Grass Valley K2 System Guide v.7.2 - Manual (Page 203)

07 April 2010 K2 System Guide 203
Active Format Description (AFD) specifications
Active Format Description (AFD) specifications
NOTE: This topic only applies to K2 Summit Production Clients, and K2 Solo Media
Servers.
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.
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 is prioritized according to the following table:
To see the full list of AFD input/output settings, refer to “AFD input/output settings”
on page 204 .
NOTE: Bar data is not supported on the K2 system.
Storing AFD in the K2 Summit Production Client and K2 Solo Media Server
The K2 Summit Production Client and K2 Solo Media Server stores clip metadata in
clip properties and uses this data throughout the workflow. You can modify the AFD
setting in AppCenter. For more information on applying AFD settings in the UI, see
“Applying AFD settings” on page 240 .
You can store AFD in a data track. Grass Valley recommends selecting this for HD
clips; if using SD, this is optional. This method takes more storage (it is approximately
equal to four tracks of audio) but this method enables AFD and CC/Teletext support
for HD.
Ingesting SDI
An SDI video signal stores AFD in the vertical ancillary data. If present, the AFD
setting from two seconds into the file is copied into the clip properties. (If selected,
the ANC data is copied into the K2 data track.)
Playback aspect ratio conversion priority
1 Clip property (ARC or AFD-based conversion rules)
2 Output channel (ARC configuration property)