I don't really do much with video with my computer, so it's not something I've looked into, but while we were in Durham we had some DVD's we wanted to watch (some episodes of Foyle's War, and also Moonrise Kingdom), and our room's DVD player wasn't cooperating so we watched them on on my laptop, which has the biggest screen of the ones we brought down.
The program I used is called LinDVD, which I think is the only remaining part of a defunct, early 2000's attempt to make a Windows-like consumer Linux; LinDVD is not what plays video files -- and in fact has no provision to just open a file and play it, you put in a DVD, and LinDVD plays it, and that's that -- and I normally use something called Totem to play an ordinary video file.
Anyway, we watched the movies, no problem, but then I went to use Totem and it crashed on startup. Uh oh -- did I break something by using LinDVD? No idea, so I tried some other video players (Gnome Mplayer, which is a GUI wrapper around the regular command-line Mplayer program, then Mplayer itself) and they also hung up pretty much at startup.
I started to think that there was something wrong with my codecs: they might have been corrupted by a recent automatic upgrade, so I removed and reinstalled them -- no change. Strangely enough, LinDVD still worked fine (it might have its own codecs), as did Kino, a video editor I have.
The next thing I do is try to put on some music -- and Rhythmbox, my music player, also hangs on startup. I try mplayer again and look at the error messages it writes to the console, and sure enough there's some problems with ALSA, the "advanced Linux sound architecture."
Linux has a very convoluted sound system, and this is another area I haven't really studied up on. Suffice to say that once upon a time, sound was controlled by something called OSS, which then got mostly supplanted by ALSA, which in turn got superseded by PulseAudio, but they all are still there, running and interoperating, not so much in layers like the network stack, but more like a mish-mash.
I'm not sure what LinDVD does, but I'm pretty sure that Kino uses OSS rather than ALSA, so I think I'm getting somewhere. What I try to do next is, remove and reinstall ALSA and PulseAudio. No results, and there seems to be nothing about this problem on The Google, unless you count messages like "your system is way out of date, you should upgrade."
A word about Ubuntu: they make new versions of their distribution about once every six months, which basically become obsolete (that is, unmaintained) within a year or so. They also put a version every two years or so, designated LTS (long term support), which is maintained for about 3 to 5 years. I've used the version 10.04 LTS distribution for years, and it's now near end-of-maintenance; I've resisted upgrading because the next LTS version changes the desktop in ways I don't like, so I'm not exactly bleeding edge in my Linux technology.
I'm basically out of options, and am now resolved to upgrade -- which means backing up my data and configurations, and making a list of all the software I installed outside of the Ubuntu system, just in case... Somewhere in this mess I also made the mistake of removing LinDVD with the intention of reinstalling it, only to find that it's not part of the Ubuntu package universe, and in fact it's not available unless you're say Dell, and planning on shipping it with your computers. D'oh!
There are ways to deal with LinDVD issue as well as the upgrade mess, I just have to jump through the hoops, and I'm working my way up to it, when an upgrade of ALSA pops up in the Update Manager. It basically took 45 minutes to run and upgraded the entire sound system.
I look at the Ubuntu website, and they say that this would basically be the last update for 10.04LTS -- and was meant to be a fix for problems in a previous update (I read that between the lines) which I took to be the planned last update for 10.04. I noticed that it also installed something called jack (yet another component of the sound architecture), this was probably what they were trying to introduce in the broken update. Basically, all my uninstall/reinstall moves just kept reinstalling the broken system; it was not corrupted in my machine per se, but in the software repositories...
So now I have my video and music back, though not DVD's at least not the ones with encryption/DRM, since I guess the only program that had that was LinDVD, and distributing the decrypting package is a legally fraught proposition in the open software world. I'm working on it, and meanwhile I now have a third volume control app (for jack, which I know even less about than the other sound components on my system). I'll skip upgrading for now...
UPDATE: After writing this, I got to thinking about watching DVD's again, so I went online to one of the video player program's websites, and they had some decoding files which are apparently less encumbered. I downloaded and installed what I needed, and sure enough, it worked! Better yet, I can use my ordinary video players, and no longer have to worry about re-installing LinDVD. I just finished watching The Matrix, the only DVD I own and an ironic choice to watch on a computer...
It's kind of funny how 15 years can really date something: The Matrix is still a cool movie (as long as you refuse to acknowledge the existence of the sequels), but 9/11 kind of made watching buildings explode a little less fun, and recent mass shootings put a different spin on the gun fetish scenes. I just finished reading a series of cultural essays, jeremiads really, in a book from the nineties called Commodify Your Dissent (I got it in a Durham bookstore), and the whole book was an indictment of The Matrix's themes and imagery before it ever got filmed...
