mixer/Plugin: pass AudioOutput to init()

Fix breakage from commit bea5681fd8

src/mixer/MixerControl.cxx

@@ -25,7 +25,7 @@
 
 Mixer *
 mixer_new(EventLoop &event_loop,
-	  const MixerPlugin &plugin, FilteredAudioOutput &ao,
+	  const MixerPlugin &plugin, AudioOutput &ao,
 	  MixerListener &listener,
 	  const ConfigBlock &block)
 {

src/mixer/MixerControl.hxx

@@ -27,7 +27,7 @@
 
 class Mixer;
 class EventLoop;
-struct FilteredAudioOutput;
+class AudioOutput;
 struct MixerPlugin;
 class MixerListener;
 struct ConfigBlock;
@@ -37,7 +37,7 @@ struct ConfigBlock;
  */
 Mixer *
 mixer_new(EventLoop &event_loop, const MixerPlugin &plugin,
-	  FilteredAudioOutput &ao,
+	  AudioOutput &ao,
 	  MixerListener &listener,
 	  const ConfigBlock &block);
 

src/mixer/MixerPlugin.hxx

@@ -28,7 +28,7 @@
 #define MPD_MIXER_PLUGIN_HXX
 
 struct ConfigBlock;
-struct FilteredAudioOutput;
+class AudioOutput;
 class Mixer;
 class MixerListener;
 class EventLoop;
@@ -43,7 +43,7 @@ struct MixerPlugin {
 	 * @param param the configuration section
 	 * @return a mixer object
 	 */
-	Mixer *(*init)(EventLoop &event_loop, FilteredAudioOutput &ao,
+	Mixer *(*init)(EventLoop &event_loop, AudioOutput &ao,
 		       MixerListener &listener,
 		       const ConfigBlock &block);
 

src/mixer/plugins/AlsaMixerPlugin.cxx

@@ -173,7 +173,7 @@ AlsaMixer::Configure(const ConfigBlock &block)
 }
 
 static Mixer *
-alsa_mixer_init(EventLoop &event_loop, gcc_unused FilteredAudioOutput &ao,
+alsa_mixer_init(EventLoop &event_loop, gcc_unused AudioOutput &ao,
 		MixerListener &listener,
 		const ConfigBlock &block)
 {

src/mixer/plugins/HaikuMixerPlugin.cxx

@@ -48,7 +48,7 @@ public:
 };
 
 static Mixer *
-haiku_mixer_init(gcc_unused EventLoop &event_loop, FilteredAudioOutput &ao,
+haiku_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		MixerListener &listener,
 		gcc_unused const ConfigBlock &block)
 {

src/mixer/plugins/NullMixerPlugin.cxx

@@ -51,7 +51,7 @@ public:
 
 static Mixer *
 null_mixer_init(gcc_unused EventLoop &event_loop,
-		gcc_unused FilteredAudioOutput &ao,
+		gcc_unused AudioOutput &ao,
 		MixerListener &listener,
 		gcc_unused const ConfigBlock &block)
 {

src/mixer/plugins/OssMixerPlugin.cxx

@@ -98,7 +98,7 @@ OssMixer::Configure(const ConfigBlock &block)
 
 static Mixer *
 oss_mixer_init(gcc_unused EventLoop &event_loop,
-	       gcc_unused FilteredAudioOutput &ao,
+	       gcc_unused AudioOutput &ao,
 	       MixerListener &listener,
 	       const ConfigBlock &block)
 {

src/mixer/plugins/PulseMixerPlugin.cxx

@@ -161,7 +161,7 @@ pulse_mixer_on_change(PulseMixer &pm,
 }
 
 static Mixer *
-pulse_mixer_init(gcc_unused EventLoop &event_loop, FilteredAudioOutput &ao,
+pulse_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		 MixerListener &listener,
 		 gcc_unused const ConfigBlock &block)
 {

src/mixer/plugins/RoarMixerPlugin.cxx

@@ -45,7 +45,7 @@ public:
 };
 
 static Mixer *
-roar_mixer_init(gcc_unused EventLoop &event_loop, FilteredAudioOutput &ao,
+roar_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		MixerListener &listener,
 		gcc_unused const ConfigBlock &block)
 {

src/mixer/plugins/SoftwareMixerPlugin.cxx

@@ -58,7 +58,7 @@ public:
 
 static Mixer *
 software_mixer_init(gcc_unused EventLoop &event_loop,
-		    gcc_unused FilteredAudioOutput &ao,
+		    gcc_unused AudioOutput &ao,
 		    MixerListener &listener,
 		    gcc_unused const ConfigBlock &block)
 {

src/mixer/plugins/WinmmMixerPlugin.cxx

@@ -64,7 +64,7 @@ winmm_volume_encode(int volume)
 }
 
 static Mixer *
-winmm_mixer_init(gcc_unused EventLoop &event_loop, FilteredAudioOutput &ao,
+winmm_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		 MixerListener &listener,
 		 gcc_unused const ConfigBlock &block)
 {