Reorder the ffmpeg detection. Please test, there is so many corner case :(

configure.ac

@@ -2348,35 +2348,13 @@ AC_CHECK_HEADERS(id3tag.h, [
 dnl
 dnl  ffmpeg decoder/demuxer plugin
 dnl
-dnl we try to find ffmpeg using : 1- ffmpeg-config, 2- pkg-config
-dnl 				3- default place, 4- given tree
+dnl we try to find ffmpeg using : 1- given tree 2- ffmpeg-config, 3- pkg-config
+dnl 				4- default place, 
 
 AC_ARG_ENABLE(ffmpeg,
 [  --enable-ffmpeg         ffmpeg codec (default enabled)])
 if test "${enable_ffmpeg}" != "no"
 then
-dnl Look for a ffmpeg-config (we are on debian )
- 
-   FFMPEG_PATH="${PATH}"
-   AC_ARG_WITH(ffmpeg-config-path,
-     [    --with-ffmpeg-config-path=PATH ffmpeg-config path (default search in \$PATH)],
-     [ if test "${with_ffmpeg_config_path}" != "no"
-       then
-         FFMPEG_PATH="${with_ffmpeg_config_path}"
-       fi ])
-   AC_PATH_PROG(FFMPEG_CONFIG, ffmpeg-config, no, ${FFMPEG_PATH})
-   if test "${FFMPEG_CONFIG}" != "no"
-   then
-     AC_CHECK_HEADERS(ffmpeg/avcodec.h)
-     AC_CHECK_HEADERS(postproc/postprocess.h)
-     VLC_ADD_PLUGINS([ffmpeg])
-     if test "${enable_sout}" != "no"; then
-         VLC_ADD_PLUGINS([stream_out_switcher])
-     fi
-     VLC_ADD_CFLAGS([ffmpeg stream_out_switcher],[`${FFMPEG_CONFIG} --cflags`])
-     VLC_ADD_LDFLAGS([ffmpeg stream_out_switcher],[`${FFMPEG_CONFIG} --plugin-libs avcodec avformat postproc`])
-  
-  else
 
 dnl Those options have to be here because the .pc can be bogus for ffmpeg previous nov 05
 
@@ -2412,53 +2390,12 @@ dnl Those options have to be here because the .pc can be bogus for ffmpeg previo
 		VLC_ADD_LDFLAGS([ffmpeg],[-lz])
      fi])
 
