DSD 1.4 and mbelib 1.2.3 released

[dsdauthor]

The Wiki Page has been updated with links to the latest versions. Special thanks to js_scan888 for figuring out the pseudorandom bit sequence required to get NXDN working. This is why I love open source software and include code for unfinished formats so others can tinker with them.

I am still waiting on confirmation that the ProVoice EA sync added in version 1.3.1 actually works.

DSD 1.4
New features:
Decodes voice from NXDN 9600 signals
NXDN96 frames enabled by default
Improved resistance to NXDN96 sync false positives

Fixed bugs:
.wav file header updated after playing .imb/.amb data files
.imb/.amb files now have correct tgid in filename

mbelib 1.2.3 Fixed bugs:
Cik array in mbe_decodeAmbe2250Parms was too small

 

[systron]

great job !

 

[racingfan360]

Thank you once again dsdauthor...Ive just run this against a very poor recording of a NXDN9600 signal and had some limited success with recovering the audio (this is most likely to be an issue with my recording not dsd btw). I honestly never thought I'd ever be able to decode NXDN at all (nor MotoTRBO either for that matter), and certainly not in 2010 !!!

Two questions:
Do you know how DSD 1.4 performs against a NXDN 4800 signal...will it decode at all, not at all, don't know? I'd need to travel to the next city and sit there wait for a user to key up to try it out...that's the closest NXDN 4800 signal I have right now.

Also with DSD 1.4, that's the first time I've been able to get the .wav file recording to work If Im right, it records all audio to one single wav file (appends each audio decode stream to the previous one until dsd is stopped). With the -d option, it creates a single .mbe file per audio session (which crucially will also contain the time/date stamp every time auser keys up). Is it possible to create a new wav file for every audio session, instead of one large wav file???

Thanks again for such a cool piece of software.

Jim

 

[ab3ai]

I tried NXDN/ IDAS with my Icom 3161 and had no luck. I think it might be 4800 baud. When I can get my Kenwood cable, I'll try it on my 210.

 

[Napalm]

Great job, excellent as usual. Recovered audio seems better than previous versions for MotoTRBO, but that could be a coincidence.

A question/request for dsdauthor, though.

Would it ever be possible to decode the Group/Unit ID from a TRBO stream?

I'm not sure if the author has any local trbo repeaters, but I have a ton (probably 20+ and some very strong, clean signals).

If I can help in any way by recording/capturing the stream, let me know.

 

[bglatour001]

Is there a way to get this to run on a WebOS based cell phone? Since WebOS is essentially Linux...

 

[df1paw]

Hi.
In mbelib's source you can read: ... description of how certain voice encoding/decoding algorythims could be implemented...

But - how to do encoding? I would like to encode and decode my own raw files for listening tests.

One second thing: I've got access to some NXDN gear and the appropriate programming software. Is there still need for Nexedge 4800 samples? But I need to get my hands on a receiver with discriminator output before I can provide you some samples.


Regards,
Andreas

 

[racingfan360]

I've now tried this with a NXDN 4800 signal and confirmed it does not decode.

dsdauthor - Ive got a short recording sample available for you if that helps develop and add it to the capability of this great software?

 

[dsdauthor]

Great job, excellent as usual. Recovered audio seems better than previous versions for MotoTRBO, but that could be a coincidence.

A question/request for dsdauthor, though.

Would it ever be possible to decode the Group/Unit ID from a TRBO stream?
I'm not sure if the author has any local trbo repeaters, but I have a ton (probably 20+ and some very strong, clean signals).
If I can help in any way by recording/capturing the stream, let me know.

MotoTRBO is based on the ETSI DMR spec which does define talkgroups etc. so it shouldn't be too hard to make that work.
I will need samples to test against.

I've now tried this with a NXDN 4800 signal and confirmed it does not decode.
dsdauthor - Ive got a short recording sample available for you if that helps develop and add it to the capability of this great software?

I think 4800 baud (6.25kHz) uses a 2400 symbols / second symbol rate which will require some minor tweaks and an option to force to that mode (won't be autodetected as most formats use 4800 sym/sec rate). Since the 9600 baud (12.5kHz) format used two equal sized frames (voice and data) it is likely that the 4800 baud format uses just the voice frames with no other changes except possibly sync.

