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jketterl / openwebrx

Open source, multi-user SDR receiver software with a web interface
https://www.openwebrx.de
GNU Affero General Public License v3.0
1.02k stars 146 forks source link

FM Demod not working properly #25

Closed dj1an closed 4 years ago

dj1an commented 4 years ago

Hi, got an issue with FM Demodulation, all other Modes work fine:

2019-11-01 10:41:42,247 - csdr - DEBUG - Command = nc -v 127.0.0.1 4950 | csdr shift_addition_cc --fifo /dev/shm/openwebrx_pipe_140155962312632_shift_pipe | csdr fir_decimate_cc 170 0.0008823529411764706 HAMMING | csdr bandpass_fir_fft_cc --fifo /dev/shm/openwebrx_pipe_140155962312632_bpf_pipe 0.0265625 HAMMING | csdr squelch_and_smeter_cc --fifo /dev/shm/openwebrx_pipe_140155962312632_squelch_pipe --outfifo /dev/shm/openwebrx_pipe_140155962312632_smeter_pipe 5 2 | csdr fmdemod_quadri_cf | csdr limit_ff | csdr fractional_decimator_ff 1.003921568627451 | csdr deemphasis_nfm_ff 12000 | csdr convert_f_s16 | csdr encode_ima_adpcm_i16_u8

2019-11-01 10:41:42,249 - owrx.source - DEBUG - adding new output of type audio csdr shift_addition_cc: fifo control mode on csdr deemphasis_nfm_ff: deemphasis_nfm_ff: invalid sample rate (this function works only with specific sample rates). fir_decimate_cc: taps_length = 4533 csdr fractional_decimator_ff: use_prefilter = 0, num_poly_points = 12, transition_bw = 0.03, window = HAMMING csdr fractional_decimator_ff: not using taps

csdr deemphasis_nfm_ff: deemphasis_nfm_ff: invalid sample rate (this function works only with specific sample rates). seems to be the problem.

I am using newest csdr from git.

73 de DJ1AN

jketterl commented 4 years ago

Hello, yes this is a known problem with csdr, it doesn't include the fm deemphasis filter for 12kHz, which is needed if your client runs at 48kHz audio. Please try to use this fork and let me know if this fixes your problems: https://github.com/jketterl/csdr/tree/48khz_filter

I will open a pull request to the original author.

dj1an commented 4 years ago

Thanks, was not aware of this Problem. Your Fork seems to fix it.

jketterl commented 4 years ago

No worries. Happy I could help you.

ofadam commented 4 years ago

Would you be able to include this fork in the instructions for initial setup? It doesn't look like the original creator of CSDR will ever pull it.

jketterl commented 4 years ago

I have included it here: https://github.com/jketterl/openwebrx/wiki/Manual-Package-installation-(including-digital-voice)

did you follow some other instructions? i'd like to change it, but i suppose i have forgotten where it's linked.

ofadam commented 4 years ago

I got to it via the readme (it's midway down the page, but linking to the original CSDR): https://github.com/jketterl/openwebrx/blob/develop/README.md

jketterl commented 4 years ago

oh, good catch. it's even in there twice. will fix. thanks :)