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Dobrica Pavlinušić's random unstructured stuff
osmocom: Revision 10
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^ voice info .pre 17:42 < dpavlin> stupid question about by first experiment with osmocom-bb http://blog.rot13.org/2011/01/osmocom-bb_-_free_software_finally_comes_to_gsm.html - are hex numbers I see scroll by voice data by any chance or controll stream? 17:42 < steve|m> dpavlin: that's the voice_ind 17:43 < steve|m> http://bb.osmocom.org/trac/changeset/a4e34316c403a49ca57fd907e55a16b721629e35/src 17:43 < steve|m> so maybe revert this commit in your local branch if you don't need that (transferring voice data to the host) 17:45 < dpavlin> Great. With something like pipe I could go a long way :-) 17:46 < dpavlin> Can I inject it over serial port? For something like text2speech? 17:46 < steve|m> tnt has code for that, but he hasn't committed it yet 17:46 < steve|m> jolly even has written an interface to LCR 17:49 < dpavlin> I would love to help test it, if such help is needed. .pre * http://bb.osmocom.org/trac/changeset/999254a3a6641ea112b48c1eca65599fb9989185 * GSM 06.10 encoder/decoder http://www.quut.com/gsm/ .pre 19:21 < dpavlin> tnt: do you have any pointers to information about calypso voice format I can read? 19:23 < dw> the code? :) 19:26 < dpavlin> I tried reading code under src/target/firmware/calypso but I'm probably looking in wrong place, because I'm not closer to understanding voice.raw format than I was few days ago. 19:30 < steve|m> dpavlin: looked at http://bb.osmocom.org/trac/browser/src/target_dsp/calypso/dsp_sniff.S?rev=d1cb8ea9b784c7acbafbb2fdcedbdf4655c2f6f5 ? 19:31 < tnt> steve|m: that's not for voice.raw 19:31 < tnt> There is just no written reference anywhere of the buffer format. 19:31 < steve|m> ah, sorry, confused that.. 19:44 < tnt> dpavlin: from memory, it's all the class 1 bits, then some bits always at 0 (4 bits IIRC), then all the class 2 bits of a GSM 610 frame. They're packet in 16 bits works, MSB first .pre .pre 1297284215 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> I have a question about burst_ind branch of bb @1297284218 <mkf00!~mkf00@85-127-108-141.dynamic.xdsl-line.inode.at> hallo @1297284279 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> In l1ctl_burst_ind I understand that the two stealing bits are in bits 58 & 59 (without the training) @1297284286 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> is this correct? @1297284318 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> this is because I think that both must be the same bit 0 for data/voice and 1 for FACCH @1297284347 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> tnt? @1297284376 <tnt!~tnt@mojito.smartwebsearching.be> no it's not correct @1297284389 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> uhm! @1297284391 <tnt!~tnt@mojito.smartwebsearching.be> the two stealing bits are at the end, the DSP puts them there. @1297284439 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> both are together? @1297284440 <tnt!~tnt@mojito.smartwebsearching.be> On the air you are correct they're in the middle but during the packing, the DSP puts the 2*57 bits and then the two stealing bits at the end. @1297284538 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> from my code: @1297284542 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> <0001> layer3.c:418 LEO BURST: 58 93 b5 f6 95 37 9c 83 f7 f1 95 f2 62 fd 10 @1297284605 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> we don't need the first 4 bits @1297284618 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> but the next one is 1 @1297284633 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> only one stealing bit filled? @1297284671 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> only one stealing bit with 1? @1297284908 <tnt!~tnt@mojito.smartwebsearching.be> Fatuo: yup. so ? @1297284945 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> I thought that both must be the same.... @1297284983 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> Can be FACCH and voice/data in the same frame? I don think so... @1297285078 <tnt!~tnt@mojito.smartwebsearching.be> well, you think wrong :) @1297285108 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> oh @1297285111 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> tanks :) @1297285111 <tnt!~tnt@mojito.smartwebsearching.be> you need to re-read GSM 05.03. TCH has diagonal block interleaving. @1297285148 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> ok, i will do right now, thanks a lot @1297285149 <tnt!~tnt@mojito.smartwebsearching.be> so the 4 * 114 bits are split into 8 half bursts and sent over 8 bursts, half mixing with the next / prev frame. @1297285247 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> I see @1297285275 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> I'll go re-reading that doc @1297285277 <Fatuo!~n0p@79.198.19.95.dynamic.jazztel.es> bye .pre ^ A5/1 * http://reflextor.com/trac/a51/browser/tinkering * http://opensource.srlabs.de/projects/a51-decrypt/files .pre git clone git://git.srlabs.de/kraken .pre * http://srlabs.de/research/decrypting_gsm/ * http://srlabs.de/uncategorized/airprobe-how-to/ ^ Neo * http://www.steve-m.de/projects/osmocom/0001-for-testing-add-TX-support-for-gta0x-devices.patch ^ BTS * http://www.246tnt.com/gsm/rx_filter.html |