If you're using miniMAD Video to playback video on a screen/projector, movie files can reach up to 4GB (the maximal size of a file on the FAT32 partition) on a 12GB partition.

The video files are transcoded to H264 / 420 pixel-format, and with default export setting an original file sized 1920x1080 & 30fps size may be downscaled to around to 1600x900 to ensure a smooth animation.

That being said, it's hard to tell the maximum length of a video file because the compression is time-based and depends on the actual content, but feel free to contact the support for specific concerns.