The 2246 frame grabber accepts HDTV formatted to the 1080i standard plus two analog video sources for real-time display and storage. HDTV from a serial digital (SDI) source is scaled and formatted for high-resolution LCD displays. Scaled data is simultaneously compressed to one of three MPEG or motion JPEG formats for efficient archiving. The 2246's processor adds bit-map images and text to the displayed image. Snapshots from the HDTV stream may be displayed and archived. The 2246 also accepts two audio signals and synchronizes them to the MPEG stream.
Image processing
The 2246's scan converter guarantees the DVI output is synchronized to LCD displays. Hence, 25 frame/second PAL sources will be displayed at the highest LCD refresh rate. Real-time image down scaling of the HDTV stream prepares it for MPEG compression. A second scaler is available for up or down scaling of images sent to the LCD display.
Captured images may be annotated with both text and bit-map image sent by the host via the USB port. Annotated image streams can then be displayed and compressed to MPEG or motion JPEG standards.
Video Overlay
The 2246 supports full screen HD image/logo overlay at 16 bit color. The 2246 allows up to 8 hardware managed overlapping images, or an unlimited number of user defined full screen bitmaps to be added to the video stream. The video with overlay is compressed for storage on the host PC, as well as passed through to the four other video outputs of the 2246. Examples of HD image overlay can be found here:
Full screen HD image/logo overlay example
Video inputs
Five video inputs are available on the 2246; two composite, two S-Video, and one HD-SDI. All inputs support both NTSC and PAL video.
Video outputs
Five types of video outputs are available including an HD-SDI video stream containing the bit-map image and text overlays. The interface to an LCD display is via a DVI port and the interface to the host computer is via a USB port. Composite video and S-video outputs are also provided.
Audio inputs
Any one of three audio sources may be embedded into the MPEG stream. A high-level microphone signal or stereo audio source is synchronized to the video streaming during MPEG encoding. The audio stream embedded within the ancillary data from the HDTV camera can be added to the MPEG stream in place of the analog sources.
Audio output
Sensoray's MPEG decoding software that runs on the host PC can decompress the video and audio. The 2246 does not directly produce an analog output.
Video pass through
Using an optional external power supply allows the analog multiplexers to pass through video inputs to video output connectors. This pass through feature is useful in the event primary power is lost or the host computer is not functioning.
General purpose digital I/O
There are two electromechanical relays each of which has two form-C contacts. Eight opto-isolated inputs are available for general purpose inputs.
Scaling and cropping
The 2246, implements a completely arbitrary video scaler. By programming the source and destination widths and heights, the scaler will scale up or scale down the source video size to the destination video size defined by the user. Some examples include the following:
When the input was standard definition, the scalers were set to scale each frame as follows:
DVI scaler - scale 720x240 to 1280x1024 (or to 720x480 or 720x576)
MPEG scaler - scale 720x240 to 720x240
When the input was high definition, the scalers were set to scale each frame as follows:
DVI scaler - scale 1920x540 to 1280x1024 (or to 720x480 or 720x576)
MPEG scaler - scale 1920x540 to 720x240
The 2246's firmware allows the user to arbitrarily crop the input image horizontally, and scale the result to the new output resolution. Example: Crop 100 pixels from the left edge of the image and 50 pixels from the right edge. Scale new 570x240 image to 1280x1024.
Host communication
The 2246's USB interface makes it immune to changing computer bus standards such as the PCI bus. It is well suited for use with single-board computers that do not have a PCI bus. Also, the 2246 may be remotely located and connected to a host computer via its high-speed USB link.
Signal terminations
An optional accessory board, model 2246TA, facilitates signal connections. It breaks out the high-density connectors into commonly used connectors such as BNC's, audio jacks, DVI connector, and the high speed serial digital interface.
Evaluation System
An evaluation system, Model 2246S, brings out the circuit board's connectors to conventional connectors. Its aluminum enclosure shields sensitive circuits and protects the 2246 from physical damage. The 2246S is supplied with the Windows demo program shown below.
