Applying parameter ramp over time for AENewTimePitch in AERenderer block

manderson

Hi all!

I have an AENewTimePitch effect that I want to randomly adjust its pitch in an AERenderer block using a ramp function to increase/decrease to the target pitch over time (lets say -500 to 500 in 0.5 secs). I was looking at a few ways to do this (AudioUnitParameterEvent, AudioUnitScheduleParameters, etc), or simply keeping track of a few variables with a loop over the frames in each callback and updating them in the render block; I was wondering if you have insights into the most optimal approach though? Is there a good and bad way of doing this? Are there any CoreAudio/Accelerate functions that I should look into?

Also, do you think it would be helpful to add this as a utility function in TAAE2 as I would imagine it is a fairly common use case?

Thanks!
Mark

markjeschke

@manderson, this example uses the varispeed filter and TAAE1, rather than the NewTimePitch filter and TAAE2. But, it demonstrates how to change an effect's parameter over time, using a controlled NSTimer:

http://forum.theamazingaudioengine.com/discussion/comment/2880/#Comment_2880

I hope this helps!

Take care,
Mark

manderson

@markjeschke Thanks for pointing me to your example. Ideally I would like to do the updating inside the renderer block, the main reason being that I would like this to also work for offline rendering (an NSTimer in that case would not be ideal since the offline renderer timing does not correspond to say, playback speed).

markjeschke

@manderson, I see. Okay, I understand your reasoning. So, you'd like to set specific timecode where you want the AENewTimePitch to start and end within an offline track, right? I unfortunately don't know how to do that. So, if you figure it out, please share your solution with the TAAE community!

Thanks,
Mark

manderson

@markjeschke will do! I will definitely report back if I find a good solution.