Lion Quicktime Not Playing Certain Video Files

As soon as I upgraded to Lion and ran a check on random files to make sure they still worked properly, this one popped up right away. I've ripped all my DVDs to mp4 using Handbrake and although most of them still work, QT returns the error "The document "..." could not be opened. A required codec isn't available." on a few of them. After some investigation, the only difference I can find between the ones that work and the ones that don't is the codec mp4s. The file is still recognized as an MPEG-4 movie but I've never encountered (noticed, really) the -s attachment. I tried to find it in the MPEG specifications but no luck there. Has anyone encountered this and/or come up with a solution? I have Perian installed, no difference. And VLC plays the file fine so it's specifically with QT.

mp4s seems to be a microsoft version of MPEG 4

Try just altering the extension to MP4, you could try Flip4mac but I am not sure if that would be any good

Sorry for the delay. The extension itself is actually .m4v and I've tried just changing it to .mp4 but the codec is still mp4s. I'm not sure how to change that, if I can. The codec I get is specific to the DVD because the handbrake settings aren't changed between DVDs. The video plays fine with VLC but QT just refuses to play it. It's also near impossible to search for that specific codec because anytime I type mp4s, the search engine shows results that refer to mp4s as in plural, I have no idea how to make the s be used as part of the codec name. Anyway, anyone have any advice?

Trust Microsoft to make a version of MP4 that only works with their garbage.

You need to transcode the video into some other format. VLC can do this but I find that quite complicated. Do you have Flip4Mac WMV Player and Perian (both free) installed?

I think transcoding the video is probably my best bet. I have both Flip4Mac and Perian installed and these very same movies worked perfectly fine with QT in Snow Leopard. I'll try exploring that feature in VLC and see if I have any luck with it.

mp4s

Hi there, having the same mp4s problem. m4v plays in VLC and in iTunes but not in Quicktime 10... Any luck since your previous post?

No I haven't found a solution, I've just resigned myself to using VLC with these files. I tried to re-encode the files using VLC but, like chas_m said above, it's a pretty complicated process and I very probably did it wrong because it produced an unusable file. I might actually read VLC's documentation and try the re-encode again, but I can't make any promises on when that will be.

I found that the problem might be that dvd's have a Vobsub subtitle file and that Quicktime can't handle that. SRT's should work. Haven't found a way yet to convert them to SRT and means extra work. iSubtitle is a program that can encode soft subtitles (using SRT) in an existing movie. Haven't tried it yet though. Can't understand why apple can't find an easy solution...

That's interesting because when I do encode subtitles in MP4s with Handbrake I make sure to choose the non-Vobsub tracks so they can be passed-through. I am noticing though that the movies that can't be played have soft subs available so maybe I made a mistake there. Considering that quicktime was able to play these files before Lion, I definitely have to blame Apple for this one; I'm really not a fan of them removing features from their new OSs.