fn write_pgmyuv(pfx: &str, strno: usize, num: u64, frmref: NAFrameRef) {
let frm = frmref.borrow();
if let NABufferType::None = frm.get_buffer() { return; }
fn write_pgmyuv(pfx: &str, strno: usize, num: u64, frmref: NAFrameRef) {
let frm = frmref.borrow();
if let NABufferType::None = frm.get_buffer() { return; }