Video playback under Linux has come a long way in general, with the addition of DVD playback the icing on the cake for many of the traditional players. There are four major projects that offer this feature, but no player is really good enough for it to be singled out as the player for Linux.
In this review, I will be looking at general features that I think are important in mainstream DVD players: available modes, ease of navigation (through menus or otherwise), subtitle support, ease of installation, reading of encrypted DVDs, and quality of sound and video.
The system I used was a Debian testing distribution on a 700 MHz Duron with 512MB of RAM, a 64MB GeForce 2 video card, and a SoundBlaster Live! sound card. I built all of the players from the latest available source code (instead of using the precompiled Debian packages, which were a little out-of-date). The four test DVDs I used were "Rammstein: Live aus Berlin", "Ghost in the Shell", "Magnolia", and Collection 0:2 of "Neon Genesis Evangelion".
Ogle features interactive menus, and was the first Linux DVD player to do so. Although fullscreen mode is really quite necessary in a "home theater" setup, it was disappointing to note that Ogle doesn't support configuration (choosing angles, etc.) whilst in fullscreen mode; the interface is only available when running in windowed mode. Subtitles were generally good and clear, and it is easy to choose between languages and subtitles from the (comparatively bland) user interface. The use of libdvdread/libdvdcss to read encrypted DVDs was an excellent choice, and made Ogle very easy to set up.
The only major gripe I had with Ogle, which prevents me from labelling it the player for Linux, is that the sound was a little flaky at times (when switching between fullscreen and windowed modes) or didn't play at all, and one of the DVDs I tested did not run -- it sat on an introductory screen and displayed mangled video.
However, apart from these issues, Ogle is quite a competent player, and shows a lot of promise. The Ogle Web page says it's also missing a Karaoke mode, but I won't hold that against it.
Xine seems to be the favorite amongst Linux DVD buffs, and you can see why. It's quite a good player, after you set up all the plugins to make it useful, and if you treat it gently (it was probably one of the easiest-to-crash players I reviewed).
The interactive menus are generally good, though a little jerky, and it's easy to return to them from within a movie by hitting Esc.
The fullscreen mode offers something over Ogle: right-clicking brings up a GUI that can be used to choose angles, languages, and subtitles, and to configure other parts of the player. The subtitle display is generally good, as is the sound. The sound was easily one of the better of the four, and nicely in sync with the video (which was mostly good, if a little jerky at times).
The issues surrounding Xine are mostly about its attitude towards the playing of encrypted DVDs, but a little searching will find various plugins that perform this feature. Although they require more fiddling to install, they bring Xine into the realms of the commercially-available DVD players.
There are several frontends available for Xine for GTK+, KDE, the console, and more.
I quickly fell in love with VLC. Although it is probably rivalling Ogle with its bland initial interface, it was a pinch to install and virtually ran "out of the box" with all of the testing DVDs (using libdvdread/libdvdcss). Although it is merely a client for a much larger-scale project, it is definitely an excellent player by itself, and has the best fullscreen navigation features of all of the players reviewed. Right-clicking lists a menu with heaps of options, including the ability to skip to different chapters quickly and easily.
It does, however, lose a little in not supporting DVD menus, which many people like (though I didn't miss them as much as I thought I would). It has good subtitle support and excellent video. With some DVDs, the sound was scratchy, which was distracting in quiet moments. Quite a promising player, VLC is definitely worth a look if you're dissatisfied with your current player.
I've long admired MPlayer's ability to play almost anything I threw at it, and when it finally supported DVDs, I immediately gave it a shot. Although it's mostly a commandline application, there is a GUI available if you compile it with the correct flags.
The video and audio were both excellent, but once again there is no menu support, and the lack of easy-to-navigate preferences, chapter selection, etc. will turn many home cinemagoers away. The seemingly endless amounts of documentation will tell you exactly what you need to do in order to get such-and-such a feature going, but sometimes, it's just nice to be able to point and click. For quick'n'dirty feature presentations, MPlayer is a good choice, but if you want to experience the DVD as a whole, you'll only get frustrated.
There are a number of projects that are aiming towards providing the Linux community with a high-quality DVD experience, and they are all on the way to that goal. You may have a favorite, but, every so often, you'll need to deviate from it in order to find one that plays "that" DVD. This issue aside, you will find the general state of DVD playback under Linux a satisfying one that is worth looking into.