SENSORAY Model 2255/2257 4-channel frame grabber

Features

• Simultaneous capture from 4 NTSC/PAL video sources
• High aggregate capture rate: up to 120/100 fps (NTSC/PAL)
• Output formats: RGB/YCrCb, packed/planar
• Output resolutions: full/half/quarter frame
• Advanced deinterlacing eliminates motion artifacts
• Field capture mode allows lower latency display for CIF resolution
• Hardware JPEG compression
• Hardware timestamps (1ms resolution)
• USB powered

Model 2255 simultaneously captures uncompressed frames from four NTSC or PAL video sources and sends them over USB 2.0 to a host computer. Model 2257 is functionally identical to the 2255 except for input types: Model 2255 has four composite video inputs, whereas Model 2257 has two S-Video and two composite inputs.

Model 2255/2257 block diagram

The maximum aggregate capture rate in full resolution color mode is 60/50 fps (NTSC/PAL), yielding a per-channel NTSC capture rate of 30 fps for two channels, or 15 fps for four channels. In monochrome and scaled-down modes all four channels can capture at full frame rates.

A variety of output resolutions and formats are supported, eliminating the need for the application program to perform format and resolution conversions. The units are capable of capturing frames in any of these formats:

• RGB packed (24 bits/pixel, bitmap compatible)
• YCrCb packed (16 bits/pixel, YUY2 compatible)
• YCrCb planar (16 bits/pixel, optimal for image processing)
• Y8 (8 bits/pixel, monochrome)

The units support Y8 and YCrCb planar natively, while conversions to RGB and YCrCb packed formats are optionally performed by Sensoray drivers. Please refer to the 2255 software documentation for details.

Each unit has a serial number that can be read through the API, thus enabling the application software to easily identify specific units in multi-unit systems.

Low latency

Models 2255/2257 have exceptionally low latency, making them especially useful in applications that require fast visual feedback.

Deinterlacing

Models 2255/2257 are capable of performing advanced video deinterlacing to reduce motion artifacts in captured images. Deinterlacing is performed by hardware so that the host computer is not burdened with this task.

Software

Sensoray offers several free, downloadable Software Development Kits (SDKs) to enable OEMs to quickly integrate Model 2255/2257 units into application systems:

• Windows API. This is recommended for most Windows applications. Image buffers are allocated by the application and then registered with the driver, thereby greatly simplifying both custom application development and integration with third-party image processing software.
• Direct Show API for Windows. This is recommended only for Direct Show application development.
• Linux API, which includes Video4Linux2 (V4L2) support.

Hardware compression facilitates JPEG capture at 30 fps on two channels, or on four channels at 15 fps.

Cables

A USB cable is supplied with models 2255 and 2257. Video cables must be purchased separately.

Packaging Options

Model 2255 is available as an OEM bare board (Model 2255), in a metal enclosure (Model 2255S), or mounted on a PC expansion bracket (Model 2255S-PC). For OEM applications, the unit can be custom-ordered to include high density headers in place of the standard connectors (Model 2255-NC).

Specifications

System requirements: USB 2.0 high-speed port, PIII 700 MHz CPU or equivalent. A high performance CPU is recommended for applications in which heavy image processing is performed.

Activation of deinterlacing is optional; when active, it reduces the maximum capture rate by a few percent.