Get the current pre-amplification value from an equalizer.
    @param p_equalizer: valid equalizer handle, must not be NULL.
    @return: preamp value (Hz).
    @version: LibVLC 2.2.0 or later.

def libvlc_audio_equalizer_get_preamp(p_equalizer):
    '''Get the current pre-amplification value from an equalizer.
    @param p_equalizer: valid equalizer handle, must not be NULL.
    @return: preamp value (Hz).
    @version: LibVLC 2.2.0 or later.
    '''
    f = _Cfunctions.get('libvlc_audio_equalizer_get_preamp', None) or \
        _Cfunction('libvlc_audio_equalizer_get_preamp', ((1,),), None,
                    ctypes.c_float, ctypes.c_void_p)
    return f(p_equalizer)