[Digikam-devel] libjpeg 8 requirement considered harmful

[Adam Tkac]

On Mon, Jan 21, 2013 at 11:29:18AM +0100, Francesco Riosa wrote:
> Il 18/01/2013 18:52, Kevin Kofler ha scritto:
> [snip]
> >* IJG libjpeg, on the other hand, started making API and ABI changes to their
> >code to support some new features. While libjpeg-turbo has some support for
> >the IJG lijpeg 8 ABI, libjpeg-turbo's upstream considers the additions and
> >changes unnecessary and useless (mainly because JPEG files using the new
> >features cannot be read with older libjpeg implementations!), will not
> >guarantee that any added functionality actually works (only ABI compatibility)
> >and strongly recommends against enabling the new ABI:
> >http://sourceforge.net/mailarchive/message.php?msg_id=30352465
> [snip]
> 
> Having some experience on packaging I do simpatize with Kevin
> arguments, but that's not the point of this email, instead there is
> one thing that really scare me:
> 
> "JPEG files using the new features cannot be read with older libjpeg
> implementations"
> 
> There is a possibility that application using the new IJG lijpeg 8
> ABI suddently start writing jpegs which can only be read from newer
> versions of softwares (on linux/win/osx)?

AFAIK not by default. You have to explicitly say in your application that you
want to use new features.

Regards, Adam

> If there is a chance that by design or by bug this is the case new
> version should be banned.

-- 
Adam Tkac, Red Hat, Inc.