I plan to implement oversampling in a plugin I am working on, and need some guidance.
For upsampling, Juce’s LagrangeInterpolator class looks appealing so that is what I plan to use. I am less sure about the downsampling process.
My first question is: can LagrangeInterpolator be used to filter & downsample too, or is that not its purpose?
Assuming that LagrangeInterpolator is not appropriate to use for decimation, my research has led me to FIR filters. If I understand correctly, FIR filters are good for decimation since you only need to process the samples that will be used in the output (downsampled) buffer, and not bother to filter the samples that will be thrown away, which makes it faster than IIR?
However when it comes to implementing an FIR filter in Juce I am clueless. Thus far the extent of my experience with filters is using Juce’s IIR filter classes, so I would be very grateful for any tips for how I might go about implementing an FIR filter for the purpose of decimation?
If you think I am barking up the wrong tree and should be pursuing a different approach to oversampling, please set me straight!