Function encoder_and_mux_elements 

fn encoder_and_mux_elements(
    format: OutputFormat,
    os: &str,
) -> Result<(Vec<&'static str>, &'static str), EncodeError>

Per-(format, OS) video encoder element(s) + muxer element, used by build_live_video_args so the encoder coverage table lives in one place.

Errors

EncodeError::Unsupported for any (format, OS) without a wired encoder.