4 ms·
A classic problem to do with hardware overlays. It's also why screenshots of videos sometimes have blacked out video in the screenshot. 'Hardware overlay' is a
by AnotherGoodName 4y ago
A classic problem to do with hardware overlays. It's also why screenshots of videos sometimes have blacked out video in the screenshot.
'Hardware overlay' is an old video acceleration trick to write processed video straight to the output framebuffer. It bypasses the OS windowing system completely and if you as a developer get it wrong in any way you get video peeking through other apps. Video playing via a hardware overlay' has caused such issues for 30 years now. Not just on xorg or Wayland as you'll sometimes see this on windows too.
- hakfoo 4y agoI recall in the old days, you could get the cheap BT848/878 TV tuner cards. They just merrily piped data into the framebuffer, so if you had things configured right, it would draw a black rectangle, expecting the card to drop video on it, and the actual video would be offset 25 pixels to the left and below the.
- LargoLasskhyfv 4y agoAnd guess what? It worked, even on NetBSD. And you could move it with the tv-stream playing without tearing. And scaling too! Still have one such thing in PCI, gathering dust in some box.