the first frame to play, or "here" to play from wherever the disc is currently playing.
the last frame to play, or "lastFrame" to play to the end of the disc.
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Start playing from frame "first" to frame "last". PlayVideo returns immediately, without waiting for the entire sequence to finish playing.
If first is "here", then start playing from wherever the disc is at the moment. If last is "lastFrame", play to the last frame of the disc. If first is greater than last, or if first is 0 or 1, play in reverse.
If the last parameter is left off, it defaults to "lastFrame". If there are no parameters, playVideo plays from "here" to "lastFrame".
If a blankVideo command was issued before the playVideo, the display will be blanked while searching for the first frame.
If a videoFramesPerSecond command was issued before the playVideo, the play speed will be set accordingly. Otherwise, 30 frames per second will be used.
If we're in chapter mode ("controlVideo chapterMode" was executed), first is the chapter number to play from. In this case, last is not allowed.