[MPlayer-dev-eng] [PATCH] A new ASS renderer

[Xidorn Quan]

On Sun, Sep 23, 2012 at 10:05 PM, wm4 <nfxjfg at googlemail.com> wrote:

> On Sat, 22 Sep 2012 20:02:36 +0800
> Xidorn Quan <quanxunzhen at gmail.com> wrote:
>
> > Hi,
> >
> > The patch attached is a new ASS renderer which is optimized for
> > subtitles with few effects. For me, this new renderer is nearly
> > 2x faster on average than the current one for those subtitles.
>
> Why does this support packed YUV only? I think most VOs are more
> comfortable with planar pixel formats. Also, in my own tests with
> "heavy" subtitle scripts, CPU rendering was always fast enough, and
> almost all time was spent in libass. That was with YV12. Is it
> different with packed YUV?
>

Support of YV12 and NV12 is in my plan. You can find that it is easy
to add new pixel format support for it, there are only two simple
functions required to be implemented.


> Why not just use vo_gl?
>

They are in different layers, so they are not comparable. Renderer in
vo layer can surely benefit performance, but there are also some
restrictions. The most obviously one is that subtitles rendered
by vo cannot be further processed by other vf, like mirror, rotate or
something like them. Even screenshot is in vf layer, therefore if you
rely on renderer in vo, you will never take a screenshot in mplayer
with subtitles. And also, mencoder can not benefit from those
renderer either. Renderer in vf is a lot more flexible.