To be honest, we didn't really know what we were doing (with regard to software peripheral to Linux) when we started this. We had a GTK+ application (on X) and a proprietary driver, neither of which is still used. The concensus was that X was too bloated, and we wanted to boot from a disk-on-chip, if needed. In fact, we see embedded Linux as the natural platform for this hardware. Hard drives are needed primarily for PVR in a set-top box. So, running without X meant that we needed a good framework to do video and graphics. We saw V4L2 as better than V4L, and as a reasonable starting point for the kernel-mode support. Someone here also recommended Microwindows as the user-mode interface -- and it has worked well. Many of us are familiar with the Win32 API, so this was a nice fit. You will see on the web site http://www.linux4.tv/ that Century Software has helped significantly with this project. There is some documentation of the software architecture burried in the tar balls somewhere. In it is where we had to deviate from the V4L2 API and why. I agree that more is needed. Because the Geode is an X86 processor, among many other things, there are some tricks that we do with video to improve the quality (genlocking) and allow alpha blending and high performance VBI capture. These tricks are not supported in any existing API, as far as I know. This is one of the reasons why we want to expose the code to the community -- so the best solutions will eventually surface. Thanks for your comments. -- Peter alan@xxxxxxxx om To: video4linux-list@xxxxxxxxxx@Internet cc: romain@xxxxxxxxxxx@Internet, (bcc: Peter 08/28/01 Lohmann/Americas/NSC) 09:50 AM Subject: Re: Fwd: Re: Re: V4L2 to-do list] > speak for NSC (I'm just an engineer). Most large companies are closed by Thanks for the background. Firstly Im curious why you would use video4linux if the sidechannel is wired to the geode and could be driven by X11, is this specifically a design decision that comes about though nanogui (which I'm pleased to see is finding real users more and more now) We do have other folks using these zv-bus and similar pixelstream inputs but so far they have relied on X11 to do the work (indeed in many cases they share registers with normal video ops so you'd go very rapidly mad trying to do the locking). A "Here is what we are adding and why" would be good to read. Mostly though you should talk to Gerd. Video4linux for 2.5 is his ball now, although I keep interfering when I shouldnt Alan _______________________________________________ Video4linux-list mailing list Video4linux-list@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/video4linux-list
