Interlacing problems

Many TV programs are interlaced ie each frame is split into two fields of alternate lines and displayed sequentially. This historically gave smoother pictures, but leads to problems when trying to display it. The interlacing looks fairly unpleasant on the desktop, and few video card and software combinations are able to sync fields correctly when playing back interlaced video streams. This leads to a shearing effect on a computer monitor, and juddery motion on a TV.

Deinterlacing filters in video players

Xine

Fortunately xine has a deinterlace option (-D or --deinterlace on the command line) which corrects this problem, but it does increase CPU usage and can cause motion blurring. You may need as much as 2GHz/XP2000+ of CPU performance to play DVB properly with deinterlacing, although the new Greedy deinterlacer is said to have considerably more modest requirements.

tvtime

I believe the Greedy filter appeared first in tvtime, a player designed for playing video from analogue capture cards, but unfortunately not optimised for displaying on a TV screen.

MPlayer

MPlayer also has deinterlace filters. Alternatively, using a Matrox card with DirectFB allows the programme's interlacing to be synchronised with the TV out, providing a "perfect" solution.

VLC (VideoLan Client)

VLC is another popular video player, optimised for networked video streams. I have not tried it, but it claims to include a deinterlacing filter.

MythTV

MythTV is not really a video player, but a PVR with integrated video player. I mention it here because it's said to be able to use vsync interrupts provided by OpenGL or DRI to synchronise interlaced fields between a video and TV in a similar manner to MPlayer's dfbmga driver with Matrox cards. This requires the framebuffer to be running at the same speed as the video (50Hz or 60Hz) so would usually be used in conjunction with X through a VGA to RGB SCART adaptor as described above, or could potentially be used with a Voodoo 3.