dsd-neo audio

[romanremus]

Hello Arancormonk, I don't know how good it is that I opened a new issue, but I haven't found the problem with SNR, in fact the problem is that there are still times when the first call comes in with a broken sound, the right ones less often, please when you can take a look at the code, otherwise for me it's super ok

[arancormonk]

Hello Arancormonk, I don't know how good it is that I opened a new issue, but I haven't found the problem with SNR, in fact the problem is that there are still times when the first call comes in with a broken sound, the right ones less often, please when you can take a look at the code, otherwise for me it's super ok

To debug this properly I need an IQ capture from a run where the first call has broken audio. Without the raw IQ, I can only guess whether this is RF/SNR, sync timing, demod state, or audio output.

Please run the same command/settings you normally use, but add IQ capture, for example:

dsd-neo <your usual options> --iq-capture broken-first-call.iq --iq-capture-max-mb 512 2> broken-first-call.log

Start the capture before traffic begins, let it catch the broken first call and ideally one normal call afterward, then stop dsd-neo cleanly. Please link zip/7z/rar/whatever:

• broken-first-call.iq
• broken-first-call.iq.json
• broken-first-call.log
• the exact command line/config used

[romanremus]

https://we.tl/t-2Hq4nyBUyucb2pHF

Hello Arancormonk, I made new recordings, I had no activity on certain channels so I did it with my own DMR station, without encryption, but it still does the same thing, from what I've noticed either at the beginning of a call, or when I come in with one call after the other. Thanks !!!

[romanremus]

Arancormonk, I have now tested with multiple audio inputs, TCP, Pulse Audio and it behaves the same.

[arancormonk]

i think your rtl gain is too high, can you lower the gain and try again? my signal analysis of the IQ shows a ton of RF clipping

[romanremus]

hello arancormonk, I installed the latest version and I have these messages as if they were calls but they are not calls, do you have any idea?

[romanremus]

Hello Arancormonk, yes I noticed that the problem was that I had the Motorola station too close to the RTL, but I did tests and the loss of audio voice is much rarer than before at the beginning of the call, but only with RTL input, with pulse audio or TCP is it ok, I noticed some decoding of TGT 0 and SRC 0 without there being any call?

[arancormonk]

try the latest commit in main, purely guessing without having any captures to go on... #176

[romanremus]

https://we.tl/t-aTTfoTJVRWau7o0o

[romanremus]

Hello Arancormonk, I made a new registration, I left the gain lower, the audio errors are somewhere in the middle

[arancormonk]

yea, still looks like an RF impairment issue... does this happen when using sdr# or sdr++ as the dsd-neo input? or does dsd-fme have this problem? signal analysis still looks like a pre-decoder issue...

[romanremus]

hello arancormonk, I don't know about dsd-fme because I don't have anywhere to run it, I don't have linux anymore, but with dsd-neo the problem is only with the RTL2832U input, when I use pulseaudio or tcp from sdrsharp as input I don't have any kind of error anymore

[arancormonk]

ok, i converted your IQ capture to a wav file and now i see the terrible performance in rtl/iq mode... investigating now....

[arancormonk]

give the latest main a try, i had to compromise on my fsk approach... but your IQ file decodes much better now... ~4000 audio errors to only like 300 now.