def stop(channel="music", fadeout=None):
    """
    This stops the music that is currently playing, and dequeues all
    queued music. If fadeout is None, the music is faded out for the
    time given in config.fade_music, otherwise it is faded for fadeout
    seconds.
    
    This sets the last queued file to None.
    """

    if renpy.game.context().init_phase:
        return

    try:        
        c = get_channel(channel)
        ctx = c.context

        if fadeout is None:
            fadeout = renpy.config.fade_music

        c.fadeout(fadeout)        
        
        t = get_serial()
        ctx.last_changed = t
        c.last_changed = t
        ctx.last_filenames = [ ]
        ctx.last_tight = False
        
    except:
        if renpy.config.debug_sound:
            raise

def queue(filenames, channel="music", loop=None, clear_queue=True, fadein=0, tight=None):
    """
    This queues the given filenames on the specified channel. If
    clear_queue is True, then the queue is cleared, making these files
    the files that are played when the currently playing file
    finishes. If it is False, then these files are placed at the back of
    the queue. In either case, if no music is playing these files
    begin playing immediately.

    Filenames may either be a single filename, or a list of filenames.

    Fadein is the number of seconds to fade the music in for, on the
    first loop only.

    If loop is True, then this music will repeat as long as it is the
    last element of the queue.

    The filenames given becomes the last queued file if loop is
    True. If loop is False, then the last queued file is set to None.

    If tight is True, then fadeouts will span into the next-queued sound.
    """

    if renpy.game.context().init_phase:
        raise Exception("Can't play music during init phase.")

    if filenames is None:
        filenames = [ ]
        loop = False

    if isinstance(filenames, basestring):
        filenames = [ filenames ]

    try:        

        c = get_channel(channel)
        ctx = c.context
        
        if loop is None:
            loop = c.default_loop
        
        if clear_queue:
            c.dequeue(True)
            
        c.enqueue(filenames, loop=loop, fadein=fadein, tight=tight)
        
        t = get_serial()
        ctx.last_changed = t
        c.last_changed = t

        if loop:
            ctx.last_filenames = filenames
            ctx.last_tight = tight
        else:
            ctx.last_filenames = [ ]
            ctx.last_tight = False
        
    except:
        if renpy.config.debug_sound:
            raise

def is_music(channel):
    """
    Returns true if "channel" will loop by default.
    """

    c = get_channel(channel)
    return c.default_loop

def playable(filename, channel="music"):
    """
    Return true if the given filename is playable on the channel. This
    takes into account the prefix and suffix.
    """

    c = get_channel(channel)
       
    return renpy.loader.loadable(c.file_prefix + filename + c.file_suffix)

def set_music(channel, flag, default=False):
    """
    Determines if channel will loop by default.
    """

    c = get_channel(channel)

    if default and c.default_loop_set:
        return

    c.default_loop = flag
    c.default_loop_set = True

def playable(filename, channel="music"):
    """
    Return true if the given filename is playable on the channel. This
    takes into account the prefix and suffix, and ignores a preceding
    specifier.
    """

    c = get_channel(channel)

    filename, _, _ = c.split_filename(filename, False)

    return renpy.loader.loadable(c.file_prefix + filename + c.file_suffix)

def stop(channel="music", fadeout=None):
    """
    :doc: audio

    This stops the music that is currently playing, and dequeues all
    queued music. If fadeout is None, the music is faded out for the
    time given in config.fade_music, otherwise it is faded for fadeout
    seconds.

    This sets the last queued file to None.

    `channel`
        The channel to stop the sound on.

    `fadeout`
        If not None, this is a time in seconds to fade for. Otherwise the
        fadeout time is taken from config.fade_music.


    """

    if renpy.game.context().init_phase:
        return

    with renpy.audio.audio.lock:

        try:
            c = get_channel(channel)
            ctx = c.context

            if fadeout is None:
                fadeout = renpy.config.fade_music

            c.fadeout(fadeout)

            t = get_serial()
            ctx.last_changed = t
            c.last_changed = t
            ctx.last_filenames = [ ]
            ctx.last_tight = False

        except:
            if renpy.config.debug_sound:
                raise

def play(filenames, channel="music", loop=None, fadeout=None, synchro_start=False, fadein=0, tight=None, if_changed=False):
    """
    This stops the music currently playing on the numbered channel, dequeues
    any queued music, and begins playing the specified file or files. If loop
    is True, the tracks will loop while they are the last thing in
    the queue. If fadeout is None, the fadeout time is taken from
    config.fade_music, otherwise it is a time in seconds to fade for.

    Filenames may be a single file, or a list of files.

    Fadein is the number of seconds to fade the music in for, on the
    first loop only.

    If synchro_start is given, all the channels that have had play
    called on them with synchro_start set to True will be started at
    the same time, in a sample accurate manner.

    The filenames given becomes the last queued files if loop is
    True. If loop is False, then there are no last queued files.

    If tight is True, then fadeouts will span into the next-queued sound.
    
