The 0.5 ffmpeg branch includes libswscale directly, not as an external,
breaking the dist (and warning in autogen.sh) about not being able to
update its revision.
Add some code to not update the svn external if the
FFMPEG_EXTERNALS_REVISION variable is empty.
Also, in autogen.sh check that the current FFmpeg checkout is from the
right branch according to ffmpegrev, and check it out again if
it's not.
Use a separate helper directory to build ffmpeg distributables
rather than replacing and corrupting (no more .svn dirs)
the existing checkout used for standard make/building.
Bring make dist in sync with autogen.sh's retrieval of ffmpeg
checkout, which also includes an update to selected revision
of libswscale external. Also include *.S files (needed for
e.g. ARM build).
Original commit message from CVS:
* ffmpegrev:
Adjust time of swscale checkout to ffmpeg revision being used.
* gst-libs/ext/Makefile.am:
Fix make distcheck
Original commit message from CVS:
* gst-libs/ext/Makefile.am:
We need to use $(MAKE) here instead of 'make' (on some
systems it's gmake that needs to be called, for example)
