Function simulate_video 

pub fn simulate_video(
    path: &Path,
    config: SimulatorConfig,
    scale: Option<(usize, usize)>,
    max_frames: Option<usize>,
    on_events: impl FnMut(EventStream) -> Result<()>,
) -> Result<(usize, usize)>

Simulates a whole video file, calling on_events with each interval’s events as they are produced.

Streaming by construction: nothing is held but the current frame pair, so a long recording costs memory proportional to one interval rather than to the whole output. scale decodes at a different resolution, which is much cheaper than decoding full-size and downsampling after. max_frames stops early.