# (de)modulation problems gnuradio 3.7.3.also GRC FFT missing axis labels **URL:** \ **Category:** GNU Radio\ **Created:** [March 18, 2014, 4:50am UTC](https://www.ruby-forum.com/t/de-modulation-problems-gnuradio-3-7-3-also-grc-fft-missing-axis-labels/239867 "2014-03-18T04:50:51Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Post date:** [March 18, 2014, 4:50am UTC](https://www.ruby-forum.com/t/de-modulation-problems-gnuradio-3-7-3-also-grc-fft-missing-axis-labels/239867/1 "2014-03-18T04:50:51Z")
I successfully? installed gnuradio 3.7.3 from source on Ubuntu 12.04 using the gnuradio-build script, but am running into problems demodulating anything from a R820T based SDR. GRC runs fine, but when I attempt to execute any blocks that include an AM, NFM, or WBFM demodulator I get a VOLK:Error allocating memory error. I also noticed that if I just pipe the RTL-SDR source to a GUI FFT Sink (either QT or WX) there are no axis labels on the graphs… Attempting to receive WBFM using rtl\_fm (per the examples on the rtl-sdr OsmoSDR website) produce only static. It’s not a signal strength issue per se as another radio can pick up the station, and the SDR hardware is functional since I can receive WBFM with it normally via gqrx on a different machine . I’m wondering if there’s a fundamental problem somewhere that’s preventing demod from happening. Any troubleshooting suggestions would be appreciated. Regards, R ---
**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\ **Post date:** [March 19, 2014, 5:04pm UTC](https://www.ruby-forum.com/t/de-modulation-problems-gnuradio-3-7-3-also-grc-fft-missing-axis-labels/239867/2 "2014-03-19T17:04:53Z")
On Mon, Mar 17, 2014 at 11:49 PM, [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > se as another radio can pick up the station, and the SDR hardware is > functional since I can receive WBFM with it normally via gqrx on a different > machine. > > I’m wondering if there’s a fundamental problem somewhere that’s preventing > demod from happening. Any troubleshooting suggestions would be appreciated. > Regards, > R Yes, these all sound like very low-level issues with your installation or machine. You told us the OS you are using, but not the platform (e.g., processor). In the build directory of GNU Radio, you can run ‘ctest’ to see what passes and what fails there. That might help clue us in. Also, you should run volk\_profile and make sure that completes without error (that will take some time to complete). Tom ---
**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\ **Post date:** [March 20, 2014, 3:26am UTC](https://www.ruby-forum.com/t/de-modulation-problems-gnuradio-3-7-3-also-grc-fft-missing-axis-labels/239867/3 "2014-03-20T03:26:54Z")
Since the LastTests.log file was so large (150K) I extracted a few error blocks from the file. I’m attempting to compile this on a PowerBook G4 (PowerPC architecture) running Ubuntu 12.04. RUN\_VOLK\_TESTS: volk\_32fc\_s32fc\_multiply\_32fc(20462,1) Volk warning: no arch found, returning generic impl unknown location(0): fatal error in “volk\_32fc\_s32fc\_multiply\_32fc\_test”: memory access violation at address: 0x105d6000: no mapping at fault address /home/fisher/gnuradio/volk/lib/testqa.cc(88): last checkpoint ## \*\*\* 1 failure detected in test suite “Master Test Suite” Test time = 2.13 sec ## Test Failed. “qa\_volk\_test\_all” end time: Mar 19 20:52 EDT “qa\_volk\_test\_all” time elapsed: 00:00:02 ## 53/178 Testing: qa\_add\_mult\_div\_sub 53/178 Test: qa\_add\_mult\_div\_sub Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-blocks/python/blocks/qa\_add\_mult\_div\_sub\_test.sh” Directory: /home/fisher/gnuradio/build/gr-blocks/python/blocks “qa\_add\_mult\_div\_sub” start time: Mar 19 20:55 EDT Output: ## Segmentation fault (core dumped) Test time = 3.47 sec Test Failed. “qa\_add\_mult\_div\_sub” end time: Mar 19 20:55 EDT “qa\_add\_mult\_div\_sub” time elapsed: 00:00:03 ## 53/178 Testing: qa\_add\_mult\_div\_sub 53/178 Test: qa\_add\_mult\_div\_sub Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-blocks/python/blocks/qa\_add\_mult\_div\_sub\_test.sh” Directory: /home/fisher/gnuradio/build/gr-blocks/python/blocks “qa\_add\_mult\_div\_sub” start time: Mar 19 20:55 EDT Output: ## Segmentation fault (core dumped) Test time = 3.47 sec ## Test Failed. “qa\_add\_mult\_div\_sub” end time: Mar 19 20:55 EDT “qa\_add\_mult\_div\_sub” time elapsed: 00:00:03 ## 78/178 Testing: test\_gr\_filter 78/178 Test: test\_gr\_filter Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-filter/lib/test\_gr\_filter\_test.sh” Directory: /home/fisher/gnuradio/build/gr-filter/lib “test\_gr\_filter” start time: Mar 19 20:57 EDT Output: ## VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) Segmentation fault (core dumped) … Test time = 1.08 sec ## Test Failed. “test\_gr\_filter” end time: Mar 19 20:57 EDT “test\_gr\_filter” time elapsed: 00:00:01 ## 79/178 Testing: qa\_interp\_fir\_filter 79/178 Test: qa\_interp\_fir\_filter Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-filter/python/filter/qa\_interp\_fir\_filter\_test.sh” Directory: /home/fisher/gnuradio/build/gr-filter/python/filter “qa\_interp\_fir\_filter” start time: Mar 19 20:57 EDT Output: ## VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) Segmentation fault (core dumped) Test time = 3.62 sec ## Test Failed. “qa\_interp\_fir\_filter” end time: Mar 19 20:57 EDT “qa\_interp\_fir\_filter” time elapsed: 00:00:03 ## 81/178 Testing: qa\_freq\_xlating\_fir\_filter 81/178 Test: qa\_freq\_xlating\_fir\_filter Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-filter/python/filter/qa\_freq\_xlating\_fir\_filter\_test.sh” Directory: /home/fisher/gnuradio/build/gr-filter/python/filter “qa\_freq\_xlating\_fir\_filter” start time: Mar 19 20:57 EDT Output: ## VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) VOLK: Error allocating memory (posix\_memalign: 22) Segmentation fault (core dumped) Test time = 4.98 sec ## Test Failed. “qa\_freq\_xlating\_fir\_filter” end time: Mar 19 20:57 EDT “qa\_freq\_xlating\_fir\_filter” time elapsed: 00:00:04 ## 82/178 Testing: qa\_fir\_filter 82/178 Test: qa\_fir\_filter Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-filter/python/filter/qa\_fir\_filter\_test.sh” Directory: /home/fisher/gnuradio/build/gr-filter/python/filter “qa\_fir\_filter” start time: Mar 19 20:57 EDT Output: ## VOLK: Error allocating memory (posix\_memalign: 22) Segmentation fault (core dumped) Test time = 5.68 sec ## Test Failed. “qa\_fir\_filter” end time: Mar 19 20:57 EDT “qa\_fir\_filter” time elapsed: 00:00:05 ## 85/178 Testing: qa\_fractional\_resampler 85/178 Test: qa\_fractional\_resampler Command: “/bin/sh” “/home/fisher/gnuradio/build/gr-filter/python/filter/qa\_fractional\_resampler\_test.sh” Directory: /home/fisher/gnuradio/build/gr-filter/python/filter “qa\_fractional\_resampler” start time: Mar 19 20:57 EDT Output: ## VOLK: Error allocating memory (posix\_memalign: 22) Segmentation fault (core dumped) Test time = 3.76 sec ## Test Failed. “qa\_fractional\_resampler” end time: Mar 19 20:57 EDT “qa\_fractional\_resampler” time elapsed: 00:00:03 ----- Original Message ----- From: “Tom R.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) To: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Cc: “GNURadio D.ion List” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Sent: Wednesday, March 19, 2014 12:02:50 PM Subject: Re: [Discuss-gnuradio] (de)modulation problems gnuradio 3.7.3…also GRC FFT missing axis labels On Mon, Mar 17, 2014 at 11:49 PM, [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > se as another radio can pick up the station, and the SDR hardware is > functional since I can receive WBFM with it normally via gqrx on a different > machine. > > I’m wondering if there’s a fundamental problem somewhere that’s preventing > demod from happening. Any troubleshooting suggestions would be appreciated. > Regards, > R Yes, these all sound like very low-level issues with your installation or machine. You told us the OS you are using, but not the platform (e.g., processor). In the build directory of GNU Radio, you can run ‘ctest’ to see what passes and what fails there. That might help clue us in. Also, you should run volk\_profile and make sure that completes without error (that will take some time to complete). Tom ---
