Same problem occured today. Playing the videos gives black screen but sound. Closing and opening it again solves it. But it hurts. I've googled and found solution in a minute. It is trying to send video stream via airplay, atv2 in my case, i turned airplay off in iTunes preferences, opened video - it's ok, than i turned airplay again in preferences and it's still ok. Try it.
This problem cropped up for me yesterday. I had just copied a new video to my iTunes library and was testing that it worked properly, but while the sound was playing, the screen was black.
Pausing/pressing the Play button resolves the issue, until I select a new video/movie to play, when I have to do it again.
I'm running MacOS X 10.6.6 and iTunes 10.1.1 (4). I tried reinstalling iTunes, with no luck. I also tried the old mainstay of replacing the Preferences file, but that also didn't help.
There is ONE new wrinkle to this situation. Yesterday, I had installed a new app named AirView to stream videos over AirPlay to my iPad. This works fine, but after this, the issue cropped up, suggesting an AirPlay issue.
I have two iMacs, so decided to try this situation on the Kitchen iMac and played a video on this other iMac just fine, video and sound. I then started up AirView on the iPad and initiated the video stream to the iPad from the Kitchen iMac. The movie played fine on the iPad. I quit AirView and went back to try the video on the Kitchen iMac, and yes, the video now failed to display until I reselected Computer from the AirPlay menu at the bottom of the screen, or used the pause/play solution, even though Computer was still selected as the default in the AirPlay menu. Doing this once seemed to be enough to resolve the issue for playing all videos on the Kitchen iMac, but not on the Office iMac.
The only other difference between iTunes on these two iMacs is that one (the Office iMac) is running its videos from a FireWire 800 attached 2TB hard drive, while the Kitchen iMac's contents are on the internal hard drive.
Deselecting the AirPlay option in Preferences/Devices to start videos correctly on the Office iMac is not a solution, since this iMac serves as our home server for our Apple TV.
Since I have a practical option, however, and since this issue doesn't affect playing videos remotely using AirPlay, this is now a buggy annoyance, but no longer a problem for me.
iTunes 10.1.2 came out today and fixes this issue for me. When it can't find the previously selected AirPlay device on the network, it either gives a message telling you so, or gives an error message indicating the same. This alerts you to reselect the Computer, Apple TV, or other AirPlay device.
So, the black screen/sound only issue is gone for me.
hey i dont know, i looked everywhere and could not find the same problem i have, its wierd every time i do ANYTHING in itunes the bar at the top of itunes that displays the song title and arist, time ect. it blinks black around the song time while a song is playing, and every time i sync my ipod, the colmn for apps turns black and i cant pick apps to sync to it. and its wierd becz i removed itunes and put it back on and it still did the same crap. so idk wat is going on, plz anyone who has this problem tell me to see if i could figure this out. thx
This is what fixed it for me: I changed the native format it defaulted to when double-clicking the file, from Windows Media Player to iTunes.
So, I guess I would say to check that. When you go to the .m4v file and double-click it, what program does the file load in? If it doesn't load iTunes, or load In iTunes, then that could be your problem. At least that's what I found.
Instructions for Windows:
1. Right-click the video file -- it has an .m4v extension -- and select Properties
2. In the Properties dialog, near the top, where it says "Type of file:" and then "Opens with:", click the "Change" button.
3. In the "Open with" dialog that displays, select the iTunes icon and click "OK" (or click "Browse" and navigate to the iTunes.exe, if iTunes isn't in the list).
Result: That action changes all of your .m4vs to automatically load iTunes when you double-click. Once I did that, any movie I play from iTunes always plays.
Let me know if you have questions.