About primary & secondary video formats – AJA IoExpress User Manual
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Io Express Installation and Operation Guide — Features
About Primary &
Secondary Video
Formats
In Io Express operation, the Primary Format is the media format written to disk and used
in your project. The Secondary format is that which may be input for capture or output
from Io Express to VTRs or other devices. Down-conversion may be applied to an input or
on output.
The Primary Format menu allows you to select the video format used in your current
project.
Down-conversion is performed based on the Primary or Secondary Format settings.
Io Express can down-convert the input format (when designated as a Secondary Format
input) to the selected Primary Format. Or you can set a Secondary Format output that will
be a down-conversion of the Primary Format.
Note: When converting an Input to the Primary Format, select the Secondary Format
option that has (I), for input only, appended to it. Conversely, when converting an
Output from the Primary Format, you must select an output signal with (O) for output
only.
Convert Mode
Convert Mode allows selection of a conversion mode for down conversion between High-
definition and Standard-definition formats. The choices offered depend on the AJA
capture device present and the Primary and Secondary format chosen. Io Express
supports down conversion plus SD-to-SD aspect ratio conversions. See the following
tables for conversion options.
All conversions use AJA 10-bit hardware on the card.
To do a down-conversion on an HD input:
Set the Primary Format as an SD format
Select the correct HD format with an (I) input designation for the Secondary Format, then
Choose a “– Secondary” Video Input type
Down-conversion display mode choices that may be available include:
•
Anamorphic: full-screen
•
Letterbox: image is reduced with black top and bottom added to image area with
the aspect ratio preserved
•
Crop: image is cropped horizontally to fit new screen size
For a list of the Primary Video Signal Formats supported by Io Express, see