A cellphone is just an example of black screen with sound video in which from my understanding what you said is my cellphone lack of software or hardware that doesn't support HD video, however my main point it's happen to windows media player on my pc too very rare situation but it happen with some videos.
It could be missing the correct codec as you mentioned in your statement?
Yes it could be a codec issue. To rule that out you can either install vlc or the codec packages by divx and xvid. For a mobile device I don't think that you really can't do anything about hardware restrictions. However I've never used a windows phone.