def setup(self, channels=None, samplerate=None, blocksize=None, totalframes=None):
<EOL>
Allocate internal resources and reset state, so that this processor is
        ready for a new run.

        The channels, samplerate and/or blocksize and/or totalframes arguments
        may be required by processors which accept input. An error will occur if any of
        these arguments is passed to an output-only processor such as a decoder.