/* we're looking for the sequence output audiounit. */
static OSStatus
GetSequenceAudioUnit(MusicSequence sequence, AudioUnit *aunit)
{
    AUGraph graph;
    UInt32 nodecount, i;
    OSStatus err;

    err = MusicSequenceGetAUGraph(sequence, &graph);
    if (err != noErr)
        return err;

    err = AUGraphGetNodeCount(graph, &nodecount);
    if (err != noErr)
        return err;

    for (i = 0; i < nodecount; i++) {
        AUNode node;

        if (AUGraphGetIndNode(graph, i, &node) != noErr)
            continue;  /* better luck next time. */

#if MAC_OS_X_VERSION_MIN_REQUIRED < 1050 /* this is deprecated, but works back to 10.0 */
        {
            struct ComponentDescription desc;
            UInt32 classdatasize = 0;
            void *classdata = NULL;
            err = AUGraphGetNodeInfo(graph, node, &desc, &classdatasize,
                                     &classdata, aunit);
            if (err != noErr)
                continue;
            else if (desc.componentType != kAudioUnitType_Output)
                continue;
            else if (desc.componentSubType != kAudioUnitSubType_DefaultOutput)
                continue;
        }
        #else  /* not deprecated, but requires 10.5 or later */
        {
        # if !defined(AUDIO_UNIT_VERSION) || ((AUDIO_UNIT_VERSION + 0) < 1060)
         /* AUGraphAddNode () is changed to take an AudioComponentDescription*
          * desc parameter instead of a ComponentDescription* in the 10.6 SDK.
          * AudioComponentDescription is in 10.6 or newer, but it is actually
          * the same as struct ComponentDescription with 20 bytes of size and
          * the same offsets of all members, therefore, is binary compatible. */
        #   define AudioComponentDescription ComponentDescription
        # endif
            AudioComponentDescription desc;
            if (AUGraphNodeInfo(graph, node, &desc, aunit) != noErr)
                continue;
            else if (desc.componentType != kAudioUnitType_Output)
                continue;
            else if (desc.componentSubType != kAudioUnitSubType_DefaultOutput)
                continue;
        }
        #endif

        return noErr;  /* found it! */
    }

    return kAUGraphErr_NodeNotFound;
}
/** Set the volume of the current sequence. */
static void DoSetVolume()
{
	if (_sequence == NULL) return;

	AUGraph graph;
	MusicSequenceGetAUGraph(_sequence, &graph);

	AudioUnit output_unit = NULL;

	/* Get output audio unit */
	UInt32 node_count = 0;
	AUGraphGetNodeCount(graph, &node_count);
	for (UInt32 i = 0; i < node_count; i++) {
		AUNode node;
		AUGraphGetIndNode(graph, i, &node);

		AudioUnit unit;
		OSType comp_type = 0;

#if (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
		if (MacOSVersionIsAtLeast(10, 5, 0)) {
			/* The 10.6 SDK has changed the function prototype of
			 * AUGraphNodeInfo. This is a binary compatible change,
			 * but we need to get the type declaration right or
			 * risk compilation errors. The header AudioComponent.h
			 * was introduced in 10.6 so use it to decide which
			 * type definition to use. */
#ifdef __AUDIOCOMPONENT_H__
			AudioComponentDescription desc;
#else
			ComponentDescription desc;
#endif
			AUGraphNodeInfo(graph, node, &desc, &unit);
			comp_type = desc.componentType;
		} else
#endif
		{
#if (MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5)
			ComponentDescription desc;
			AUGraphGetNodeInfo(graph, node, &desc, NULL, NULL, &unit);
			comp_type = desc.componentType;
#endif
		}

		if (comp_type == kAudioUnitType_Output) {
			output_unit = unit;
			break;
		}
	}
	if (output_unit == NULL) {
		DEBUG(driver, 1, "cocoa_m: Failed to get output node to set volume");
		return;
	}

	Float32 vol = _volume / 127.0f;  // 0 - +127 -> 0.0 - 1.0
	AudioUnitSetParameter(output_unit, kHALOutputParam_Volume, kAudioUnitScope_Global, 0, vol, 0);
}
Example #3
0
/* we're looking for the sequence output audiounit. */
static OSStatus
GetSequenceAudioUnit(MusicSequence sequence, AudioUnit *aunit)
{
    AUGraph graph;
    UInt32 nodecount, i;
    OSStatus err;

    err = MusicSequenceGetAUGraph(sequence, &graph);
    if (err != noErr)
        return err;

    err = AUGraphGetNodeCount(graph, &nodecount);
    if (err != noErr)
        return err;

    for (i = 0; i < nodecount; i++) {
        AUNode node;

        if (AUGraphGetIndNode(graph, i, &node) != noErr)
            continue;  /* better luck next time. */

