/* * Copyright (C) 2003-2013 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 "thread/Mutex.hxx" #include "thread/Cond.hxx" #include "util/Error.hxx" #include #include struct Song; class MusicBuffer; class MusicPipe; enum decoder_state { DECODE_STATE_STOP = 0, DECODE_STATE_START, DECODE_STATE_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. */ DECODE_STATE_ERROR, }; struct decoder_control { /** the handle of the decoder thread, or NULL if the decoder thread isn't running */ GThread *thread; /** * This lock protects #state and #command. */ mutable 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. */ Cond client_cond; enum decoder_state state; DecoderCommand command; /** * The error that occurred in the decoder thread. This * attribute is only valid if #state is #DECODE_STATE_ERROR. * The object must be freed when this object transitions to * any other state (usually #DECODE_STATE_START). */ Error error; bool quit; 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. */ Song *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; char *mixramp_start; char *mixramp_end; char *mixramp_prev_end; decoder_control(); ~decoder_control(); /** * 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 #decoder_control 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. */ void WaitForDecoder() { client_cond.wait(mutex); } bool IsIdle() const { return state == DECODE_STATE_STOP || state == DECODE_STATE_ERROR; } gcc_pure bool LockIsIdle() const { Lock(); bool result = IsIdle(); Unlock(); return result; } bool IsStarting() const { return state == DECODE_STATE_START; } gcc_pure bool LockIsStarting() const { Lock(); bool result = IsStarting(); Unlock(); return result; } bool HasFailed() const { assert(command == DecoderCommand::NONE); return state == DECODE_STATE_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 != DECODE_STATE_ERROR || error.IsDefined()); Error result; if (state == DECODE_STATE_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 == DECODE_STATE_ERROR) { error.Clear(); state = DECODE_STATE_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 Song *_song) const; gcc_pure bool LockIsCurrentSong(const Song *_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 #decoder_control * @param end_ms see #decoder_control * @param pipe the pipe which receives the decoded chunks (owned by * the caller) */ void Start(Song *song, unsigned start_ms, unsigned end_ms, MusicBuffer &buffer, MusicPipe &pipe); void Stop(); bool Seek(double where); void Quit(); void MixRampStart(char *_mixramp_start); void MixRampEnd(char *_mixramp_end); void MixRampPrevEnd(char *_mixramp_prev_end); }; #endif