Frame grabber captures 720 x 480pixel video at 30fps

Video acquisition board maker Sensoray has a $328 PC/104+ Model 314 frame grabber that processes MPEG-1, MPEG-2 and MPEG-4 video. The Model 314 also works as an MJPEG frame grabber.

In use, the Model 314 captures full-frame 720 x 480pixel video at 30fps. MPEG data rates range from 800Kbps to 10Mbps. In addition to MPEG compression, uncompressed video is available through the PC/104+ bus for previewing.

The board also has two synchronized audio input channels and on-screen display (OSD) of text. A 96-character buffer can add text to each frame. The OSD text is within a transparent box that can be positioned anywhere within a frame.

Model 314 can also perform motion detection in three firmware regions of interest; each region is programmable. That is, for each separate region of interest, you can set up different motion detection sensitivity levels. Within the regions of interest motion can be further localized to a 16 x 16pixel block. A motion map shows where the motion was detected.

The motion detection system's regions are described in pixels. In operation, you specify an upper left co-ordinate and a lower right pixel coordinate for each region. In each region, motion is detected on the basis of threshold values. The first threshold is a sum of absolute differences (SAD). It represents changes in intensity. In general, SAD will catch fast motion across a target.

The second threshold is a motion vector threshold. It can detect slow motion across a target better than SAD. Finally, there's a programmable sensitivity value.

Linux, QNX, Windows 2000 and Windows XP drivers are supplied. Moreover, a Fast Windows stream player is also available.

- Alex Mendelsohn
eeProductCenter