26 files changed, 913 insertions, 1006 deletions

diff --git a/Makefile.am b/Makefile.am
index 0d94ddee0..23974e23c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -961,7 +961,7 @@ OUTPUT_API_SRC = \
 	src/output/OutputAPI.hxx \
 	src/output/OutputInternal.hxx \
 	src/output/OutputList.cxx src/output/OutputList.hxx \
-	src/output/OutputAll.cxx src/output/OutputAll.hxx \
+	src/output/MultipleOutputs.cxx src/output/MultipleOutputs.hxx \
 	src/output/OutputThread.cxx src/output/OutputThread.hxx \
 	src/output/OutputError.cxx src/output/OutputError.hxx \
 	src/output/OutputControl.cxx src/output/OutputControl.hxx \
@@ -985,7 +985,7 @@ MIXER_API_SRC = \
 	src/mixer/MixerList.hxx \
 	src/mixer/MixerControl.cxx src/mixer/MixerControl.hxx \
 	src/mixer/MixerType.cxx src/mixer/MixerType.hxx \
-	src/mixer/MixerAll.cxx src/mixer/MixerAll.hxx \
+	src/mixer/MixerAll.cxx \
 	src/mixer/MixerInternal.hxx
 
 libmixer_plugins_a_SOURCES = \
diff --git a/src/Main.cxx b/src/Main.cxx
index f790ec574..87a35eca2 100644
--- a/src/Main.cxx
+++ b/src/Main.cxx
@@ -37,7 +37,6 @@
 #include "command/AllCommands.hxx"
 #include "Partition.hxx"
 #include "mixer/Volume.hxx"
-#include "output/OutputAll.hxx"
 #include "tag/TagConfig.hxx"
 #include "ReplayGainConfig.hxx"
 #include "Idle.hxx"
@@ -458,7 +457,7 @@ int mpd_main(int argc, char *argv[])
 	initialize_decoder_and_player();
 	volume_init();
 	initAudioConfig();
-	audio_output_all_init(instance->partition->pc);
+	instance->partition->outputs.Configure(instance->partition->pc);
 	client_manager_init();
 	replay_gain_global_init();
 
@@ -500,7 +499,7 @@ int mpd_main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
-	audio_output_all_set_replay_gain_mode(replay_gain_get_real_mode(instance->partition->playlist.queue.random));
+	instance->partition->outputs.SetReplayGainMode(replay_gain_get_real_mode(instance->partition->playlist.queue.random));
 
 	if (config_get_bool(CONF_AUTO_UPDATE, false)) {
 #ifdef ENABLE_INOTIFY
@@ -567,7 +566,6 @@ int mpd_main(int argc, char *argv[])
 
 	playlist_list_global_finish();
 	input_stream_global_finish();
-	audio_output_all_finish();
 	mapper_finish();
 	delete instance->partition;
 	command_finish();
diff --git a/src/Partition.cxx b/src/Partition.cxx
index ea801f827..71ded4309 100644
--- a/src/Partition.cxx
+++ b/src/Partition.cxx
@@ -20,6 +20,7 @@
 #include "config.h"
 #include "Partition.hxx"
 #include "DetachedSong.hxx"
+#include "output/MultipleOutputs.hxx"
 
 void
 Partition::DatabaseModified()
diff --git a/src/Partition.hxx b/src/Partition.hxx
index 4a5bcc6c7..3ee110654 100644
--- a/src/Partition.hxx
+++ b/src/Partition.hxx
@@ -21,9 +21,11 @@
 #define MPD_PARTITION_HXX
 
 #include "Playlist.hxx"
+#include "output/MultipleOutputs.hxx"
 #include "PlayerControl.hxx"
 
 struct Instance;
+class MultipleOutputs;
 
 /**
  * A partition of the Music Player Daemon.  It is a separate unit with
@@ -34,6 +36,8 @@ struct Partition {
 
 	struct playlist playlist;
 
+	MultipleOutputs outputs;
+
 	PlayerControl pc;
 
 	Partition(Instance &_instance,
@@ -41,8 +45,7 @@ struct Partition {
 		  unsigned buffer_chunks,
 		  unsigned buffered_before_play)
 		:instance(_instance), playlist(max_length),
-		 pc(buffer_chunks, buffered_before_play) {
-	}
+		 pc(outputs, buffer_chunks, buffered_before_play) {}
 
 	void ClearQueue() {
 		playlist.Clear(pc);
diff --git a/src/PlayerControl.cxx b/src/PlayerControl.cxx
index 7ba703ea0..bca3cc937 100644
--- a/src/PlayerControl.cxx
+++ b/src/PlayerControl.cxx
@@ -26,9 +26,11 @@
 
 #include <assert.h>
 
-PlayerControl::PlayerControl(unsigned _buffer_chunks,
+PlayerControl::PlayerControl(MultipleOutputs &_outputs,
+			     unsigned _buffer_chunks,
 			     unsigned _buffered_before_play)
-	:buffer_chunks(_buffer_chunks),
+	:outputs(_outputs),
+	 buffer_chunks(_buffer_chunks),
 	 buffered_before_play(_buffered_before_play),
 	 command(PlayerCommand::NONE),
 	 state(PlayerState::STOP),
diff --git a/src/PlayerControl.hxx b/src/PlayerControl.hxx
index 4847958c7..a7237167c 100644
--- a/src/PlayerControl.hxx
+++ b/src/PlayerControl.hxx
@@ -29,6 +29,7 @@
 
 #include <stdint.h>
 
+class MultipleOutputs;
 class DetachedSong;
 
 enum class PlayerState : uint8_t {
@@ -91,6 +92,8 @@ struct player_status {
 };
 
 struct PlayerControl {
+	MultipleOutputs &outputs;
+
 	unsigned buffer_chunks;
 
 	unsigned int buffered_before_play;
@@ -170,7 +173,8 @@ struct PlayerControl {
 	 */
 	bool border_pause;
 
-	PlayerControl(unsigned buffer_chunks,
+	PlayerControl(MultipleOutputs &_outputs,
+		      unsigned buffer_chunks,
 		      unsigned buffered_before_play);
 	~PlayerControl();
 
diff --git a/src/PlayerThread.cxx b/src/PlayerThread.cxx
index 4fb045bda..d90f281c6 100644
--- a/src/PlayerThread.cxx
+++ b/src/PlayerThread.cxx
@@ -28,7 +28,7 @@
 #include "system/FatalError.hxx"
 #include "CrossFade.hxx"
 #include "PlayerControl.hxx"
-#include "output/OutputAll.hxx"
+#include "output/MultipleOutputs.hxx"
 #include "tag/Tag.hxx"
 #include "Idle.hxx"
 #include "GlobalEvents.hxx"
@@ -125,7 +125,7 @@ class Player {
 	/**
 	 * The time stamp of the chunk most recently sent to the
 	 * output thread.  This attribute is only used if
-	 * audio_output_all_get_elapsed_time() didn't return a usable
+	 * MultipleOutputs::GetElapsedTime() didn't return a usable
 	 * value; the output thread can estimate the elapsed time more
 	 * precisely.
 	 */
@@ -228,8 +228,8 @@ private:
 	bool WaitForDecoder();
 
 	/**
-	 * Wrapper for audio_output_all_open().  Upon failure, it pauses the
-	 * player.
+	 * Wrapper for MultipleOutputs::Open().  Upon failure, it
+	 * pauses the player.
 	 *
 	 * @return true on success
 	 */
@@ -393,7 +393,7 @@ Player::OpenOutput()
 	       pc.state == PlayerState::PAUSE);
 
 	Error error;
-	if (audio_output_all_open(play_audio_format, buffer, error)) {
+	if (pc.outputs.Open(play_audio_format, buffer, error)) {
 		output_open = true;
 		paused = false;
 
@@ -444,7 +444,7 @@ Player::CheckDecoderStartup()
 		pc.Unlock();
 
 		if (output_open &&
-		    !audio_output_all_wait(pc, 1))
+		    !pc.outputs.Wait(pc, 1))
 			/* the output devices havn't finished playing
 			   all chunks yet - wait for that */
 			return true;
@@ -504,7 +504,7 @@ Player::SendSilence()
 	memset(chunk->data, 0, chunk->length);
 
 	Error error;
-	if (!audio_output_all_play(chunk, error)) {
+	if (!pc.outputs.Play(chunk, error)) {
 		LogError(error);
 		buffer.Return(chunk);
 		return false;
@@ -582,7 +582,7 @@ Player::SeekDecoder()
 	/* re-fill the buffer after seeking */
 	buffering = true;
 
-	audio_output_all_cancel();
+	pc.outputs.Cancel();
 
 	return true;
 }
@@ -599,7 +599,7 @@ Player::ProcessCommand()
 
 	case PlayerCommand::UPDATE_AUDIO:
 		pc.Unlock();
-		audio_output_all_enable_disable();
+		pc.outputs.EnableDisable();
 		pc.Lock();
 		pc.CommandFinished();
 		break;
@@ -618,7 +618,7 @@ Player::ProcessCommand()
 
 		paused = !paused;
 		if (paused) {
-			audio_output_all_pause();
+			pc.outputs.Pause();
 			pc.Lock();
 
 			pc.state = PlayerState::PAUSE;
@@ -669,11 +669,11 @@ Player::ProcessCommand()
 	case PlayerCommand::REFRESH:
 		if (output_open && !paused) {
 			pc.Unlock();
-			audio_output_all_check();
+			pc.outputs.Check();
 			pc.Lock();
 		}
 
