Function split_segments_at_points 

pub fn split_segments_at_points<H: Clone>(
    frames: &[AnalyzedFrame<H>],
    segments: &[Segment],
    frame_ops: &FrameOps,
) -> (Vec<AnalyzedFrame<H>>, Vec<Segment>)

Partition existing segments into new ones based on FrameOp::SplitAfter markers.

Returns (new_analyzed_frames, new_segments).