#32 gw_amp_stereo.lv2 "double free or corruption"

[Xavier]

Hello,

I recorded some tracks with guitarix amp in ardour, the plugin works pretty well, I saved a preset from ardour. But when re-openning ardour loading of guitarix_amp_stereo hangs.

Backtrace from ardour attached.

[brummer]

Hi

This looks to me like a crash in fftw3.
I didn't know what Ardour does different on re-opening a session
You should report this to the ardour dev's as well.
Did it only happen with the stereo amp, or with the mono amp as well?
Which version of guitarix do you've installed?

[Xavier]

Effectively, other tries shown that the bug appears when openning a session containing saved parameters of the lv2 by ardour's plugin interface.
Installed guitarix is 2:0.35.0+git20160505
It seems to happend with gx_amp mono too. There's gdb logs attached

Now guitarix freeze at the splash screen opening stand-alone, I can't figure out why actually.

I'm gonna do an update ardour side here http://tracker.ardour.org/view.php?id=6875

[brummer]

Now guitarix freeze at the splash screen opening stand-alone, I can't figure out why actually.

Mhh, delete the folder ~/.config/guitarix

To the gx_amps
You may build guitarix with the --convolver-ffmpeg flag, to use ffmpeg instead fftw3
It may also be related that the gx plugins didn't support the state extension in LV2, and Ardour now try to force to save a state. Maybe ardour needs to better check if a plug support "state".

regards
hermann

[brummer]

Hi

I running some tests with Ardour 4.7.0 and unfortunately I can't reproduce your issues.
I could save presets in ardour, I could re-open my sessions with multiple Gxamp instances, stereo and mono, gxcabinet, without a single issuee.

[Xavier]

Hello

It effectively seems to be fftw. I'll run new tests in same circumstances during the week, comparing both ffmpeg ang fftw builds.

GX stand-alone has always worked pretty well!

x42@ is thinking about memory corruption from fftw as well, he noticed on the ardour's bug page.

[brummer]

In Guitarix we use a Module Sequencer to init the plugins, this avoid the conflicts with the fftw3 issue x42@ mention on the Ardour Bug tracker.

[Xavier]

Hello,

I was unable to reproduce too with or without --convolver-ffmpeg. So i've reinstalled the packaged version from KXStudio, tried again and then it crashed, as I get initially.

The makefile for that package only configures with --no-faust. I'm gonna ask falktx@ what he think about the bug.

Thanks you very much sirs, I've learned lot of good things!

Best regards.

PS: Can you please close the ticket at SF.