-		pc.elapsed_time = audio_output_all_get_elapsed_time();
+		pc.elapsed_time = pc.outputs.GetElapsedTime();
 		if (pc.elapsed_time < 0.0)
 			pc.elapsed_time = elapsed_time;
 
@@ -733,7 +733,7 @@ play_chunk(PlayerControl &pc,
 
 	/* send the chunk to the audio outputs */
 
-	if (!audio_output_all_play(chunk, error))
+	if (!pc.outputs.Play(chunk, error))
 		return false;
 
 	pc.total_play_time += (double)chunk->length /
@@ -744,7 +744,7 @@ play_chunk(PlayerControl &pc,
 inline bool
 Player::PlayNextChunk()
 {
-	if (!audio_output_all_wait(pc, 64))
+	if (!pc.outputs.Wait(pc, 64))
 		/* the output pipe is still large enough, don't send
 		   another chunk */
 		return true;
@@ -883,7 +883,7 @@ Player::SongBorder()
 
 	ReplacePipe(dc.pipe);
 
-	audio_output_all_song_border();
+	pc.outputs.SongBorder();
 
 	if (!WaitForDecoder())
 		return false;
@@ -933,7 +933,7 @@ Player::Run()
 		    pc.command == PlayerCommand::EXIT ||
 		    pc.command == PlayerCommand::CLOSE_AUDIO) {
 			pc.Unlock();
-			audio_output_all_cancel();
+			pc.outputs.Cancel();
 			break;
 		}
 
@@ -949,7 +949,7 @@ Player::Run()
 				/* not enough decoded buffer space yet */
 
 				if (!paused && output_open &&
-				    audio_output_all_check() < 4 &&
+				    pc.outputs.Check() < 4 &&
 				    !SendSilence())
 					break;
 
@@ -1029,7 +1029,7 @@ Player::Run()
 			   to the audio output */
 
 			PlayNextChunk();
-		} else if (audio_output_all_check() > 0) {
+		} else if (pc.outputs.Check() > 0) {
 			/* not enough data from decoder, but the
 			   output thread is still busy, so it's
 			   okay */
@@ -1054,7 +1054,7 @@ Player::Run()
 			if (pipe->IsEmpty()) {
 				/* wait for the hardware to finish
 				   playback */
-				audio_output_all_drain();
+				pc.outputs.Drain();
 				break;
 			}
 		} else if (output_open) {
@@ -1130,7 +1130,7 @@ player_task(void *arg)
 
 		case PlayerCommand::STOP:
 			pc.Unlock();
-			audio_output_all_cancel();
+			pc.outputs.Cancel();
 			pc.Lock();
 
 			/* fall through */
@@ -1145,7 +1145,7 @@ player_task(void *arg)
 		case PlayerCommand::CLOSE_AUDIO:
 			pc.Unlock();
 
-			audio_output_all_release();
+			pc.outputs.Release();
 
 			pc.Lock();
 			pc.CommandFinished();
@@ -1156,7 +1156,7 @@ player_task(void *arg)
 
 		case PlayerCommand::UPDATE_AUDIO:
 			pc.Unlock();
-			audio_output_all_enable_disable();
+			pc.outputs.EnableDisable();
 			pc.Lock();
 			pc.CommandFinished();
 			break;
@@ -1166,7 +1166,7 @@ player_task(void *arg)
 
 			dc.Quit();
 
-			audio_output_all_close();
+			pc.outputs.Close();
 
 			player_command_finished(pc);
 			return;
diff --git a/src/StateFile.cxx b/src/StateFile.cxx
index b28e8c617..7c0e24439 100644
--- a/src/StateFile.cxx
+++ b/src/StateFile.cxx
@@ -75,7 +75,7 @@ StateFile::Write()
 	}
 
 	save_sw_volume_state(fp);
-	audio_output_state_save(fp);
+	audio_output_state_save(fp, partition.outputs);
 	playlist_state_save(fp, partition.playlist, partition.pc);
 
 	fclose(fp);
@@ -99,8 +99,8 @@ StateFile::Read()
 
 	const char *line;
 	while ((line = file.ReadLine()) != NULL) {
-		success = read_sw_volume_state(line) ||
-			audio_output_state_read(line) ||
+		success = read_sw_volume_state(line, partition.outputs) ||
+			audio_output_state_read(line, partition.outputs) ||
 			playlist_state_restore(line, file, partition.playlist,
 					       partition.pc);
 		if (!success)
diff --git a/src/command/OtherCommands.cxx b/src/command/OtherCommands.cxx
index 328683d3d..359fa9fe3 100644
--- a/src/command/OtherCommands.cxx
+++ b/src/command/OtherCommands.cxx
@@ -45,6 +45,7 @@
 #include "db/PlaylistVector.hxx"
 #include "client/ClientFile.hxx"
 #include "client/Client.hxx"
+#include "Partition.hxx"
 #include "Idle.hxx"
 
 #include <assert.h>
@@ -254,7 +255,7 @@ handle_setvol(Client &client, gcc_unused int argc, char *argv[])
 		return CommandResult::ERROR;
 	}
 
-	success = volume_level_change(level);
+	success = volume_level_change(client.partition.outputs, level);
 	if (!success) {
 		command_error(client, ACK_ERROR_SYSTEM,
 			      "problems setting volume");
@@ -276,7 +277,7 @@ handle_volume(Client &client, gcc_unused int argc, char *argv[])
 		return CommandResult::ERROR;
 	}
 
-	const int old_volume = volume_level_get();
+	const int old_volume = volume_level_get(client.partition.outputs);
 	if (old_volume < 0) {
 		command_error(client, ACK_ERROR_SYSTEM, "No mixer");
 		return CommandResult::ERROR;
@@ -288,7 +289,8 @@ handle_volume(Client &client, gcc_unused int argc, char *argv[])
 	else if (new_volume > 100)
 		new_volume = 100;
 
-	if (new_volume != old_volume && !volume_level_change(new_volume)) {
+	if (new_volume != old_volume &&
+	    !volume_level_change(client.partition.outputs, new_volume)) {
 		command_error(client, ACK_ERROR_SYSTEM,
 			      "problems setting volume");
 		return CommandResult::ERROR;
diff --git a/src/command/OutputCommands.cxx b/src/command/OutputCommands.cxx
index 4ed3b89f1..03058d7ed 100644
--- a/src/command/OutputCommands.cxx
+++ b/src/command/OutputCommands.cxx
@@ -23,18 +23,17 @@
 #include "output/OutputCommand.hxx"
 #include "protocol/Result.hxx"
 #include "protocol/ArgParser.hxx"
+#include "client/Client.hxx"
+#include "Partition.hxx"
 
 CommandResult
 handle_enableoutput(Client &client, gcc_unused int argc, char *argv[])
 {
 	unsigned device;
-	bool ret;
-
 	if (!check_unsigned(client, &device, argv[1]))
 		return CommandResult::ERROR;
 
-	ret = audio_output_enable_index(device);
-	if (!ret) {
+	if (!audio_output_enable_index(client.partition.outputs, device)) {
 		command_error(client, ACK_ERROR_NO_EXIST,
 			      "No such audio output");
 		return CommandResult::ERROR;
@@ -47,13 +46,10 @@ CommandResult
 handle_disableoutput(Client &client, gcc_unused int argc, char *argv[])
 {
 	unsigned device;
-	bool ret;
-
 	if (!check_unsigned(client, &device, argv[1]))
 		return CommandResult::ERROR;
 
-	ret = audio_output_disable_index(device);
-	if (!ret) {
+	if (!audio_output_disable_index(client.partition.outputs, device)) {
 		command_error(client, ACK_ERROR_NO_EXIST,
 			      "No such audio output");
 		return CommandResult::ERROR;
@@ -69,7 +65,7 @@ handle_toggleoutput(Client &client, gcc_unused int argc, char *argv[])
 	if (!check_unsigned(client, &device, argv[1]))
 		return CommandResult::ERROR;
 
-	if (!audio_output_toggle_index(device)) {
+	if (!audio_output_toggle_index(client.partition.outputs, device)) {
 		command_error(client, ACK_ERROR_NO_EXIST,
 			      "No such audio output");
 		return CommandResult::ERROR;
@@ -82,7 +78,7 @@ CommandResult
 handle_devices(Client &client,
 	       gcc_unused int argc, gcc_unused char *argv[])
 {
-	printAudioDevices(client);
+	printAudioDevices(client, client.partition.outputs);
 
 	return CommandResult::OK;
 }
diff --git a/src/command/PlayerCommands.cxx b/src/command/PlayerCommands.cxx
index 28258dded..5dc55b485 100644
--- a/src/command/PlayerCommands.cxx
+++ b/src/command/PlayerCommands.cxx
@@ -25,7 +25,6 @@
 #include "db/update/UpdateGlue.hxx"
 #include "client/Client.hxx"
 #include "mixer/Volume.hxx"
-#include "output/OutputAll.hxx"
 #include "Partition.hxx"
 #include "protocol/Result.hxx"
 #include "protocol/ArgParser.hxx"
@@ -140,7 +139,7 @@ handle_status(Client &client,
 		      COMMAND_STATUS_PLAYLIST_LENGTH ": %i\n"
 		      COMMAND_STATUS_MIXRAMPDB ": %f\n"
 		      COMMAND_STATUS_STATE ": %s\n",
-		      volume_level_get(),
+		      volume_level_get(client.partition.outputs),
 		      playlist.GetRepeat(),
 		      playlist.GetRandom(),
 		      playlist.GetSingle(),
@@ -277,7 +276,7 @@ handle_random(Client &client, gcc_unused int argc, char *argv[])
 		return CommandResult::ERROR;
 
 	client.partition.SetRandom(status);
-	audio_output_all_set_replay_gain_mode(replay_gain_get_real_mode(client.partition.GetRandom()));
+	client.partition.outputs.SetReplayGainMode(replay_gain_get_real_mode(client.partition.GetRandom()));
 	return CommandResult::OK;
 }
 
