source: src/mlx/sound.py@ 585:1a277e09c6b9

from util import utf2unicode

import os
import traceback

#------------------------------------------------------------------------------

## @package mlx.sound
#
# Sound playback handling.
#
# This is the low level sound playback handling. The \ref initializeSound
# function should be called to initialize the sound handling with the directory
# containing the sound files. Then the \ref startSound function should be
# called to start the playback of a certain sound file. A callback may be
# called when the playback of a certain file has finished.
#
# See also the \ref mlx.soundsched module.

#------------------------------------------------------------------------------

if os.name=="nt":
    import time
    import threading
    from ctypes import windll, c_buffer

    class MCIException(Exception):
        """MCI exception."""
        def __init__(self, mci, command, errorCode):
            """Construct an MCI exception for the given error code."""
            message = "MCI error: %s: %s" % (command, mci.getErrorString(errorCode))
            super(MCIException, self).__init__(message)

    class MCI:
        """Interface for the Media Control Interface."""
        def __init__(self):
            """Construct the interface."""
            self.w32mci = windll.winmm.mciSendStringA
            self.w32mcierror = windll.winmm.mciGetErrorStringA

        def send(self, command):
            """Send the given command to the MCI."""
            buffer = c_buffer(255)
            errorCode = self.w32mci(str(command), buffer, 254, 0)
            if errorCode:
                raise MCIException(self, command, errorCode)
            else:
                return buffer.value

        def getErrorString(self, errorCode):
            """Get the string representation of the given error code."""
            buffer = c_buffer(255)
            self.w32mcierror(int(errorCode), buffer, 254)
            return buffer.value

    class SoundThread(threading.Thread):
        """The thread controlling the playback of sounds."""
        def __init__(self, soundsDirectory):
            threading.Thread.__init__(self)

            self._soundsDirectory = soundsDirectory
            self._mci = MCI()

            self._requestCondition = threading.Condition()
            self._requests = []
            self._pending = []
            self._count = 0

            self.daemon = True

        def requestSound(self, name, finishCallback = None, extra = None):
            """Request the playback of the sound with the given name."""
            path = name if os.path.isabs(name) \
                   else os.path.join(self._soundsDirectory, name)
            with self._requestCondition:
                self._requests.append((path, (finishCallback, extra)))
                self._requestCondition.notify()

        def run(self):
            """Perform the operation of the thread.

            It waits for a request or a timeout. If a request is received, that
            is started to be played back. If a timeout occurs, the file is
            closed."""

            while True:
                with self._requestCondition:
                    if not self._requests:
                        if self._pending:
                            timeout = max(self._pending[0][0] - time.time(),
                                          0.0)
                        else:
                            timeout = 10.0

                        #print "Waiting", timeout
                        self._requestCondition.wait(timeout)

                    requests = []
                    for (path, finishData) in self._requests:
                        requests.append((path, finishData, self._count))
                        self._count += 1
                    self._requests = []

                    now = time.time()
                    toClose = []
                    while self._pending and \
                          self._pending[0][0]<=now:
                        toClose.append(self._pending[0][1])
                        del self._pending[0]

                for (alias, (finishCallback, extra)) in toClose:
                    success = True
                    try:
                        print "Closing", alias
                        self._mci.send("close " + alias)
                        print "Closed", alias
                    except Exception, e:
                        print "Failed closing " + alias + ":",
                        print utf2unicode(str(e))
                        success = False

                    if finishCallback is not None:
                        try:
                            finishCallback(success, extra)
                        except:
                            traceback.print_exc()

