Function paint_over_desc 

pub fn paint_over_desc(
    settings: &RustCaptureSettings,
    fixed: Option<&str>,
    holds: bool,
) -> Option<String>

The paint-over field of a stream’s log line, or None where paint-over changes nothing. The cleanup reads a still screen from its content, so it acts with Turbo as without. JPEG resends a still stripe at the paint-over quality when it is above the stream’s. At a constant quality the cleanup, where the paint-over CRF is below the stream’s, moves the session to that CRF for its frames and their burst, except on a backend with one rate control (fixed), which takes no quality from the caller and sends them at its own. At a constant rate it acts wherever the rate control codes coarser than the paint-over quantizer: held at it where the session holds a frame at a quantizer (holds, FrameEncoder::holds_quantizer), and as a refresh and its burst at the rate control’s own quality elsewhere.