Hello! I'm new to this forum (and fairly new to Mac) and am having a slight issue with getting Quicktime and Logic 9 to play an mp4 file correctly. When the file is opened, the window goes black, with the audio playing throughout the clip - very inconvenient since I am on a film composition course where I need the video, NOT the audio. However, if I open the file in VLC Media Player, it plays perfectly fine. The problem is, I need to write music to go with the clip, which means using Logic. When the clip is imported into Logic, the same thing happens as with Quicktime; black screen, full audio. I read on a thread somewhere on this forum that Quicktime may not be using the right codec, but have no idea which codec I would need or how to use it through Quicktime (or where to get it from). The strange thing is, Quicktime and Logic both managed to open and play an mp4 file from my boyfriend's phone with no problems whatsoever, but the files that I transferred from my university will not play, which doesn't make much sense really. I've tried transferring them via an external hard drive, USB stick and DVD - same case for each one! Any help would be very much appreciated, I need to make a decent start on this project by Tuesday so would like for it to be resolved this weekend! I have a Mac Mini, if that even matters?