mpd/src/DecoderControl.hxx
2013-01-04 09:41:45 +01:00

340 lines
7.5 KiB
C++

/*
* 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 "decoder_command.h"
#include "audio_format.h"
#include <glib.h>
#include <assert.h>
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.
*/
GMutex *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.
*/
GCond *cond;
/**
* The trigger of this object's client. It is signalled
* whenever an event occurs.
*/
GCond *client_cond;
enum decoder_state state;
enum decoder_command 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).
*/
GError *error;
bool quit;
bool seek_error;
bool seekable;
double seek_where;
/** the format of the song file */
struct audio_format in_audio_format;
/** the format being sent to the music pipe */
struct audio_format out_audio_format;
/**
* The song currently being decoded. This attribute is set by
* the player thread, when it sends the #DECODE_COMMAND_START
* command.
*
* This is a duplicate, and must be freed when this attribute
* is cleared.
*/
struct 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 */
struct music_buffer *buffer;
/**
* The destination pipe for decoded chunks. The caller thread
* owns this object, and is responsible for freeing it.
*/
struct music_pipe *pipe;
float replay_gain_db;
float replay_gain_prev_db;
char *mixramp_start;
char *mixramp_end;
char *mixramp_prev_end;
};
G_GNUC_MALLOC
struct decoder_control *
dc_new(GCond *client_cond);
void
dc_free(struct decoder_control *dc);
/**
* Locks the #decoder_control object.
*/
static inline void
decoder_lock(struct decoder_control *dc)
{
g_mutex_lock(dc->mutex);
}
/**
* Unlocks the #decoder_control object.
*/
static inline void
decoder_unlock(struct decoder_control *dc)
{
g_mutex_unlock(dc->mutex);
}
/**
* 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.
*/
static inline void
decoder_wait(struct decoder_control *dc)
{
g_cond_wait(dc->cond, dc->mutex);
}
/**
* Signals the #decoder_control object. This function is only valid
* in the player thread. The object should be locked prior to calling
* this function.
*/
static inline void
decoder_signal(struct decoder_control *dc)
{
g_cond_signal(dc->cond);
}
static inline bool
decoder_is_idle(const struct decoder_control *dc)
{
return dc->state == DECODE_STATE_STOP ||
dc->state == DECODE_STATE_ERROR;
}
static inline bool
decoder_is_starting(const struct decoder_control *dc)
{
return dc->state == DECODE_STATE_START;
}
static inline bool
decoder_has_failed(const struct decoder_control *dc)
{
assert(dc->command == DECODE_COMMAND_NONE);
return dc->state == DECODE_STATE_ERROR;
}
/**
* Checks whether an error has occurred, and if so, returns a newly
* allocated copy of the #GError object.
*
* Caller must lock the object.
*/
static inline GError *
dc_get_error(const struct decoder_control *dc)
{
assert(dc != NULL);
assert(dc->command == DECODE_COMMAND_NONE);
assert(dc->state != DECODE_STATE_ERROR || dc->error != NULL);
return dc->state == DECODE_STATE_ERROR
? g_error_copy(dc->error)
: NULL;
}
/**
* Like dc_get_error(), but locks and unlocks the object.
*/
static inline GError *
dc_lock_get_error(struct decoder_control *dc)
{
decoder_lock(dc);
GError *error = dc_get_error(dc);
decoder_unlock(dc);
return error;
}
/**
* Clear the error condition and free the #GError object (if any).
*
* Caller must lock the object.
*/
static inline void
dc_clear_error(struct decoder_control *dc)
{
if (dc->state == DECODE_STATE_ERROR) {
g_error_free(dc->error);
dc->state = DECODE_STATE_STOP;
}
}
static inline bool
decoder_lock_is_idle(struct decoder_control *dc)
{
bool ret;
decoder_lock(dc);
ret = decoder_is_idle(dc);
decoder_unlock(dc);
return ret;
}
static inline bool
decoder_lock_is_starting(struct decoder_control *dc)
{
bool ret;
decoder_lock(dc);
ret = decoder_is_starting(dc);
decoder_unlock(dc);
return ret;
}
static inline bool
decoder_lock_has_failed(struct decoder_control *dc)
{
bool ret;
decoder_lock(dc);
ret = decoder_has_failed(dc);
decoder_unlock(dc);
return ret;
}
/**
* 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
decoder_is_current_song(const struct decoder_control *dc,
const struct song *song);
gcc_pure
static inline bool
decoder_lock_is_current_song(struct decoder_control *dc,
const struct song *song)
{
decoder_lock(dc);
const bool result = decoder_is_current_song(dc, song);
decoder_unlock(dc);
return result;
}
/**
* Start the decoder.
*
* @param 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
dc_start(struct decoder_control *dc, struct song *song,
unsigned start_ms, unsigned end_ms,
struct music_buffer *buffer, struct music_pipe *pipe);
void
dc_stop(struct decoder_control *dc);
bool
dc_seek(struct decoder_control *dc, double where);
void
dc_quit(struct decoder_control *dc);
void
dc_mixramp_start(struct decoder_control *dc, char *mixramp_start);
void
dc_mixramp_end(struct decoder_control *dc, char *mixramp_end);
void
dc_mixramp_prev_end(struct decoder_control *dc, char *mixramp_prev_end);
#endif