-dnl Trying with pkg-config
-   PKG_CHECK_MODULES(FFMPEG,[libavcodec, libavformat],
-    [
-     AC_CHECK_HEADERS(ffmpeg/avcodec.h)
-     AC_CHECK_HEADERS(postproc/postprocess.h)
-     VLC_ADD_BUILTINS([ffmpeg])
-     if test "${enable_sout}" != "no"; then
-         VLC_ADD_BUILTINS([stream_out_switcher])
-     fi
-     VLC_ADD_CFLAGS([ffmpeg stream_out_switcher],[${FFMPEG_CFLAGS}])
-     VLC_ADD_LDFLAGS([ffmpeg],[${FFMPEG_LIBS}])
-
-    ],[
-     
-    dnl
-    dnl test for !(--with-ffmpeg-tree)
-    dnl
-    if test "${with_ffmpeg_tree}" = "no" -o -z "${with_ffmpeg_tree}"; then
-      CPPFLAGS="${CPPFLAGS_save} ${CPPFLAGS_ffmpeg}"
-      LDFLAGS="${LDFLAGS_save} ${LDFLAGS_ffmpeg}"
-      AC_CHECK_HEADERS(ffmpeg/avcodec.h, [], [AC_MSG_ERROR([Missing header file ffmpeg/avcodec.h.])] )
-      AC_CHECK_HEADERS(postproc/postprocess.h, [], [AC_MSG_ERROR([Missing header file postproc/postprocess.h.])] )
-
-      AC_CHECK_LIB(avutil, av_add_i, [
-        VLC_ADD_LDFLAGS([ffmpeg],[-lavutil])
-        LDAVUTIL="-lavutil"])
-
-      AC_CHECK_LIB(avcodec, avcodec_init, [
-        VLC_ADD_BUILTINS([ffmpeg])
-
-
-        VLC_ADD_LDFLAGS([ffmpeg],[-lavcodec])
-        if test "${enable_sout}" != "no"; then
-            VLC_ADD_BUILTINS([stream_out_switcher])
-        fi],
-         [ AC_MSG_ERROR([Could not find ffmpeg on your system: you may get it from http://ffmpeg.sf.net/ (cvs version is recommended). Alternatively you can use --disable-ffmpeg to disable the ffmpeg plugins.]) ], [$LDAVUTIL])
-      AC_CHECK_LIB(avformat, av_open_input_stream, [
-        AC_DEFINE(HAVE_LIBAVFORMAT, 1,
-        [Define if you have ffmpeg's libavformat.])
-        VLC_ADD_LDFLAGS([ffmpeg],[-lavformat -lz]) ], [], [-lavcodec -lz $LDAVUTIL])
-      LDFLAGS="${LDFLAGS_save}"
-      CPPFLAGS="${CPPFLAGS_save}"
-    fi
-
  dnl
  dnl test for --with-ffmpeg-tree
  dnl
+ AC_ARG_WITH(ffmpeg-tree,
+   [    --with-ffmpeg-tree=PATH ffmpeg tree for static linking])
+
  if test "${with_ffmpeg_tree}" != "no" -a -n "${with_ffmpeg_tree}"; then
    AC_MSG_CHECKING(for libavcodec.a in ${with_ffmpeg_tree})
    real_ffmpeg_tree="`cd ${with_ffmpeg_tree} 2>/dev/null && pwd`"
@@ -2532,16 +2469,79 @@ dnl Trying with pkg-config
      VLC_ADD_LDFLAGS([ffmpeg],[-L${real_ffmpeg_tree}/libavformat ${real_ffmpeg_tree}/libavformat/libavformat.a])
      VLC_ADD_CPPFLAGS([ffmpeg stream_out_switcher],[-I${real_ffmpeg_tree}/libavformat])
    fi
+else    
+    
+dnl Look for a ffmpeg-config (we are on debian )
+ 
+  FFMPEG_PATH="${PATH}"
+  AC_ARG_WITH(ffmpeg-config-path,
+    [    --with-ffmpeg-config-path=PATH ffmpeg-config path (default search in \$PATH)],
+    [ if test "${with_ffmpeg_config_path}" != "no"
+      then
+        FFMPEG_PATH="${with_ffmpeg_config_path}"
+      fi ])
+  AC_PATH_PROG(FFMPEG_CONFIG, ffmpeg-config, no, ${FFMPEG_PATH})
+  if test "${FFMPEG_CONFIG}" != "no"
+  then
+    AC_CHECK_HEADERS(ffmpeg/avcodec.h)
+    AC_CHECK_HEADERS(postproc/postprocess.h)
+    VLC_ADD_PLUGINS([ffmpeg])
+    if test "${enable_sout}" != "no"; then
+        VLC_ADD_PLUGINS([stream_out_switcher])
+    fi
+    VLC_ADD_CFLAGS([ffmpeg stream_out_switcher],[`${FFMPEG_CONFIG} --cflags`])
+    VLC_ADD_LDFLAGS([ffmpeg stream_out_switcher],[`${FFMPEG_CONFIG} --plugin-libs avcodec avformat postproc`])
+ 
+ else
+
+dnl Trying with pkg-config
+   PKG_CHECK_MODULES(FFMPEG,[libavcodec, libavformat],
+    [
+     AC_CHECK_HEADERS(ffmpeg/avcodec.h)
+     AC_CHECK_HEADERS(postproc/postprocess.h)
+     VLC_ADD_BUILTINS([ffmpeg])
+     if test "${enable_sout}" != "no"; then
+         VLC_ADD_BUILTINS([stream_out_switcher])
      fi
-    ])
-    AC_ARG_WITH(ffmpeg-tree,
-      [    --with-ffmpeg-tree=PATH ffmpeg tree for static linking])
+     VLC_ADD_CFLAGS([ffmpeg stream_out_switcher],[${FFMPEG_CFLAGS}])
+     VLC_ADD_LDFLAGS([ffmpeg],[${FFMPEG_LIBS}])
+
+    ],[
+     
+    dnl
+    dnl last chance: at the default place
+    dnl
+      CPPFLAGS="${CPPFLAGS_save} ${CPPFLAGS_ffmpeg}"
+      LDFLAGS="${LDFLAGS_save} ${LDFLAGS_ffmpeg}"
+      AC_CHECK_HEADERS(ffmpeg/avcodec.h, [], [AC_MSG_ERROR([Missing header file ffmpeg/avcodec.h.])] )
+      AC_CHECK_HEADERS(postproc/postprocess.h, [], [AC_MSG_ERROR([Missing header file postproc/postprocess.h.])] )
+
+      AC_CHECK_LIB(avutil, av_add_i, [
+        VLC_ADD_LDFLAGS([ffmpeg],[-lavutil])
+        LDAVUTIL="-lavutil"])
+
+      AC_CHECK_LIB(avcodec, avcodec_init, [
+        VLC_ADD_BUILTINS([ffmpeg])
+
 
+        VLC_ADD_LDFLAGS([ffmpeg],[-lavcodec])
+        if test "${enable_sout}" != "no"; then
+            VLC_ADD_BUILTINS([stream_out_switcher])
+        fi],
+         [ AC_MSG_ERROR([Could not find ffmpeg on your system: you may get it from http://ffmpeg.sf.net/ (cvs version is recommended). Alternatively you can use --disable-ffmpeg to disable the ffmpeg plugins.]) ], [$LDAVUTIL])
+      AC_CHECK_LIB(avformat, av_open_input_stream, [
+        AC_DEFINE(HAVE_LIBAVFORMAT, 1,
+        [Define if you have ffmpeg's libavformat.])
+        VLC_ADD_LDFLAGS([ffmpeg],[-lavformat -lz]) ], [], [-lavcodec -lz $LDAVUTIL])
+      LDFLAGS="${LDFLAGS_save}"
+      CPPFLAGS="${CPPFLAGS_save}"
+    ])
+  fi
  fi 
 fi
 
 dnl
-dnl  ffmpeg decoder/demuxer plugin
+dnl  ffmpegaltivec plugin
 dnl
 AC_ARG_ENABLE(ffmpegaltivec,
 [  --enable-ffmpegaltivec  ffmpegaltivec codec (DO NOT USE)])