Video overlay - essential for fast video playback

[Crumb]

Hello

>1. Offloading the video scaling to hardware.
But the existing CompositeTags() can do hardware resizing on x1000...

>2. Offloading the YCbCr -> RGB conversion to hardware.
But Altivec can (may) do that...

So when when you say "we need overlay" what exactly is needed ? a full gxvideo.library implementation ? or just a function to convert/display an YCbCr buffer ?

Alain Thellier

These *PIP* functions expect a driver with working overlay:
http://amiga.sourceforge.net/amigadevhelp/phpwebdev.php?action=List&funcgroup=Picasso96 otherwise current videoplayers won't be able to open a PIP/overlay windows and will have to switch to other rendering methods.

[Crumb]

Hans isn't saying that the drivers don't need video support, he's saying it should be done via 3D, not overlay.

And OS4 should support various cpu cores and include memory protection but it doesn't and most probably won't.

My understanding is that Overlay is a hardware device - it's where the graphics card renders its frame buffer and then renders a seperate area (the overlay).

There's an API to handle overlay/PIP or whatever name you want to use. The graphic card drivers should take care of providing an implementation for that interface. It doesn't matter how you implement overlay, what matters is if it's supported or not because all amiga video players from the nineties to 2012 use PIP/overlay API.

Hans has said gpu is very complex and you can expect creating working 3d drivers will take much more time. If you plan to implement overlay compatibility after 3d drivers are done it will take much more time. Permedia2 lacked true overlay and CGX coders implemented Overlay support using a pair of textures. It didn't require full OpenGL support.