User Guide

936 Chapter 14: Properties
preLoadRAM
Usage
the preLoadRAM
Description
System property; specifies the amount of RAM that can be used for preloading a digital video.
This property can be set and tested.
This property is useful for managing memory, limiting digital video cast members to a certain
amount of memory, so that other types of cast members can still be preloaded. When
preLoadRAM is FALSE, all available memory can be used for preloading digital video cast
members.
However, it’s not possible to reliably predict how much RAM a digital video will require once it is
preloaded, because memory requirements are affected by the content of the movie, how much
compression was performed, the number of keyframes, changing imagery, and so on.
It is usually safe to preload the first couple of seconds of a video and then continue streaming
from that point on.
If you know the data rate of your movie, you can estimate the setting for
preLoadRAM. For
example, if your movie has a data rate of 300K per second, set
preLoadRAM to 600K if you
want to preload the first 2 seconds of the video file. This is only an estimate, but it works in
most situations.
Example
This statement sets preLoadRAM to 600K, to preload the first 2 seconds of a movie with a data
rate of 300K per second:
set the preLoadRAM = 600
See also
loop (keyword), next
preLoadTime
Usage
-- Lingo syntax
memberObjRef.preLoadTime
// JavaScript syntax
memberObjRef.preLoadTime;
Description
Cast member and sound channel property; for cast members, specifies the amount of the
Shockwave Audio (SWA) streaming cast member to download, in seconds, before playback begins
or when a
preLoadBuffer command is used. The default value is 5 seconds.
This property can be set only when the SWA streaming cast member is stopped.
For sound channels, the value is for the given sound in the queue or the currently playing sound if
none is specified.