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Diffstat (limited to '')
-rw-r--r-- | src/decoder/DecoderControl.hxx | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/src/decoder/DecoderControl.hxx b/src/decoder/DecoderControl.hxx new file mode 100644 index 000000000..4e5c43b5a --- /dev/null +++ b/src/decoder/DecoderControl.hxx @@ -0,0 +1,395 @@ +/* + * 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_DECODER_CONTROL_HXX +#define MPD_DECODER_CONTROL_HXX + +#include "DecoderCommand.hxx" +#include "AudioFormat.hxx" +#include "MixRampInfo.hxx" +#include "thread/Mutex.hxx" +#include "thread/Cond.hxx" +#include "thread/Thread.hxx" +#include "util/Error.hxx" + +#include <assert.h> +#include <stdint.h> + +/* damn you, windows.h! */ +#ifdef ERROR +#undef ERROR +#endif + +class DetachedSong; +class MusicBuffer; +class MusicPipe; + +enum class DecoderState : uint8_t { + STOP = 0, + START, + DECODE, + + /** + * The last "START" command failed, because there was an I/O + * error or because no decoder was able to decode the file. + * This state will only come after START; once the state has + * turned to DECODE, by definition no such error can occur. + */ + ERROR, +}; + +struct DecoderControl { + /** + * The handle of the decoder thread. + */ + Thread thread; + + /** + * This lock protects #state and #command. + * + * This is usually a reference to PlayerControl::mutex, so + * that both player thread and decoder thread share a mutex. + * This simplifies synchronization with #cond and + * #client_cond. + */ + Mutex &mutex; + + /** + * Trigger this object after you have modified #command. This + * is also used by the decoder thread to notify the caller + * when it has finished a command. + */ + Cond cond; + + /** + * The trigger of this object's client. It is signalled + * whenever an event occurs. + * + * This is usually a reference to PlayerControl::cond. + */ + Cond &client_cond; + + DecoderState state; + DecoderCommand command; + + /** + * The error that occurred in the decoder thread. This + * attribute is only valid if #state is #DecoderState::ERROR. + * The object must be freed when this object transitions to + * any other state (usually #DecoderState::START). + */ + Error error; + + bool quit; + + /** + * Is the client currently waiting for the DecoderThread? If + * false, the DecoderThread may omit invoking Cond::signal(), + * reducing the number of system calls. + */ + bool client_is_waiting; + + bool seek_error; + bool seekable; + double seek_where; + + /** the format of the song file */ + AudioFormat in_audio_format; + + /** the format being sent to the music pipe */ + AudioFormat out_audio_format; + + /** + * The song currently being decoded. This attribute is set by + * the player thread, when it sends the #DecoderCommand::START + * command. + * + * This is a duplicate, and must be freed when this attribute + * is cleared. + */ + DetachedSong *song; + + /** + * The initial seek position (in milliseconds), e.g. to the + * start of a sub-track described by a CUE file. + * + * This attribute is set by dc_start(). + */ + unsigned start_ms; + + /** + * The decoder will stop when it reaches this position (in + * milliseconds). 0 means don't stop before the end of the + * file. + * + * This attribute is set by dc_start(). + */ + unsigned end_ms; + + float total_time; + + /** the #music_chunk allocator */ + MusicBuffer *buffer; + + /** + * The destination pipe for decoded chunks. The caller thread + * owns this object, and is responsible for freeing it. + */ + MusicPipe *pipe; + + float replay_gain_db; + float replay_gain_prev_db; + + MixRampInfo mix_ramp, previous_mix_ramp; + + /** + * @param _mutex see #mutex + * @param _client_cond see #client_cond + */ + DecoderControl(Mutex &_mutex, Cond &_client_cond); + ~DecoderControl(); + + /** + * Locks the object. + */ + void Lock() const { + mutex.lock(); + } + + /** + * Unlocks the object. + */ + void Unlock() const { + mutex.unlock(); + } + + /** + * Signals the object. This function is only valid in the + * player thread. The object should be locked prior to + * calling this function. + */ + void Signal() { + cond.signal(); + } + + /** + * Waits for a signal on the #DecoderControl object. This function + * is only valid in the decoder thread. The object must be locked + * prior to calling this function. + */ + void Wait() { + cond.wait(mutex); + } + + /** + * Waits for a signal from the decoder thread. This object + * must be locked prior to calling this function. This method + * is only valid in the player thread. + * + * Caller must hold the lock. + */ + void WaitForDecoder(); + + bool IsIdle() const { + return state == DecoderState::STOP || + state == DecoderState::ERROR; + } + + gcc_pure + bool LockIsIdle() const { + Lock(); + bool result = IsIdle(); + Unlock(); + return result; + } + + bool IsStarting() const { + return state == DecoderState::START; + } + + gcc_pure + bool LockIsStarting() const { + Lock(); + bool result = IsStarting(); + Unlock(); + return result; + } + + bool HasFailed() const { + assert(command == DecoderCommand::NONE); + + return state == DecoderState::ERROR; + } + + gcc_pure + bool LockHasFailed() const { + Lock(); + bool result = HasFailed(); + Unlock(); + return result; + } + + /** + * Checks whether an error has occurred, and if so, returns a + * copy of the #Error object. + * + * Caller must lock the object. + */ + gcc_pure + Error GetError() const { + assert(command == DecoderCommand::NONE); + assert(state != DecoderState::ERROR || error.IsDefined()); + + Error result; + if (state == DecoderState::ERROR) + result.Set(error); + return result; + } + + /** + * Like dc_get_error(), but locks and unlocks the object. + */ + gcc_pure + Error LockGetError() const { + Lock(); + Error result = GetError(); + Unlock(); + return result; + } + + /** + * Clear the error condition and free the #Error object (if any). + * + * Caller must lock the object. + */ + void ClearError() { + if (state == DecoderState::ERROR) { + error.Clear(); + state = DecoderState::STOP; + } + } + + /** + * Check if the specified song is currently being decoded. If the + * decoder is not running currently (or being started), then this + * function returns false in any case. + * + * Caller must lock the object. + */ + gcc_pure + bool IsCurrentSong(const DetachedSong &_song) const; + + gcc_pure + bool LockIsCurrentSong(const DetachedSong &_song) const { + Lock(); + const bool result = IsCurrentSong(_song); + Unlock(); + return result; + } + +private: + /** + * Wait for the command to be finished by the decoder thread. + * + * To be called from the client thread. Caller must lock the + * object. + */ + void WaitCommandLocked() { + while (command != DecoderCommand::NONE) + WaitForDecoder(); + } + + /** + * Send a command to the decoder thread and synchronously wait + * for it to finish. + * + * To be called from the client thread. Caller must lock the + * object. + */ + void SynchronousCommandLocked(DecoderCommand cmd) { + command = cmd; + Signal(); + WaitCommandLocked(); + } + + /** + * Send a command to the decoder thread and synchronously wait + * for it to finish. + * + * To be called from the client thread. This method locks the + * object. + */ + void LockSynchronousCommand(DecoderCommand cmd) { + Lock(); + ClearError(); + SynchronousCommandLocked(cmd); + Unlock(); + } + + void LockAsynchronousCommand(DecoderCommand cmd) { + Lock(); + command = cmd; + Signal(); + Unlock(); + } + +public: + /** + * Start the decoder. + * + * @param song the song to be decoded; the given instance will be + * owned and freed by the decoder + * @param start_ms see #DecoderControl + * @param end_ms see #DecoderControl + * @param pipe the pipe which receives the decoded chunks (owned by + * the caller) + */ + void Start(DetachedSong *song, unsigned start_ms, unsigned end_ms, + MusicBuffer &buffer, MusicPipe &pipe); + + void Stop(); + + bool Seek(double where); + + void Quit(); + + const char *GetMixRampStart() const { + return mix_ramp.GetStart(); + } + + const char *GetMixRampEnd() const { + return mix_ramp.GetEnd(); + } + + const char *GetMixRampPreviousEnd() const { + return previous_mix_ramp.GetEnd(); + } + + void SetMixRamp(MixRampInfo &&new_value) { + mix_ramp = std::move(new_value); + } + + /** + * Move mixramp_end to mixramp_prev_end and clear + * mixramp_start/mixramp_end. + */ + void CycleMixRamp(); +}; + +#endif |