@Override
    public FrameData getInterframe(int index) {
        if (index < numInterframes.get()) {
            return interframes.get(index);
        }
        return null;
    }
@ Override public FrameData getInterframe ( int index ) { if ( index < numInterframes . get ( ) ) { return interframes . get ( index ) ; } return null ; }
{@inheritDoc}