[Ffmpeg-devel] [PATCH] Cygwin vhook, always static avformat

[Diego Biurrun]

On Tue, Aug 01, 2006 at 01:01:10PM +0200, V?ctor Paesa wrote:
> > On Mon, Jul 31, 2006 at 01:57:27PM +0200, V?ctor Paesa wrote:
> >>
> >> > Diego Biurrun <diego at biurrun.de> writes:
> >> >
> >> >> This thread was dormant for a short while, let's revive it..
> >> >>
> >> >> On Sun, Jul 16, 2006 at 02:00:20PM +0100, M?ns Rullg?rd wrote:
> >> >>> V?ctor Paesa <wzrlpy at arsystel.com> writes:
> >> >>>
> >> >>> > The next attempt on the vhook, shared lib Cygwin patches,
> >> attached.
> >> >>> >
> >> >>> > --- ffmpeg-5754-old/configure	2006-07-15 23:00:24.468750000 +0200
> >> >>> > +++ ffmpeg/configure	2006-07-16 00:09:57.265625000 +0200
> >> >>> > @@ -587,7 +587,11 @@
> >> >>> >  v4l2="no"
> >> >>> >  audio_oss="yes"
> >> >>> >  dv1394="no"
> >> >>> > -vhook="no"
> >> >>> > +VHOOKFLAGS="-shared"
> >> >>> > +VHOOKLIBS='-Wl,--no-whole-archive \
> >> >>> > +           -L../libavformat -lavformat$(BUILDSUF) \
> >> >>> > +           -L../libavcodec  -lavcodec$(BUILDSUF)  \
> >> >>> > +           -L../libavutil   -lavutil$(BUILDSUF) $(EXTRALIBS)'
> >> >>>
> >> >>> Why is this needed on cygwin but not elsewhere?  I guess it has
> >> >>> something to do with now dynamic symbols are resolved.  Wouldn't be
> >> >>> just as well to always link the vhook libs against lav[cfu]?  Doing
> >> so
> >> >>> would allow us to get rid of the -rdynamic stuff which is
> >> problematic
> >> >>> anyway (as in syntax and semantics varying wildly between
> >> platforms).
> >> >>
> >> >> Sounds like a good idea..
> >> >
> >> > On second thoughts, this might not be such a good idea after all.  If
> >> > static libs are used, linking them into the vhook modules is not at
> >> > all good.
> >>
> >> Right, if you configure with "--enable-static --disable-shared" under
> >> Cygwin (after having applied ffmpeg.cygwin.vhook.6.patch) the vhook
> >> modules
> >> show pretty hefty sizes (even after strip):
> >>
> >> $ ls -lrt *.dll
> >> -rwxr-xr-x 1 wzrlpy Users 2059264 Jul 31 09:23 drawtext.dll
> >> -rwxr-xr-x 1 wzrlpy Users 2056192 Jul 31 09:23 fish.dll
> >> -rwxr-xr-x 1 wzrlpy Users 2055680 Jul 31 09:23 imlib2.dll
> >> -rwxr-xr-x 1 wzrlpy Users 2052608 Jul 31 09:23 null.dll
> >> -rwxr-xr-x 1 wzrlpy Users 2056704 Jul 31 09:23 ppm.dll
> >> -rwxr-xr-x 1 wzrlpy Users 3476992 Jul 31 09:23 watermark.dll
> >>
> >>
> >> If you use "--enable-shared --disable-static", the modules are lovely
> >> slim:
> >>
> >> $ ls -lrt *.dll
> >> -rwxr-xr-x 1 wzrlpy Users 10752 Jul 31 09:48 drawtext.dll
> >> -rwxr-xr-x 1 wzrlpy Users  9216 Jul 31 09:48 fish.dll
> >> -rwxr-xr-x 1 wzrlpy Users  9216 Jul 31 09:48 imlib2.dll
> >> -rwxr-xr-x 1 wzrlpy Users  5120 Jul 31 09:48 null.dll
> >> -rwxr-xr-x 1 wzrlpy Users  7680 Jul 31 09:48 ppm.dll
> >> -rwxr-xr-x 1 wzrlpy Users  9728 Jul 31 09:48 watermark.dll
> >>
> >>
> >> I have read in http://edll.sourceforge.net/ that Gimp authors (and
> >> others)
> >> have found a way to actually trick the linker in creating a DLL plug-in
> >> which will back link to the main application.
> >> Hence it is possible to link statically and have small vhooks at the
> >> same time.
> >> Being tricky, and related to Win32, the chances of that being accepted
> >> in
> >> FFMpeg are fairly low, so I have not investigated further, specially
> >> because
> >> linking dinamically already fulfills my needs.
> >>
> >> So for me (probably the only vhook user under Cygwin) the fat statically
> >> compiled Cygwin vhooks are acceptable.
> >
> > Would the attached patch help you already?  It's a small and clean part
> > of your patch and may shared libs work already.  Does it fail with
> > static libs.  Is it worse than what we currently have?
> 
> Mmmh, where is your attached patch?
> Are you referring to your r5874, r5875 recent changes in common.mak ?

No, I was just suffering from unattached patch disease...

This time it's attached for real.

Diego
-------------- next part --------------
Index: common.mak
===================================================================
--- common.mak	(revision 5875)
+++ common.mak	(working copy)
@@ -61,16 +61,12 @@
 
 install-lib-shared: $(SLIBNAME)
 	install -d "$(shlibdir)"
-ifeq ($(CONFIG_MINGW),yes)
-	install $(INSTALLSTRIP) -m 755 $(SLIBNAME) "$(prefix)"
-else
 	install $(INSTALLSTRIP) -m 755 $(SLIBNAME) \
 		$(shlibdir)/$(SLIBNAME_WITH_VERSION)
 	ln -sf $(SLIBNAME_WITH_VERSION) \
 	       $(shlibdir)/$(SLIBNAME_WITH_MAJOR)
 	ln -sf $(SLIBNAME_WITH_VERSION) \
 	       $(shlibdir)/$(SLIBNAME)
-endif
 
 install-lib-static: $(LIB)
 	install -d "$(libdir)"
@@ -85,13 +81,9 @@
 uninstall: uninstall-libs uninstall-headers
 
 uninstall-libs:
-ifeq ($(CONFIG_MINGW),yes)
-	-rm -f $(prefix)/$(SLIBNAME)
-else
 	-rm -f $(libdir)/$(SLIBNAME_WITH_MAJOR) \
 	       $(libdir)/$(SLIBNAME)            \
 	       $(libdir)/$(SLIBNAME_WITH_VERSION)
-endif
 	-rm -f $(libdir)/$(LIB)
 
 uninstall-headers: