[FFmpeg-devel] usage of Requires.private in *.pc files

Reinhard Tartler siretart
Mon Nov 10 18:30:12 CET 2008

M?ns Rullg?rd <mans at mansr.com> writes:

> If you link libavcodec with an external library, you'll need to have
> that external library.

That's obvious and not my question.

Because you're mentioning it, in debian these dependencies are
automatically caluculated. Each ELF executable (both programs and share
libraries) are automatically inspected with objdump and the the library
packages satisfying the SONAMES are identified. Even versioned
dependencies are possible here, if the library maintainer thinks they
are to be used.

This is totally not what I'm talking about here. Here pkg-config fails
if the .pc files referenced by Requires.private are not present. This
can be intended or not, see below.

> Only the package maintainer for each distro will know what it happens
> to be called there, and whether it has been split in some obscure way.

In order for the package maintainer (for ffmpeg that would be me) I'd
need to know implementation details. And that's what I've been asking
for.  If I have that knowledge, I can make a decision, but not sooner.

In detail: I need to know how and in what way libavcodec exposes
implementation details (structures, enums, etc) of libraw1394, dirac,
theora, vorbisenc. I believe avcodec does not at all, but I want to be

If that is true, I can start working on a patch for the .pc file
generation expressing that implementation detail. The effects on this
are (depending on your POV).

If that is not true, and Requires.private is indeed used on purpose, I
'just' need to add some additional dependencies, just as requested by
the bug submitter of debian bug #504220.

Reinhard Tartler, KeyID 945348A4

More information about the ffmpeg-devel mailing list