@@ -379,8 +378,7 @@ handle_replay_gain_mode(Client &client,
 		return CommandResult::ERROR;
 	}
 
-	audio_output_all_set_replay_gain_mode(replay_gain_get_real_mode(client.playlist.queue.random));
-
+	client.partition.outputs.SetReplayGainMode(replay_gain_get_real_mode(client.playlist.queue.random));
 	return CommandResult::OK;
 }
 
diff --git a/src/mixer/MixerAll.cxx b/src/mixer/MixerAll.cxx
index 3cc92baee..483660a45 100644
--- a/src/mixer/MixerAll.cxx
+++ b/src/mixer/MixerAll.cxx
@@ -18,11 +18,10 @@
  */
 
 #include "config.h"
-#include "MixerAll.hxx"
+#include "output/MultipleOutputs.hxx"
 #include "MixerControl.hxx"
 #include "MixerInternal.hxx"
 #include "MixerList.hxx"
-#include "output/OutputAll.hxx"
 #include "output/OutputInternal.hxx"
 #include "pcm/Volume.hxx"
 #include "util/Error.hxx"
@@ -34,39 +33,33 @@
 static constexpr Domain mixer_domain("mixer");
 
 static int
-output_mixer_get_volume(unsigned i)
+output_mixer_get_volume(const audio_output &ao)
 {
-	struct audio_output *output;
-	int volume;
-
-	assert(i < audio_output_count());
-
-	output = audio_output_get(i);
-	if (!output->enabled)
+	if (!ao.enabled)
 		return -1;
 
-	Mixer *mixer = output->mixer;
+	Mixer *mixer = ao.mixer;
 	if (mixer == nullptr)
 		return -1;
 
 	Error error;
-	volume = mixer_get_volume(mixer, error);
+	int volume = mixer_get_volume(mixer, error);
 	if (volume < 0 && error.IsDefined())
 		FormatError(error,
 			    "Failed to read mixer for '%s'",
-			    output->name);
+			    ao.name);
 
 	return volume;
 }
 
 int
-mixer_all_get_volume(void)
+MultipleOutputs::GetVolume() const
 {
-	unsigned count = audio_output_count(), ok = 0;
-	int volume, total = 0;
+	unsigned ok = 0;
+	int total = 0;
 
-	for (unsigned i = 0; i < count; i++) {
-		volume = output_mixer_get_volume(i);
+	for (auto ao : outputs) {
+		int volume = output_mixer_get_volume(*ao);
 		if (volume >= 0) {
 			total += volume;
 			++ok;
@@ -80,59 +73,47 @@ mixer_all_get_volume(void)
 }
 
 static bool
-output_mixer_set_volume(unsigned i, unsigned volume)
+output_mixer_set_volume(audio_output &ao, unsigned volume)
 {
-	struct audio_output *output;
-	bool success;
-
-	assert(i < audio_output_count());
 	assert(volume <= 100);
 
-	output = audio_output_get(i);
-	if (!output->enabled)
+	if (!ao.enabled)
 		return false;
 
-	Mixer *mixer = output->mixer;
+	Mixer *mixer = ao.mixer;
 	if (mixer == nullptr)
 		return false;
 
 	Error error;
-	success = mixer_set_volume(mixer, volume, error);
+	bool success = mixer_set_volume(mixer, volume, error);
 	if (!success && error.IsDefined())
 		FormatError(error,
 			    "Failed to set mixer for '%s'",
-			    output->name);
+			    ao.name);
 
 	return success;
 }
 
 bool
-mixer_all_set_volume(unsigned volume)
+MultipleOutputs::SetVolume(unsigned volume)
 {
-	bool success = false;
-	unsigned count = audio_output_count();
-
 	assert(volume <= 100);
 
-	for (unsigned i = 0; i < count; i++)
-		success = output_mixer_set_volume(i, volume)
+	bool success = false;
+	for (auto ao : outputs)
+		success = output_mixer_set_volume(*ao, volume)
 			|| success;
 
 	return success;
 }
 
 static int
-output_mixer_get_software_volume(unsigned i)
+output_mixer_get_software_volume(const audio_output &ao)
 {
-	struct audio_output *output;
-
-	assert(i < audio_output_count());
-
-	output = audio_output_get(i);
-	if (!output->enabled)
+	if (!ao.enabled)
 		return -1;
 
-	Mixer *mixer = output->mixer;
+	Mixer *mixer = ao.mixer;
 	if (mixer == nullptr || !mixer->IsPlugin(software_mixer_plugin))
 		return -1;
 
@@ -140,13 +121,13 @@ output_mixer_get_software_volume(unsigned i)
 }
 
 int
-mixer_all_get_software_volume(void)
+MultipleOutputs::GetSoftwareVolume() const
 {
-	unsigned count = audio_output_count(), ok = 0;
-	int volume, total = 0;
+	unsigned ok = 0;
+	int total = 0;
 
-	for (unsigned i = 0; i < count; i++) {
-		volume = output_mixer_get_software_volume(i);
+	for (auto ao : outputs) {
+		int volume = output_mixer_get_software_volume(*ao);
 		if (volume >= 0) {
 			total += volume;
 			++ok;
@@ -160,16 +141,15 @@ mixer_all_get_software_volume(void)
 }
 
 void
-mixer_all_set_software_volume(unsigned volume)
+MultipleOutputs::SetSoftwareVolume(unsigned volume)
 {
-	unsigned count = audio_output_count();
-
 	assert(volume <= PCM_VOLUME_1);
 
-	for (unsigned i = 0; i < count; i++) {
-		struct audio_output *output = audio_output_get(i);
-		if (output->mixer != nullptr &&
-		    output->mixer->plugin == &software_mixer_plugin)
-			mixer_set_volume(output->mixer, volume, IgnoreError());
+	for (auto ao : outputs) {
+		const auto mixer = ao->mixer;
+
+		if (mixer != nullptr &&
+		    mixer->plugin == &software_mixer_plugin)
+			mixer_set_volume(mixer, volume, IgnoreError());
 	}
 }
diff --git a/src/mixer/MixerAll.hxx b/src/mixer/MixerAll.hxx
deleted file mode 100644
index f868f64b5..000000000
--- a/src/mixer/MixerAll.hxx
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright (C) 2003-2014 The Music Player Daemon Project
- * http://www.musicpd.org
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-/** \file
- *
- * Functions which affect the mixers of all audio outputs.
- */
-
-#ifndef MPD_MIXER_ALL_HXX
-#define MPD_MIXER_ALL_HXX
-
-#include "Compiler.h"
-
-/**
- * Returns the average volume of all available mixers (range 0..100).
- * Returns -1 if no mixer can be queried.
- */
-gcc_pure
-int
-mixer_all_get_volume(void);
-
-/**
- * Sets the volume on all available mixers.
- *
- * @param volume the volume (range 0..100)
- * @return true on success, false on failure
- */
-bool
-mixer_all_set_volume(unsigned volume);
-
-/**
- * Similar to mixer_all_get_volume(), but gets the volume only for
- * software mixers.  See #software_mixer_plugin.  This function fails
- * if no software mixer is configured.
- */
-gcc_pure
-int
-mixer_all_get_software_volume(void);
-
-/**
- * Similar to mixer_all_set_volume(), but sets the volume only for
- * software mixers.  See #software_mixer_plugin.  This function cannot
- * fail, because the underlying software mixers cannot fail either.
- */
-void
-mixer_all_set_software_volume(unsigned volume);
-
-#endif
diff --git a/src/mixer/Volume.cxx b/src/mixer/Volume.cxx
index 4c897b21f..aaae5d9ee 100644
--- a/src/mixer/Volume.cxx
+++ b/src/mixer/Volume.cxx
@@ -19,7 +19,7 @@
 
 #include "config.h"
 #include "Volume.hxx"
-#include "MixerAll.hxx"
+#include "output/MultipleOutputs.hxx"
 #include "Idle.hxx"
 #include "GlobalEvents.hxx"
 #include "util/StringUtil.hxx"
@@ -59,36 +59,40 @@ void volume_init(void)
 	GlobalEvents::Register(GlobalEvents::MIXER, mixer_event_callback);
 }
 
-int volume_level_get(void)
+int
+volume_level_get(const MultipleOutputs &outputs)
 {
 	if (last_hardware_volume >= 0 &&
 	    !hardware_volume_clock.CheckUpdate(1000))
 		/* throttle access to hardware mixers */
 		return last_hardware_volume;
 
-	last_hardware_volume = mixer_all_get_volume();
+	last_hardware_volume = outputs.GetVolume();
 	return last_hardware_volume;
 }
 
-static bool software_volume_change(unsigned volume)
+static bool
+software_volume_change(MultipleOutputs &outputs, unsigned volume)
 {
 	assert(volume <= 100);
 
 	volume_software_set = volume;
-	mixer_all_set_software_volume(volume);
+	outputs.SetSoftwareVolume(volume);
 
 	return true;
 }
 
-static bool hardware_volume_change(unsigned volume)
+static bool
+hardware_volume_change(MultipleOutputs &outputs, unsigned volume)
 {
 	/* reset the cache */
 	last_hardware_volume = -1;
 
-	return mixer_all_set_volume(volume);
+	return outputs.SetVolume(volume);
 }
 
-bool volume_level_change(unsigned volume)
+bool
+volume_level_change(MultipleOutputs &outputs, unsigned volume)
 {
 	assert(volume <= 100);
 
