Frame Rate; Resolution - PRG MBOX User Manual

Frame Rate

Movie frame rate must be considered when creating content for Mbox. For the best results in typical usage, content
should be rendered at a frame rate that is exactly one-half of the refresh frequency of Mbox's video output. If the
connected display has a 60Hz refresh, movies that play at 30fps will synchronize exactly with the output to the display.
While content with high or lower frame rates can be used, there may be some noticeable effects depending on the frame
rate. In the above example, if the movie has fewer than 30fps, then the Graphics card will periodically need to repeat
some frames and the movie would appear to play less smoothly. Depending on the frame rate of the movie or the
motion in the movie's imagery, this effect may be more or less noticeable.
If the movie's frame rate divides evenly into Mbox's output refresh frequency, then the movie will play more smoothly;
20fps content looks better with a 60Hz output than 24fps content does. If the Mbox output frequency is 50Hz, then
it would be best to create content that is rendered at 25fps. If output frequency is 59.94Hz, then content should be
rendered at 29.97fps, and so on.
Refer to "Connected Displays and Fullscreen Mode Interactions" on page 68 for more information the interaction
between Mbox's outputs, connected displays, and refresh frequency.
Mbox is able to play content that has a framerate higher than one-half of the output refresh frequency. Within the
performance limits of the computer hardware, higher framerates can provide smooth playback if they are exactly the
same as, or a multiple of, the refresh frequency. If the output refresh frequency is 60Hz, then movies can have a frame
rate of 60fps or 120fps, and so on...
Generally all custom content for a specific event is rendered using a common framerate; all movie files for one show
might be 30fps, rather than some being 30fps and others being 29.97fps. Therefore, it's important to ensure that all
video outputs from the Mbox computer use the same refresh frequency, and that the refresh rate is a multiple of the
movie framerate. In setups where Mbox has multiple outputs with dissimilar refresh frequencies, video will only be
rendered in sync with the first output's refresh. Therefore content displayed on the outputs having dissimilar refresh
frequencies may not appear to play as smoothly.

Resolution

Movie resolution - the movie's dimensions in pixels - has an impact on the performance of the Mbox server. To put it
simply, the larger the movie's pixel dimensions, the harder it is to play. For best results, always try to play the smallest
movie possible. Of course, there are factors outside of Mbox that need to be taken into consideration when choosing a
content resolution - type of output signal, display device native resolution, size of projection surface - but for the most
part, there is not much point in playing content that has a higher resolution than the display it will be viewed on. But
admittedly, sometimes the smallest possible movie is not the one that looks the best with every particular setup, so
make sure to test in advance if possible.
Mbox v4 does not have any limit to the resolution of movie content. As long as the Mbox computer's hardware can
support reading the movie from the hard drive, decompressing it, and rendering it without dropping frames then that
content is fine. In real-world conditions, 4K resolution (3840 x 2160 pixels) is about the largest useful size for content if
more than one movie is going to be played at the same time.
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