[MPlayer-dev-eng] Re: [PATCH] SSA/ASS subtitles support

[Uoti Urpala]

On Wed, 2006-05-31 at 22:28 +0400, Evgeniy Stepanov wrote:
> The architecture is now like Reimar suggested: ass_render_frame() produces a 
> list of bitmaps, that are blended later by vf_ass.

I think his suggestion wasn't quite that, but rather that vf_ass create
the list of bitmaps without necessarily blending them to the image,
which could be done inside the vo instead in some cases. This might
avoid an extra copy of the frame in case the original image vf_ass gets
cannot be changed, but the vo needs to do a copy internally anyway and
that copy can be changed before displaying it. The way you currently
implement it won't get the timecodes quite right (though it's hard to
see when they're not right anyway in the current MPlayer - I intended to
improve that when CVS went down and will probably continue some time
after SVN is finally up). You should code it so that the time of current
frame used by subtitle rendering can be read from the pts argument to
vf_ass (though that argument isn't yet set in current unpatched
MPlayer).


+.B \-ass-top-margin <value>
+Adds a black band at the top of the frame. SSA/ASS renderer will place toptitles there

+.B \-ass-bottom-margin <value>
+Adds a black band at the bottom of the frame. SSA/ASS renderer will place subtitles there.

Any reason to have these separately from the existing "-vf expand"
functionality? How do they interact with it?