The bktr driver provides support for PCI video capture and VBI capture on low cost, high performance boards. The driver is based on the Matrox Meteor driver and uses the same API. The bktr driver should support most video cards based on the "Brooktree Bt848/849/878/879 Video Capture Chip". Also supported are most "Pinnacle PCTV" video cards. Furthermore, the driver supports FM Radio if the tuner supports it.
The driver currently supports the following features:
PCI to PCI dma transfer
On the supported 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. Therefore, iicbus(4), iicbb(4) and smbus(4) controller declarations are mandatory to activate bktr support.
The following kernel parameters may be used to further configure the driver:
options "BROOKTREE_ALLOC_PAGES=xxx" 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.
.Cd options BROOKTREE_SYSTEM_DEFAULT=BROOKTREE_PAL
.Cd options BROOKTREE_SYSTEM_DEFAULT=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.
The following sysctls may be used to further configure the driver:
sysctl hw.bt848.card=nnnn This can be used to override the card make which was detected at boot time. nnnn is set to an integer from 1 to 13 taken from the following table: