W dniu 2013-09-13 15:22, Miroslav Slugeň pisze:
Hi again,
I am working on my own SDR project for Stereo FM radio support, but i
would like to also improve quality for rtl_fm application, i made
unoficial patch to add:
Complex FIR - to filter strong signals close to wanted signal
Real FIR - to filter pilot from FM
Stereo FIR
Stereo Deemphasis
AGC support - it can give better resolution of IQ data
Some other improvments in FM radio code.
All FIR filters has 3 possible variants, simple, LUT, SSE2 instricts,
of course SSE is the fastest one and it should works on Intel Atoms,
but not on ARM.
Feel free to use any part of code in any of you programs, I know that
this code is little to much to add it into rtl_fm, but maybe it could
somebody help to recieve HW stereo FM radio.
Speed of SSE code is much better than anything you can get around
here, on Core i7 it consume only 5% of one CPU, so i could demodulate
at least 80 channels at the same time in stereo quality of course.
I tried this code only on AMD64 and GCC Linux, so i am not sure if it
can be compiled under windows.
Hi! Very nice to hear, that someone working on Stereo FM reception. I'm
building a small remote devices with rtl-dongles as fm stereo receivers.
Now i'm using gnu-radio to decode fm-stereo, but as you all know,
gnu-radio is a large and heavy project and it's wasting its
capatibilities in that role.
It would be very nice if native rtl-sdr software can decode fm-stereo.
Which version of rtl-sdr was used as base version? I'm getting errors
after applying the patch to last version:
patching file rtl_fm.c
Hunk #2 succeeded at 47 (offset 5 lines).
Hunk #3 succeeded at 87 (offset 9 lines).
Hunk #4 succeeded at 144 (offset 9 lines).
Hunk #5 succeeded at 169 (offset 9 lines).
Hunk #6 succeeded at 190 (offset 9 lines).
Hunk #7 FAILED at 239.
Hunk #8 FAILED at 258.
Hunk #9 succeeded at 314 (offset 13 lines).
Hunk #10 succeeded at 420 (offset 13 lines).
Hunk #11 succeeded at 994 (offset 13 lines).
Hunk #12 FAILED at 1106.
Hunk #13 succeeded at 1148 (offset 15 lines).
Hunk #14 succeeded at 1259 (offset 35 lines).
Hunk #15 succeeded at 1268 (offset 35 lines).
Hunk #16 succeeded at 1290 (offset 35 lines).
Hunk #17 succeeded at 1301 with fuzz 2 (offset 36 lines).
Hunk #18 succeeded at 1351 (offset 38 lines).
Hunk #19 succeeded at 1378 (offset 38 lines).
Hunk #20 succeeded at 1389 (offset 38 lines).
Hunk #21 succeeded at 1508 (offset 50 lines).
Hunk #22 succeeded at 1527 (offset 50 lines).
3 out of 22 hunks FAILED -- saving rejects to file rtl_fm.c.rej
P.S. Are you planning to add support for RDS in the future?
Regards, Michał.