Pitch Shift audio quality degrades with automation envelope

FMOD Studio
1

I’m having an issue where automating the pitch parameter in Pitch Shifter is causing a degrade in audio quality over time. If I have the below envelope set, then no matter what the parameter value is, the sound quality will degrade over time, even if the parameter is unchanging (I tested it on read-only as well). The audio quality can be ‘brought back’ temporarily by changing the fft size or moving some of the envelope nodes. It will then start degrading again. The only way to stop this is to remove the envelope entirely.

Is there any way I can still automate the pitch but avoid this behaviour?

image
image1253×422 44.1 KB

2

After a bit more playing around if I put a flat section in the envelope like this:

image
image1256×405 43.1 KB

it avoids the audio degradation. It is weird though that a static parameter causes the behaviour described in my first post!

3

Unfortunately, I haven’t been able to reproduce the issue you’re describing. There is a slight difference between no pitch shifter and a pitch shifter with the default settings, but I have been unable to reproduce anything I would classify as degradation.

Can I get you to provide your FMOD Studio version, as well as a simple set of steps that consistently reproduces the issue? If possible, could I also get you to upload the asset you’re playing, and a copy of it after pitch shifter where the issue is observable? A video showcasing the issue would also do. You can upload elsewhere and link here, or alternatively upload to your FMOD user profile - note that you’ll have to register a project with us to do the latter.

4

Hi Louis sorry for the big delay in replying to you, I’ve only just had time to get back to this. I’ve taken a video of the behaviour - you can hear that when the automation points are removed the audio quality changes and we lose the transients, until I put the points back in and the quality returns. This is in Studio version 2.02.13.

Is this enough or do you still need me to send you the project file?

5

I’ve experienced the same issue but with the Pitch Shifter in Unity, which I believe is based on FMODs API (Correct me if I’m wrong @Leah_FMOD ). Over time, almost for each playback, it degraded the audio and blurred the transients and positioning even if the settings were static. Disabling and enabeling the effect or changing any settings would reset the blurring “effect”.

Decided to pre-render all assets that needed to be pitched and swap them dynamically instead.

6

Thank you, this is enough to demonstrate the issue. I’ve passed it along to the development team for further investigation.

The “resetting” lines up with the expected behavior of the effect, which effectively reinitializes internally on a parameter change.