commit 10dfd45 crashed when loading existing project

[suedwestlicht]

commit 10dfd4593d15ef4f0ee5a23fc95a08fb3dceb72a Author: rncbc rncbc@rncbc.org Date: Sun May 14 12:02:17 2023 +0100

- Fixed a zero-day blunder that was keeping the real-time process
  cycle from having the uniform block-size of 64 frames per period;
  (thus, probably inefective since v0.9.30). (EXPERIMENTAL)

This commit crashes Qtractor immediately after loading the project I am working on. Returning to 6fd9182a00b13c7a3e42d0916898dfe087d2c8e6 fixes it.

[rncbc]

can you build for debug (cmake -DCMAKE_BUILD_TYPE=Debug ...) and watch for a stacktrace dump?

also, does it crash on every project you load or is there sth special with that one? and what buffer-size?

[suedwestlicht]

Maybe the compiler warning gives a hint, too. warning.txt dump.txt

[rncbc]

the compiler warning is of no consequence here (warning.txt)

the crash seems to be on some old JUCE plugin, KlangFalter? what happens if you don't use or activate that plugin?

[suedwestlicht]

Compiling the most recent DISTRHO-ports (klangfalter) doesn't help.

Inactivating klangfalter in the qtr-File with an text editor helps a bit. I can load the song. Activating a klangfalter instance immediately crashes Qtractor.

[rncbc]

definitely an issue with klangfalter; I suspect it doesn't support short periods/buffer-sizes (eg. 64 frames)

may you investigate on the klangfalter/juce source and tell what the heck is going in there?

JUCE Assertion failure in juce_AudioSampleBuffer.h:747
JUCE Assertion failure in juce_AudioSampleBuffer.h:596

[suedwestlicht]

These asserts are on multiple places, e.g. in a clear function and in an applygain function:

jassert (startSample >= 0 && numSamples >= 0 && startSample + numSamples <= size);

I see these asserts in juce5, 6 and 7 header files.

[rncbc]

what happens if you comment out those jasserts?

but again, what's or was your nominal buffer-size?

also please. what happens if you change this line from 64 to 128? https://github.com/rncbc/qtractor/blob/10dfd4593d15ef4f0ee5a23fc95a08fb3dceb72a/src/qtractorAudioEngine.cpp#L70

[suedwestlicht]

Usually I use a jack_bufsize of 256.

When I delete the asserts then Qtractor crashes as well – except when I use a jack_bufsize of 64.

When I don't delete the asserts then Qtractor crashes even with a jack_bufsize of 64.

Changing BLOCK_SIZE to 128: no crash with jack_bufsize of 64 or 128, crash with 256

[rncbc]

but all crashes are due on klangfalter plugin and only right?

[suedwestlicht]

Yes. There are several other plugins in the session but only klangfalter crashes Qtractor when activated.

[rncbc]

I assume you're using the KlangFalter.lv2

what about the vst2 plugin version which I think is also bundled in distrho?

[suedwestlicht]

Yes it is: /usr/local/lib/vst/KlangFalter.so

But Qtractor doesn't recognize it, even after a rescan.

It's built with: cmake -DCONFIG_LV2_UI_GTKMM2=no -DCONFIG_VST3SDK=/home/hm/src/qtractor/vst3sdk ..

  Qtractor 0.9.33.18git.10dfd4.dirty (Qt 5.5.1)

  Build target . . . . . . . . . . . . . . . . . . .: release

  JACK Audio Connection Kit support  . . . . . . . .: yes
  ALSA MIDI Sequencer support  . . . . . . . . . . .: yes
  General audio file support (libsndfile)  . . . . .: yes
  Ogg Vorbis audio file support (libvorbis)  . . . .: yes
  MPEG-1 Audio Layer 3 file support (libmad) . . . .: yes
  Sample-rate conversion support (libsamplerate) . .: yes
  Pitch-shifting support (librubberband) . . . . . .: yes
  Beat-detection support (libaubio)  . . . . . . . .: yes
  OSC service support (liblo)  . . . . . . . . . . .: yes
  Archive/Zip file support (zlib)  . . . . . . . . .: yes
  IEEE 32bit float optimizations . . . . . . . . . .: yes
  SSE optimization support (x86) . . . . . . . . . .: yes
  LADSPA plug-in support . . . . . . . . . . . . . .: yes
  DSSI plug-in support . . . . . . . . . . . . . . .: yes
  VST2 plug-in support . . . . . . . . . . . . . . .: yes
  VST3 plug-in support . . . . . . . . . . . . . . .: yes
  CLAP plug-in support . . . . . . . . . . . . . . .: yes
  LV2 plug-in support  . . . . . . . . . . . . . . .: yes

[suedwestlicht]

I have to investigate what happened. There was a time when I could load vst plugins.

[rncbc]

indeed there's sth funky with the KlangFalter plugins: the lv2 does crash on small jack-buffer-sizes/periods; but the vst2 doesn't; however, the later may present a larger head-latency (>=1024) than its lv2 counterpart, when it runs on the same jack-buffer-size setting (>=128) and doesn't crash :(

[suedwestlicht]

I had old qtractor plugin programs in /usr/local/bin. I deleted them and now I can load vst plugins. Will investigate it tomorrow.

[rncbc]

maybe this would make no harm: qtractor >= 0.9.33.19git.58cbd3

just maybe, you tell me ;)

[suedwestlicht]

Partial successful. The crash is avoided but klangfalter's reverb sounds metallic. kick.mp3.zip

[rncbc]

ok. thanks. that's positive progress :)

now please try qtractor >= 0.9.33.20git.7f74de

[suedwestlicht]

Works. Thank you, Rui. klangfalter_ok.mp3.zip

[rncbc]

thanks, please report if you find any other glitch, most esp. re. inserts and aux-sends (which I believe you abuse of ;)

cheers