Grass Valley K2 System Guide v.7.2 - Manual (Page 92)

92 K2 System Guide 07 April 2010
Chapter 3 System connections and configuration
Compressed VBI import
The K2 system can be set up to import Standard Definition (SD) Compressed VBI
closed captioning. The feature can be useful for workflows that include SD clips from
Profile XP and other video servers, or for facilities transitioning from SD to HD. If
you are interested in this feature, contact Grass Valley Support to determine if it is
appropriate for your system design. If appropriate, Grass Valley Support can provide
you with the instructions to enable the feature.
About compressed VBI import processes
The K2 system extracts closed captioning by decoding the compressed video. The K2
system then inserts the extracted closed captioning as an SD ancillary data track into
the K2 clip. These processes occur as the material is being transferred into the K2
system.
These processes take place on the K2 device performing the import. This can be a
stand-alone or SAN K2 system. During these import processes the CPU consumption
on the system performing the import is higher than with conventional imports. Take
this into consideration when planning to use this feature.
Specifications
The compressed VBI import is supported as follows:
• SD MPEG only.
• All forms of import are supported, such as FTP, automation protocols, AppCenter,
Capture services, and InSync.
• GXF, MXF, MPEG, and MOV imports extract closed captioning from SD
720x512 video.
• D-10/IMX SD MPEG video is supported
• SD 525 line (NTSC) closed captioning is supported
• SD 625 line (PAL) teletext is not supported
• The first SD video track encountered is processed for compressed VBI. Multiple
video tracks are not processed.
• If the incoming video contains compressed VBI lines but closed caption data is not
present, the resultant K2 clip has an ancillary data track containing “blank” closed
caption data. On playout, the blank closed caption data is inserted into the video,
but no closed caption is displayed for the video.
• If an MPEG program/transport stream contains both ATSC Closed Captioning
inserted into the MPEG picture user data and compressed VBI lines, the K2 system
ignores the compressed VBI lines and processes for the ATSC Closed Captioning
instead.
• The K2 system does not process the incoming video when the following occurs:
• The video does not contain compressed VBI lines
• The video already contains an ancillary data track