choppy waveforms with Qt5 on old laptop with GNU/Linux

[Be]

When running Mixxx with Qt5 on my old laptop with an Intel i5 2410 M CPU with Intel HD Graphics 3000, the waveforms do not move across the screen as smoothly as with Qt4. This is using the RGB GL renderer. Curiously, like Bug #1665583, the waveforms look smoother when focusing a different window.

With my new laptop with an Intel i7 8550U CPU with Intel UHD Graphics 620, the waveforms work great with Qt5.

[RJ Skerry-Ryan (rryan)]

Did you have the RGB GLSL renderer available with Qt 4 or are you comparing RGB GL on Qt 4 to RGB GL on Qt 5?

[Attila Schler (atskler)]

I observed the same problem on my system.

I can’t speak about the QT4 vs QT5 part, but what I can observe is exactly the same:

“the waveforms do not move across the screen [as] smoothly” ... “the waveforms look smoother when focusing a different window” for example when opening the settings window.

When the waveforms are not smooth: frames are continuously dropped. (This can be viewed in the Preferences → Waveforms → Average frame rate.)

I also found that this problem appears only when mixxx is started in KDE Plasma.
But not in Gnome, Xfce, LXQt, IceWM.

Mixxx v2.1.6-pre
mixxx-unstable-20181110.0f5e3b9fd-1.8.x86_64.rpm
http://packman.links2linux.com/package/mixxx-unstable/886069

Operating System: openSUSE Tumbleweed 20190201
KDE Plasma Version: 5.14.5
Qt Version: 5.12.0
KDE Frameworks Version: 5.54.0
Kernel Version: 4.20.4-1-default
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-2540M CPU @ 2.60GHz
Memory: 15,5 GiB of RAM

Graphics: Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics driver: i915 v: kernel
Display: x11 server: X.Org 1.20.3 driver: modesetting resolution: 1920x1080~60Hz
OpenGL: renderer: Mesa DRI Intel Sandybridge Mobile v: 3.3 Mesa 18.3.1

[Be (be.ing)]

Mixxx 2.1.6 is no longer supported. Do you also have the issue with Mixxx 2.2.0? I tested again on my old laptop (master, https://github.com/mixxxdj/mixxx/pull/1974 , and 2.2) and cannot reproduce this anymore.

[Attila Schler (atskler)]

Be (be.ing),

I tried to compile the latest source but I got an error (In file included from src/library/dlganalysis.h:11:10: fatal error: library/ui_dlganalysis.h: No such file or directory) so for now I can't test it on my system :(

Beforehand I tired an older 2.2.0 binary release (it's source now cca 2 months old) and in that the problem was still there. (https://build.opensuse.org/package/show/multimedia:apps/mixxx)

[mm-mbs (mm-mbs)]

I can confirm the choppy waveform on KDE with Mixxx 2.2.0: https://bugs.launchpad.net/mixxx/+bug/1815341

[Launchpad Janitor (janitor)]

[Expired for Mixxx because there has been no activity for 60 days.]

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/9225