[pkg-nvidia-devel] Bug#558434: Bug#558434: libvdpau1 should not depend on the libvdpau-driver metapackage

[Andres Mejia]

On Saturday 28 November 2009 20:43:49 Mario Limonciello wrote:
> Hi Anres:
> 
> On Sat, Nov 28, 2009 at 18:56, Andres Mejia <mcitadel at gmail.com> wrote:
> > On Saturday 28 November 2009 17:09:21 Mario Limonciello wrote:
> > > Package: libvdpau
> > > Version: 0.3-1
> > > Severity: normal
> > >
> > > Currently, libvdpau1 depends on libvdpau-driver which in turn only
> >
> > depends
> >
> > >  upon an NVIDIA closed source library.
> > >
> > > This means that any package that depends on libvdpau1 to be able to
> > >  optionally provide support for VDPAU will depend on the NVIDIA
> > > library. The dependency should be dropped, and individual packages that
> > > will "require" VDPAU support should depend upon the driver package.
> >
> > The idea with the libvdpau-driver was for it to depend on the multiple
> > implementations of the vdpau driver that may exist. It would have a
> > Depends field like.
> >
> > Depends: ati-libvdpau1-driver |
> >              intel-libvdpau1-driver |
> >              . . .
> >              nvidia-libvdpau1-driver [amd64 i386]
> >
> > In this way, only one package (libvdpau-driver) has to be updated when a
> > new
> > vdpau driver implementation is available, rather than updating however
> > many packages that may depend on libvdpau1.
> 
> This i'm not arguing with.  I think it's a great idea to have such a
> metapackage, I just don't think the metapackage should be an explicit
> dependency of libvdpau1.

libvdpau without a vdpau driver is not very useful, thus the reason why 
libvdpau1 depends on libvdpau-driver.

> Some apps (i'm looking at mythtv and mplayer
>  here) can build with vdpau support, but work just fine in other modes.  So
>  look at this hypothetical situation for how it is today:
> 
> Lets say I'm on an intel graphics system.  There's no VDPAU support yet on
> Intel.
> 
> 1) You build-depends mplayer on libvdpau-dev.  It gets VDPAU support.
> 2) Via shlibdeps, mplayer's binary package now depends upon libvdpau1.
> 3) libvdpau1 depends on libvdpau-driver.
> 4) libvdpau-driver pulls in the non-free nvidia vdpau stuff
> 
> That non-free nvidia stuff isn't desirable on such a system.  If you were
>  to however go and say build an NVIDIA rig, the NVIDIA glx package would
>  pull in the vdpau things automatically and you'd be able to benefit from
>  VDPAU then.

Seeing that the nvidia vdpau driver is the only vdpau driver implementation 
available, that's why you see libvdpau-driver have only one dependency. Once 
more vdpau driver implementations are available, libvdpau-driver will be 
updated and users may freely choose what vdpau driver they want to use, or 
install all of the drivers (libvdpau can handle picking a suitable driver), or 
simply let apt install the default vdpau driver (the first package in the 
Depends field out of all the alternatives). Also, once a free vdpau 
implementation becomes available, libvdpau can enter main.

Also, nvidia-glx doesn't depend on any of the libvdpau packages so installing 
nvidia-glx won't install libvdpau.

-- 
Regards,
Andres