Re: tetra Digest, Vol 9, Issue 3
Hi again. We have the etsi cdecoder and speech decoder which works fine with sample code what we need is to link it with real time bitstream from osmo tetra decode. I understood this had already been achieved with Dieter's proof of concept code. Any chance of viewing this code even if incomplete ?. regards. graham ________________________________ From: "tetra-request@lists.osmocom.org" <tetra-request@lists.osmocom.org> To: tetra@lists.osmocom.org Sent: Saturday, 24 September 2011, 16:04 Subject: tetra Digest, Vol 9, Issue 3 Send tetra mailing list submissions to tetra@lists.osmocom.org To subscribe or unsubscribe via the World Wide Web, visit https://lists.osmocom.org/mailman/listinfo/tetra or, via email, send a message with subject or body 'help' to tetra-request@lists.osmocom.org You can reach the person managing the list at tetra-owner@lists.osmocom.org When replying, please edit your Subject line so it is more specific than "Re: Contents of tetra digest..." Today's Topics: 1. Re: tetra Digest, Vol 9, Issue 2 (Graham Palmer) 2. Re: play the voice signal ? (Dieter Spaar) 3. Re: play the voice signal ? (Pepijn van den Berkhof) 4. Re[2]: play the voice signal ? (Mccauley) 5. Re: play the voice signal ? (Holger Hans Peter Freyther) 6. Re: play the voice signal ? (Dieter Spaar) 7. tetra voice (fe8769) Hi all I am still learning this level of coding. I am struggling to get the descrambled bitstream from the lower mac to the channel decoder of the etsi codec. My setup has no problem decoding the data and reading it with Wireshark. Any help would be appreciated. Best regards. Graham ________________________________ From: "tetra-request@lists.osmocom.org" <tetra-request@lists.osmocom.org> To: tetra@lists.osmocom.org Sent: Saturday, 24 September 2011, 11:00 Subject: tetra Digest, Vol 9, Issue 2 Send tetra mailing list submissions to tetra@lists.osmocom.org To subscribe or unsubscribe via the World Wide Web, visit https://lists.osmocom.org/mailman/listinfo/tetra or, via email, send a message with subject or body 'help' to tetra-request@lists.osmocom.org You can reach the person managing the list at tetra-owner@lists.osmocom.org When replying, please edit your Subject line so it is more specific than "Re: Contents of tetra digest..." Today's Topics: 1. play the voice signal ? (Bigsat) 2. Re: play the voice signal ? (Dieter Spaar) 3. Re: play the voice signal ? (Pepijn van den Berkhof) 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 Hello Bigsat, On Fri, 23 Sep 2011 13:49:43 +0200, "Bigsat" <bigsat@gmail.com> wrote:
Is it possible to release some part of the code necessary to decode Tetra voice or give some explaination of Gsmtap usage ?
Just in case, I have sent my "proof of concept" modification for voice decoding to the authors of Osmocom TETRA for proper integration a while ago. As far as I am aware the current source code should be able to decode voice or at least contain the instructions how to do it (the ETSI reference codec is most certainly not included for copyright reasons). Best regards, Dieter -- Dieter Spaar, Germany spaar@mirider.augusta.de Hi, The instructions to download the ETSI reference codec can be found here: http://tetra.osmocom.org/trac/wiki/Speech_Codec although I never got it working completely. There is an output stream but there is no audio data in it. Just (random?) clicks and pops. Cheers, Pepijn Op 23 sep. 2011, om 15:20 heeft Dieter Spaar het volgende geschreven: Hello Bigsat,
On Fri, 23 Sep 2011 13:49:43 +0200, "Bigsat" <bigsat@gmail.com> wrote:
Is it possible to release some part of the code necessary to decode
Tetra voice or give some explaination of Gsmtap usage ?
Just in case, I have sent my "proof of concept" modification for voice decoding to the authors of Osmocom TETRA for proper integration a while ago. As far as I am aware the current source code should be able to decode voice or at least contain the instructions how to do it (the ETSI reference codec is most certainly not included for copyright reasons).
