Grass Valley K2 AppCenter v.9.0 - Manual (Page 237)

Active Format Description (AFD) specifications
NOTE: This topic applies to K2 Summit/Solo systems.
Active Format Description (AFD) settings automatically determine the proper aspect ratio to use
for up- and down-conversions, based on the AFD information embedded in the clip metadata. If no
AFD was set on the incoming SDI input, you can assign the AFD setting in K2 AppCenter. A related
setting, aspect ratio conversion (ARC), makes settings in K2 AppCenter on a clip-by-clip basis or
per channel basis but does not embed settings in clip metadata.
Related Topics
About video scaling settings on page 164
About Active Format Description
The AFD is defined during production. By inserting metadata about the aspect ratio into the vertical
ancillary data, AFD can define the aspect ratio of the signal as it progresses through ingest, editing,
up/down conversion and playout. If the aspect ratio is altered during processing, then the AFD
passed on downstream might need to be modified to ensure the correct aspect ratio is obtained.
NOTE: If ARC leads to unsupported active video format (postage stamp), the new AFD code will be the
‘undefined’ value of 0000.
The playback Aspect Ratio Conversion (ARC) is prioritized according to the following table:
Playback aspect ratio conversion priority
Clip property (ARC or AFD-based conversion rules) 1
Output channel (ARC configuration property) 2
NOTE: Bar data is not supported on the K2 system.
AFD output flowchart
The K2 Summit/Solo system determines AFD code values in output as illustrated by the following
flowchart.
29 October 2012 K2 AppCenter User Manual 237
Specifications