For screenshots at intervals you could perhaps use ffdshow's "Grab"-feature.
(Grab every ... frame).
To check whether ffdshow-video decoder is used (and to access ffdshow's features):
rightclick (with moviefile loaded) > Options > Filters > Advanced
Concerning ambilight: did you find this
old post by RafkeP re. Movie Mood Light or
MoMoLight (thread dating back to mid-2006, i.e. about the time that the very first build of BS.Player version 2 was launched)?