[Ffmpeg-devel] [RFC] dlopen vs linking for external libraries

[Michael Niedermayer]

Hi

On Mon, Feb 12, 2007 at 07:57:36AM +0200, Uoti Urpala wrote:
> On Mon, 2007-02-12 at 03:13 +0100, Michael Niedermayer wrote:
> > well i do have many gb but i still feel fairly unhappy if i have to install
> > 100mb of things i dont need and which may even make my system less secure
> 
> I wouldn't consider 100 MiB for the whole distro bad. In Debian you

i would 


> could probably save more in easier ways such as moving all documentation
> away from binary packages.

thats a good idea too but its independant of the current subject 


[...]
> 
> > > In addition to the extra complexity in the program code dlopen() makes
> > > the program more brittle and creates other problems for distros. It
> > > makes it impossible to verify correct dependencies from the binary
> > > directly (which is usually done in Debian) and makes it harder for other
> > > packages to depend on the program (if I need functionality X how do I
> > > express that when program Y might or might not support that depending on
> > > what else is installed? Depend on Y+exactly what?).
> > 
> > for example
> > myprog 2.3.4
> > depends: ffmpeg-faad >= 1.2.3
> > 
> > ffmpeg-faad 1.2.3 (virtual package)
> > depends: ffmpeg=1.2.3, faad >= 3.4
> 
> It cannot be a virtual package if it has dependencies.

in debian? did i say iam talking about debian? anyway then make it a dummy
package ...


> 
> > or a million variations of that ...
> 
> Creating lots of extra packages like that would cause problems (bigger
> package lists, more things for people to browse through etc).

that are purely organisatorial problems (not displaying these extra
packages), also the lists will grow exponentially anyway over time so if
you system isnt scalable you have a problem anyway

[...]
> > furthermore for the embeded case the storeage space for
> > excutables might differ from that for media files (how many dvds bought in the
> > shop contain a ffplay execuatble? or how many satelite trasmissions of movies
> > contain libavcodec?)
> 
> For the embedded case I'd expect people to want custom executables. If
> you consider modularity of binaries so important how about making each
> codec in FFmpeg a separate .so?

that would be alot of work, compared to dlopen existing .so or even just
keeping existing dlopen functionality which is near zero work

> 
> > > If the dlopen() features do not interfere with other code then I have
> > > nothing against keeping the option to use them in FFmpeg.
> > 
> > great so we agree
> 
> I disagree with your earlier "keep dlopen and drop linking if you want
> to drop something". Plus your earlier complaining about distro
> dependencies - I think the distros mostly do that right.

so you agree on the points which are on topic on ffmpeg-dev
and no i wasnt serious with the "drop linking" ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The worst form of inequality is to try to make unequal things equal.
-- Aristotle
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20070212/dbafd8ff/attachment.pgp>