multimedia/gnash fails with certain options

[d.den.brok%uni-bonn.de@localhost (Dennis den Brok)]

Building with PKG_OPTIONS.gnash = ffmpeg cairo, the build fails
with the following:

 c++ -DHAVE_CONFIG_H -I. -I../.. -I../../libnet -I../../backend -I../../server 
-I../../server/swf -I../../server/parser -I../../server/vm -I../../libbase 
-I../../libgeometry -I../../libamf -I../../libltdl -I../../libmedia -pthread 
-I/usr/pkgsrc/multimedia/gnash/work/.buildlink/include/glib/glib-2.0 
-I/usr/pkgsrc/multimedia/gnash/work/.buildlink/lib/glib-2.0/include 
-I/usr/pkgsrc/multimedia/gnash/work/.buildlink/include 
-I/usr/pkgsrc/multimedia/gnash/work/.buildlink/include/libxml2 
-I/usr/pkgsrc/multimedia/gnash/work/.x11-buildlink/include/freetype2 
-I/usr/pkgsrc/multimedia/gnash/work/.x11-buildlink/include 
-I/usr/pkgsrc/multimedia/gnash/work/.buildlink/include/SDL -D_GNU_SOURCE=1 
-D_REENTRANT -D_THREAD_SAFE -I../../libmedia/ffmpeg -I/usr/include/krb5 -O2 
-pipe -pthread -pthread -W -Wall -Wcast-align -Wcast-qual -Wpointer-arith 
-Wreturn-type -fvisibility-inlines-hidden -MT NetStream.lo -MD -MP -MF 
.deps/NetStream.Tpo -c NetStream.cpp  -fPIC -DPIC -o .libs/NetStream.o
NetStreamFfmpeg.h:95: error: 'offset_t' does not name a type
gmake[3]: *** [NetStream.lo] Error 1
gmake[3]: Leaving directory 
`/usr/pkgsrc/multimedia/gnash/work/gnash-0.8.3/server/asobj'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory 
`/usr/pkgsrc/multimedia/gnash/work/gnash-0.8.3/server'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/usr/pkgsrc/multimedia/gnash/work/gnash-0.8.3'
gmake: *** [all] Error 2
*** Error code 2

According to the bulk logs, this doesn't seem to occur with the
default options, which include gstreamer instead of ffmpeg, so this
might be the cause. Maybe someone knows how to fix this?

TIA,

Dennis den Brok