In article <7hv7md$rgf@eris.giga.or.at>,
	Thomas Klausner <wiz@danbala.ifoer.tuwien.ac.at> writes:
> Since both FreeBSD and OpenBSD/i386 already have it -- how hard would
> it be to support tv/video grabber cards with the Brooktree 848/878
> chips?

It would require a lot of work.

> FreeBSD bt848 Driver Project:
> http://www.freebsd.org/~ahasty/Bt848.html

The FreeBSD - the OpenBSD driver is only a port of it - can be hacked to
compile under NetBSD. However, there are several problems:

1.) Because the driver uses direct memory access to read and modify the
    registers of the BT8x8 chips it will not work on any port except i386.
    It must be made bus_space(9) compliant.

2.) The API is really lousy. The application basically tells the driver
    where to DMA the captured video signal. If the application tells it
    to use kernel memory space your system will be quiet unhappy.

3.) The driver uses several global variables. Idoubt that it will really
    work with more than one board as it should.

4.) The application has to use XFree86's DGA server extension for decent
    performance. Unfortunately DGA 1.0 has some design flaws which cause
    e.g. problems with Matrox boards using more than 4MB of video memory.
    And DGA 2.0 will not be available before XFree86 4.0.

-- 
Matthias Scheler                                http://home.owl.de/~tron/