[MEncoder-users] Xvid bff/tff field order issue

[Dr.O.Muth at habmalnefrage.de]

Hi,

here an update to this topic:

- I forgot to mention that the movies are in PAL format.

- The exact same issue was discussed on this list already before:
http://lists.mplayerhq.hu/pipermail/mencoder-users/2010-March/011334.html
However, no solution for mencoder/xvid was suggested (other than to change the codec).

- I have made a few more tests with different files, all tff. 
Results: Mencoder/xvid does not honor the field order, regardless which field-dominance=0 or =1 is passed to it. The resulting files are identical (same md5sum) and all bottom field first.

- The problem applies to all PAL movies I tested. Even in those I mentioned in my previous posting, where the effect is not easily visible due to many  still pictures or slow motions, the effect is there: e.g. subtitles flicker. When they fade in, they are shown for a split second, then disappear for a split second and then stay for good.

- Bug?
Since mencoder when used with the xvid codec and basic options as given in the manual completely screws up good, working PAL movies, I think it's safe to call this a bug. ;-)

- Solution?
The only solution I found so far is: -vf phase=t

I'm not an expert. So I don't know whether this is a perfect solution.
Could any of the experts please let me know whether it has any drawbacks?

The results look fine to me, but this may be due to the low quality of either my video files, my analog TV, or my eyes. ;-)


One more question:
Is there any way to change the field order flag in an already encoded AVI? 
Without introducing further quality losses by re-encoding?
With mencoder or another Linux-tool?

Thanks in advance
-- 
NEU: FreePhone - kostenlos mobil telefonieren und surfen!			
Jetzt informieren: http://www.gmx.net/de/go/freephone