iOS, Restarting animation when coming out of the background

when my app comes out of the background the animation has stopped. which is normal. but i want to restart my animation from the current state. how do i do that without my snapping all over the place.

[UIView animateWithDuration:60 delay:0 options:(UIViewAnimationOptionCurveLinear |UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat | UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState) animations:^{
    [bg setFrame:CGRectMake(0, 0, 1378, 1005)];
} completion:nil];

i tried putting a set frame in front of the animation but that just makes it snap.

[bg setFrame:CGRectMake(0, 0, 1378, 1005)];

any ideas?