Grass Valley K2 System Guide v.9.0 - Manual (Page 122)

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.
Compressed VBI import 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
• The video is High Definition (HD)
• The video is a GXF complex movie, such as a program or a playlist.
122 K2 System Guide 06 November 2012
Import/export services