/*
* Copyright (C) 2003-2015 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.
*/
#ifndef MPD_OUTPUT_INTERNAL_HXX
#define MPD_OUTPUT_INTERNAL_HXX
#include "AudioFormat.hxx"
#include "pcm/PcmBuffer.hxx"
#include "pcm/PcmDither.hxx"
#include "ReplayGainInfo.hxx"
#include "thread/Mutex.hxx"
#include "thread/Cond.hxx"
#include "thread/Thread.hxx"
#include "system/PeriodClock.hxx"
class Error;
class Filter;
class MusicPipe;
class EventLoop;
class Mixer;
class MixerListener;
struct MusicChunk;
struct ConfigBlock;
struct PlayerControl;
struct AudioOutputPlugin;
struct AudioOutput {
enum class Command {
NONE,
ENABLE,
DISABLE,
OPEN,
/**
* This command is invoked when the input audio format
* changes.
*/
REOPEN,
CLOSE,
PAUSE,
/**
* Drains the internal (hardware) buffers of the device. This
* operation may take a while to complete.
*/
DRAIN,
CANCEL,
KILL
};
/**
* The device's configured display name.
*/
const char *name;
/**
* The plugin which implements this output device.
*/
const AudioOutputPlugin &plugin;
/**
* The #mixer object associated with this audio output device.
* May be nullptr if none is available, or if software volume is
* configured.
*/
Mixer *mixer;
/**
* Will this output receive tags from the decoder? The
* default is true, but it may be configured to false to
* suppress sending tags to the output.
*/
bool tags;
/**
* Shall this output always play something (i.e. silence),
* even when playback is stopped?
*/
bool always_on;
/**
* Has the user enabled this device?
*/
bool enabled;
/**
* Is this device actually enabled, i.e. the "enable" method
* has succeeded?
*/
bool really_enabled;
/**
* Is the device (already) open and functional?
*
* This attribute may only be modified by the output thread.
* It is protected with #mutex: write accesses inside the
* output thread and read accesses outside of it may only be
* performed while the lock is held.
*/
bool open;
/**
* Is the device paused? i.e. the output thread is in the
* ao_pause() loop.
*/
bool pause;
/**
* When this flag is set, the output thread will not do any
* playback. It will wait until the flag is cleared.
*
* This is used to synchronize the "clear" operation on the
* shared music pipe during the CANCEL command.
*/
bool allow_play;
/**
* True while the OutputThread is inside ao_play(). This
* means the PlayerThread does not need to wake up the
* OutputThread when new chunks are added to the MusicPipe,
* because the OutputThread is already watching that.
*/
bool in_playback_loop;
/**
* Has the OutputThread been woken up to play more chunks?
* This is set by audio_output_play() and reset by ao_play()
* to reduce the number of duplicate wakeups.
*/
bool woken_for_play;
/**
* If not nullptr, the device has failed, and this timer is used
* to estimate how long it should stay disabled (unless
* explicitly reopened with "play").
*/
PeriodClock fail_timer;
/**
* The configured audio format.
*/
AudioFormat config_audio_format;
/**
* The audio_format in which audio data is received from the
* player thread (which in turn receives it from the decoder).
*/
AudioFormat in_audio_format;
/**
* The audio_format which is really sent to the device. This
* is basically config_audio_format (if configured) or
* in_audio_format, but may have been modified by
* plugin->open().
*/
AudioFormat out_audio_format;
/**
* The buffer used to allocate the cross-fading result.
*/
PcmBuffer cross_fade_buffer;
/**
* The dithering state for cross-fading two streams.
*/
PcmDither cross_fade_dither;
/**
* The filter object of this audio output. This is an
* instance of chain_filter_plugin.
*/
Filter *filter;
/**
* The replay_gain_filter_plugin instance of this audio
* output.
*/
Filter *replay_gain_filter;
/**
* The serial number of the last replay gain info. 0 means no
* replay gain info was available.
*/
unsigned replay_gain_serial;
/**
* The replay_gain_filter_plugin instance of this audio
* output, to be applied to the second chunk during
* cross-fading.
*/
Filter *other_replay_gain_filter;
/**
* The serial number of the last replay gain info by the
* "other" chunk during cross-fading.
*/
unsigned other_replay_gain_serial;
/**
* The convert_filter_plugin instance of this audio output.
