Advantages
MPEG2 data reduces the amount of memory required to store full motion video. The compressed data requires a smaller transmission bandwidth. This makes it possible to transmit 30 frames/sec video over a 10/100 Base-T Ethernet. The hardware compression circuit uses a motion estimation algorithm to produce smooth images from interlaced cameras.  The length of MPEG2 video streams is not limited by the viewing software.

Real-time viewing
The uncompressed video stream may be displayed in real-time on the host computer’s monitor while the MPEG circuit is compressing it. Uncompressed video is sent directly to the graphic adapter’s video memory under the control of Video for Linux.

Decompression
Encoded MPEG2 data can also be decompressed by the 616’s hardware to produce composite video and audio. The video output is also available as S-video.  The audio output is available at an audio jack on the hold-down bracket.

Digital I/O
Two optically coupled inputs and two relay outputs share a common terminal block on the hold-down bracket. The relay outputs can be configured as normally open or normally closed.

Text caption buffer
A 32 character buffer is available for adding text to each frame.  The text is within a transparent box that may be positioned anywhere within the frame.

Self test
Digitized video and audio inputs can be looped back to the output circuits to allow camera and sound adjustments.  The 616’s video D/A can be programmed to generate color test bars. This is useful for testing the video output channel.

Application Notes
Pixel Jitter in Frame Grabbers | Frame Grabbers: FIFO vs. Memory Buffered

Software and Manuals
The 616 is supplied with drivers for Linux that allow register and memory buffer initialization, reading and writing MPEG2 data. The driver synchronizes the audio channel with the MPEG2 video channel during recording and playback.

Linux players are included with the SDK. They allow simultaneous viewing and recording of the video stream.

Video outputs
In addition to the MPEG data stream two types of uncompressed video output are available. The digitized video input may be looped back to the 616’s digital-to-analog converter to produce composite and s-video outputs. These analog signals will contain the text in the caption buffer.

The uncompressed images are also available over the PCI bus. The 616’s driver can optionally write full-size images directly to the host’s video memory. This allows previewing the camera stream at the same time the MPEG stream is recorded to the host’s main memory.

Lost video detection
The status of the camera’s vertical and horizontal sync signals may be used to detect the presence or absence of the camera signal. The included software allows reading these signals to detect a lost video signal.