DSP block size affects FX resolution when using Jack


(portabello) #1

Description:
When using FX in the main editor on an instrument that uses phrases, the DSP block size in Jack effects the resolution of the effect. This occurs in both playback and rendering. It doesn’t occur when using ALSA. It also doesn’t occur when not using a phrase.

Steps to reproduce look like this:

Start renoise on Linux using Jack
Create an instrument with a simple phrase:

[sharedmedia=core:attachments:7972]

Add some data with glide effects in the main editor (not the phrase editor):

[sharedmedia=core:attachments:7973]

Change Jack’s block size to something like 2048.

Expected results:
Smooth gliding between pitches,

Actual results:
Stepped transitions between pitches.

Block Size = 64

[sharedmedia=core:attachments:7974]

Block Size = 2048

[sharedmedia=core:attachments:7975]

Block Size = 8192

[sharedmedia=core:attachments:7976]

Block Size = 8192 without phrase

[sharedmedia=core:attachments:7977]