If an open window obscures the area where the screen will be grabbed, the first frame of your movie will display part of the window. This can also occur when a screensaver appears partway through playblasting a long animation.
The Encoding drop-down updates automatically with associated codecs.
The scene plays in the active view for the playback range in the Time Slider. After each time frame is drawn, Maya takes a screen grab of the active view.
Depending on your platform and which output Format you selected, a new window opens and previews the playblasted animation. For more information, see Window > Playblast.
To output single frames of your animation to Playblast
playblast -frame 1 -frame 4 -frame 7
outputs frames 1, 4, and 7 of your current animation to Playblast.
For more information, see Help > MEL Command Reference.
To run Playblast when Maya is minimized on your screen (Linux only)
For more information, see Help > MEL Command Reference.