/*
* 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.
*/
#ifndef MPD_OUTPUT_INTERNAL_HXX
#define MPD_OUTPUT_INTERNAL_HXX
#include "AudioFormat.hxx"
#include "pcm/PcmBuffer.hxx"
#include "pcm/PcmDither.hxx"
#include "thread/Mutex.hxx"
#include "thread/Cond.hxx"
#include "thread/Thread.hxx"
#include "system/PeriodClock.hxx"
class Error;
class Filter;
class MusicPipe;
struct config_param;
struct PlayerControl;
enum audio_output_command {
AO_COMMAND_NONE = 0,
AO_COMMAND_ENABLE,
AO_COMMAND_DISABLE,
AO_COMMAND_OPEN,
/**
* This command is invoked when the input audio format
* changes.
*/
AO_COMMAND_REOPEN,
AO_COMMAND_CLOSE,
AO_COMMAND_PAUSE,
/**
* Drains the internal (hardware) buffers of the device. This
* operation may take a while to complete.
*/
AO_COMMAND_DRAIN,
AO_COMMAND_CANCEL,
AO_COMMAND_KILL
};
struct audio_output {
/**
* The device's configured display name.
*/
const char *name;
/**
* The plugin which implements this output device.
*/
const struct audio_output_plugin *plugin;
/**
* The #mixer object associated with this audio output device.
* May be nullptr if none is available, or if software volume is
* configured.
*/
class 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.
*/
enum audio_output_command command;
/**
* The music pipe which provides music chunks to be played.
*/
const MusicPipe *pipe;
/**
* This mutex protects #open, #fail_timer, #chunk and
* #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 #music_chunk 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 struct music_chunk *chunk;
/**
* Has the output finished playing #chunk?
*/
bool chunk_finished;
};
/**
* 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;
static inline bool
audio_output_is_open(const struct audio_output *ao)
{
return ao->open;
}
static inline bool
audio_output_command_is_finished(const struct audio_output *ao)
{
return ao->command == AO_COMMAND_NONE;
}
struct audio_output *
audio_output_new(const config_param ¶m,
PlayerControl &pc,
Error &error);
bool
ao_base_init(struct audio_output *ao,
const struct audio_output_plugin *plugin,
const config_param ¶m, Error &error);
void
ao_base_finish(struct audio_output *ao);
void
audio_output_free(struct audio_output *ao);
#endif