@@ -96,11 +100,11 @@ bool volume_level_change(unsigned volume)
 
 	idle_add(IDLE_MIXER);
 
-	return hardware_volume_change(volume);
+	return hardware_volume_change(outputs, volume);
 }
 
 bool
-read_sw_volume_state(const char *line)
+read_sw_volume_state(const char *line, MultipleOutputs &outputs)
 {
 	char *end = nullptr;
 	long int sv;
@@ -111,7 +115,7 @@ read_sw_volume_state(const char *line)
 	line += sizeof(SW_VOLUME_STATE) - 1;
 	sv = strtol(line, &end, 10);
 	if (*end == 0 && sv >= 0 && sv <= 100)
-		software_volume_change(sv);
+		software_volume_change(outputs, sv);
 	else
 		FormatWarning(volume_domain,
 			      "Can't parse software volume: %s", line);
diff --git a/src/mixer/Volume.hxx b/src/mixer/Volume.hxx
index 06d3551eb..b86328d88 100644
--- a/src/mixer/Volume.hxx
+++ b/src/mixer/Volume.hxx
@@ -24,15 +24,19 @@
 
 #include <stdio.h>
 
+class MultipleOutputs;
+
 void volume_init(void);
 
 gcc_pure
-int volume_level_get(void);
+int
+volume_level_get(const MultipleOutputs &outputs);
 
-bool volume_level_change(unsigned volume);
+bool
+volume_level_change(MultipleOutputs &outputs, unsigned volume);
 
 bool
-read_sw_volume_state(const char *line);
+read_sw_volume_state(const char *line, MultipleOutputs &outputs);
 
 void save_sw_volume_state(FILE *fp);
 
