Pyro Industries API-1394PCI Manual de usuario descargar pdf (Pagina 294)

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■ REAL-TIME EFFECT PLAYBACK

When you create effects, you may have to determine whether elements are within

the title safe or action safe areas. Using the Grid button will allow you to turn on and

off a grid over the monitor so that you can see these areas. Title safe is the inner grid;

no titles should extend beyond or over this area. Action safe is the outer grid, which

covers most of the video image. In general, no significant action should take place out-

side of this area because it won’t show up on some video monitors and televisions.

Real-Time Effect Playback

The better your understanding of Avid systems, the easier it is to determine how your

system will perform using vertical layers of real-time effects. To play back a sequence,

Xpress Pro will do three things:

• Build the pipes

• Load the RAM buffer

• Begin playing back

Building the Pipes

When you press the Play button, the system immediately begins a process known as

“building the pipes.” This is the function of “reading” the sequence and determining

what media it will need to play back, what effects will need to be preloaded, and so

forth.

In many cases, it will take an insignificant amount of time to build the pipes; the

process goes unnoticed in the background. But when a large amount of media is accessed,

when there are many cuts, or when the effects are fairly extensive, the time between

pushing Play and the media actually playing can be long and frustrating. In cases such

as these, the PlayLength toggle button (Xpress Pro only) comes in handy.

The PlayLength toggle switch allows the system to build the pipes for only

one minute. This way, it will take a shorter amount of time to build the pipes and play

back the sequence.

Xpress Pro indicates that PlayLength is active by switching your Play button

from its normal color to white. When PlayLength is toggled again, the system returns

to normal playback mode, and the Play button resumes its usual characteristics.

Loading the RAM Buffer

Although one might assume that Xpress Pro reads media directly from the drives, this

isn’t the case. The system will normally preload 20 frames into a temporary RAM

buffer before beginning playback. This RAM buffer allows your system to catch up

with itself by preloading the frames ahead of time. If it has difficulty reading media, as

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Pyro Industries API-1394PCI Manual de usuario Pagina 294