Complex FIR and Stereo support for rtl_fm

historical

W dniu 2013-09-16 15:05, Miroslav Slugeň pisze:
> Thanks for testing, is it 32bit arch?
Right.
>
> All memory buffers used in SSE should be 16bit aligned, please try no 
> SSE version:
>
> rtl_fm -X -F 2 -J 5 -f yourfreq
>
> Also you can try modified rtl_fm version i send as attachment which 
> use memalign to allocate buffers instead of malloc, but it is only for 
> gcc.
Yeah! The code attached works perfectly! Thank you so much! :)
>
> On X86_64 platform all malloc are 16bit aligned so i missed this.
>
> Those errors when compiling are not important, but also in SSE part.
>
> Miroslav Slugeň
> +420 724 825 885
>
> Michał Morański napsal(a):
>> W dniu 2013-09-16 11:38, Miroslav Slugeň pisze:
>>> Hi, i used git from 14.9.2013, if you get errors from actual git it
>>> could be because some functions might go into upstream, i also add as
>>> attachment just rtl_fm.c so just replace it your version with this
>>> version and it should work.
>> Thanks for rapid answer. I just compiled your code.
>> First, i got this message when compiling:
>> /usr/lib/gcc/i486-linux-gnu/4.4.3/include/emmintrin.h:32:3: error:
>> #error "SSE2 instruction set not enabled"
>> Then i've added line to CMakeLists.txt:
>> set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} "-msse -msse2 -msse3")
>> After that i was able to compile the code, but with some warnings:
>>
>> /usr/src/rtl-sdr/src/rtl_fm.c: In function ‘low_pass_complex’:
>> /usr/src/rtl-sdr/src/rtl_fm.c:451: warning: dereferencing pointer ‘v_r’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:436: note: initialized from here
>> /usr/src/rtl-sdr/src/rtl_fm.c:452: warning: dereferencing pointer ‘v_i’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:436: note: initialized from here
>> /usr/src/rtl-sdr/src/rtl_fm.c: In function ‘low_pass_real’:
>> /usr/src/rtl-sdr/src/rtl_fm.c:769: warning: dereferencing pointer ‘v_m’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:755: note: initialized from here
>> /usr/src/rtl-sdr/src/rtl_fm.c:850: warning: dereferencing pointer ‘v_m’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:872: warning: dereferencing pointer ‘v_m’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:834: note: initialized from here
>> /usr/src/rtl-sdr/src/rtl_fm.c:851: warning: dereferencing pointer ‘v_p’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:834: note: initialized from here
>> /usr/src/rtl-sdr/src/rtl_fm.c:852: warning: dereferencing pointer ‘v_s’
>> does break strict-aliasing rules
>> /usr/src/rtl-sdr/src/rtl_fm.c:873: warning: dereferencing pointer ‘v_s’
>> does break strict-aliasing rules
>>
>> Now i got segfaults when i try to run rtl_fm -X -f 90.4e6 :
>> root at dabplus:/usr/src/rtl-sdr# rtl_fm -X -f 90.4e6 -
>> Found 1 device(s):
>> 0: Realtek, RTL2838UHIDIR, SN: 00000001
>>
>> Using device 0: Lifeview LV5TDeluxe
>> Found Fitipower FC0013 tuner
>> Oversampling input by: 6x.
>> Oversampling output by: 1x.
>> Buffer size: 7.11ms
>> Tuned to 90704000 Hz.
>> Sampling at 1152000 Hz.
>> Output at 48000 Hz.
>> LP Complex: FIR hamming (SSE2), size: 32
>> LP Real: FIR hamming stereo (SSE2), size: 64
>> Tuner gain set to automatic.
>> Tuner AGC ON.
>> De-epmhasis IIR: 50.0 us
>> Segmentation fault
>>
>> My processor:
>> root at dabplus:/usr/src/rtl-sdr# cat /proc/cpuinfo
>> processor : 0
>> vendor_id : GenuineIntel
>> cpu family : 6
>> model : 28
>> model name : Intel(R) Atom(TM) CPU D525 @ 1.80GHz
>> .....
>> root at dabplus:/usr/src/rtl-sdr# cat /etc/issue
>> Ubuntu 10.04.4 LTS \n \l
>>
>> root at dabplus:/usr/src/rtl-sdr# uname -r
>> 2.6.32-38-generic-pae
>>
>>
>>
>>>
>>> I have RDS decoder also, but it is very ugly and not all issues are
>>> solved.
>> Wow :) If you searching for help with that you can count on me.
>>
>>>
>>> Miroslav Slugeň
>>> +420 724 825 885
>>>
>>> Michał Morański napsal(a):
>>>> 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.
>>>>
>>>>
>>
>>