Quicktime Pro 7 on Snow Leopard displays black with uncompressed Quicktime

Question

Hi, I have searched these discussions but with no luck so far. Any help will be greatly appreciated but I have the feeling there may be no solution to my problem. Perhaps the new 64 Bit Quicktime 7 is missing the codecs I need.
For more than five years I have been exporting uncompressed Quicktimes from an online workstation (Autodesk Flame) to my G5 to make small quicktimes to email clients to see work in progress, or to make file sequences for upload and also to make DVDs fro client presentations outside my online suite. I would export an uncompressed Quicktimes of, (for instance), a 30" TV Commercials (of around 1GB) from my online workstation fro my Mac to deal with. This week I changed my five year old G5 for a Snow Leopard Mac Mini. My Quicktime 7 Pro license transferred fine, but it seems to me Quicktime 7 is working quite differently and iDVD also. When I open an uncompressed quicktime created from my online workstation the video is Black , but I can hear the audio. It still allows me to make a small H264 quicktime but I can't export file sequences correctly. The frames created are black. iDVD also creates black DVDs but with sound. BTW I have the same problem if I export an uncompressed AVI from Flame.
I thought it might be hardware limitation of the Mac-mini, but some simple tests indicate that's not the case. From my online machine I can export an uncompressed Targa file sequence of the Commercial and an uncompressed wav sound file instead of an uncompressed Quicktime. I can then use Quicktime 7 to put them together make an uncompresses quicktime from the Targa sequences combined with audio and it displays the video fine and I can do whatever I want with it, but it takes time to create. This uncompressed quicktime file is around the same size 1GB as the uncompressed movie file that I am trying to get Quicktime 7 to display, that I normally export from Flame. (And BTW the Mac Mini renders quicktimes nearly three times faster than my 2004 G5 and can play back the 1GB uncompressesd file it made with hardly a glitch, The G5 would choke if i tried to play an uncompressed movie).
This kind of uncompressed Quicktime that I can make from Targa files using Quicktime 7 Pro seem to be exactly the same as the uncompressed Quicktimes my Autodesk Flame exports. In the properties window the video codec is "None, 720 x 576 Millions+" in both cases, and it is of course a .mov. So why the difference? My big problem is that the uncompressed quicktimes exported from Flame are not able to be handled as well by my Mac as before. I know I can export file sequences with a separate audio files and put them together in Quicktime but when I am working on a commercial I might want to do this 20 times a day. Exporting an uncompressed file with audio is much less hassle. I would just drop it in iDVD and make a DVD or get Quicktime to re-encode it for email. My Post Production clients pay me to work on the online workstation and I don't want to spend extra time on my Mac-mini. I was hoping to spend less....
I hope I have been clear enough explaining my problem. Thanks very much for any tips.
Regards,
Harold

Answer 1

Hi there,
I can confirm that this seems to be a bug in Quicktime where it tries to multiply the alpha channel against the contents of your movie file.
I had a bunch of Apple Animation quicktimes that are suddenly playing back as all black. I opened one of these movies in Shake and noticed that it had an all black alpha channel. So, as an experiment, I added an ellipse as an alpha channel (making sure it was not pre-multiplied against the image) and wrote this movie out as an Apple Animation. Sure enough, quicktime would now play back an image where the contents were only visible inside the the ellipse. I.e. it is multiplying the image by the alpha channel.
So, the issue is that quicktime multiplies the alpha channel against the contents of the movie.
The workaround is to re-encode your movies with solid white alpha channels (I have been unable to write out an Apple Animation movie without any alpha channel at all). Most likely you don't care what is in your alpha channel (the Apple Animation codec seems to add it whether you actively request it or not), but if you do, then I don't know how to get around this problem.
Also... what a pain. I don't really relish re-encoding all of my quicktimes. I will also file a bug (or piggy back on the one already filed). Hopefully we can get this fixed soon.