Process as volume?

[Saga Musix]

So, what is actually the difference between "process as volume" and "use note volume" for VSTis? To me, it seems that "Process as volume" also takes the instrument volume into account while note volume doesn't, but both don't suppport channel volume at all. So what's the real difference?

[LPChip]

So, what is actually the difference between "process as volume" and "use note volume" for VSTis? To me, it seems that "Process as volume" also takes the instrument volume into account while note volume doesn't, but both don't suppport channel volume at all. So what's the real difference?

I experimented with this to get FM8 do it right, so I can answer this

when set to process as volume, it will use the channel volume (FX:M40) instead of the note volume (VOL:v64)

[Relabsoluness]

When velocity handling is set to "process as volume", note volume command is not interpreted as velocity but as volume, meaning that note velocity gets some constant value. Although in some cases it doesn't really matter which one is used, there is a notable difference between the two. Consider the following example:

When volume handling is set to Dry/wet with VST instrument assigned to instrument 01...

process as volume
C-4 01 v50...| C-6 01 v15...
Latter v15 sets active dry/wet for the plugin. Since dry/wet affects the whole plugin, also the note in channel 1 is affected.

Use note volume
C-4 01 v50...| C-6 01 v15...
Volume commands set only the note velocities instead of affecting dry/wet ratio, which would affect the whole plugin. Thus the latter v15 should not affect note on channel 1. Not all plugins seem to respond reasonably to velocity-data, and in these cases 'use note volume' doesn't work while 'process as volume' does given the limitation descripted above.

[Saga Musix]

Thanks, the example really made it clear now.

[Harbinger]

When velocity handling is set to "process as volume", note volume command is not interpreted as velocity but as volume, meaning that note velocity gets some constant value. Although in some cases it doesn't really matter which one is used, there is a notable difference between the two. Consider the following example:

When volume handling is set to Dry/wet with VST instrument assigned to instrument 01...

process as volume
C-4 01 v50...| C-6 01 v15...
Latter v15 sets active dry/wet for the plugin. Since dry/wet affects the whole plugin, also the note in channel 1 is affected.

This confuses me. Does 100% Wet means the full VSTi volume is heard, and 100% Dry means no volume. What exactly is made "wet"? Usually wet/dry applies to an effect, so i'm not sure how that would apply here...

Use note volume
C-4 01 v50...| C-6 01 v15...
Volume commands set only the note velocities instead of affecting dry/wet ratio, which would affect the whole plugin. Thus the latter v15 should not affect note on channel 1. Not all plugins seem to respond reasonably to velocity-data, and in these cases 'use note volume' doesn't work while 'process as volume' does given the limitation descripted above.

So where is the volume processed, at and by the VSTi, or within MPT -- post-processing whatever signal comes thru? I can vouch for the fact that there seems to be no universal Volume Control for VSTi's; it would be great though if MPT would auto detect the volume control for any given VSTi, if it could.

[Saga Musix]

Wet/Dry is the only "postprocessing", if you want to call it like that. Wet/Dry is the same thing as in VSTs: It is the ratio between the original sound (Dry) and the new sound (Wet), just that for VSTis, there is no original sound (= silence).

[rewbs]

Hi, sorry to revive an old thread. I fired up OpenMPT for the first time in ages today and it seems there's some great stuff going on - thanks Relabsoluness, Jojo & everyone else!

Even after reading this thread, I admit I'm still a little confused by the new VST volume/velocity options in the instrument tab.

I think the purpose of these options is to define the behaviour of the volume column when applied to an instrument that maps to a plugin, right?

If so, as far as I can tell, there are 4 possible behaviours:
1. Volume column sets the velocity in note MIDI messages (default and original behaviour)
2. Volume column sends volume MIDI CC messages to the plugin
3. Volume column sets the plugin's dry/wet ratio
4. Volume column does nothing at all to the plugin (at first I couldn't see why you'd want this, but I guess it could be useful if the instrument maps to samples AND a plugin)

However, the first combo box allows for 2 options and the second for 3 options, meaning there are a total of 6 possible options. What are the other options? I can't quite figure it out from the names of the options or by experimentation.

Thanks for your help!

[Harbinger]

Boy is it great to see your name again! Welcome back and we hope you lend yourself to the project! (You do remember how to program right? )

Actually you've prob'ly crystallized the volume command better than anyone else. I don't know if anyone completely knows what each one means under what situation. Myself i use mostly VSTI's nowadays, and i have to reset all the volume commands to MIDI volume for each channel.

[Sam_Zen]

Hi, rewbs !!

[Relabsoluness]

Hi rewbs, indeed nice to see you around.

The explanations:
Velocity handling: defines behaviour of volume command when used with note-command.
Volume handling: defines behaviour of lone volume command.

Code Select Expand

|C-501v10...  Velocity handling
|...........
|.....v20...  Volume handling


Closest option to old behaviour is "use note volume" && "none", which means that lone volume commands are ignored in VST handling. There's also a flag in song properties to use exactly the old behaviour.

[rewbs]

Hi Harbinger, Sam_Zen & Relabsoluness!
Relabsoluness - thank you for the explanation, I get it now!