diff --git a/src/output/MultipleOutputs.cxx b/src/output/MultipleOutputs.cxx
new file mode 100644
index 000000000..50f686843
--- /dev/null
+++ b/src/output/MultipleOutputs.cxx
@@ -0,0 +1,477 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "MultipleOutputs.hxx"
+#include "PlayerControl.hxx"
+#include "OutputInternal.hxx"
+#include "OutputControl.hxx"
+#include "OutputError.hxx"
+#include "MusicBuffer.hxx"
+#include "MusicPipe.hxx"
+#include "MusicChunk.hxx"
+#include "system/FatalError.hxx"
+#include "util/Error.hxx"
+#include "config/ConfigData.hxx"
+#include "config/ConfigGlobal.hxx"
+#include "config/ConfigOption.hxx"
+#include "notify.hxx"
+
+#include <assert.h>
+#include <string.h>
+
+MultipleOutputs::MultipleOutputs()
+	:buffer(nullptr), pipe(nullptr),
+	 elapsed_time(-1)
+{
+}
+
+MultipleOutputs::~MultipleOutputs()
+{
+	for (auto i : outputs) {
+		audio_output_disable(i);
+		audio_output_finish(i);
+	}
+}
+
+static audio_output *
+LoadOutput(PlayerControl &pc, const config_param &param)
+{
+	Error error;
+	audio_output *output = audio_output_new(param, pc, error);
+	if (output == nullptr) {
+		if (param.line > 0)
+			FormatFatalError("line %i: %s",
+					 param.line,
+					 error.GetMessage());
+		else
+			FatalError(error);
+	}
+
+	return output;
+}
+
+void
+MultipleOutputs::Configure(PlayerControl &pc)
+{
+	const config_param *param = nullptr;
+	while ((param = config_get_next_param(CONF_AUDIO_OUTPUT,
+					      param)) != nullptr) {
+		auto output = LoadOutput(pc, *param);
+		if (FindByName(output->name) != nullptr)
+			FormatFatalError("output devices with identical "
+					 "names: %s", output->name);
+
+		outputs.push_back(output);
+	}
+
+	if (outputs.empty()) {
+		/* auto-detect device */
+		const config_param empty;
+		auto output = LoadOutput(pc, empty);
+		outputs.push_back(output);
+	}
+}
+
+audio_output *
+MultipleOutputs::FindByName(const char *name) const
+{
+	for (auto i : outputs)
+		if (strcmp(i->name, name) == 0)
+			return i;
+
+	return nullptr;
+}
+
+void
+MultipleOutputs::EnableDisable()
+{
+	for (auto ao : outputs) {
+		bool enabled;
+
+		ao->mutex.lock();
+		enabled = ao->really_enabled;
+		ao->mutex.unlock();
+
+		if (ao->enabled != enabled) {
+			if (ao->enabled)
+				audio_output_enable(ao);
+			else
+				audio_output_disable(ao);
+		}
+	}
+}
+
+bool
+MultipleOutputs::AllFinished() const
+{
+	for (auto ao : outputs) {
+		const ScopeLock protect(ao->mutex);
+		if (audio_output_is_open(ao) &&
+		    !audio_output_command_is_finished(ao))
+			return false;
+	}
+
+	return true;
+}
+
+void
+MultipleOutputs::WaitAll()
+{
+	while (!AllFinished())
+		audio_output_client_notify.Wait();
+}
+
+void
+MultipleOutputs::AllowPlay()
+{
+	for (auto ao : outputs)
+		audio_output_allow_play(ao);
+}
+
+static void
+audio_output_reset_reopen(struct audio_output *ao)
+{
+	const ScopeLock protect(ao->mutex);
+
+	ao->fail_timer.Reset();
+}
+
+void
+MultipleOutputs::ResetReopen()
+{
+	for (auto ao : outputs)
+		audio_output_reset_reopen(ao);
+}
+
+bool
+MultipleOutputs::Update()
+{
+	bool ret = false;
+
+	if (!input_audio_format.IsDefined())
+		return false;
+
+	for (auto ao : outputs)
+		ret = audio_output_update(ao, input_audio_format, *pipe)
+			|| ret;
+
+	return ret;
+}
+
+void
+MultipleOutputs::SetReplayGainMode(ReplayGainMode mode)
+{
+	for (auto ao : outputs)
+		audio_output_set_replay_gain_mode(ao, mode);
+}
+
+bool
+MultipleOutputs::Play(music_chunk *chunk, Error &error)
+{
+	assert(buffer != nullptr);
+	assert(pipe != nullptr);
+	assert(chunk != nullptr);
+	assert(chunk->CheckFormat(input_audio_format));
+
+	if (!Update()) {
+		/* TODO: obtain real error */
+		error.Set(output_domain, "Failed to open audio output");
+		return false;
+	}
+
+	pipe->Push(chunk);
+
+	for (auto ao : outputs)
+		audio_output_play(ao);
+
+	return true;
+}
+
+bool
+MultipleOutputs::Open(const AudioFormat audio_format,
+		      MusicBuffer &_buffer,
+		      Error &error)
+{
+	bool ret = false, enabled = false;
+
+	assert(buffer == nullptr || buffer == &_buffer);
+	assert((pipe == nullptr) == (buffer == nullptr));
+
+	buffer = &_buffer;
+
+	/* the audio format must be the same as existing chunks in the
+	   pipe */
+	assert(pipe == nullptr || pipe->CheckFormat(audio_format));
+
+	if (pipe == nullptr)
+		pipe = new MusicPipe();
+	else
+		/* if the pipe hasn't been cleared, the the audio
+		   format must not have changed */
+		assert(pipe->IsEmpty() || audio_format == input_audio_format);
+
+	input_audio_format = audio_format;
+
+	ResetReopen();
+	EnableDisable();
+	Update();
+
+	for (auto ao : outputs) {
+		if (ao->enabled)
+			enabled = true;
+
+		if (ao->open)
+			ret = true;
+	}
+
+	if (!enabled)
+		error.Set(output_domain, "All audio outputs are disabled");
+	else if (!ret)
+		/* TODO: obtain real error */
+		error.Set(output_domain, "Failed to open audio output");
+
+	if (!ret)
+		/* close all devices if there was an error */
+		Close();
+
+	return ret;
+}
+
+/**
+ * Has the specified audio output already consumed this chunk?
+ */
+gcc_pure
+static bool
+chunk_is_consumed_in(const struct audio_output *ao,
+		     gcc_unused const MusicPipe *pipe,
+		     const struct music_chunk *chunk)
+{
+	if (!ao->open)
+		return true;
+
+	if (ao->chunk == nullptr)
+		return false;
+
+	assert(chunk == ao->chunk || pipe->Contains(ao->chunk));
+
+	if (chunk != ao->chunk) {
+		assert(chunk->next != nullptr);
+		return true;
+	}
+
+	return ao->chunk_finished && chunk->next == nullptr;
+}
+
+bool
+MultipleOutputs::IsChunkConsumed(const music_chunk *chunk) const
+{
+	for (auto ao : outputs) {
+		const ScopeLock protect(ao->mutex);
+		if (!chunk_is_consumed_in(ao, pipe, chunk))
+			return false;
+	}
+
+	return true;
+}
+
+inline void
+MultipleOutputs::ClearTailChunk(gcc_unused const struct music_chunk *chunk,
+				bool *locked)
+{
+	assert(chunk->next == nullptr);
+	assert(pipe->Contains(chunk));
+
+	for (unsigned i = 0, n = outputs.size(); i != n; ++i) {
+		audio_output *ao = outputs[i];
+
+		/* this mutex will be unlocked by the caller when it's
+		   ready */
+		ao->mutex.lock();
+		locked[i] = ao->open;
+
+		if (!locked[i]) {
+			ao->mutex.unlock();
+			continue;
+		}
+
+		assert(ao->chunk == chunk);
+		assert(ao->chunk_finished);
+		ao->chunk = nullptr;
+	}
+}
+
+unsigned
+MultipleOutputs::Check()
+{
+	const struct music_chunk *chunk;
+	bool is_tail;
+	struct music_chunk *shifted;
+	bool locked[outputs.size()];
+
+	assert(buffer != nullptr);
+	assert(pipe != nullptr);
+
+	while ((chunk = pipe->Peek()) != nullptr) {
+		assert(!pipe->IsEmpty());
+
+		if (!IsChunkConsumed(chunk))
+			/* at least one output is not finished playing
+			   this chunk */
+			return pipe->GetSize();
+
+		if (chunk->length > 0 && chunk->times >= 0.0)
+			/* only update elapsed_time if the chunk
+			   provides a defined value */
+			elapsed_time = chunk->times;
+
+		is_tail = chunk->next == nullptr;
+		if (is_tail)
+			/* this is the tail of the pipe - clear the
+			   chunk reference in all outputs */
+			ClearTailChunk(chunk, locked);
+
+		/* remove the chunk from the pipe */
+		shifted = pipe->Shift();
+		assert(shifted == chunk);
+
+		if (is_tail)
+			/* unlock all audio outputs which were locked
+			   by clear_tail_chunk() */
+			for (unsigned i = 0, n = outputs.size(); i != n; ++i)
+				if (locked[i])
+					outputs[i]->mutex.unlock();
+
+		/* return the chunk to the buffer */
+		buffer->Return(shifted);
+	}
+
+	return 0;
+}
+
+bool
+MultipleOutputs::Wait(PlayerControl &pc, unsigned threshold)
+{
+	pc.Lock();
+
+	if (Check() < threshold) {
+		pc.Unlock();
+		return true;
+	}
+
+	pc.Wait();
+	pc.Unlock();
+
+	return Check() < threshold;
+}
+
+void
+MultipleOutputs::Pause()
+{
+	Update();
+
+	for (auto ao : outputs)
+		audio_output_pause(ao);
+
+	WaitAll();
+}
+
+void
+MultipleOutputs::Drain()
+{
+	for (auto ao : outputs)
+		audio_output_drain_async(ao);
+
+	WaitAll();
+}
+
+void
+MultipleOutputs::Cancel()
+{
+	/* send the cancel() command to all audio outputs */
+
+	for (auto ao : outputs)
+		audio_output_cancel(ao);
+
+	WaitAll();
+
+	/* clear the music pipe and return all chunks to the buffer */
+
+	if (pipe != nullptr)
+		pipe->Clear(*buffer);
+
+	/* the audio outputs are now waiting for a signal, to
+	   synchronize the cleared music pipe */
+
+	AllowPlay();
+
+	/* invalidate elapsed_time */
+
+	elapsed_time = -1.0;
+}
+
+void
+MultipleOutputs::Close()
+{
+	for (auto ao : outputs)
+		audio_output_close(ao);
+
+	if (pipe != nullptr) {
+		assert(buffer != nullptr);
+
+		pipe->Clear(*buffer);
+		delete pipe;
+		pipe = nullptr;
+	}
+
+	buffer = nullptr;
+
+	input_audio_format.Clear();
+
+	elapsed_time = -1.0;
+}
+
+void
+MultipleOutputs::Release()
+{
+	for (auto ao : outputs)
+		audio_output_release(ao);
+
+	if (pipe != nullptr) {
+		assert(buffer != nullptr);
+
+		pipe->Clear(*buffer);
+		delete pipe;
+		pipe = nullptr;
+	}
+
+	buffer = nullptr;
+
+	input_audio_format.Clear();
+
+	elapsed_time = -1.0;
+}
+
+void
+MultipleOutputs::SongBorder()
+{
+	/* clear the elapsed_time pointer at the beginning of a new
+	   song */
+	elapsed_time = 0.0;
+}
diff --git a/src/output/MultipleOutputs.hxx b/src/output/MultipleOutputs.hxx
new file mode 100644
index 000000000..e1a8602a9
--- /dev/null
+++ b/src/output/MultipleOutputs.hxx
@@ -0,0 +1,271 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * Functions for dealing with all configured (enabled) audion outputs
+ * at once.
+ *
+ */
+
+#ifndef OUTPUT_ALL_H
+#define OUTPUT_ALL_H
+
+#include "AudioFormat.hxx"
+#include "ReplayGainInfo.hxx"
+#include "Compiler.h"
+
+#include <vector>
+
+#include <assert.h>
+
+struct AudioFormat;
+class MusicBuffer;
+class MusicPipe;
+struct music_chunk;
+struct PlayerControl;
+struct audio_output;
+class Error;
+
+class MultipleOutputs {
+	std::vector<audio_output *> outputs;
+
+	AudioFormat input_audio_format;
+
+	/**
+	 * The #MusicBuffer object where consumed chunks are returned.
+	 */
+	MusicBuffer *buffer;
+
+	/**
+	 * The #MusicPipe object which feeds all audio outputs.  It is
+	 * filled by audio_output_all_play().
+	 */
+	MusicPipe *pipe;
+
+	/**
+	 * The "elapsed_time" stamp of the most recently finished
+	 * chunk.
+	 */
+	float elapsed_time;
+
+public:
+	/**
+	 * Load audio outputs from the configuration file and
+	 * initialize them.
+	 */
+	MultipleOutputs();
+	~MultipleOutputs();
+
+	void Configure(PlayerControl &pc);
+
+	/**
+	 * Returns the total number of audio output devices, including
