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Alpha Keyer Module in ProPresenter 4 and ProPresenter 5

Before you can configure the Alpha Keyer Module, you need to register the module on your Mac. Alpha Keyer module codes are 25-digits long and start with ALP. If you have purchasd the module but not activated your code yet, please read this article on activating module code. Once you activate your module code, you need to register it in ProPresenter. To do this, open ProPresenter's Preferences, then go to the Modules tab. Enter your 25-digit code in the "New Module Code" box and then click the plus button to add the code. You may be asked to enter your administrator password. When the code is successfully registered, you will see a green check next to your module.

Configuring the Blackmagic Design settings

As of January 2014, the Blackmagic DeckLink 4K Extreme ($995 USD) and the UltraStudio 4K ($995 USD) are the only two current models that are supported by the Alpha Keyer Module. Some older hardware, like the DeckLink 3D Extreme and the UltraStudio 3D, still support the Alpha Keyer Module. However, these two models are now discontinued and may stop working at any time.

After you have installed or connected your Blackmagic 4K, you will need to install the software to make your device operational. You can download the latest driver software from Blackmagic here. After you have installed the driver, open System Preferences and click on the Blackmagic Design control panel.

There are a few settings you need to configure to ensure the device is setup properly to work with your video system and ProPresenter. The marked fields are the only ones you should need to adjust on this screen. You want to make sure that Set default video standard as matches your video signal requirement. The other settings should be the same for your setup, with the exception of the Set input option at the top.



Switch to the Processing tab and make sure that the output and input processing are both set to Off. There are no other settings that need to be configured.

Blackmagic has updated their Desktop Video software. The instructions below cover the new version.

If you have not already done so, you will need to first install the Blackmagic Desktop Video Utility from the Blackmagic Support page. The software is listed in the Laste Downloads column below the Product Family grid. Click the link for the Mac or Windows version of the software. You can ignore the form and just click the Download Only link the bottom left corner of the pop-up window unless you want to register a new device. Install and then launch the software. On Windows, just search for "Blackmagic Desktop Video Utility". On Mac, it's added at the bottom of System Preferences.

Your device will show up on the window when the Desktop Video Utility opens. Click the device image to adjust your settings. 

These settings may vary depending on your device. In general, you will select the proper Video Input, set your Output Format, and uncheck the Remove Field Jitter On Pause. All other settings can be left alone unless you have been told to specifically change them by your system integrator or someone from Renewed Vision.

 Configuring ProPresenter Display Settings

One important thing to know when setting up the Alpha Keyer Module is that your needed output resolution has to be equal to or lower than the resolution of an attached monitor. If you need to output 1920x1080, but your computer doesn't have a monitor with that resolution or higher, then ProPresenter won't be able to send the signal. This is due to how the output signal being sent from ProPresenter to the SDI output is rendered.

Open ProPresenter's Preferences and go to the Display tab. At the top of the screen, uncheck the box for Scale to Fit Output Display. You will need to manually enter your Output Screen settings at the bottom. The most common resolutions are:

NTSC: 720x480

720p: 1280x720

1080i: 1920x1080

After you have typed in your resolution, click the Update box.

The reason for unchecking the Scale to Fit Output Display is so that you are sending the exact resolution to SDI. When this option is checked, it will distort the output if the detected screen size is larger. Since you aren't outputting to the same display that this is being detected with, you don't want this to happen.

If your 4K output looks distorted, confirm that these settings are correct before troubleshooting anything else.

Configure Alpha Keyer Module Settings

In ProPresenter Preferences, click on the Advanced tab. This is where you enable the settings for the Alpha Keyer Module.

The Output Device Settings is where you select your Blackmagic device and the output mode. The output mode needs to be the same that is required by your video system. Compression should be "None".

There are three options under Alpha Keyer Settings.

The "Blend" slider allows you to change the amount of blending in your signal. Typically this will always be to the right.

The "Alpha Channel" option is where you turn on keying. If your video signal is being sent into your Mac, you will be using "Internal Key". If you are using a linear key on a switcher, you will use "External Key" to send a key and fill signal to your switcher. The key signal is black and white, and represents where content exists on the slides. The fill signal will look like your slides, and is what gets filled in on your broadcast signal.

The "Additive Blend" option improves the transition between text while using Alpha Keyer.

You should now be able to test your settings. If you have configured everything properly, then you should see your content shown over your live video source. If anything doesn't look correct, double-check all of your settings.

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  1. Chris Rouse

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