Geoff Poister / Equipment Reviews
10.31.2013 11:00 PM
AJA’s ROI DVI-to-SDI Converter

The AJA ROI miniconverter is a small device about the size of a deck of cards that converts a standard DVI or HDMI output from a computer or other device into SDI video that can be recorded, displayed or streamed. It uses sophisticated algorithms to perform very high-quality aspect ratio and frame rate conversions, and also includes the ability to add audio.

FEATURES

The AJA ROI DVI-to-SDI converter is an unassuming little box that’s packed with sophisticated technology. Its main purpose is to convert anything that you can display on your computer screen into high-quality HD video over an SDI link.

The unit’s distinctive features are found in the software interface called MiniConfig (compatible with Mac or PC platforms) which allows you to select any portion of the computer screen and turn it into high-definition video.

While performing this task, the portion of the screen selected is upscaled and processed to maximize and enhance image clarity. The AJA ROI converter unit provides excellent resolution and its frame rate conversion capability makes it possible to create video for just about any destination desired. For example, one could select a window on a computer screen playing a video clip, resize it and convert it over SDI to HD video at 1080i 59.94 or 24 fps.

In fact the list of output formats covers just about any requirement that anyone could possibly encounter. They include 1080i (50, 59.94), 1080p (23.98, 24, 25, 29.97, 30), and 720p (23.98, 24, 25, 29.97, 30, 50, 59.94, 60).

In spite of its small size, the AJA ROI is well designed for a studio environment, as it includes a reference input for multi-switching compatibility with other devices and cameras. The converter has a DVI loopthrough to maintain full monitoring of the original DVI screen while using the interface to select a portion for output through the SDI channel.

The device also has audio input capacity, making it possible to embed audio into the SDI output. Audio can be input via an analog 3.5 mm TRS two-channel input or via HDMI-embedded audio. The output format is SDI embedded audio, 24-bits, in two- or eight-channel configurations.

IN USE

I connected the AJA ROI to a MacBook Pro using a DVI connection adapter. I also connected audio from the laptop’s headphone output into the audio input on the ROI, as this allows the embedding of the audio into the SDI output.

I then connected the SDI output on the ROI to a Panasonic BT-LH1700W HD SDI monitor. On the MacBook Pro, the display is automatically configured so that the main screen is sent through the DVI output, and hence to the SDI HD monitor.

While I tested this with an SDI HD video monitor, it’s also possible to connect the ROI the same way to a monitor/recorder so that the signal can be recorded onto a memory card for later use in editing. Any recording device with a monitor could do this, including the AJA Ki Pro Mini, Sound Devices PIX240, or the Atomos Ninja. This enables you to acquire anything from the computer screen and record it on high-quality media for the editing process.

I basically found the AJA ROI setup to be simple and straightforward. It’s intuitively logical, and designed simply enough so that one can just hook it up and make it work, even without taking the time to read the manual.

The AJA ROI’s interface application provides two tabs (Region of Interest and Output) that are of special interest. Region of Interest enables you to select any portion of the computer screen and resize it for the SDI output. The Output tab provides a long list of output formats, achieved through advanced algorithms that maximize the clarity when upscaling the image.

In my test, I selected a small YouTube video screen, resized it to occupy the full screen and examined the output on the SDI monitor. The output video was surprisingly sharp, and the motion of the video was flawless, even when altering frame rate rates.

As an alternate path, I connected the AJA ROI directly to an Avid Media Composer by going through a Matrox MXO2 LE, which accepts an SDI video input. By going through the Avid, I was able to capture the output from my laptop in 1080i resolution and have it immediately stored in a clip bin for editing.

(I did encounter a small glitch with this method, although it was not the fault of the AJA ROI. The Avid Media Composer requires an exact format match when capturing video from a “deck.” After some experimenting, I found that if I changed the SDI output to exactly match the project format, then I could capture the signal as if it were coming from a digital tape deck.)

For my purposes as a project editor, this proved to be an ideal configuration. I created a project in 720p 29.97 and then set the AJA ROI output to the same configuration. I found that I could capture anything from my laptop computer in clips of any length. The upscaling was very sharp when I selected small screen portions, and I was able to generate clips in Avid DNxHD, which I could later edit into a project on the timeline.

I was very impressed by the image clarity and the ease by which I could select sections of the laptop screen and resize them to full screen SDI output. The device also produced excellent still images that look much sharper and richer than an ordinary screen grab.

Aside from creating media clips by capturing on a recorder or NLE, the AJA ROI provides excellent live image and sound over SDI. It would be a nice addition to a broadcasting facility when live feeds have to be taken from a computer. The ROI also provides a reference input to facilitate live switching.

The AJA ROI can also be used for presentations. A microphone can be plugged into the unit to add voiceover in connection with images projected on a large screen. This would also be an ideal way to make high-quality training videos, as the laptop image is faithfully captured while one adds a simultaneous voiceover. And gamers who like to show and describe their adventures and post them on You- Tube or other sites will find this to be an indispensable tool.

SUMMARY

The AJA ROI is a very efficient converter that provides the ability to take any portion of a computer display and turn it into full high-definition video via SDI. The ability to select small portions of the display screen and upscale them to full HD video in virtually all of the useable frame rates and resolutions provides users with many useful applications. This small unit can function equally well in a large television control room or in an individual editing suite where a user needs to generate high-quality media. It streams live, so it can be used for on-air applications or for live presentations. While it is useful as a converter, its main feature is that it creates exceedingly high-quality images through advanced upscaling and frame rate conversion.

Geoff Poister, Ph.D., is a member of the Film and Television faculty at Boston University and a regular contributor to TV Technology.

FAST FACTS

APPLICATION
Conversion of computer images to SDI video

KEY FEATURES
Excellent image quality, small profile, operates in multiple line and field rates

PRICE
$995, MSRP

CONTACT
AJA Video Systems
530-274-2048
www.aja.com



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