AudioSampleBuffer audioSampleBuffer

How do I write into the audioSampleBuffer? I previously had audioSampleBuffer = input; where audioSampleBuffer was an array.

Could you provide a bit more context? Some sample code showing what you’re trying to do would be useful.

Maybe have a look at the copy functions of AudioBuffer like AudioBuffer::copyFrom() and alike.

Keep in mind, that AudioSampleBuffer is just a synonym for AudioBuffer<float>.
This is the working code now. AudioBuffer seems to have functions which allow to to write in to blocks of memory ?