#if MAC_OS_X_VERSION_MIN_REQUIRED < 1060 /* this is deprecated, but works back to 10.0 */
        {
            struct ComponentDescription desc;
            UInt32 classdatasize = 0;
            void *classdata = NULL;
            err = AUGraphGetNodeInfo(graph, node, &desc, &classdatasize,
                                     &classdata, aunit);
            if (err != noErr)
                continue;
            else if (desc.componentType != kAudioUnitType_Output)
                continue;
            else if (desc.componentSubType != kAudioUnitSubType_DefaultOutput)
                continue;
        }
        #else  /* not deprecated, but requires 10.5 or later */
        {
            AudioComponentDescription desc;
            if (AUGraphNodeInfo(graph, node, &desc, aunit) != noErr)
                continue;
            else if (desc.componentType != kAudioUnitType_Output)
                continue;
            else if (desc.componentSubType != kAudioUnitSubType_DefaultOutput)
                continue;
        }
        #endif

        return noErr;  /* found it! */
    }

    return kAUGraphErr_NodeNotFound;
}
/**
 * Starts playing a new song.
 *
 * @param filename Path to a MIDI file.
 */
void MusicDriver_Cocoa::PlaySong(const char *filename)
{
	DEBUG(driver, 2, "cocoa_m: trying to play '%s'", filename);

	this->StopSong();
	if (_sequence != NULL) {
		DisposeMusicSequence(_sequence);
		_sequence = NULL;
	}

	if (NewMusicSequence(&_sequence) != noErr) {
		DEBUG(driver, 0, "cocoa_m: Failed to create music sequence");
		return;
	}

	const char *os_file = OTTD2FS(filename);
	CFURLRef url = CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, (const UInt8*)os_file, strlen(os_file), false);

#if (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
	if (MacOSVersionIsAtLeast(10, 5, 0)) {
		if (MusicSequenceFileLoad(_sequence, url, 0, 0) != noErr) {
			DEBUG(driver, 0, "cocoa_m: Failed to load MIDI file");
			CFRelease(url);
			return;
		}
	} else
#endif
	{
#if (MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5)
		FSRef ref_file;
		if (!CFURLGetFSRef(url, &ref_file)) {
			DEBUG(driver, 0, "cocoa_m: Failed to make FSRef");
			CFRelease(url);
			return;
		}
		if (MusicSequenceLoadSMFWithFlags(_sequence, &ref_file, 0) != noErr) {
			DEBUG(driver, 0, "cocoa_m: Failed to load MIDI file old style");
			CFRelease(url);
			return;
		}
#endif
	}
	CFRelease(url);

	/* Construct audio graph */
	AUGraph graph = NULL;

	MusicSequenceGetAUGraph(_sequence, &graph);
	AUGraphOpen(graph);
	if (AUGraphInitialize(graph) != noErr) {
		DEBUG(driver, 0, "cocoa_m: Failed to initialize AU graph");
		return;
	}

	/* Figure out sequence length */
	UInt32 num_tracks;
	MusicSequenceGetTrackCount(_sequence, &num_tracks);
	_seq_length = 0;
	for (UInt32 i = 0; i < num_tracks; i++) {
		MusicTrack     track = NULL;
		MusicTimeStamp track_length = 0;
		UInt32         prop_size = sizeof(MusicTimeStamp);
		MusicSequenceGetIndTrack(_sequence, i, &track);
		MusicTrackGetProperty(track, kSequenceTrackProperty_TrackLength, &track_length, &prop_size);
		if (track_length > _seq_length) _seq_length = track_length;
	}
	/* Add 8 beats for reverb/long note release */
	_seq_length += 8;

	DoSetVolume();
	MusicPlayerSetSequence(_player, _sequence);
	MusicPlayerPreroll(_player);
	if (MusicPlayerStart(_player) != noErr) return;
	_playing = true;

	DEBUG(driver, 3, "cocoa_m: playing '%s'", filename);
}
Example #5
0
int main (int argc, const char * argv[]) 
{
	if (argc == 1) {
		fprintf (stderr, "%s\n", usageStr);
		exit(0);
	}
	
	char* filePath = 0;
	bool shouldPlay = false;
	bool shouldSetBank = false;
    bool shouldUseMIDIEndpoint = false;
	bool shouldPrint = true;
	bool waitAtEnd = false;
	bool diskStream = false;
	
	OSType dataFormat = 0;
	Float64 srate = 0;
	const char* outputFilePath = 0;
	