+	 * those which are disabled right now.
+	 */
+	gcc_pure
+	unsigned Size() const {
+		return outputs.size();
+	}
+
+	/**
+	 * Returns the "i"th audio output device.
+	 */
+	const audio_output &Get(unsigned i) const {
+		assert(i < Size());
+
+		return *outputs[i];
+	}
+
+	audio_output &Get(unsigned i) {
+		assert(i < Size());
+
+		return *outputs[i];
+	}
+
+	/**
+	 * Returns the audio output device with the specified name.
+	 * Returns nullptr if the name does not exist.
+	 */
+	gcc_pure
+	audio_output *FindByName(const char *name) const;
+
+	/**
+	 * Checks the "enabled" flag of all audio outputs, and if one has
+	 * changed, commit the change.
+	 */
+	void EnableDisable();
+
+	/**
+	 * Opens all audio outputs which are not disabled.
+	 *
+	 * @param audio_format the preferred audio format
+	 * @param buffer the #music_buffer where consumed #music_chunk objects
+	 * should be returned
+	 * @return true on success, false on failure
+	 */
+	bool Open(const AudioFormat audio_format, MusicBuffer &_buffer,
+		  Error &error);
+
+	/**
+	 * Closes all audio outputs.
+	 */
+	void Close();
+
+	/**
+	 * Closes all audio outputs.  Outputs with the "always_on"
+	 * flag are put into pause mode.
+	 */
+	void Release();
+
+	void SetReplayGainMode(ReplayGainMode mode);
+
+	/**
+	 * Enqueue a #music_chunk object for playing, i.e. pushes it to a
+	 * #MusicPipe.
+	 *
+	 * @param chunk the #music_chunk object to be played
+	 * @return true on success, false if no audio output was able to play
+	 * (all closed then)
+	 */
+	bool Play(music_chunk *chunk, Error &error);
+
+	/**
+	 * Checks if the output devices have drained their music pipe, and
+	 * returns the consumed music chunks to the #music_buffer.
+	 *
+	 * @return the number of chunks to play left in the #MusicPipe
+	 */
+	unsigned Check();
+
+	/**
+	 * Checks if the size of the #MusicPipe is below the #threshold.  If
+	 * not, it attempts to synchronize with all output threads, and waits
+	 * until another #music_chunk is finished.
+	 *
+	 * @param threshold the maximum number of chunks in the pipe
+	 * @return true if there are less than #threshold chunks in the pipe
+	 */
+	bool Wait(PlayerControl &pc, unsigned threshold);
+
+	/**
+	 * Puts all audio outputs into pause mode.  Most implementations will
+	 * simply close it then.
+	 */
+	void Pause();
+
+	/**
+	 * Drain all audio outputs.
+	 */
+	void Drain();
+
+	/**
+	 * Try to cancel data which may still be in the device's buffers.
+	 */
+	void Cancel();
+
+	/**
+	 * Indicate that a new song will begin now.
+	 */
+	void SongBorder();
+
+	/**
+	 * Returns the "elapsed_time" stamp of the most recently finished
+	 * chunk.  A negative value is returned when no chunk has been
+	 * finished yet.
+	 */
+	gcc_pure
+	float GetElapsedTime() const {
+		return elapsed_time;
+	}
+
+	/**
+	 * Returns the average volume of all available mixers (range
+	 * 0..100).  Returns -1 if no mixer can be queried.
+	 */
+	gcc_pure
+	int GetVolume() const;
+
+	/**
+	 * Sets the volume on all available mixers.
+	 *
+	 * @param volume the volume (range 0..100)
+	 * @return true on success, false on failure
+	 */
+	bool SetVolume(unsigned volume);
+
+	/**
+	 * Similar to GetVolume(), but gets the volume only for
+	 * software mixers.  See #software_mixer_plugin.  This
+	 * function fails if no software mixer is configured.
+	 */
+	gcc_pure
+	int GetSoftwareVolume() const;
+
+	/**
+	 * Similar to SetVolume(), but sets the volume only for
+	 * software mixers.  See #software_mixer_plugin.  This
+	 * function cannot fail, because the underlying software
+	 * mixers cannot fail either.
+	 */
+	void SetSoftwareVolume(unsigned volume);
+
+private:
+	/**
+	 * Determine if all (active) outputs have finished the current
+	 * command.
+	 */
+	gcc_pure
+	bool AllFinished() const;
+
+	void WaitAll();
+
+	/**
+	 * Signals all audio outputs which are open.
+	 */
+	void AllowPlay();
+
+	/**
+	 * Resets the "reopen" flag on all audio devices.  MPD should
+	 * immediately retry to open the device instead of waiting for
+	 * the timeout when the user wants to start playback.
+	 */
+	void ResetReopen();
+
+	/**
+	 * Opens all output devices which are enabled, but closed.
+	 *
+	 * @return true if there is at least open output device which
+	 * is open
+	 */
+	bool Update();
+
+	/**
+	 * Has this chunk been consumed by all audio outputs?
+	 */
+	bool IsChunkConsumed(const music_chunk *chunk) const;
+
+	/**
+	 * There's only one chunk left in the pipe (#pipe), and all
+	 * audio outputs have consumed it already.  Clear the
+	 * reference.
+	 */
+	void ClearTailChunk(const struct music_chunk *chunk, bool *locked);
+};
+
+#endif
diff --git a/src/output/OutputAll.cxx b/src/output/OutputAll.cxx
deleted file mode 100644
index ded9fa1e1..000000000
--- a/src/output/OutputAll.cxx
+++ /dev/null
@@ -1,589 +0,0 @@
-/*
- * Copyright (C) 2003-2014 The Music Player Daemon Project
- * http://www.musicpd.org
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#include "config.h"
-#include "OutputAll.hxx"
-#include "PlayerControl.hxx"
-#include "OutputInternal.hxx"
-#include "OutputControl.hxx"
-#include "OutputError.hxx"
-#include "MusicBuffer.hxx"
-#include "MusicPipe.hxx"
-#include "MusicChunk.hxx"
-#include "system/FatalError.hxx"
-#include "util/Error.hxx"
-#include "config/ConfigData.hxx"
-#include "config/ConfigGlobal.hxx"
-#include "config/ConfigOption.hxx"
-#include "notify.hxx"
-
-#include <assert.h>
-#include <string.h>
-
-static AudioFormat input_audio_format;
-
-static struct audio_output **audio_outputs;
-static unsigned int num_audio_outputs;
-
-/**
- * The #MusicBuffer object where consumed chunks are returned.
- */
-static MusicBuffer *g_music_buffer;
-
-/**
- * The #MusicPipe object which feeds all audio outputs.  It is filled
- * by audio_output_all_play().
- */
-static MusicPipe *g_mp;
-
-/**
- * The "elapsed_time" stamp of the most recently finished chunk.
- */
-static float audio_output_all_elapsed_time = -1.0;
-
-unsigned int audio_output_count(void)
-{
-	return num_audio_outputs;
-}
-
-struct audio_output *
-audio_output_get(unsigned i)
-{
-	assert(i < num_audio_outputs);
-
-	assert(audio_outputs[i] != nullptr);
-
-	return audio_outputs[i];
-}
-
-struct audio_output *
-audio_output_find(const char *name)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_output_get(i);
-
-		if (strcmp(ao->name, name) == 0)
-			return ao;
-	}
-
-	/* name not found */
-	return nullptr;
-}
-
-gcc_const
-static unsigned
-audio_output_config_count(void)
-{
-	unsigned int nr = 0;
-	const struct config_param *param = nullptr;
-
-	while ((param = config_get_next_param(CONF_AUDIO_OUTPUT, param)))
-		nr++;
-	if (!nr)
-		nr = 1; /* we'll always have at least one device  */
-	return nr;
-}
-
-void
-audio_output_all_init(PlayerControl &pc)
-{
-	const struct config_param *param = nullptr;
-	unsigned int i;
-	Error error;
-
-	num_audio_outputs = audio_output_config_count();
-	audio_outputs = new audio_output *[num_audio_outputs];
-
-	const config_param empty;
-
-	for (i = 0; i < num_audio_outputs; i++)
-	{
-		unsigned int j;
-
-		param = config_get_next_param(CONF_AUDIO_OUTPUT, param);
-		if (param == nullptr) {
-			/* only allow param to be nullptr if there
-			   just one audio output */
-			assert(i == 0);
-			assert(num_audio_outputs == 1);
-
-			param = &empty;
-		}
-
-		audio_output *output = audio_output_new(*param, pc, error);
-		if (output == nullptr) {
-			if (param != nullptr)
-				FormatFatalError("line %i: %s",
-						 param->line,
-						 error.GetMessage());
-			else
-				FatalError(error);
-		}
-
-		audio_outputs[i] = output;
-
-		/* require output names to be unique: */
-		for (j = 0; j < i; j++) {
-			if (!strcmp(output->name, audio_outputs[j]->name)) {
-				FormatFatalError("output devices with identical "
-						 "names: %s", output->name);
-			}
-		}
-	}
-}
-
-void
-audio_output_all_finish(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_audio_outputs; i++) {
-		audio_output_disable(audio_outputs[i]);
-		audio_output_finish(audio_outputs[i]);
-	}
-
-	delete[] audio_outputs;
-	audio_outputs = nullptr;
-	num_audio_outputs = 0;
-}
-
-void
-audio_output_all_enable_disable(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; i++) {
-		struct audio_output *ao = audio_outputs[i];
-		bool enabled;
-
-		ao->mutex.lock();
-		enabled = ao->really_enabled;
-		ao->mutex.unlock();
-
-		if (ao->enabled != enabled) {
-			if (ao->enabled)
-				audio_output_enable(ao);
-			else
-				audio_output_disable(ao);
-		}
-	}
-}
-
-/**
- * Determine if all (active) outputs have finished the current
- * command.
- */
-static bool
-audio_output_all_finished(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		const ScopeLock protect(ao->mutex);
-		if (audio_output_is_open(ao) &&
-		    !audio_output_command_is_finished(ao))
-			return false;
-	}
-
-	return true;
-}
-
-static void audio_output_wait_all(void)
-{
-	while (!audio_output_all_finished())
-		audio_output_client_notify.Wait();
-}
-
-/**
- * Signals all audio outputs which are open.
- */
-static void
-audio_output_allow_play_all(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i)
-		audio_output_allow_play(audio_outputs[i]);
-}
-
-static void
-audio_output_reset_reopen(struct audio_output *ao)
-{
-	const ScopeLock protect(ao->mutex);
-
-	ao->fail_timer.Reset();
-}
-
-/**
- * Resets the "reopen" flag on all audio devices.  MPD should
- * immediately retry to open the device instead of waiting for the
- * timeout when the user wants to start playback.
- */
-static void
-audio_output_all_reset_reopen(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		audio_output_reset_reopen(ao);
-	}
-}
-
-/**
- * Opens all output devices which are enabled, but closed.
- *
- * @return true if there is at least open output device which is open
- */
-static bool
-audio_output_all_update(void)
-{
-	unsigned int i;
-	bool ret = false;
-
-	if (!input_audio_format.IsDefined())
-		return false;
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		ret = audio_output_update(audio_outputs[i],
-					  input_audio_format, *g_mp) || ret;
-
-	return ret;
-}
-
-void
-audio_output_all_set_replay_gain_mode(ReplayGainMode mode)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i)
-		audio_output_set_replay_gain_mode(audio_outputs[i], mode);
-}
-
-bool
-audio_output_all_play(struct music_chunk *chunk, Error &error)
-{
-	bool ret;
-	unsigned int i;
-
-	assert(g_music_buffer != nullptr);
-	assert(g_mp != nullptr);
