Avid Technology Pro Tools HD 7.2 - Manual (Page 115)

Chapter 9: New Pro Tools Features for Avid Video Peripherals 109
Playback of QuickTime
Movies through Avid Video
Peripherals
Pro Tools lets you play most standard-definition
or high-definition QuickTime movies through
an Avid video peripheral to an external moni-
tor.
Digidesign has specifically tested DV25 and
H.264 movies. Other codecs may work but have
not been tested. (“Uncompressed” QuickTime
movies are known to play back poorly.) In gen-
eral, performance varies depending on the
movie dimensions and compression rates, the
number of tracks, plug-ins and automation in
your session, and the speed of your processor.
When playing back QuickTime movies through
Avid video peripherals, the following rules ap-
ply:
• Playing QuickTime video through any
FireWire peripheral, including an Avid
video peripheral, will delay the output. You
can compensate for this with the Quick-
Time Video Offset setting (located in the
Set Video Sync Offset dialog). The best set-
ting depends on your specific system, but
when using Avid video peripherals
18 quarter frames is a good starting point.
See “Compensating for Video Monitoring
Delays” on page 105 for details.
• Large-dimension movies (such as 1080i)
may affect processor speed, so you may
want to work with movies of smaller di-
mensions.
• Avid video peripherals output only stan-
dard-definition images with a 4:3 aspect ra-
tio. When playing back files with different
aspect ratios (such as 16:9), the image will
be stretched to 4:3. Some professional
monitors can compensate for this by letter-
boxing the image.
• Avid video peripherals only accept video
reference input at standard definition rates
(25 and 29.97 fps). When playing back
QuickTime movies with higher frame rates,
only every other frame will output to the
NTSC/PAL monitor.
• When playing back movies with frame
rates of 50, 59.94, or 60 fps, set the Pro
Tools session rate to one half of the movie's
frame rate.
Adjusting Video Black Output
Level
When outputting NTSC Avid video from
Pro Tools, you can adjust the level of NTSC
video black output to 7.5 IRE or 0 IRE.
The black level of NTSC signals for the United
States and many other countries are generally
calibrated to 7.5 IRE, also known as Setup. Some
other countries (such as Japan) require NTSC
signals to be output at a black level of 0 IRE.
To adjust the level of black output in Pro Tools:
1 Choose Setup > Preferences, and click the Op-
eration tab.
2 Do one of the following:
• To output black level at 7.5 IRE, select the
NTSC Has Setup option.
– or –
• To output black level at 0 IRE, deselect the
NTSC Has Setup option.
3 Click OK.
4 Restart Pro Tools.
Changing this option requires you to restart
Pro Tools.