Implementing Live Video

MediaShout believes that the best way to superimpose lyrics, verses, or other text over a live camera in a church or other venue is with a keyer. 

Currently, the best way to implement live video in a church is to have a video switcher/mixer that takes various inputs and can add live video to MediaShout's output.  That is how every church who is looking for a professional presentation does it.  The MediaShout PC, cameras, DVD, CD, etc. are input into the video switcher and the different feeds can be mixed and matched any way you want, "keying" video behind text and other images.  This gives you an incredible amount of control and flexibility.  It is very easy to do if you have the right equipment.

The most common way to do this is as follows:

  1. Send the MediaShout display screen's output to a scan converter, which will convert it from a VGA signal to a standard television signal (NTSC in North America).  If you are taking an S-Video feed from the computer, this step in not necessary.
  2. Send the video signal to a keyer.  A keyer is a video device that replaces certain elements of one video source with elements from another source.  In this case, MediaShout is the key source.  Your camera or VCR output is the program source.  The two sources are combined and sent to your TV monitor or video projector.

There are 2 types of keyers:

Luminance Key:

Replaces the darkest (or brightest) elements of the key source with the program source.  For example, if you have white or yellow text displayed on a black background, set the keyer to replace the MediaShout cue's black background with the program source so that the bright text appears over the live camera shot.  Or, if you have dark text, place it on a white background and reverse the setting on the keyer.

Chroma Key:

Replaces a particular color in the key source with the program source.  This is the same technology used when the weather man is standing in front of a blue (or other color) screen and you see the weather map projected behind him.  Using a chroma key with song lyrics lets you choose a font color that's neither dark nor bright.  As long as you set the keyer to replace only the background color and use a different color for the text it will replace only the background.

If you're switching between two or more program sources (i.e. 2 cameras, VCR, DVD, MediaShout), it makes sense to get a switcher with a built-in keyer.  The most popular switchers used in churches are called AV mixers.  These are "prosumer" or "industrial grade" video switchers that synchronize and switch between two or more audio/video sources.  Most AV mixers also have a built-in luminance keyer.  Some offer chroma keying.  Prices can range from $1000 to several  times that.