User manual

Small Vision System User Manual 14
The framegrabber interface must be set up before starting smallv; it cannot be changed while the
program is running.
Under Linux, the interface to either the Matrox Meteor cards or a Bt848 card (PXC200, Intel Smart
Video Recorder, etc.) is with the shared library bttvcap.so. Copy this library to bin/libcap.so to
use it. You must load the proper low-level driver for the card, namely, the BTTV drivers. These drivers
are included with almost every distribution of Linux; we recommend the current Red Hat distribution.
The framegrabber interface used by smallv under MS Windows or Linux is indicated in the message
window at startup.
There are some limitations in framegrabber drivers that should be noted. First, there are currently no
good analog framegrabbers for portables. For the digital interface, any standard IEEE 1394 OHCI card can
be used; this is one of the advantages of the digital interface.
2.1.3 IEEE 1394 (FireWire) Framegrabber
The SVS has an interface to digital stereo heads from Videre Design via the IEEE 1394 serial bus.
Any OHCI-compliant IEEE 1394 PCI or PCMCIA card can be used, under MS Windows 98/2000 or
Linux. Please check the stereo head manual for instructions on installing the 1394 card and drivers.
The relevant interface libraries are given in Table 2-2 below. To set up a particular interface in Linux,
copy the library file to bin/libcap.so. Under MS Windows, execute the setup file in the bin\
directory by double-clicking on it in Windows Explorer.
Operating
System
Stereo Head Library MSW Installation File
MEGA-D
libpix.so
Linux
Dual DCAM
libdcam.so
MEGA-D
svspix.dll setup_megad.bat
MS Windows
98/ME/2000
Dual DCAM
svsdcam.dll setup_dcam.bat
Table 2-2 Interface libraries for Videre Design digital stereo heads.
2.1.4 Selecting Devices
The Device menu button lets you tell the SVS library what kind of video input you are using. For
Videre Design digital heads (MEGA-D and Dual DCAM), you can select among multiple devices attached
to any IEEE 1394 card on your computer. For analog stereo heads, you can choose how to input images
from the analog framegrabber boards. Currently, there is no way to select multiple analog stereo heads
connected to the same computer.
Digital Stereo Devices (MEGA-D and Dual DCAM)
A digital stereo head attached to the IEEE 1394 bus is recognized by smallv, and the Device menu
button will drop down a list of these devices when selected. Devices have a number, which starts at 1 for
the first device encountered. These numbers can change as devices are added or dropped from the bus.
Devices also have an id, which is a numeric string that is unique to the device. The Device list shows both
the current device number, and its unique id. The currently selected device is indicated by a checked box;
you can change the current device by selecting any available device. This choice becomes active the next
time Video input is selected in the input choice box.
Only one type of device, the MEGA-D or Dual DCAMs, will be seen by the smallv program. The
choice depends on which interface library has been loaded (see Section 2.1.3). It is possible to mix these
devices on the same IEEE 1394 bus, but a given application will see only one type of device or the other.
Analog Stereo Devices (STH-V3 and user cameras)