GRASS VALLEY PROFILE XP PVS Series, System Manual

Page: 165 / 352

Recording VBI information uncompressed
23 July 2004 Profile XP System Guide
165
Recording VBI information uncompressed
NOTE: VBI information is not present in HD video. Instead, this information is
carried in the video stream as ancillary data.
For DVCPRO 25, Closed Captioning and V-chip data is extracted and stored on
input, inserted on output.
For DVCPRO 50, Closed Captioning and V-chip data is compressed.
The Profile XP Media Platform provides the ability to store up to 6 lines of
uncompressed Vertical Blanking Interval (VBI) information along with your MPEG
clips. This feature is desirable for uses such as closed captioning, which might be
seriously degraded by losses incurred at lower video compression data rates. However,
storing VBI information in uncompressed form can add up to 3Mb/s to your storage
requirements.
Specifying lines of VBI information to store uncompressed involves using the Channel
Configuration dialog box to select which lines the channel will treat as uncompressed
data.
To select which VBI lines to record as uncompressed data:
1. Choose Channel Configuration in the Configuration Manager dialog box. The
Channel Configuration dialog box appears.
2. Click the tab for the channel you want to modify, then the Video Track icon ( )
in the configuration tree.