[box57l]

Platform: ATV2 MC572X/A (5.0/4099)
XBMC: 11.0 Git:20120331-ebfd899 (Compiled: Apr 1 2012)
Install Method: apt-get
Issue: Frame Rate, Skipped/Dropped Frames

I have a few hundred DVD’s (PAL) which I have ripped to separate folders with a VIDEO_TS subfolder, VOB files. When playing the videos via XBMC I notice a frame rate or skipped/dropped frames problem every 2s, mostly noticeable when there is a lot of movement/panning. I have a number of HD MKV video files as well which don’t exhibit this as bad, although you can still see a frame skipped/dropped every 10s, but it is much less noticeable. This is using the default video settings from within the ATV and XBMC.

If I go into the ATV’s “Audio & Video” menu and set the TV Resolution to “720p HD – 50Hz” then boot into XBMC the entire DVD (PAL) rips play perfectly. But the HD MKV video files and a few of my DVD rips start to exhibit the same issue as the PAL DVD’s did originally.
Looking at the differences between the videos it appears the main difference is the encoded frame rate, being the PAL DVD’s are at 25FPS and almost all HD videos (and a few DVD rips) are at 23.976FPS. So from my tests it seems the issue is related to the frame rate of the video encoding, where 25FPS encodings play nice on 720P @ 50hz and 23.976FPS plays nicer (not perfect) on 720P @ 60hz.

Is this a known limitation of XBMC? I would prefer not to have to re-encode my DVD collection if possible. Any help would be appreciated in getting around this problem.


*XBMC Log along with media information for 2 video files tested are below.

XBMC Log
Video 1
Video 2

[Memphiz]

Well you got it pretty clear. This is a known issue not only with XBMC but in general.

For smooth playback on XBMC on other platforms we are able to switch the displays refreshrate to match the fps of the movie (or to match a multiple of the fps).

This is not doable with atv2 (limited by apples API). We don't have any info if apple will change this in the future - but for now we can't do anything about it.