Hi all,

I need to use libjpeg-turbo for some apps that rely on specific
libjpeg-turbo extensions that are not available in the standard (IJG's)
libjpeg library. So I started to create a set of ptxdist rules for
libjpeg-turbo.

libjpeg-turbo is supposed to provide a drop-in replacement for the standard
IJG's libjpeg, and in fact many Linux distributions have already switched
to it. So most packages that currently depend on LIBJPEG should be able to
use libjpeg-turbo as well without any changes.

Example: gst-plugins-good1.in currently does the following:

select LIBJPEG if GST_PLUGINS_GOOD1_JPEG

However, gst-plugins-good1 should work just fine with libjpeg-turbo as
well. In fact the upstream gst-plugins already switched to libjpeg-turbo
some time ago (see the Cerbero scripts)

So, what is the recommended way to approach this in ptxdist? I can imagine
some options:

1. Provide a separate set of .in/.make files for libjpeg-turbo and a
separate LIBJPEG_TURBO package. So new packages that want to use
libjpeg-turbo would need to explicitly select LIBJPEG_TURBO (instead of
LIBJPEG). But this means that packages that currently use libjpeg would not
be able to benefit from the performance improvements in libjpeg-turbo. Also
I am not sure whether these two libraries (libjpeg and libjpeg-turbo) can
actually coexist in the same system.

2. Modify the LIBJPEG rules to provide an option to select between the
standard (IJG) libjpeg, or libjpeg-turbo. This would be similar to what is
done in alsa.in/alsa.make to select between the "full" and "light" versions
of the library.

3. Other?

Thank you,

Guillermo Rodriguez Garcia
guille.rodriguez@gmail.com