[cairo] cairo built against libpng16

Chris Wilson chris at chris-wilson.co.uk
Tue Apr 16 08:02:19 PDT 2013

On Tue, Apr 16, 2013 at 04:28:50PM +0200, Ingmar Runge wrote:
> On Tue, Apr 16, 2013 at 12:06 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > The advice from the png authors is that set_read_transform_info is even
> > more dangerous than set_read_transform_fn.
> >
> > "The git head of libpng16 (and libpng17) has a fix that should allow user
> > transforms (but not png_set_user_transform_info) to be called after
> > png_read_update_info." - John Bowler
> Sounds reasonable to me since there's no way to call
> png_set_user_transform_info with the user data (pointer) only, you
> always have to pass the depth and channels arguments too. They should
> just add the ARGB32 and RGB24 conversions as built-in transforms while
> they are at it, hehe. ;-) Is there a public libpng git repository by
> the way? The one on sourceforge shows only "synched from tarball"
> commits.

Try: git://git.code.sf.net/p/libpng/code

If you want to convince libpng to support a pre-multiplied transform,
please be my guest :)

Chris Wilson, Intel Open Source Technology Centre

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