**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\ **Post date:** [March 22, 2014, 1:28am UTC](https://www.ruby-forum.com/t/de-modulation-problems-gnuradio-3-7-3-also-grc-fft-missing-axis-labels/239867/4 "2014-03-22T01:28:21Z")
Progress of sorts. Made the modification to volk\_malloc.c and rebuilt gnuradio. Ctest still returns some errors (LastTest log attached), but using a (de)modulator no longer crashes with the volk memory error…so that’s a plus. Oddly enough the FFT display still doesn’t show axis labels… ----- Original Message ----- From: “Tom R.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) To: “Robert Fisher” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Cc: “GNURadio D.ion List” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Sent: Wednesday, March 19, 2014 11:29:32 PM Subject: Re: [Discuss-gnuradio] (de)modulation problems gnuradio 3.7.3…also GRC FFT missing axis labels On Wed, Mar 19, 2014 at 10:25 PM, [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Since the LastTests.log file was so large (150K) I extracted a few error > blocks from the file. I’m attempting to compile this on a PowerBook G4 > (PowerPC architecture) running Ubuntu 12.04. Wow. Haven’t had anyone report using a PowerPC with GNU Radio for a while. But I’m not surprised that there are VOLK related issues; a fairly untested platform for us these days. This is failing using volk\_malloc, which looks to see if your system is POSIX compliant and if so, use posix\_malloc; otherwise, use an internally developed way of allocating aligned memory. In your case, posix\_memalign is being called and throwing that warning, which is strange. If you can apply this diff (a one-line change) and rebuild, it will disable using posix\_memalign. It’ll be interesting to see if the backup method will work for you. Tom diff --git a/volk/lib/volk\_malloc.c b/volk/lib/volk\_malloc.c index b2b77dd..e913ffc 100644 — a/volk/lib/volk\_malloc.c +++ b/volk/lib/volk\_malloc.c @@ -54,7 +54,8 @@ // Otherwise, test if we are a POSIX or X/Open system // This only has a restriction that alignment be a power of 2. -#if \_POSIX\_C\_SOURCE \>= 200112L || \_XOPEN\_SOURCE \>= 600 +//#if \_POSIX\_C\_SOURCE \>= 200112L || \_XOPEN\_SOURCE \>= 600 +#if 0 void \*volk\_malloc(size\_t size, size\_t alignment) { ---
**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\ **Post date:** [March 20, 2014, 4:31am UTC](https://www.ruby-forum.com/t/de-modulation-problems-gnuradio-3-7-3-also-grc-fft-missing-axis-labels/239867/5 "2014-03-20T04:31:09Z")
On Wed, Mar 19, 2014 at 10:25 PM, [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Since the LastTests.log file was so large (150K) I extracted a few error > blocks from the file. I’m attempting to compile this on a PowerBook G4 > (PowerPC architecture) running Ubuntu 12.04. Wow. Haven’t had anyone report using a PowerPC with GNU Radio for a while. But I’m not surprised that there are VOLK related issues; a fairly untested platform for us these days. This is failing using volk\_malloc, which looks to see if your system is POSIX compliant and if so, use posix\_malloc; otherwise, use an internally developed way of allocating aligned memory. In your case, posix\_memalign is being called and throwing that warning, which is strange. If you can apply this diff (a one-line change) and rebuild, it will disable using posix\_memalign. It’ll be interesting to see if the backup method will work for you. Tom diff --git a/volk/lib/volk\_malloc.c b/volk/lib/volk\_malloc.c index b2b77dd..e913ffc 100644 — a/volk/lib/volk\_malloc.c +++ b/volk/lib/volk\_malloc.c @@ -54,7 +54,8 @@ // Otherwise, test if we are a POSIX or X/Open system // This only has a restriction that alignment be a power of 2. -#if \_POSIX\_C\_SOURCE \>= 200112L || \_XOPEN\_SOURCE \>= 600 +//#if \_POSIX\_C\_SOURCE \>= 200112L || \_XOPEN\_SOURCE \>= 600 +#if 0 void \*volk\_malloc(size\_t size, size\_t alignment) {