View Issue Details

IDCategoryLast Update
0008562bugs2021-03-03 20:24
ReporterDBAAssigned To 
Reproducibilityalways 
Status newResolutionopen 
PlatformMicrosoftOSWindowsOS Version10
Product Version6.5 
Fixed in Version 
Summary0008562: MIDI driven knob (VST plugin) moves the displayed value of the knob but not its value
DescriptionMIDI driven knob (VST plugin) moves the displayed value of the knob but not its value in the plugin while the SAME knob moved with the mouse cursor is actually changing value in the plugin.

Also see https://discourse.ardour.org/t/midi-control-knob-and-switch-of-a-vst-plugin-works-with-mouse-but-when-driven-by-midi-displays-the-action-without-doing-it/105445
Steps To Reproduce- Setup MIDI, and don't forget to change this fXXXXg "Smooth" parameter to 127 as it should be by default (this used 3 hours of my life)
- Install Helix Native 3.01 VST3 (maybe it works with other VST pluging)
- make a track for your guitar and put an instance of the plugin in the sound path
- in Helix Native, put a Wah and assign "knob1" to the position parameter so knob 1 will control the effect.
- display knob of the VST plugin
- execute MIDI learn and assign it to an expression pedal (in my case Roland FC-200 via a Berhinger UMC 1820)

So here the fun begin.
- move the knob value with the mouse cursor -> the display of the knob (the bar) moves and the sound of the guitar changes
- move the knob value with the expression pedal -> the display of the knob (the bar) moves but the plugin receives no event and the guitar sound is unchanged.
Tags6.5, MIDI control, plugin, VST3, Windows

Activities

DBA

2021-02-04 08:06

reporter   ~0025488

IMPORTANT

I discovered that in fact the knob is active but very weirdly and only with slow motion which is what happen when the Smooth parameter is at a low value. But I put it to a high value!

So my guess is the following: Smoothing parameter is not applied to the actual communication of the plugin, only to some ardour stuff and that's why the parameter in the VST plugin is not tracked correctly.

DBA

2021-02-04 13:09

reporter   ~0025490

To be very clear about my previous comment (0025488).

The knob jauge, attached to the VST plugin, in the effect loop of the track is moving with the expression pedal (because I set up Smoothing to 127) but inside the plugin, the parameter moves like the Smoothing was still on 10.

DBA

2021-02-04 13:12

reporter   ~0025491

Here is the knob jauge I talk about.

MIDI Control.png (16,879 bytes)
MIDI Control.png (16,879 bytes)

paul

2021-03-03 20:24

administrator   ~0025590

"don't forget to change this fXXXXg "Smooth" parameter to 127 as it should be by default (this used 3 hours of my life)"

I believe I explained elsewhere why it should not be 127 by default, and why there is fact no suitable default for this value. The correct value depends on the MIDI hardware in use.

Issue History

Date Modified Username Field Change
2021-02-04 00:26 DBA New Issue
2021-02-04 00:26 DBA Tag Attached: 6.5
2021-02-04 00:27 DBA Tag Attached: CC
2021-02-04 00:27 DBA Tag Attached: MIDI control
2021-02-04 00:27 DBA Tag Detached: CC
2021-02-04 00:27 DBA Tag Attached: plugin
2021-02-04 00:27 DBA Tag Attached: VST3
2021-02-04 00:27 DBA Tag Attached: Windows
2021-02-04 08:06 DBA Note Added: 0025488
2021-02-04 13:09 DBA Note Added: 0025490
2021-02-04 13:12 DBA File Added: MIDI Control.png
2021-02-04 13:12 DBA Note Added: 0025491
2021-03-03 20:24 paul Note Added: 0025590