Description:
The synfig package is built without dv and libavcodec support, because of these two lines in the PKGBUID :

[...] ./configure --prefix=/usr --sysconfdir=/etc \
--without-libavcodec --without-libdv

Therefore, synfig complains for missing modules :

synfig: warning: Unable to find module "mod_magickpp" (mod_magickpp.so: cannot open shared object file: No such file or directory)
synfig: warning: Unable to find module "mod_dv" (mod_dv.so: cannot open shared object file: No such file or directory)
synfig: warning: Unable to find module "mod_libavcodec" (mod_libavcodec.so: cannot open shared object file: No such file or directory)

I don't know the reason of this configuration choice, but dv and libavcodec support can be easily added by removing "--without-libdv" and adding "--with-libavcodec" (it is not enabled by default). Of course, libdv and ffmpeg have to be installed. Since ffmpeg is already a dependency of synfig, only libdv has to be added to depends().

After recompiling the package, synfig still complains for the lack of magickpp module, although imagemagick is installed - but that's another problem.
At least, it is able to export animations to dv format (NTSC only, however) and HQ Mpeg-4 avi.

Feature request:
- please enable support for libavcodec (--with-libavcodec)
- please add libdv as a dependency and remove --without-libdv

Additional info:
* package version(s)
Latest at the time of writing (0.62.00) but also previous versions.