User Manual

Vertical Blanking Information
1090
The following problems may occur:
• If the frame contains vertical blanking information, the picture quality of the entire frame
might be slightly degraded due to the added entropy or complexity from the vertical
blanking lines.
The higher the compression ratio, the greater the number of artifacts that might be visible.
For a compression ratio of 2:1, the number of artifacts might not be noticeable at all.
• Depending on the compression ratio, the vertical blanking information itself may be
distorted.
If you want to preserve vertical blanking information, either use the 1:1 (uncompressed)
resolution or experiment with different compression ratios to make sure the captured footage or
the vertical blanking information is not unacceptably affected by the compression.
Comparison with Vertical Blanking Information on Meridien Systems
The following table shows the differences between how VBI is treated on systems with Meridien
hardware (for example, Media Composer v12.0 or Avid Symphony v5.0) and systems with
current Avid input/output hardware.
Feature Meridien Current
When does the system give you the opportunity to
blank VBI information?
During capture and during a
digital cut
During playback and
during a digital cut
n
In order to view VBI on a Meridien system you must disable the 3D hardware.
What dialog box or tool do you use to set VBI
blanking?
General Settings dialog box Video Output tool
Is VBI supported for DV resolutions? No No
Is VBI supported for MPEG IMX? No Yes
Does NewsCutter support VBI? No Yes
Is VBI supported for JFIF and uncompressed
resolutions?
Yes Yes
Is VBI information preserved when you apply
effects?
Not always
n
For example, a color
effect can modify the
VBI information on a
Meridien system.
Yes (see “Editing a
Sequence with Vertical
Blanking Information”
on page 1089.)
Can you use a two layer effect to wipe in VBI
information?
Yes No