Function play_on 

pub fn play_on(
    ctx: &Ctx,
    canvas: Canvas,
    input: &str,
    fps: u32,
    fit: Fit,
    looping: bool,
    p: &mut dyn Progress,
) -> Result<()>

Play a video source onto canvas. Reports N frames, F fps every 60 frames as a transient line and once at the end; stops when cancelled.