Best regards, Dieter -- Dieter Spaar, Germany spaar@mirider.augusta.de
_______________________________________________ tetra mailing list tetra@lists.osmocom.org https://lists.osmocom.org/mailman/listinfo/tetra 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@mirider.augusta.de 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@mirider.augusta.de
Apart from the codec patches for ETSI codec i cant find any other voice decoding source code in osmocom-tetra trunk. Neither seems to have entered you in the AUTHORS file. FAQ on the site says: "Can your software actually play the voice signal? Currently we have no support for that. However, a yet unreleased proof-of-concept version exists." Why this secrecy for publishing source to decode unencrypted networks?. Have osmocom been threatened by the tetra manufacturers? Would damage sysmocom commercial interests
Just in case, I have sent my "proof of concept" modification for voice decoding to the authors of Osmocom TETRA for proper integration a while ago. As far as I am aware the current source code should be able to decode voice or at least contain the instructions how to do it (the ETSI reference codec is most certainly not included for copyright reasons).
Best regards, Dieter -- Dieter Spaar, Germany spaar@mirider.augusta.de
-- <> On 09/24/2011 03:37 PM, Mccauley wrote:
Why this secrecy for publishing source to decode unencrypted networks?. Have osmocom been threatened by the tetra manufacturers? Would damage sysmocom commercial interests
Hi, sysmocom is building a GSM BTS, right now there is no interest in doing something commercially with tetra. We can not integrate the ETSI audio code in our (A)GPL software, the result would not be freely distributable. From my side I was mostly interested in the signalling part, or if time would permit try transmitting. So if you either find a legal way to include the ETSI code at build time, or preferable write a GPL compatible audio decoder, I think we would be happy to include it in the git repository. cheers holger Hello Pepijn, On Sat, 24 Sep 2011 15:49:37 +0200, "Pepijn van den Berkhof" <vandenberkhof.pepijn@gmail.com> wrote:
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)
I know that others have used the current code to decode speech, maybe someone can confirm it. I haven't worked with the code for a while and so can't confirm it, but it has worked for me in the past. Maybe I find the time to try it within the next few weeks, if possible I will also try to provide a sample capture from a test TETRA network so everyone can try the sample. "Test TETRA Network" means from a network under our control run in a faraday cage so that there are no legal issues providing the capture. Best regards, Dieter -- Dieter Spaar, Germany spaar@mirider.augusta.de is that could help us for voice decoding : ? http://www.joys99.com/d-4784.html -- _______________________________________________ tetra mailing list tetra@lists.osmocom.org https://lists.osmocom.org/mailman/listinfo/tetra
On Sat, Sep 24, 2011 at 8:56 PM, Graham Palmer <graham.palmer69@yahoo.co.uk> wrote:
Hi again. We have the etsi cdecoder and speech decoder which works fine with sample code what we need is to link it with real time bitstream from osmo tetra decode. I understood this had already been achieved with Dieter's proof of concept code. Any chance of viewing this code even if incomplete ?.
It doesn't apply anymore because of a lot of change in the code since then. This should save the data in the bursts : 1) It's completely untested but that's where Dieters POC got the bits previously 2) It saves the data as '0' and '1' in a text file, you may need to change the etsi codec to read that 3) It will only give out garbage is there is multiple voice channel at once since it doesn't do any meta data interpretation to isolate channels and just save anything that's traffic (that was a limitation of dieter's POC as well) 4) I'm pretty sure it saves 'packet data' as well which obviously gives garbage. diff --git a/src/lower_mac/tetra_lower_mac.c b/src/lower_mac/tetra_lower_mac.c index 7b62bb4..8a41ccb 100644 --- a/src/lower_mac/tetra_lower_mac.c +++ b/src/lower_mac/tetra_lower_mac.c @@ -184,6 +184,15 @@ void tp_sap_udata_ind(enum tp_sap_data_type type, const uint8_t *bits, unsigned DEBUGP("%s %s type4: %s\n", tbp->name, time_str, osmo_ubit_dump(type4, tbp->type345_bits)); + if (tms->cur_burst.is_traffic) { + FILE *f = fopen("traffic.out", "ab"); + + for(i = 0; i < 216*2; i++) + fprintf(f, "%d", bits[i]); + + fclose(f); + } + if (tbp->interleave_a) { /* Run block deinterleaving: type-3 bits */ block_deinterleave(tbp->type345_bits, tbp->interleave_a, type4, type3);
participants (2)
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Graham Palmer -
Sylvain Munaut