[MPlayer-users] Re: soft telecine for DVDs: can't this be applied (in principle) to framerates other than 24 or 24000/1001?

[Ivan Middleton]

> > Incidentally, does vstrict=-2 have any potentially bad side effects?
>
> Yes.  Just recently it was reported that a user gets "green blocks" on
> their DVD player, unless the MPEG-2 video has been encoded with
> vstrict=0 (or 1), so even the default may not conform to specs.

Well, I looked through the code carefully, and the only effects of the
vstrict flag which are pertinent to MPEG2 seem to be the following:

1) Enforcement of a valid framerate.  This should be fixed to allow
the new arbitrary soft telecining to work even when vstrict=0.

2) Enforcement of GOP size (not really relevant for DVDs since the
keyint is always already set to something low).

3) Restriction of the range of motion estimation to 256 (this is my
interpretation of the code; hopefully that's correct).  Is this what
causes green blocks?  I'm chagrined to notice that the default for
vstrict is -1, which allows unlimited range.  I've seen green blocks
myself on a hardware player from some of my encodes, but I didn't
worry too much since they were infrequent.