* It is the last item in the filter chain, and is responsible
* for converting the input data into the appropriate format
* for this audio output.
*/
Filter *convert_filter;
/**
* The thread handle, or nullptr if the output thread isn't
* running.
*/
Thread thread;
/**
* The next command to be performed by the output thread.
*/
Command command;
/**
* The music pipe which provides music chunks to be played.
*/
const MusicPipe *pipe;
/**
* This mutex protects #open, #fail_timer, #current_chunk and
* #current_chunk_finished.
*/
Mutex mutex;
/**
* This condition object wakes up the output thread after
* #command has been set.
*/
Cond cond;
/**
* The PlayerControl object which "owns" this output. This
* object is needed to signal command completion.
*/
PlayerControl *player_control;
/**
* The #MusicChunk which is currently being played. All
* chunks before this one may be returned to the
* #music_buffer, because they are not going to be used by
* this output anymore.
*/
const MusicChunk *current_chunk;
/**
* Has the output finished playing #current_chunk?
*/
bool current_chunk_finished;
AudioOutput(const AudioOutputPlugin &_plugin);
~AudioOutput();
bool Configure(const ConfigBlock &block, Error &error);
void StartThread();
void StopThread();
void Finish();
bool IsOpen() const {
return open;
}
bool IsCommandFinished() const {
return command == Command::NONE;
}
/**
* Waits for command completion.
*
* Caller must lock the mutex.
*/
void WaitForCommand();
/**
* Sends a command, but does not wait for completion.
*
* Caller must lock the mutex.
*/
void CommandAsync(Command cmd);
/**
* Sends a command to the #AudioOutput object and waits for
* completion.
*
* Caller must lock the mutex.
*/
void CommandWait(Command cmd);
/**
* Lock the #AudioOutput object and execute the command
* synchronously.
*/
void LockCommandWait(Command cmd);
/**
* Enables the device.
*/
void LockEnableWait();
/**
* Disables the device.
*/
void LockDisableWait();
void LockPauseAsync();
/**
* Same LockCloseWait(), but expects the lock to be
* held by the caller.
*/
void CloseWait();
void LockCloseWait();
/**
* Closes the audio output, but if the "always_on" flag is set, put it
* into pause mode instead.
*/
void LockRelease();
void SetReplayGainMode(ReplayGainMode mode);
/**
* Caller must lock the mutex.
*/
bool Open(const AudioFormat audio_format, const MusicPipe &mp);
/**
* Opens or closes the device, depending on the "enabled"
* flag.
*
* @return true if the device is open
*/
bool LockUpdate(const AudioFormat audio_format,
const MusicPipe &mp);
void LockPlay();
void LockDrainAsync();
/**
* Clear the "allow_play" flag and send the "CANCEL" command
* asynchronously. To finish the operation, the caller has to
* call LockAllowPlay().
*/
void LockCancelAsync();
/**
* Set the "allow_play" and signal the thread.
*/
void LockAllowPlay();
private:
void CommandFinished();
bool Enable();
void Disable();
void Open();
void Close(bool drain);
void Reopen();
/**
* Close the output plugin.
*
* Mutex must not be locked.
*/
void CloseOutput(bool drain);
AudioFormat OpenFilter(AudioFormat &format, Error &error_r);
/**
* Mutex must not be locked.
*/
void CloseFilter();
void ReopenFilter();
/**
* Wait until the output's delay reaches zero.
*
* @return true if playback should be continued, false if a
* command was issued
*/
bool WaitForDelay();
gcc_pure
const MusicChunk *GetNextChunk() const;
bool PlayChunk(const MusicChunk *chunk);
/**
* Plays all remaining chunks, until the tail of the pipe has
* been reached (and no more chunks are queued), or until a
* command is received.
*
* @return true if at least one chunk has been available,
* false if the tail of the pipe was already reached
*/
bool Play();
void Pause();
/**
* The OutputThread.
*/
void Task();
static void Task(void *arg);
};
/**
* Notify object used by the thread's client, i.e. we will send a
* notify signal to this object, expecting the caller to wait on it.
*/
extern struct notify audio_output_client_notify;
AudioOutput *
audio_output_new(EventLoop &event_loop, const ConfigBlock &block,
MixerListener &mixer_listener,
PlayerControl &pc,
Error &error);
void
audio_output_free(AudioOutput *ao);
#endif
