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windytan / redsea

Command-line FM-RDS decoder with JSON output.
MIT License
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Decoding not working after release v0.15 #60

Closed sm3ulc closed 6 years ago

sm3ulc commented 6 years ago

Up to v0.15 it's working like charm but after the we are not able to get any output whatsoever. OS is Ubuntu (18) but same result on OSX.

redsea-0.15.0/src# rtl_fm -M fm -l 0 -A std -p -52 -s 171k -g 0 -F 9 -f 103.3M | ./redsea -E Found 1 device(s): 0: NOXON, DAB Stick, SN: 0 Using device 0: Terratec NOXON DAB/DAB+ USB dongle (rev 1) Found Fitipower FC0013 tuner Tuner gain set to -5.40 dB. Tuner error set to -52 ppm. Tuned to 103642000 Hz. Oversampling input by: 8x. Oversampling output by: 1x. Buffer size: 5.99ms Exact sample rate is: 1368000.013046 Hz Sampling at 1368000 S/s. Output at 171000 Hz. {"bler":2,"debug":["TODO 10A"],"group":"10A","pi":"0xEC24","prog_type":"Information","tp":true} ....

But on 0.16 an onwards we get no data. We tried also with '-c 0/1/2' in case it maybe was related with the support for multichannel.

redsea-0.16.0/src# rtl_fm -M fm -l 0 -A std -p -52 -s 171k -g 0 -F 9 -f 103.3M | ./redsea -E Found 1 device(s): 0: NOXON, DAB Stick, SN: 0 Using device 0: Terratec NOXON DAB/DAB+ USB dongle (rev 1) Found Fitipower FC0013 tuner Tuner gain set to -5.40 dB. Tuner error set to -52 ppm. Tuned to 103642000 Hz. Oversampling input by: 8x. Oversampling output by: 1x. Buffer size: 5.99ms Exact sample rate is: 1368000.013046 Hz Sampling at 1368000 S/s. Output at 171000 Hz.

Any ideas of how to troubleshoot further?

windytan commented 6 years ago

Thanks for the report. Could you possibly upload 10 seconds worth of output from that rtl_fm command somewhere for testing purposes? Also, some basic information about your system:

I'm suspecting it has to do with the cosine lookup table introduced in 0.16; it could make redsea more sensitive to noise. I'll take a look at it, maybe it could be made optional for faster computers. In the meantime, maybe try adding 10 to 20 decibels in the rtl_fm gain option -g?

sm3ulc commented 6 years ago

Trying to do an attachement. We have the transmitter with 60 kW EIRP a few km away and clear LoS so we get overload with higher gain. First dump is with -g 0 and second with -g 1.

Tried -g 10 & 20 but same result as before.

rtlfmdump_p4_stockholm_gain1.raw.gz

rtlfmdump_p4_stockholm.raw.gz

We made a fresh 18.04 usb-stick with latest liquid-dsp from source and libsnd from package tested with another dvb-dongle and on another computer with same result.

windytan commented 6 years ago

Thanks. The bug seems to be in the --feed-through feature which reserved stdout even when the feature was not being used at all. For me, it only seems to affect Linux builds, but macOS builds work fine.

I've now made a fix in the master branch (0.17.1-SNAPSHOT) – are you able to build from the master to test it? I can make a release a bit later today.

sm3ulc commented 6 years ago

Pulled latest master. Works like a charm again. :) Thanks for great support and software! Using redsea as one of the tools to verify a fresh implemenation of a RDS-encoder.

windytan commented 6 years ago

Great to hear it's being used in real-life applications!