	MusicSequenceLoadFlags	loadFlags = 0;
	
	char* bankPath = 0;
	Float32 startTime = 0;
	UInt32 numFrames = 512;
	
	std::set<int> trackSet;
	
	for (int i = 1; i < argc; ++i)
	{
		if (!strcmp ("-p", argv[i]))
		{
			shouldPlay = true;
		}
		else if (!strcmp ("-w", argv[i]))
		{
			waitAtEnd = true;
		}
		else if (!strcmp ("-d", argv[i]))
		{
			diskStream = true;
		}
		else if (!strcmp ("-b", argv[i])) 
		{
			shouldSetBank = true;
			if (++i == argc) goto malformedInput;
			bankPath = const_cast<char*>(argv[i]);
		}
		else if (!strcmp ("-n", argv[i]))
		{
			shouldPrint = false;
		}
		else if ((filePath == 0) && (argv[i][0] == '/' || argv[i][0] == '~'))
		{
			filePath = const_cast<char*>(argv[i]);
		}
		else if (!strcmp ("-s", argv[i])) 
		{
			if (++i == argc) goto malformedInput;
			sscanf (argv[i], "%f", &startTime);
		}
		else if (!strcmp ("-t", argv[i])) 
		{
			int index;
			if (++i == argc) goto malformedInput;
			sscanf (argv[i], "%d", &index);
			trackSet.insert(--index);
		}
		else if (!strcmp("-e", argv[i]))
        {
            shouldUseMIDIEndpoint = true;
        }
		else if (!strcmp("-c", argv[i]))
        {
            loadFlags = kMusicSequenceLoadSMF_ChannelsToTracks;
        }
        else if (!strcmp ("-i", argv[i])) 
		{
			if (++i == argc) goto malformedInput;
			sscanf (argv[i], "%lu", (unsigned long*)(&numFrames));
		}
        else if (!strcmp ("-f", argv[i])) 
		{
			if (i + 3 >= argc) goto malformedInput;
			outputFilePath = argv[++i];
			StrToOSType (argv[++i], dataFormat);
			sscanf (argv[++i], "%lf", &srate);
		}
		else
		{
malformedInput:
			fprintf (stderr, "%s\n", usageStr);
			exit (1);
		}
	}
	
	if (filePath == 0) {
		fprintf (stderr, "You have to specify a MIDI file to print or play\n");
		fprintf (stderr, "%s\n", usageStr);
		exit (1);
	}
	
	if (shouldUseMIDIEndpoint && outputFilePath) {
		printf ("can't write a file when you try to play out to a MIDI Endpoint\n");
		exit (1);
	}
	
	MusicSequence sequence;
	OSStatus result;
	
	FailIf ((result = LoadSMF (filePath, sequence, loadFlags)), fail, "LoadSMF");
			
	if (shouldPrint) 
		CAShow (sequence);
	
	if (shouldPlay)
	{
        AUGraph graph = 0;
        AudioUnit theSynth = 0;
		
		FailIf ((result = MusicSequenceGetAUGraph (sequence, &graph)), fail, "MusicSequenceGetAUGraph");
		FailIf ((result = AUGraphOpen (graph)), fail, "AUGraphOpen");     
		  
		FailIf ((result = GetSynthFromGraph (graph, theSynth)), fail, "GetSynthFromGraph");
		FailIf ((result = AudioUnitSetProperty (theSynth,
										kAudioUnitProperty_CPULoad,
										kAudioUnitScope_Global, 0,
										&maxCPULoad, sizeof(maxCPULoad))), fail, "AudioUnitSetProperty: kAudioUnitProperty_CPULoad");

        if (shouldUseMIDIEndpoint) 
		{
			MIDIClientRef	theMidiClient;
			MIDIClientCreate(CFSTR("Play Sequence"), NULL, NULL, &theMidiClient);		
            
			ItemCount destCount = MIDIGetNumberOfDestinations();
            if (destCount == 0) {
                fprintf (stderr, "No MIDI Endpoints to play to.\n");
                exit(1);
            }
            