-	assert(chunk != nullptr);
-	assert(chunk->CheckFormat(input_audio_format));
-
-	ret = audio_output_all_update();
-	if (!ret) {
-		/* TODO: obtain real error */
-		error.Set(output_domain, "Failed to open audio output");
-		return false;
-	}
-
-	g_mp->Push(chunk);
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_play(audio_outputs[i]);
-
-	return true;
-}
-
-bool
-audio_output_all_open(const AudioFormat audio_format,
-		      MusicBuffer &buffer,
-		      Error &error)
-{
-	bool ret = false, enabled = false;
-	unsigned int i;
-
-	assert(g_music_buffer == nullptr || g_music_buffer == &buffer);
-	assert((g_mp == nullptr) == (g_music_buffer == nullptr));
-
-	g_music_buffer = &buffer;
-
-	/* the audio format must be the same as existing chunks in the
-	   pipe */
-	assert(g_mp == nullptr || g_mp->CheckFormat(audio_format));
-
-	if (g_mp == nullptr)
-		g_mp = new MusicPipe();
-	else
-		/* if the pipe hasn't been cleared, the the audio
-		   format must not have changed */
-		assert(g_mp->IsEmpty() || audio_format == input_audio_format);
-
-	input_audio_format = audio_format;
-
-	audio_output_all_reset_reopen();
-	audio_output_all_enable_disable();
-	audio_output_all_update();
-
-	for (i = 0; i < num_audio_outputs; ++i) {
-		if (audio_outputs[i]->enabled)
-			enabled = true;
-
-		if (audio_outputs[i]->open)
-			ret = true;
-	}
-
-	if (!enabled)
-		error.Set(output_domain, "All audio outputs are disabled");
-	else if (!ret)
-		/* TODO: obtain real error */
-		error.Set(output_domain, "Failed to open audio output");
-
-	if (!ret)
-		/* close all devices if there was an error */
-		audio_output_all_close();
-
-	return ret;
-}
-
-/**
- * Has the specified audio output already consumed this chunk?
- */
-static bool
-chunk_is_consumed_in(const struct audio_output *ao,
-		     const struct music_chunk *chunk)
-{
-	if (!ao->open)
-		return true;
-
-	if (ao->chunk == nullptr)
-		return false;
-
-	assert(chunk == ao->chunk || g_mp->Contains(ao->chunk));
-
-	if (chunk != ao->chunk) {
-		assert(chunk->next != nullptr);
-		return true;
-	}
-
-	return ao->chunk_finished && chunk->next == nullptr;
-}
-
-/**
- * Has this chunk been consumed by all audio outputs?
- */
-static bool
-chunk_is_consumed(const struct music_chunk *chunk)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		const ScopeLock protect(ao->mutex);
-		if (!chunk_is_consumed_in(ao, chunk))
-			return false;
-	}
-
-	return true;
-}
-
-/**
- * There's only one chunk left in the pipe (#g_mp), and all audio
- * outputs have consumed it already.  Clear the reference.
- */
-static void
-clear_tail_chunk(gcc_unused const struct music_chunk *chunk, bool *locked)
-{
-	assert(chunk->next == nullptr);
-	assert(g_mp->Contains(chunk));
-
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		/* this mutex will be unlocked by the caller when it's
-		   ready */
-		ao->mutex.lock();
-		locked[i] = ao->open;
-
-		if (!locked[i]) {
-			ao->mutex.unlock();
-			continue;
-		}
-
-		assert(ao->chunk == chunk);
-		assert(ao->chunk_finished);
-		ao->chunk = nullptr;
-	}
-}
-
-unsigned
-audio_output_all_check(void)
-{
-	const struct music_chunk *chunk;
-	bool is_tail;
-	struct music_chunk *shifted;
-	bool locked[num_audio_outputs];
-
-	assert(g_music_buffer != nullptr);
-	assert(g_mp != nullptr);
-
-	while ((chunk = g_mp->Peek()) != nullptr) {
-		assert(!g_mp->IsEmpty());
-
-		if (!chunk_is_consumed(chunk))
-			/* at least one output is not finished playing
-			   this chunk */
-			return g_mp->GetSize();
-
-		if (chunk->length > 0 && chunk->times >= 0.0)
-			/* only update elapsed_time if the chunk
-			   provides a defined value */
-			audio_output_all_elapsed_time = chunk->times;
-
-		is_tail = chunk->next == nullptr;
-		if (is_tail)
-			/* this is the tail of the pipe - clear the
-			   chunk reference in all outputs */
-			clear_tail_chunk(chunk, locked);
-
-		/* remove the chunk from the pipe */
-		shifted = g_mp->Shift();
-		assert(shifted == chunk);
-
-		if (is_tail)
-			/* unlock all audio outputs which were locked
-			   by clear_tail_chunk() */
-			for (unsigned i = 0; i < num_audio_outputs; ++i)
-				if (locked[i])
-					audio_outputs[i]->mutex.unlock();
-
-		/* return the chunk to the buffer */
-		g_music_buffer->Return(shifted);
-	}
-
-	return 0;
-}
-
-bool
-audio_output_all_wait(PlayerControl &pc, unsigned threshold)
-{
-	pc.Lock();
-
-	if (audio_output_all_check() < threshold) {
-		pc.Unlock();
-		return true;
-	}
-
-	pc.Wait();
-	pc.Unlock();
-
-	return audio_output_all_check() < threshold;
-}
-
-void
-audio_output_all_pause(void)
-{
-	unsigned int i;
-
-	audio_output_all_update();
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_pause(audio_outputs[i]);
-
-	audio_output_wait_all();
-}
-
-void
-audio_output_all_drain(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i)
-		audio_output_drain_async(audio_outputs[i]);
-
-	audio_output_wait_all();
-}
-
-void
-audio_output_all_cancel(void)
-{
-	unsigned int i;
-
-	/* send the cancel() command to all audio outputs */
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_cancel(audio_outputs[i]);
-
-	audio_output_wait_all();
-
-	/* clear the music pipe and return all chunks to the buffer */
-
-	if (g_mp != nullptr)
-		g_mp->Clear(*g_music_buffer);
-
-	/* the audio outputs are now waiting for a signal, to
-	   synchronize the cleared music pipe */
-
-	audio_output_allow_play_all();
-
-	/* invalidate elapsed_time */
-
-	audio_output_all_elapsed_time = -1.0;
-}
-
-void
-audio_output_all_close(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_close(audio_outputs[i]);
-
-	if (g_mp != nullptr) {
-		assert(g_music_buffer != nullptr);
-
-		g_mp->Clear(*g_music_buffer);
-		delete g_mp;
-		g_mp = nullptr;
-	}
-
-	g_music_buffer = nullptr;
-
-	input_audio_format.Clear();
-
-	audio_output_all_elapsed_time = -1.0;
-}
-
-void
-audio_output_all_release(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_release(audio_outputs[i]);
-
-	if (g_mp != nullptr) {
-		assert(g_music_buffer != nullptr);
-
-		g_mp->Clear(*g_music_buffer);
-		delete g_mp;
-		g_mp = nullptr;
-	}
-
-	g_music_buffer = nullptr;
-
-	input_audio_format.Clear();
-
-	audio_output_all_elapsed_time = -1.0;
-}
-
-void
-audio_output_all_song_border(void)
-{
-	/* clear the elapsed_time pointer at the beginning of a new
-	   song */
-	audio_output_all_elapsed_time = 0.0;
-}
-
-float
-audio_output_all_get_elapsed_time(void)
-{
-	return audio_output_all_elapsed_time;
-}
diff --git a/src/output/OutputAll.hxx b/src/output/OutputAll.hxx
deleted file mode 100644
index b6166eb48..000000000
--- a/src/output/OutputAll.hxx
+++ /dev/null
@@ -1,174 +0,0 @@
-/*
- * Copyright (C) 2003-2014 The Music Player Daemon Project
- * http://www.musicpd.org
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-/*
- * Functions for dealing with all configured (enabled) audion outputs
- * at once.
- *
- */
-
-#ifndef OUTPUT_ALL_H
-#define OUTPUT_ALL_H
-
-#include "ReplayGainInfo.hxx"
-#include "Compiler.h"
-
-struct AudioFormat;
-class MusicBuffer;
-struct music_chunk;
-struct PlayerControl;
-class Error;
-
-/**
- * Global initialization: load audio outputs from the configuration
- * file and initialize them.
- */
-void
-audio_output_all_init(PlayerControl &pc);
-
-/**
- * Global finalization: free memory occupied by audio outputs.  All
- */
-void
-audio_output_all_finish(void);
-
-/**
- * Returns the total number of audio output devices, including those
- * who are disabled right now.
- */
-gcc_const
-unsigned int audio_output_count(void);
-
-/**
- * Returns the "i"th audio output device.
- */
-gcc_const
-struct audio_output *
-audio_output_get(unsigned i);
-
-/**
- * Returns the audio output device with the specified name.  Returns
- * NULL if the name does not exist.
- */
-gcc_pure
-struct audio_output *
-audio_output_find(const char *name);
-
-/**
- * Checks the "enabled" flag of all audio outputs, and if one has
- * changed, commit the change.
- */
-void
-audio_output_all_enable_disable(void);
-
-/**
- * Opens all audio outputs which are not disabled.
- *
- * @param audio_format the preferred audio format
- * @param buffer the #music_buffer where consumed #music_chunk objects
- * should be returned
- * @return true on success, false on failure
- */
-bool
-audio_output_all_open(AudioFormat audio_format,
-		      MusicBuffer &buffer,
-		      Error &error);
-
-/**
- * Closes all audio outputs.
- */
-void
-audio_output_all_close(void);
-
-/**
- * Closes all audio outputs.  Outputs with the "always_on" flag are
- * put into pause mode.
- */
-void
-audio_output_all_release(void);
-
-void
-audio_output_all_set_replay_gain_mode(ReplayGainMode mode);
-
-/**
- * Enqueue a #music_chunk object for playing, i.e. pushes it to a
- * #MusicPipe.
- *
- * @param chunk the #music_chunk object to be played
- * @return true on success, false if no audio output was able to play
- * (all closed then)
- */
-bool
-audio_output_all_play(music_chunk *chunk, Error &error);
-
-/**
- * Checks if the output devices have drained their music pipe, and
- * returns the consumed music chunks to the #music_buffer.
- *
- * @return the number of chunks to play left in the #MusicPipe
- */
-unsigned
-audio_output_all_check(void);
-
-/**
- * Checks if the size of the #MusicPipe is below the #threshold.  If
- * not, it attempts to synchronize with all output threads, and waits
- * until another #music_chunk is finished.
- *
- * @param threshold the maximum number of chunks in the pipe
- * @return true if there are less than #threshold chunks in the pipe
- */
-bool
-audio_output_all_wait(PlayerControl &pc, unsigned threshold);
-
-/**
- * Puts all audio outputs into pause mode.  Most implementations will
- * simply close it then.
- */
-void
-audio_output_all_pause(void);
-
-/**
- * Drain all audio outputs.
- */
-void
-audio_output_all_drain(void);
-
-/**
- * Try to cancel data which may still be in the device's buffers.
- */
-void
-audio_output_all_cancel(void);
-
-/**
- * Indicate that a new song will begin now.
- */
-void
-audio_output_all_song_border(void);
-
-/**
- * Returns the "elapsed_time" stamp of the most recently finished
- * chunk.  A negative value is returned when no chunk has been
- * finished yet.
- */
-gcc_pure
-float
-audio_output_all_get_elapsed_time(void);
-
-#endif
diff --git a/src/output/OutputCommand.cxx b/src/output/OutputCommand.cxx
index d82b7c696..d4c1d844d 100644
--- a/src/output/OutputCommand.cxx
+++ b/src/output/OutputCommand.cxx
@@ -26,7 +26,7 @@
 
