Problems
Triangle Man Hates Particle Man
The problem is XvMC. Because VIA's C7 CPU is so weak, smooth video playback requires use of GPU acceleration. The standard method for GPU accelerated video playback in Linux is a library called XvMC (which only supports MPEG2, but that's another issue). Enabling XvMC in MythTV causes it to crash as soon as a video is played.
Why is that? The key is in the X.Org log:
(WW) CHROME(0): [XvMC] Not supported on this chipset.
Oh dear. Without the acceleration features of the UniChrome chipset, the board simply isn't useful for media playback either, making two-for-two on VIA's failure to render the board useful for the enthusiast.
Wait, is that an alternative option on the horizon? Why yes, it is! Firstly, we replace the open-source OpenChrome driver with VIA's proprietary UniChrome driver. Does that improve things? Well, not really. Rather than white rectangles, Elisa now shows red lines (and nothing else). Rather than jerking, Quake 3 is now smooth - other than all the textures being multicolored blobs, which might be considered annoying to some players. Is MythTV happy? No, the closed source driver lacks XvMC support too.
But there is ONE final trick up VIA's sleeve: VeMP. VeMP (VIA Enhanced MPlayer) is a forked version of the popular MPlayer media player application, with an extra video output mode, which runs decoding of MPEG2 and "MPEG4" files through the board's hardware acceleration. A solution, right? Well, no, not really. Firstly, VeMP is horribly unstable (I couldn't get it to play for more than five seconds before crashing somewhere in the audio code). Secondly, VIA doesn't understand what "MPEG4" means (VeMP will accelerate MPEG4 Part 2 files, such as XviD or DivX, but not MPEG4 Part 10 files, i.e. H.264). Thirdly, compiling VeMP on a CPU as slow as a 1.0 GHz C7 is painful. Finally, perhaps most importantly, VeMP only runs as root. That's right - unless you run your media player with full system-killing access, it crashes as soon as decoding starts.
And really, VeMP misses a crucial point - people who run Linux don't expect to be forced to use a single application out of a selection, due to hardware issues. There are an enormous number of media players for Linux, each of which exists to fill a specific need, and each of which has users who have reasons for using it. By simply hacking on a single player, they're completely removing the choice that Linux users expect. Want to watch TV with MythTV? Well, tough - but there's VeMP! Want to watch HEXUS.tv? Well, tough - but there's VeMP! It's a poor solution to a major problem.
