Io 4K Plus Capture, Display, Convert v14.0r2 41 www.aja.com
Mode
Downstream Keyer Off - When this pulldown menu item is selected the
downstream keyer will be turned off
• Frame Buffer over Matte - Places the keyed video with alpha channel currently
in the Frame Buffer over a fixed color matte determined by the “Matte Color”
setting set separately.
• Frame Buffer over Video In - Places the keyed video currently in the Frame
Buffer over the video input for playout or print-to-tape.
• Graphic over Matte - Places a graphics file having an alpha channel (chosen in
“Graphic File” pulldown) over a fixed color matte determined by the “Matte
Color” setting set separately.
• Graphic over Video In - Places a graphics file having an alpha channel (chosen
in “Graphic File” pulldown) over the video input for playout or print-to-tape.
• Graphic over Frame Buffer - Places a graphics file having an alpha channel
(chosen in “Graphic File” pulldown) over the current contents of the Io 4K Plus
Frame Buffer (which might be from storage, video In, etc.).
Matte Color
Only available when the pulldown “Frame Buffer over Matte” or “Graphic over
Matte” are selected-pressing this button brings up a color selection dialog. The
dialog provides a variety of ways to select a matte color including a color wheel,
color picker (choose from a location anywhere on the computer screen), numeric
sliders, swatches, “crayons”, and spectrums. The matte chosen will be used as a
video background under the keyed video.
Foreground pre-multiplied (checkbox)
Use to avoid “matte lines” and improve the appearance of the foreground (key)
being composited over the background.
Audio Out
• Frame Buffer - Select audio out to be routed from the Frame Buffer.
• Audio In - Select audio out to be routed from the Io 4K Plus’s selected input(s).
Graphic File
This pulldown allows you to choose from any recently accessed file or select a
new file (“Load File...”), which then brings up a file dialogue. You can load any
standard RGB graphics file (.tif,.psd, etc.) into the frame buffer for display, but
some graphics formats and bit depths may not be supported.
The file raster (pixel x pixel count) should match the primary format in the frame
buffer or the secondary format if up-converting. For example, you wish to key a
logo on top of a 1920x1080 footage, the still image with alpha channel that you
load should be 1920x1080.
Loaded graphic files are retained for redisplay if another file is chosen, and even if
the Io 4K Plus is power cycled.
NOTE: A loaded graphics file will not be scaled to fit. If it’s smaller than the current frame
buffer format,Io 4K Plus will center it in the frame. If larger than the current frame
buffer format it will be cropped.