For both of you (and anyone else requesting new format support), Please capture a recording, upload it somewhere and provide the download link. The recording must be from a discriminator tap, 48000Hz sample rate, 16 bits per channel, mono, .wav format. Make sure the signal peaks are not maxing out the input.

 

[systron]

For both of you (and anyone else requesting new format support), Please capture a recording, upload it somewhere and provide the download link.

will/can you expand the codec section (mbelib) for european digital voice systems like Tetra and Tetrapol ?

 

[SCPD]

will/can you expand the codec section (mbelib) for european digital voice systems like Tetra and Tetrapol ?

Apparently, Tetra uses ACELP and full time encryption.

http://www.signalspaning.se/tetra/1.pdf

Here's the codec description:

http://www.etsi.org/deliver/etsi_en/300300_300399/30039502/01.03.01_60/en_30039502v010301p.pdf

 

[systron]

Apparently, Tetra uses ACELP and full time encryption.
http://www.signalspaning.se/tetra/1.pdf

maybe there are some unencrypted systems in europe.... (until nationwide roll out)

winradio TETRA decoder (data mode, unencrypted of course)

http://www.signalspaning.se/tetra/WiNRADiO TETRA demodular info.pdf

 

[racingfan360]

>For both of you (and anyone else requesting new format support), Please capture a recording, upload it >somewhere and provide the download link. The recording must be from a discriminator tap, 48000Hz >sample rate, 16 bits per channel, mono, .wav format. Make sure the signal peaks are not maxing out >the input.

Thanks dsdauthor.....here's a link to 3 uploads: Free File Hosting Made Simple - MediaFire
includes a short sample for NXDN4800 (likely to be voice?), a sample for MotoTRBO voice (for reference - recorded the same way as the NXDN4800 and sucessfully decoded using DSD 1.4), plus a NXDN9600 (poor quality recording and some voice decoding using DSD 1.4). Hope these are ok (esp the NXDN4800 sample).

Jim

 

[brandon]

Anyone want to record some iDEN samples? Perhaps a trip to Disneyland is in order.

 

[dsdauthor]

>For both of you (and anyone else requesting new format support), Please capture a recording, upload it >somewhere and provide the download link. The recording must be from a discriminator tap, 48000Hz >sample rate, 16 bits per channel, mono, .wav format. Make sure the signal peaks are not maxing out >the input.

Thanks dsdauthor.....here's a link to 3 uploads: Free File Hosting Made Simple - MediaFire
includes a short sample for NXDN4800 (likely to be voice?), a sample for MotoTRBO voice (for reference - recorded the same way as the NXDN4800 and sucessfully decoded using DSD 1.4), plus a NXDN9600 (poor quality recording and some voice decoding using DSD 1.4). Hope these are ok (esp the NXDN4800 sample).

Jim

The signal level during the transmissions is very low. For the supported formats DSD shows only 2%. I'm surprised the TRBO decoded as well as it did at that level. The NXDN48 sounds even lower level (probably due to the lower deviation used). It's ok if the white noise between transmissions maxes out the recording as long as the transmission itself is not maxed out. Try to get at least 40% input level during the transmissions.

 

[c5corvette]

Wiki says "P25 Phase 2 - standard not finalized yet, vocoder is supported by mbelib "

What does this mean? My local county uses a current Motorola version of P25 Phase 2 called X2. Can I decode that?

 

[JBuff27]

DSD 1.4 & mbelib 1.2.3

Post #1 References DSD 1.4.

The WIKI References DSD 1.3.

Which is being addressed?


JBuff27

 

[MattSR]

Wiki says "P25 Phase 2 - standard not finalized yet, vocoder is supported by mbelib "

What does this mean? My local county uses a current Motorola version of P25 Phase 2 called X2. Can I decode that?

You missed the bit in the wiki that says DSD supports "X2-TDMA - Motorola public safety TDMA system with P25 style signaling (mostly based on DMR)"

 

[fourthhorseman]

Wiki says "P25 Phase 2 - standard not finalized yet, vocoder is supported by mbelib "

What does this mean? My local county uses a current Motorola version of P25 Phase 2 called X2. Can I decode that?

Means they got samples,most likely have identified the signal,and the vocoders format ,for lack of the tech term,has been determined..

someone's probably got a better answer...

 

[c5corvette]

You missed the bit in the wiki that says DSD supports "X2-TDMA - Motorola public safety TDMA system with P25 style signaling (mostly based on DMR)"

Thanks - must not have been wearing my glasses ;-)