inline void srccpy( float * _dst, float * _src, int wavelength )
	{
		int err;
		const int margin = 64;

		// copy to temp array
		float tmps [ wavelength + margin ]; // temp array in stack
		float * tmp = &tmps[0];

		memcpy( tmp, _src, sizeof( float ) * wavelength );
		memcpy( tmp + wavelength, _src, sizeof( float ) * margin );
		SRC_STATE * src_state = src_new( SRC_SINC_FASTEST, 1, &err );
		SRC_DATA src_data;
		src_data.data_in = tmp;
		src_data.input_frames = wavelength + margin;
		src_data.data_out = _dst;
		src_data.output_frames = wavelength * WAVERATIO;
		src_data.src_ratio = static_cast<double>( WAVERATIO );
		src_data.end_of_input = 0;
		err = src_process( src_state, &src_data );
		if( err ) { qDebug( "Microwave SRC error: %s", src_strerror( err ) ); }
		src_delete( src_state );
	}