[MPlayer-dev-eng] Re: [PATCH] New mode for 'tinterlace' filter

[Ivan Kalvachev]

2006/4/9, Walter Belhaven <wbelhaven at yahoo.com>:
> Ivan Kalvachev writes:
> > 2006/4/2, Walter Belhaven :
> > >
> > > Here's a patch to libmpcodecs/vf_tinterlace.c which adds a new
> > > mode (-vf tinterlace=4).
> >
> > Committed.
>
> Thanks, but I was hoping to get some feedback/advice on the question I
> posed in my original E-mail and within the comments of the code.
> Namely, how should I set dmpi->fields of the image returned by
> vf_get_image() -- should I set MP_IMGFIELD_INTERLACED? -- how about
> MP_IMGFIELD_TOP_FIRST? etc.
>
> [NOTE: I should have placed those comment/lines inside the "if", right
> after dmpi=vf_get_image(...), not outside the "if".  Uncommenting them
> where they are right now will causes a dereference-of-null segfault.]
>
These were added only as hints mainly to export soft telecine to
filters or to allow hard_telecine->soft_telecine conversion.
You must ask Rich (dalias) about them. E.g. _ORDERED seems to indicate
that the flags are valid and actually used. (tff & rff on progresive
image are used as soft telecine flags).

However it seems good idea to proper flags when the content is know to
be interlaced. This however means that these flags should be added and
for other tinterlace modes, not only your :)

however maybe there would be good idea to have tff and bff as options.

> > Next time add to the patch and entry for the man page (i wrote one, i
> > hope you like it. if not, send patch ;)
>
> Can you point me to where I would find such a thing?  Yours is fine,
> but I think the original documentation of tinterlace=0 is broken -- it
> should say double-height, and I'm not sure it's correct regarding field
> order.

man page is in DOCS/man/en/ . There is dedicated maillist called
mplayer-docs where you can get help, advices etc..

About the first mode. I think you are right.

Something more, I think that mode 0 and 3 shuold not double d_height,
as it breaks the aspect ratio calculations. (makes people to
egg-heads)