diff --git a/Makefile.am b/Makefile.am index 808fce77d..023f7e45a 100644 --- a/Makefile.am +++ b/Makefile.am @@ -1256,6 +1256,7 @@ MIXER_API_SRC = \ src/mixer/MixerInternal.hxx libmixer_plugins_a_SOURCES = \ + src/mixer/plugins/NullMixerPlugin.cxx \ src/mixer/plugins/SoftwareMixerPlugin.cxx \ src/mixer/plugins/SoftwareMixerPlugin.hxx libmixer_plugins_a_CPPFLAGS = $(AM_CPPFLAGS) \ diff --git a/NEWS b/NEWS index b956c3881..31a034763 100644 --- a/NEWS +++ b/NEWS @@ -7,6 +7,8 @@ ver 0.20 (not yet released) - ape: drop support for non-standard tag "album artist" * output - pulse: set channel map to WAVE-EX +* mixer + - null: new plugin * reset song priority on playback ver 0.19.5 (2014/11/26) diff --git a/doc/user.xml b/doc/user.xml index bc43a4167..920454377 100644 --- a/doc/user.xml +++ b/doc/user.xml @@ -572,7 +572,7 @@ systemctl start mpd.socket mixer_type - hardware|software|none + hardware|software|null|none Specifies which mixer should be used for this audio @@ -580,7 +580,9 @@ systemctl start mpd.socket linkend="alsa_output">ALSA, OSS and PulseAudio), the - software mixer or no mixer + software mixer, the "null" mixer + (null; allows setting the + volume, but with no effect) or no mixer (none). By default, the hardware mixer is used for devices which support it, and none for the others. diff --git a/src/mixer/MixerList.hxx b/src/mixer/MixerList.hxx index e75b2e6ff..8be74adf2 100644 --- a/src/mixer/MixerList.hxx +++ b/src/mixer/MixerList.hxx @@ -27,6 +27,7 @@ struct MixerPlugin; +extern const MixerPlugin null_mixer_plugin; extern const MixerPlugin software_mixer_plugin; extern const MixerPlugin alsa_mixer_plugin; extern const MixerPlugin oss_mixer_plugin; diff --git a/src/mixer/MixerType.cxx b/src/mixer/MixerType.cxx index 0605f0979..8972118e5 100644 --- a/src/mixer/MixerType.cxx +++ b/src/mixer/MixerType.cxx @@ -34,6 +34,8 @@ mixer_type_parse(const char *input) return MixerType::HARDWARE; else if (strcmp(input, "software") == 0) return MixerType::SOFTWARE; + else if (strcmp(input, "null") == 0) + return MixerType::NULL_; else return MixerType::UNKNOWN; } diff --git a/src/mixer/MixerType.hxx b/src/mixer/MixerType.hxx index 9831e3db6..40f60203d 100644 --- a/src/mixer/MixerType.hxx +++ b/src/mixer/MixerType.hxx @@ -27,6 +27,9 @@ enum class MixerType { /** mixer disabled */ NONE, + /** "null" mixer (virtual fake) */ + NULL_, + /** software mixer with pcm_volume() */ SOFTWARE, diff --git a/src/mixer/plugins/NullMixerPlugin.cxx b/src/mixer/plugins/NullMixerPlugin.cxx new file mode 100644 index 000000000..b8894d443 --- /dev/null +++ b/src/mixer/plugins/NullMixerPlugin.cxx @@ -0,0 +1,67 @@ +/* + * 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 "mixer/MixerInternal.hxx" + +class NullMixer final : public Mixer { + /** + * The current volume in percent (0..100). + */ + unsigned volume; + +public: + NullMixer(MixerListener &_listener) + :Mixer(null_mixer_plugin, _listener), + volume(100) + { + } + + /* virtual methods from class Mixer */ + bool Open(gcc_unused Error &error) override { + return true; + } + + void Close() override { + } + + int GetVolume(gcc_unused Error &error) override { + return volume; + } + + bool SetVolume(unsigned _volume, gcc_unused Error &error) override { + volume = _volume; + return true; + } +}; + +static Mixer * +null_mixer_init(gcc_unused EventLoop &event_loop, + gcc_unused AudioOutput &ao, + MixerListener &listener, + gcc_unused const config_param ¶m, + gcc_unused Error &error) +{ + return new NullMixer(listener); +} + +const MixerPlugin null_mixer_plugin = { + null_mixer_init, + true, +}; diff --git a/src/output/Init.cxx b/src/output/Init.cxx index 3518c5c64..9418b6414 100644 --- a/src/output/Init.cxx +++ b/src/output/Init.cxx @@ -126,6 +126,10 @@ audio_output_load_mixer(EventLoop &event_loop, AudioOutput &ao, case MixerType::UNKNOWN: return nullptr; + case MixerType::NULL_: + return mixer_new(event_loop, null_mixer_plugin, ao, listener, + param, error); + case MixerType::HARDWARE: if (plugin == nullptr) return nullptr;