Function write_all_frame 

fn write_all_frame<W: Write>(
    stream: &mut W,
    buf: &[u8],
    stop: &AtomicBool,
) -> Result<()>

Write one whole frame to a recorder’s socket, resuming across the soft timeouts a slow reader induces so a partial NAL or OBU is never left behind. Aborts if stop is set (the client was dropped by RecordingSink::write_frame) or a hard error occurs.