Call MangedBean using onSlide event instead of SlideEndEvent event

Currently we are using ajax slideEnd event and in backEndBean we are doing some % calculation

<h:outputText id="brightness" value="#{brightnessBean.brightnessLevelValue} %" />
    <h:inputHidden id="brightnessLevel" value="#{brightnessBean.editingObj.brightnessLevel}" />
    <p:slider for="brightnessLevel" minValue="0" maxValue="255" step="1" >
        <p:ajax event="slideEnd" listener="#{brightnessBean.brightnessSildeEnd}" update="brightness"></p:ajax>
    </p:slider>

Our backendBean is doing some percentage calculation using

public void brightnessSildeEnd(SlideEndEvent endEvent) {
        brightnessLevelValue = (100 * endEvent.getValue()) / 255;
    }

But now we want to do this using onSlide event but <p:ajax></p:ajax> is not supporting this event.
Please guide me the way we can display % when user uses slider instead of end of the slider.