Mytharchivehelper needs libav libs to link

[Mark Buechler <Mark.Buechler@…>]

In mythplugins, mytharchive/mytharchivehelper fails to link without "-lmythavcodec-0.20 -lmythavutil-0.20 -lmythavformat-0.20" if a system installed ffmpeg is not found in the standard lib paths.

[paulh]

Not really sure what your problem is? mytharchivehelper uses some of the libmythav* stuff so needs to link to them. It shouldn't be using any of the libraries from ffmpeg only the myth versions.

I did just spot a possible problem with the mytharchivehelper.pro were it is was only telling the linker to use the mythav* libraries for the macx build and not other builds. It doesn't seem to make any difference in my build environment the correct libraries are linked to any way. I'll change this shortly so all builds will explicitly use the myth versions. See if that fixes things for you.

[paulh]

(In [14830]) Explicitly tell the linker we want to use the mythav* libraries when linking mytharchivehelper. That was already being done for the macx build but wasn't for other builds.

Probably fixes #4152.