000 samples/second. For example Audacity can play
it without problems.
(And no, its no "magic", it just requires to read a few comment lines in
the source code of the codec).
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
4597
days inactive
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Bigsat -
Dieter Spaar -
Pepijn van den Berkhof