                for (path, finishData, counter) in requests:
                    try:
                        alias = "mlxsound%d" % (counter,)
                        print "Starting to play", path, "as", alias
                        self._mci.send("open \"%s\" alias %s" % \
                                       (path, alias))
                        self._mci.send("set %s time format milliseconds" % \
                                       (alias,))
                        lengthBuffer = self._mci.send("status %s length" % \
                                                      (alias,))
                        self._mci.send("play %s from 0 to %s" % \
                                       (alias, lengthBuffer))
                        length = int(lengthBuffer)
                        timeout = time.time() + length / 1000.0
                        with self._requestCondition:
                            self._pending.append((timeout, (alias, finishData)))
                            self._pending.sort()
                        print "Started to play", path
                    except Exception, e:
                        print "Failed to start playing " + path + ":",
                        print utf2unicode(str(e))
                        (finishCallback, extra) = finishData
                        if finishCallback is not None:
                            try:
                                finishCallback(None, extra)
                            except:
                                traceback.print_exc()

    _thread = None

    def initializeSound(soundsDirectory):
        """Initialize the sound handling with the given directory containing
        the sound files."""
        global _thread
        _thread = SoundThread(soundsDirectory)
        _thread.start()

    def startSound(name, finishCallback = None, extra = None):
        """Start playing back the given sound.

        name should be the name of a sound file relative to the sound directory
        given in initializeSound."""
        _thread.requestSound(name, finishCallback = finishCallback,
                             extra = extra)

    def finalizeSound():
        """Finalize the sound handling."""
        pass

#------------------------------------------------------------------------------

else: # os.name!="nt"
    import threading
    import time
    try:
        from common import gst_init, gobject, gst_element_factory_make
        from common import GST_STATE_PLAYING, GST_MESSAGE_EOS

        _soundsDirectory = None
        _bins = set()

        def initializeSound(soundsDirectory):
            """Initialize the sound handling with the given directory containing
            the sound files."""
            gst_init()
            global _soundsDirectory
            _soundsDirectory = soundsDirectory

        def startSound(name, finishCallback = None, extra = None):
            """Start playing back the given sound."""
            try:
                playBin = gst_element_factory_make("playbin")

                bus = playBin.get_bus()
                bus.enable_sync_message_emission()
                bus.add_signal_watch()
                bus.connect("message", _handlePlayBinMessage,
                            playBin, finishCallback, extra)

                path = os.path.join(_soundsDirectory, name)
                playBin.set_property( "uri", "file://%s" % (path,))

                playBin.set_state(GST_STATE_PLAYING)
                _bins.add(playBin)
            except Exception, e:
                print "mlx.sound.startSound: " + str(e)
                if finishCallback is not None:
                    finishCallback(False, extra)

        def finalizeSound():
            """Finalize the sound handling."""
            pass

        def _handlePlayBinMessage(bus, message, bin, finishCallback, extra):
            """Handle the end of the playback of a sound file."""

            # if message.type==GST_MESSAGE_EOS:
            #     _bins.remove(bin)
            #     if finishCallback is not None:
            #         finishCallback(True, extra)

    except:
        print "The Gst library is missing from your system. It is needed for sound playback on Linux"
        traceback.print_exc()
        def initializeSound(soundsDirectory):
            """Initialize the sound handling with the given directory containing
            the sound files."""
            pass

        def startSound(name, finishCallback = None, extra = None):
            """Start playing back the given sound.

            FIXME: it does not do anything currently, but it should."""
            print "sound.startSound:", name

        def finalizeSound():
            """Finalize the sound handling."""
            pass

#------------------------------------------------------------------------------
#------------------------------------------------------------------------------

if __name__ == "__main__":
    def callback(result, extra):
        print "callback", result, extra

    initializeSound("e:\\home\\vi\\tmp")
    startSound("malev.mp3", finishCallback = callback, extra="malev.mp3")
    time.sleep(5)
    startSound("ding.wav", finishCallback = callback, extra="ding1.wav")
    time.sleep(5)
    startSound("ding.wav", finishCallback = callback, extra="ding2.wav")
    time.sleep(5)
    startSound("ding.wav", finishCallback = callback, extra="ding3.wav")
    time.sleep(50)

#------------------------------------------------------------------------------