How to customize Exoplayer material buttons?

I am using this predefined Styled Player view XML code but I want to customize some of the buttons of this player view. Functions like (setClickable,setEnabled,setAlpha) are working fine on Buttons and ImageButtons but these functions are not working on MaterialButton as fast forward and rewind buttons are material buttons so these functions are not working on these buttons. Any other solution to customize these buttons..?

<com.google.android.exoplayer2.ui.StyledPlayerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/player_view"
    app:use_controller="true"
    android:keepScreenOn="true"

    />