 #include "config.h"
 #include "OutputCommand.hxx"
-#include "OutputAll.hxx"
+#include "MultipleOutputs.hxx"
 #include "OutputInternal.hxx"
 #include "PlayerControl.hxx"
 #include "mixer/MixerControl.hxx"
@@ -35,21 +35,19 @@
 extern unsigned audio_output_state_version;
 
 bool
-audio_output_enable_index(unsigned idx)
+audio_output_enable_index(MultipleOutputs &outputs, unsigned idx)
 {
-	struct audio_output *ao;
-
-	if (idx >= audio_output_count())
+	if (idx >= outputs.Size())
 		return false;
 
-	ao = audio_output_get(idx);
-	if (ao->enabled)
+	audio_output &ao = outputs.Get(idx);
+	if (ao.enabled)
 		return true;
 
-	ao->enabled = true;
+	ao.enabled = true;
 	idle_add(IDLE_OUTPUT);
 
-	ao->player_control->UpdateAudio();
+	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
 
@@ -57,27 +55,25 @@ audio_output_enable_index(unsigned idx)
 }
 
 bool
-audio_output_disable_index(unsigned idx)
+audio_output_disable_index(MultipleOutputs &outputs, unsigned idx)
 {
-	struct audio_output *ao;
-
-	if (idx >= audio_output_count())
+	if (idx >= outputs.Size())
 		return false;
 
-	ao = audio_output_get(idx);
-	if (!ao->enabled)
+	audio_output &ao = outputs.Get(idx);
+	if (!ao.enabled)
 		return true;
 
-	ao->enabled = false;
+	ao.enabled = false;
 	idle_add(IDLE_OUTPUT);
 
-	Mixer *mixer = ao->mixer;
+	Mixer *mixer = ao.mixer;
 	if (mixer != nullptr) {
 		mixer_close(mixer);
 		idle_add(IDLE_MIXER);
 	}
 
-	ao->player_control->UpdateAudio();
+	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
 
@@ -85,26 +81,24 @@ audio_output_disable_index(unsigned idx)
 }
 
 bool
-audio_output_toggle_index(unsigned idx)
+audio_output_toggle_index(MultipleOutputs &outputs, unsigned idx)
 {
-	struct audio_output *ao;
-
-	if (idx >= audio_output_count())
+	if (idx >= outputs.Size())
 		return false;
 
-	ao = audio_output_get(idx);
-	const bool enabled = ao->enabled = !ao->enabled;
+	audio_output &ao = outputs.Get(idx);
+	const bool enabled = ao.enabled = !ao.enabled;
 	idle_add(IDLE_OUTPUT);
 
 	if (!enabled) {
-		Mixer *mixer = ao->mixer;
+		Mixer *mixer = ao.mixer;
 		if (mixer != nullptr) {
 			mixer_close(mixer);
 			idle_add(IDLE_MIXER);
 		}
 	}
 
-	ao->player_control->UpdateAudio();
+	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
 
diff --git a/src/output/OutputCommand.hxx b/src/output/OutputCommand.hxx
index 4c44dff53..53fc5c95e 100644
--- a/src/output/OutputCommand.hxx
+++ b/src/output/OutputCommand.hxx
@@ -27,25 +27,27 @@
 #ifndef MPD_OUTPUT_COMMAND_HXX
 #define MPD_OUTPUT_COMMAND_HXX
 
+class MultipleOutputs;
+
 /**
  * Enables an audio output.  Returns false if the specified output
  * does not exist.
  */
 bool
-audio_output_enable_index(unsigned idx);
+audio_output_enable_index(MultipleOutputs &outputs, unsigned idx);
 
 /**
  * Disables an audio output.  Returns false if the specified output
  * does not exist.
  */
 bool
-audio_output_disable_index(unsigned idx);
+audio_output_disable_index(MultipleOutputs &outputs, unsigned idx);
 
 /**
  * Toggles an audio output.  Returns false if the specified output
  * does not exist.
  */
 bool
-audio_output_toggle_index(unsigned idx);
+audio_output_toggle_index(MultipleOutputs &outputs, unsigned idx);
 
 #endif
diff --git a/src/output/OutputPrint.cxx b/src/output/OutputPrint.cxx
index 66826f140..7e0536bf5 100644
--- a/src/output/OutputPrint.cxx
+++ b/src/output/OutputPrint.cxx
@@ -24,22 +24,20 @@
 
 #include "config.h"
 #include "OutputPrint.hxx"
-#include "OutputAll.hxx"
+#include "MultipleOutputs.hxx"
 #include "OutputInternal.hxx"
 #include "client/Client.hxx"
 
 void
-printAudioDevices(Client &client)
+printAudioDevices(Client &client, const MultipleOutputs &outputs)
 {
-	const unsigned n = audio_output_count();
-
-	for (unsigned i = 0; i < n; ++i) {
-		const struct audio_output *ao = audio_output_get(i);
+	for (unsigned i = 0, n = outputs.Size(); i != n; ++i) {
+		const audio_output &ao = outputs.Get(i);
 
 		client_printf(client,
 			      "outputid: %i\n"
 			      "outputname: %s\n"
 			      "outputenabled: %i\n",
-			      i, ao->name, ao->enabled);
+			      i, ao.name, ao.enabled);
 	}
 }
diff --git a/src/output/OutputPrint.hxx b/src/output/OutputPrint.hxx
index 2d94226fd..29aa2b11c 100644
--- a/src/output/OutputPrint.hxx
+++ b/src/output/OutputPrint.hxx
@@ -1,4 +1,3 @@
-
 /*
  * Copyright (C) 2003-2014 The Music Player Daemon Project
  * http://www.musicpd.org
@@ -27,8 +26,9 @@
 #define MPD_OUTPUT_PRINT_HXX
 
 class Client;
+class MultipleOutputs;
 
 void
-printAudioDevices(Client &client);
+printAudioDevices(Client &client, const MultipleOutputs &outputs);
 
 #endif
diff --git a/src/output/OutputState.cxx b/src/output/OutputState.cxx
index 1141abeda..abd5dd2ae 100644
--- a/src/output/OutputState.cxx
+++ b/src/output/OutputState.cxx
@@ -24,7 +24,7 @@
 
 #include "config.h"
 #include "OutputState.hxx"
-#include "OutputAll.hxx"
+#include "MultipleOutputs.hxx"
 #include "OutputInternal.hxx"
 #include "OutputError.hxx"
 #include "Log.hxx"
@@ -38,27 +38,22 @@
 unsigned audio_output_state_version;
 
 void
-audio_output_state_save(FILE *fp)
+audio_output_state_save(FILE *fp, const MultipleOutputs &outputs)
 {
-	unsigned n = audio_output_count();
-
-	assert(n > 0);
-
-	for (unsigned i = 0; i < n; ++i) {
-		const struct audio_output *ao = audio_output_get(i);
+	for (unsigned i = 0, n = outputs.Size(); i != n; ++i) {
+		const audio_output &ao = outputs.Get(i);
 
 		fprintf(fp, AUDIO_DEVICE_STATE "%d:%s\n",
-			ao->enabled, ao->name);
+			ao.enabled, ao.name);
 	}
 }
 
 bool
-audio_output_state_read(const char *line)
+audio_output_state_read(const char *line, MultipleOutputs &outputs)
 {
 	long value;
 	char *endptr;
 	const char *name;
-	struct audio_output *ao;
 
 	if (!StringStartsWith(line, AUDIO_DEVICE_STATE))
 		return false;
@@ -74,7 +69,7 @@ audio_output_state_read(const char *line)
 		return true;
 
 	name = endptr + 1;
-	ao = audio_output_find(name);
+	audio_output *ao = outputs.FindByName(name);
 	if (ao == NULL) {
 		FormatDebug(output_domain,
 			    "Ignoring device state for '%s'", name);
diff --git a/src/output/OutputState.hxx b/src/output/OutputState.hxx
index a68180ae4..32f4bbcce 100644
--- a/src/output/OutputState.hxx
+++ b/src/output/OutputState.hxx
@@ -27,11 +27,13 @@
 
 #include <stdio.h>
 
+class MultipleOutputs;
+
 bool
-audio_output_state_read(const char *line);
+audio_output_state_read(const char *line, MultipleOutputs &outputs);
 
 void
-audio_output_state_save(FILE *fp);
+audio_output_state_save(FILE *fp, const MultipleOutputs &outputs);
 
 /**
  * Generates a version number for the current state of the audio
diff --git a/test/run_output.cxx b/test/run_output.cxx
index 522db5e1e..fe377158d 100644
--- a/test/run_output.cxx
+++ b/test/run_output.cxx
@@ -74,8 +74,10 @@ find_named_config_block(ConfigOption option, const char *name)
 	return NULL;
 }
 
-PlayerControl::PlayerControl(gcc_unused unsigned _buffer_chunks,
-			       gcc_unused unsigned _buffered_before_play) {}
+PlayerControl::PlayerControl(gcc_unused MultipleOutputs &_outputs,
+			     gcc_unused unsigned _buffer_chunks,
+			     gcc_unused unsigned _buffered_before_play)
+	:outputs(_outputs) {}
 PlayerControl::~PlayerControl() {}
 
 static struct audio_output *
@@ -89,7 +91,8 @@ load_audio_output(const char *name)
 		return nullptr;
 	}
 
-	static struct PlayerControl dummy_player_control(32, 4);
+	static struct PlayerControl dummy_player_control(*(MultipleOutputs *)nullptr,
+							 32, 4);
 
 	Error error;
 	struct audio_output *ao =