Command line interface for testing.

def _main():
    """ Command line interface for testing.
    """
    if len(sys.argv) <= 1:
        print("Usage: python -m auvyon.imaging.waveforms <mediafile>...")
    else:
        try:
            print("Created %s" % waveform_stack(sys.argv[1:], (640, 48)))
        except subprocess.CalledProcessError, exc:
            print("Conversion error: %s" % exc)