If PDC is turned on in CLAP, parameter automation is acquired late for PDC.

[lewloiwc]

For example, when setting the PDC (Plug-in Delay Compensation) in CLAP to 1024, the automation values obtained through CLAP are delayed by 1024 samples compared to the actual signal. In plugins that require a PDC of 1024 samples for processing, any parameter changes typically affect the output signal 1024 samples later. Therefore, if the automation timing is shifted by the host, the processing time becomes insufficient.

In other words, when PDC is set to 1024, I would like to access the input signal 1024 samples earlier and retrieve values from parameters 1024 samples sooner. This is especially important for plugins that require a PDC of 1024 samples.

In REAPER's VST, there is a setting called "Plug-in delay compensation (PDC) (1024 spls)/Adjust automation" that is always enabled in CLAP. I would appreciate it if CLAP could add a similar setting to allow users to control this behavior. Additionally, I would like CLAP to have "Adjust automation" off by default. This is because I believe that aligning the timing of automation in plugins with PDC is the responsibility of the plugin, not the host.

What are your thoughts on this?

Windows 10 Home | REAPER v7.08/win64

(Translation by ChatGPT)

[lewloiwc]

Please at least give me the option of Plug-in delay compensation (PDC) (1024 spls)/Adjust automation in CLAP as well, since the default can be left on!
Or is there something wrong with Bitwig that does not adjust automation automatically on the host side...?
Personally, I still think it is the responsibility of the plug-ins to take into account the automation shift caused by PDC...

Translated with www.DeepL.com/Translator (free version)

[lewloiwc]

To be honest, I'm having trouble with differences in the timing of CLAP automation with PDC between Bitwig and REAPER. In other words, when trying to synchronize one with the other, one of them becomes out of sync. In Bitwig, the values from automation arrive to the plugin input with PDC samples taken earlier. Currently, in REAPER, while the plugin input can be obtained with PDC samples taken earlier, the values from automation arrive with a delay of PDC samples (meaning "Plug-in delay compensation (PDC) (1024 spls)/Adjust automation" is implicitly enabled).

If CLAP had an option for "Plug-in delay compensation (PDC) (1024 spls)/Adjust automation," I could communicate instructions in the manual, such as "If using this CLAP in REAPER, please turn off 'Plug-in delay compensation (PDC) (1024 spls)/Adjust automation.'" As it stands, this is not possible. I'm not aware of the background behind the addition of "Plug-in delay compensation (PDC) (1024 spls)/Adjust automation" to VST, but I speculate that it might be an option for plugins created in an earlier era, similar to options like "Reduce denormalization from plug-ins." However, since there is no information in CLAP's specifications about how automation is handled with PDC, it's unclear which approach is correct.

(Translation by ChatGPT)

[Justin]

We will add a similar option for CLAP, thank you.

[lewloiwc]

Thank you very much!
I tried Snap Heap and it seems that this VST adjusts the timing internally when PDC is present, so if "Adjust automation" is on, the timing will be off.
.
Is there a way to set the default "Adjust automation" for each VST/CLAP instead of setting it every time when using such a plug-in?

[Justin]

Originally Posted by lewloiwc

Thank you very much!
I tried Snap Heap and it seems that this VST adjusts the timing internally when PDC is present, so if "Adjust automation" is on, the timing will be off.
.
Is there a way to set the default "Adjust automation" for each VST/CLAP instead of setting it every time when using such a plug-in?

Save a default preset for that plug-in with that setting tweaked