Found this in the manual, page 733
Additional Cell Parameters for QuickTime Movies
If you create a particle system using a QuickTime movie as a cell, additional parameters
appear. These five parameters are:
Play Frames: This checkbox controls playback. If it’s turned on, it loops the playback of
the animation or movie clip used to generate each particle. If it’s turned off, particles
are generated using the still frame specified by either the Random Start Frame
parameter or the Source Start Frame parameter.
Random Start Frame: This checkbox introduces variation into animated particles
generated from QuickTime objects. If it’s turned on, each newly generated particle
begins at a different frame of the animation. Stills are chosen randomly if Play Frames is
turned off.
Source Start Frame: Chooses the frame to begin animation, if Play Frames is turned on,
or the still frame to display if Play Frames is turned off. This parameter only appears if
Random Start Frame is turned off.
Hold Frames: The number of times each frame of the source movie is repeated during
playback. The larger the Hold Frames value, the slower your playback.
Hold Frames Randomness: Varies the number of frames to “hold.” See the Hold Frames
parameter description.
bogiesan
This is my standard sigfile so do not take it personally: “For crying out loud, read the freakin’ manual.”