    If if_changed is True, and the music file is currently playing,
    then it will not be stopped/faded out and faded back in again, but
    instead will be kept playing. (This will always queue up an additional
    loop of the music.)
    """

    if renpy.game.context().init_phase:
        raise Exception("Can't play music during init phase.")
    
    if filenames is None:
        filenames = [ ]
        loop = False
        
    if isinstance(filenames, basestring):
        filenames = [ filenames ]

    try:        
        c = get_channel(channel)
        ctx = c.context
        
        if loop is None:
            loop = c.default_loop

        c.dequeue()

        if fadeout is None:
            fadeout = renpy.config.fade_music

        if if_changed and c.get_playing() in filenames:
            fadein = 0
        else:
            c.fadeout(fadeout)

        c.enqueue(filenames, loop=loop, synchro_start=synchro_start, fadein=fadein, tight=tight)
        
        t = get_serial()
        ctx.last_changed = t
        c.last_changed = t

        if loop:
            ctx.last_filenames = filenames            
            ctx.last_tight = tight            
        else:
            ctx.last_filenames = [ ]
            ctx.last_tight = False
        
    except:
        if renpy.config.debug_sound:
            raise

def play(filenames, channel="music", loop=None, fadeout=None, synchro_start=False, fadein=0, tight=None, if_changed=False):
    """
    :doc: audio

    This stops the music currently playing on the numbered channel, dequeues
    any queued music, and begins playing the specified file or files.

    `filenames`
        This may be a single file, or a list of files to be played.

    `channel`
        The channel to play the sound on.

    `loop`
        If this is True, the tracks will loop while they are the last thing
        in the queue.

    `fadeout`
        If not None, this is a time in seconds to fade for. Otherwise the
        fadeout time is taken from config.fade_music.

    `synchro_start`
        Ren'Py will ensure that all channels of with synchro_start set to true
        will start playing at exactly the same time. Synchro_start should be
        true when playing two audio files that are meant to be synchronized
        with each other.

    `fadein`
        This is the number of seconds to fade the music in for, on the
        first loop only.

    `tight`
        If this is True, then fadeouts will span into the next-queued sound.

    `if_changed`
        If this is True, and the music file is currently playing,
        then it will not be stopped/faded out and faded back in again, but
        instead will be kept playing. (This will always queue up an additional
        loop of the music.)
    """

    if renpy.game.context().init_phase:
        raise Exception("Can't play music during init phase.")

    if filenames is None:
        return

    if isinstance(filenames, basestring):
        filenames = [ filenames ]

    try:
        c = get_channel(channel)
        ctx = c.context

        if loop is None:
            loop = c.default_loop

        c.dequeue()

        if fadeout is None:
            fadeout = renpy.config.fade_music

        if if_changed and c.get_playing() in filenames:
            fadein = 0
        else:
            c.fadeout(fadeout)

        c.enqueue(filenames, loop=loop, synchro_start=synchro_start, fadein=fadein, tight=tight)

        t = get_serial()
        ctx.last_changed = t
        c.last_changed = t

        if loop:
            ctx.last_filenames = filenames
            ctx.last_tight = tight
        else:
            ctx.last_filenames = [ ]
            ctx.last_tight = False

    except:
        if renpy.config.debug_sound:
            raise

def queue(filenames, channel="music", loop=None, clear_queue=True, fadein=0, tight=None):
    """
    :doc: audio

    This queues the given filenames on the specified channel.

    `filenames`
        This may be a single file, or a list of files to be played.

    `channel`
        The channel to play the sound on.

    `loop`
        If this is True, the tracks will loop while they are the last thing
        in the queue.

    `clear_queue`
        If True, then the queue is cleared, making these files the files that
        are played when the currently playing file finishes. If it is False,
        then these files are placed at the back of the queue. In either case,
        if no music is playing these files begin playing immediately.

    `fadein`
        This is the number of seconds to fade the music in for, on the
        first loop only.

    `tight`
        If this is True, then fadeouts will span into the next-queued sound. If
        None, this is true when loop is True, and false otherwise.

    This clears the pause flag for `channel`.
    """

    if renpy.game.context().init_phase:
        raise Exception("Can't play music during init phase.")

    if filenames is None:
        filenames = [ ]
        loop = False

    if isinstance(filenames, basestring):
        filenames = [ filenames ]

    with renpy.audio.audio.lock:

        try:

            c = get_channel(channel)
            ctx = c.context

            if loop is None:
                loop = c.default_loop

            if (tight is None) and renpy.config.tight_loop_default:
                tight = loop

            if clear_queue:
                c.dequeue(True)

            c.enqueue(filenames, loop=loop, fadein=fadein, tight=tight)

            t = get_serial()
            ctx.last_changed = t
            c.last_changed = t

            if loop:
                ctx.last_filenames = filenames
                ctx.last_tight = tight
            else:
                ctx.last_filenames = [ ]
                ctx.last_tight = False

            ctx.pause = False

        except:
            if renpy.config.debug_sound:
                raise