Figure 1. Possible configurations

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.

Video outputs
Five types of video outputs are available including an 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.

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.

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.

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.

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.

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 image size to the destination image size defined by the user. Some examples include the following:

When the input was standard definition, the scalers were set to scale each frame 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 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 output resolution. Example: Remove 100 pixels at image left and 50 pixels at image right. Scale new 570x240 image to 1280x1024.

Host communication
The 2246’s USB interface make 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.

Software and Manuals
A windows driver containing an MPEG software decoder is supplied for software developers. This low-latency decoder will decode the audio and video on the MPEG stream sent from the 2246.

2246 Hardware Manual >> 9/21/05
2246 Software Manual >> 9/21/05
 

Mechanical Drawings and Images

2246 Demo Application
2246 Data flow