BruteFir Fails to generate filter ..... Unable to open output file: Permission denied

Volumio Information

Volumio Version: volumio-2.873-2021-02-19-x86
Hardware: MacBook 2008


after successfully producing a filter for DRC from wav file the other day, I wanted to do L and R measurements and produce a filter for each channel.

I exported the wav from REW and put in filter-sources:
volumio@volumio:/data/INTERNAL/Dsp/filter-sources$ ls -l
total 2580
-rwxr–r-- 1 nobody nogroup 524332 Apr 22 20:49 REW_Apr_22_at_22_14_01.wav
-rwxr–r-- 1 volumio volumio 524332 Apr 23 17:36 Smit-Left-Friday.wav
-rwxr–r-- 1 volumio volumio 524332 Apr 23 17:36 Smit-Right-Friday.wav
-rw-r–r-- 1 root root 524332 Apr 23 17:39 demo-impulse-left.wav
-rw-r–r-- 1 root root 524332 Apr 23 17:39 demo-impulse-right.wav

The use the pugin to generate filter, and receive error

Even if expanding browser to the right the right part of message doesn’t show.

It does however create a file, as seen:

volumio@volumio:/data/INTERNAL/Dsp/filters$ ls -l
total 2304
-rw-r–r-- 1 volumio volumio 262144 Apr 23 22:41 R-soft-44.1kHz-JK.pcm
-rw-r–r-- 1 volumio volumio 262144 Apr 23 19:45 Smit-Left-soft-44.1kHz-JK.pcm
-rw-r–r-- 1 volumio volumio 262144 Apr 23 19:47 Smit-Right-soft-44.1kHz-JK.pcm
-rw-r–r-- 1 root root 262144 Apr 23 17:39 demo-left-soft-44.1kHz-HK5.pcm
-rw-r–r-- 1 root root 262144 Apr 23 17:39 demo-right-soft-44.1kHz-HK5.pcm
-rw-r–r-- 1 root root 262144 Apr 23 17:39 demo_swap_left_1.pcm
-rw-r–r-- 1 root root 262144 Apr 23 17:39 demo_swap_left_2.pcm
-rw-r–r-- 1 root root 262144 Apr 23 17:39 demo_swap_right_1.pcm
-rw-r–r-- 1 root root 262144 Apr 23 17:39 demo_swap_right_2.pcm

same size as the other files. But when selected as filter for playback, no sound is audible.

I booted. I deleted plugin and reinstalled it, same problem.

I do get left hanging when I install the plugin, but has happened every time so far, also when it initially worked, and I have to control-C:

Progress: 100
Status :DSP for Volumio Successfully Installed, Do you want to enable the plugin now?
Downloading plugin at
Creating install location
Unpacking plugin
Checking for duplicate plugin
Copying plugin to location
Installing necessary utilities
Installing brutefir dependencies
unload Loopback module if exists
remove previous configuration
file doesn’t exist, nothing to do
Ign jessie InRelease
Hit jessie Release.gpg
Hit jessie Release
Hit jessie/main Sources
Hit jessie/contrib Sources
Hit jessie/non-free Sources
Hit jessie/main i386 Packages
Hit jessie/contrib i386 Packages
Hit jessie/non-free i386 Packages
Hit jessie/contrib Translation-en
Hit jessie/main Translation-en
Hit jessie/non-free Translation-en
Reading package lists…
Reading package lists…
Building dependency tree…
Reading state information…
brutefir is already the newest version.
drc is already the newest version.
The following package was automatically installed and is no longer required:
Use ‘apt-get autoremove’ to remove it.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
creating filters folder and copying demo filters
copying demo flters
copying hw detection script
Detected cpu architecture as i686
Finalizing installation
Finalizing installation
volumio@volumio:~/brutefir$ rm -Rf brutefir*

The directory seems OK - but then again, it wouldn’t write a file if not.
volumio@volumio:/data/INTERNAL/Dsp$ ls -la
total 52
drwxrwxrwx 7 root root 4096 Apr 22 20:54 .
drwxrwxrwx 1 root root 4096 Apr 22 20:54 …
-rwxr–r-- 1 nobody nogroup 8196 Apr 23 13:14 .DS_Store
-rwxr–r-- 1 nobody nogroup 4096 Apr 22 20:54 ._.DS_Store
-rw-r–r-- 1 root root 37 Apr 23 17:39 .mpdignore
drwxrwxrwx 2 root root 4096 Apr 22 16:50 VoBAFfilters
drwxrwxrwx 2 root root 4096 Apr 23 19:42 filter-sources
drwxrwxrwx 2 root root 4096 Apr 23 22:39 filters
-rw-r–r-- 1 root root 1508 Apr 23 17:39 readme.txt
drwxrwxrwx 2 root root 4096 Apr 23 13:09 target-curves
drwxrwxrwx 2 root root 4096 Apr 22 18:55 tools

What can be the problem ?

Log here:


@balbuze maybe you could shine your light on this…

This error is known on x86 only. I never understood why and how to fix it. Something is different from arm version in Volumio.
Sorry… I need to check if it occurs in buster Volumio too…

Hey @balbuze
Did you find a solution to above ?.
I am struggling quite a bit to produce the filters manually.

I use single point measuring using sweep files, 4 different measuring points, doing L and R.
At Making Measurment - Volumio Documentation is stated regarding “exporting to next step” at bottom:
Export “File > Export > Export impulse response as wav” - I did that, though I don’t seem to need it.

File > Export > Export measurement as text - I did that also. One for a measurement for each channel, though not stated if that is nessesary

Then to create filters.
At Making filters - Volumio Documentation i go through “Variant 1”, and at #8 Save filter settings to file. I do that for each channel, and it generates XML.

So go to “Variant 2”.
I do this for L and R cahnnel respectively.
I import the REW text measurement file.
The import the XML using “Tools - import REW filter settings”.
I make suggested adjustments, and at #7 Hit generate and save FIR filter. This produces a filetype of rephase, with content that appears binary.

I skip “variant 3” since it no longer works.

Then, in Using filters in Volumio - Volumio Documentation I copy the newly generated rephase files to Dsp/filters as described. The other files at that location are not “.rephase”, and though my new files can be selected as filters in BruteFir, BruteFir fails to use them when pressing ‘apply’, stating wrong format.

What am I doing wrong, please ?

Thanks Flemming

If you want to use DRC-FIR included in the plugin, you have to save the impulse wav from REW for both channels and place them in /INTERNAL/Dsp/filter-sources/
If you generate from Rephase, you save your settings in one of allowed format in the plugin.

text- 32/64 bits floats line (.txt) in rephase
S16_LE- 16 bits LPCM mono (.wav) in rePhase
S24_LE- 24 bits LPCM mono (.wav) in rePhase
S24_LE- 32 bits LPCM mono (.wav) in rePhase
FLOAT_LE- 32 bits floating point (.pcm)
FLOAT64_LE- 64 bits mono (.wav) from Acourate
FLOAT64_LE- 64 bits IEEE-754 (.dbl) in rephase

Or from REW as explain here : Brutefir for Volumio now supports REW EQ filters | Audio Science Review (ASR) Forum
A calculated filter must be in /INTERNAL/Dsp/filters/ to be used. You may need to refresh the page to see it.
An yes maybe the doc needs to be more clear…