.\" $OpenBSD: bktr.4,v 1.10 2002/10/01 07:14:14 miod Exp $
.\" $FreeBSD: /c/ncvs/src/share/man/man4/bktr.4,v 1.9.2.5 2001/03/06 19:08:09 ru Exp $
.\"
.Dd January 28, 1998
.Dt BKTR 4 i386
.Os
.Sh NAME
.Nm bktr
.Nd video capture driver
.Sh SYNOPSIS
.Cd bktr* at pci? dev ? function ?
.Cd radio* at bktr?
.Pp
.Cd option BROOKTREE_ALLOC_PAGES=nnn
.Cd option BROOKTREE_SYSTEM_DEFAULT=XXX
.Sh DESCRIPTION
The
.Nm
driver provides support for PCI video capture and VBI capture on low cost,
high performance boards.
This should support most video cards based on the
Brooktree Bt848/849/878/879 Video Capture Chip.
The driver also supports FM Radio if the Tuner supports it.
.Pp
Specifically, the following cards are known to work: 
.Bd -unfilled -offset indent
Hauppage Wincast TV and WinTV/PCI
STB TV PCI Television Tuner
Miro PC TV
Intel Smart Video Recorder III
AverMedia cards
Video Highway XTreme
VideoLogic Captivator PCI
.Ed
.Pp
The driver currently supports the following features:
.Bd -unfilled -offset indent
PCI to PCI dma transfer
clipping
yuv
rgb16
rgb24
rgb32
.Ed
.Pp
On these cards, tuners and other components are interconnected with an I2C bus.
The Brooktree848 chips act as a master device on the bus to control them.
.Pp
The following kernel configuration options are available:
.Pp
.Bl -tag -width xxxxxxxx
.It Cd option BROOKTREE_ALLOC_PAGES=nnn
Specifies the number of contiguous pages to allocate when successfully
probed.
The default number of pages allocated by the kernel is 216.
This means that there are (216*4096) bytes available for use.
.It Cd option BROOKTREE_SYSTEM_DEFAULT="(BROOKTREE_PAL | BROOKTREE_NTSC)"
One of these options can be used to set the default video format for the driver.
This fixed random hangs and lockups with the VideoLogic Captivator PCI card.
.El
.Sh SEE ALSO
.Xr intro 4 ,
.Xr pci 4 ,
.Xr radio 4
.Sh AUTHORS
The
.Nm
driver is based on the work of
.An Jim Lowe Aq james@miller.cs.uwm.edu ,
.An Mark Tinguely Aq tinguely@plains.nodak.edu ,
.An Amancio Hasty Aq hasty@star\-gate.com ,
.An Roger Hardiman Aq roger@FreeBSD.org
and a bunch of other people.
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 2.2 .