VST3 playback delay bug introduced recently

[cjunekim]

Hi

Today I recognized a strange and annoying behavior introduced in the latest reaper(5.17pre16/x64). Probably, this is a regression bug introduced recently.

Steps to reproduce(windows 10 64bit):

1. Create an empty track in an empty project
2. Add iZotope RX6 Voice de-noise VST3 plugin
3. Deselect the plugin
4. Play from anywhere (in the empty track)

Now you see the playback cursor reacts after 1.2 or so seconds. Strange thing is, Voice de-noise plugin works at 0 samples delay : the status of the fx window shows "0/0 spls".

However, this playback delay occurs even when I am not using it. If I make it to be offline(ctrl-alt-b), the playback reacts immediately again.

What's stranger still is, the playback works okay with the VST version(not VST3) of the same plugin.

It used to be okay with previous betas.

I've tested with recent betas:

1. 571pre15 : PASS
2. 571pre16 : FAIL
3. 571pre16a: FAIL
4. 571pre17 : FAIL

Hence, this bug seems to have been introduced in 571pre16, and it hasn't been identified and fixed yet. Maybe this has something to do with:

+ VST3: add compatibility setting to flush buffers with hard vs soft reset [p=1946500]


Why does this happen? Is there any way to circumvent this in reaper?

UPDATE: I figured out one way to circumvent this. Right click on the plugin from the FX browser directory and deselect "Hard reset on playback start". I am not sure what it's doing.

[Allspice]

Probably test pre17 and then make this report in the relevant pre-release thread. They’re currently working these issues out in there with the help of user feedback.

https://forum.cockos.com/showthread.php?t=202739

[Justin]

Moved to the pre-release forum

[cjunekim]

Thanks. This buggy behavior of playback delay seems to have been fixed in v5.71pre20. Whether "Hard reset on playback start" option is on or off, there is no apparent playback delay.

Bonus with this new option added was one year old bug can be circumvented with this option. https://forum.cockos.com/showthread.php?t=190043

If you set "Hard reset on playback start" off, the Learn button in RX plugins do not get deactivated automatically when playback is started. If "Hard reset on playback start" is on, the Learn button gets deactivated as soon as the playback is started, just as before.

Originally Posted by Justin

Moved to the pre-release forum