manipulating input buffers

[pressplay]

Hi,

I have a class that can process audio buffers with this function:

void FilteredFeedbackDelay<S>::processAudio(double** inputs, double** outputs, int nFrames) { ... }

In ProcessDoubleReplacing I call this function, however, I'm passing the input buffers as inputs AND outputs, like this:

delay.processAudio(inputs, inputs, nFrames);

So basically, I'm manipulating the input buffers here and later I'm calling another function where the output buffers are calculated. In most cases I don't see/hear any problems. But sometimes there are glitches and feedback where I wouldn't expect them and I assume it's coming from this function call.

Is manipulating the input buffers "dangerous"? Is it better to store the samples in another array/container first?

Thanks
Peat

[Xenakios]

It's best to assume the input buffers are owned by the host or the plugin framework and that one should not manipulate the data in them.

[pressplay]

I don't want to allocate and deallocate new arrays and copy data in each processing block. And it seemed an elegant solution to use the input buffers as an intermediate storage and apply a dry/wet stage later. I will try to find a better way...

By the way, I'm pretty sure now that problems occur in debug mode only!

[Tale]

You know the maximum buffer size in Reset() via GetBlockSize(), so you can (re)allocate internal buffers there. That way you don't have to don't have to reallocate all the time, but you would still have to copy data around.

[pressplay]

I would then prefer to use some standard containers instead of raw arrays. Unfortunatelly, this would also mean a lot of refactoring, as my "processing blocks" operate on arrays. I would do it like this: Copy **inputs into my own containers, do the processing, and at the end of ProcessDoubleReplacing copy results into **outputs. Good idea? Bad idea?