On Wed, Aug 18, 2010 at 10:13:56AM +0200, jori.hamalainen@xxxxxxxxxxxxxxx wrote: > Computer hardware usually cannot provide 50.000Hz, 59.940Hz or 23.976Hz > outputs to your TV/Monitor. This will cause some judder on display output > as MPEG/AVC input-stream is not synchronized to output framerate. it's correct that computer hardware normally cannot provide 50.000Hz. Nor can it adapt the framerate dynamically as I did for some handpicked hardware in my sync-fields-project [1]. But even in the case of non synchronized output framerate (VDPAU) it does not necessarily mean that judder will result. Nvidia graphics use excellent deinterlacers. These produce a stream of progressive frames with field frequency (e.g. 50Hz) out of an interlaced source. Single frame doubler/losses at 50Hz are not visible to the human eye. To put that in other words: VDPAU uses some brute force (deinterlacing) to work around their design flaw (missing synchronization). In practice this works very well. Surely it's not an optimal solution: the price for that is excess graphics power requirement if you think in terms of 5W units. But nonetheless the smoothness of picture flow is excellent. If some people report they observe judder though this mostly is a result of a wrong setup (xorg.conf) or use of temporarily broken beta software (xine derivates). With VDPAU design there exists nothing like inherent judder. For the future I wish there once will become available some graphics with native dynamic framerate support. Never seen such thing until today. cheers Thomas [1] http://lowbyte.de/vga-sync-fields/vga-sync-fields/ _______________________________________________ vdr mailing list vdr@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/vdr
