Deinterlacing errors are tricky to capture in a still screenshot.
I have discussed these issues before, in this thread: Deinterlacing / extraneous scaling issues . There are some attempts at screenshots in there (first post in that thread) but as far as diagonal filtering is concerned, it’s easier to compare by eye the difference between decoding in hardware (no diagonal filtering) and decoding in software (correctly filtered).
Go here: Dropbox - Deinterlacing test patterns - Simplify your life and download the Time Flight clip. Decoding in hardware, you’ll notice there’s a constant flicker at the top left of the screen; also, watch the control console between 00:10 and 00:15, and between 00:34 and 00:39 - note the jagged edges and “crawling” effect along the edges of the metallic strips. Software decoding mostly fixes both issues.
(“Then why not just use software decoding?” you may well ask: that does indeed work okay for 576i stuff, but there’s a separate, much longer-standing problem that messes up 480i playback with software decoding - also described in the thread I linked to above, if you’re curious; but as that wasn’t a regression in the 4.9 kernel, I’m less hopeful of a fix.)