On Mac OS X, make CoreAudio default and Mad non-default.

build/features.py

@@ -141,14 +141,19 @@ class Mad(Feature):
     def description(self):
         return "MAD MP3 Decoder"
 
+    def default(self, build):
+        return 0 if build.platform_is_osx else 1
+
     def enabled(self, build):
-        build.flags['mad'] = util.get_flags(build.env, 'mad', 1)
+        build.flags['mad'] = util.get_flags(build.env, 'mad',
+                                            self.default(build))
         if int(build.flags['mad']):
             return True
         return False
 
     def add_options(self, build, vars):
-        vars.Add('mad', 'Set to 1 to enable MAD MP3 decoder support.', 1)
+        vars.Add('mad', 'Set to 1 to enable MAD MP3 decoder support.',
+                 self.default(build))
 
     def configure(self, build, conf):
         if not self.enabled(build):
@@ -168,14 +173,18 @@ class CoreAudio(Feature):
     def description(self):
         return "CoreAudio MP3/AAC Decoder"
 
+    def default(self, build):
+        return 1 if build.platform_is_osx else 0
+
     def enabled(self, build):
-        build.flags['coreaudio'] = util.get_flags(build.env, 'coreaudio', 0)
+        build.flags['coreaudio'] = util.get_flags(build.env, 'coreaudio', self.default(build))
         if int(build.flags['coreaudio']):
             return True
         return False
 
     def add_options(self, build, vars):
-        vars.Add('coreaudio', 'Set to 1 to enable CoreAudio MP3/AAC decoder support.', 0)
+        vars.Add('coreaudio', 'Set to 1 to enable CoreAudio MP3/AAC decoder support.',
+                 self.default(build))
 
     def configure(self, build, conf):
         if not self.enabled(build):
@@ -1073,4 +1082,3 @@ def sources(self, build):
                 'library/bundledsongswebview.cpp',
                 "library/featuredartistswebview.cpp",
                 ]
-