            FailIf ((result = MusicSequenceSetMIDIEndpoint (sequence, MIDIGetDestination(0))), fail, "MusicSequenceSetMIDIEndpoint");
        } 
		else 
		{   
			if (shouldSetBank) {
				CFURLRef soundBankURL = CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, (const UInt8*)bankPath, strlen(bankPath), false);
								
				printf ("Setting Sound Bank:%s\n", bankPath);
					
				result = AudioUnitSetProperty (theSynth,
                                               kMusicDeviceProperty_SoundBankURL,
                                               kAudioUnitScope_Global, 0,
                                               &soundBankURL, sizeof(soundBankURL));
                if (soundBankURL) CFRelease(soundBankURL);
                FailIf (result, fail, "AudioUnitSetProperty: kMusicDeviceProperty_SoundBankURL");								
			}
						
			if (diskStream) {
				UInt32 value = diskStream;
				FailIf ((result = AudioUnitSetProperty (theSynth,
											kMusicDeviceProperty_StreamFromDisk,
											kAudioUnitScope_Global, 0,
											&value, sizeof(value))), fail, "AudioUnitSetProperty: kMusicDeviceProperty_StreamFromDisk");
			}

			if (outputFilePath) {
				// need to tell synth that is going to render a file.
				UInt32 value = 1;
				FailIf ((result = AudioUnitSetProperty (theSynth,
												kAudioUnitProperty_OfflineRender,
												kAudioUnitScope_Global, 0,
												&value, sizeof(value))), fail, "AudioUnitSetProperty: kAudioUnitProperty_OfflineRender");
			}
			
			FailIf ((result = SetUpGraph (graph, numFrames, srate, (outputFilePath != NULL))), fail, "SetUpGraph");
			
			if (shouldPrint) {
				printf ("Sample Rate: %.1f \n", srate);
				printf ("Disk Streaming is enabled: %c\n", (diskStream ? 'T' : 'F'));
			}
			
			FailIf ((result = AUGraphInitialize (graph)), fail, "AUGraphInitialize");

            if (shouldPrint)
				CAShow (graph);
        }
        
		MusicPlayer player;
		FailIf ((result = NewMusicPlayer (&player)), fail, "NewMusicPlayer");

		FailIf ((result = MusicPlayerSetSequence (player, sequence)), fail, "MusicPlayerSetSequence");

		// figure out sequence length
		UInt32 ntracks;
		FailIf ((MusicSequenceGetTrackCount (sequence, &ntracks)), fail, "MusicSequenceGetTrackCount");
		MusicTimeStamp sequenceLength = 0;
		bool shouldPrintTracks = shouldPrint && !trackSet.empty();
		if (shouldPrintTracks)
			printf ("Only playing specified tracks:\n\t");
		
		for (UInt32 i = 0; i < ntracks; ++i) {
			MusicTrack track;
			MusicTimeStamp trackLength;
			UInt32 propsize = sizeof(MusicTimeStamp);
			FailIf ((result = MusicSequenceGetIndTrack(sequence, i, &track)), fail, "MusicSequenceGetIndTrack");
			FailIf ((result = MusicTrackGetProperty(track, kSequenceTrackProperty_TrackLength,
							&trackLength, &propsize)), fail, "MusicTrackGetProperty: kSequenceTrackProperty_TrackLength");
			if (trackLength > sequenceLength)
				sequenceLength = trackLength;
			
			if (!trackSet.empty() && (trackSet.find(i) == trackSet.end()))
			{
				Boolean mute = true;
				FailIf ((result = MusicTrackSetProperty(track, kSequenceTrackProperty_MuteStatus, &mute, sizeof(mute))), fail, "MusicTrackSetProperty: kSequenceTrackProperty_MuteStatus");
			} 
			else if (shouldPrintTracks) {
				printf ("%d, ", int(i+1));
			}
		}
		if (shouldPrintTracks) 
			printf ("\n");
			
	// now I'm going to add 8 beats on the end for the reverb/long releases to tail off...
		sequenceLength += 8;
		
		FailIf ((result = MusicPlayerSetTime (player, startTime)), fail, "MusicPlayerSetTime");
		
		FailIf ((result = MusicPlayerPreroll (player)), fail, "MusicPlayerPreroll");
		
		if (shouldPrint) {
			printf ("Ready to play: %s, %.2f beats long\n\t<Enter> to continue: ", filePath, sequenceLength); 

			getc(stdin);
		}
		
        startRunningTime = CAHostTimeBase::GetTheCurrentTime();
		
/*		if (waitAtEnd && graph)
			AUGraphStart(graph);
*/		
		FailIf ((result = MusicPlayerStart (player)), fail, "MusicPlayerStart");
		
		if (outputFilePath) 
			WriteOutputFile (outputFilePath, dataFormat, srate, sequenceLength, shouldPrint, graph, numFrames, player);
		else
			PlayLoop (player, graph, sequenceLength, shouldPrint, waitAtEnd);
					
		FailIf ((result = MusicPlayerStop (player)), fail, "MusicPlayerStop");
		if (shouldPrint) printf ("finished playing\n");

/*		if (waitAtEnd) {
			CFRunLoopRunInMode(kCFRunLoopDefaultMode, 10, false);
			if (graph)
				AUGraphStop(graph);
			if (shouldPrint) printf ("disposing\n");
		}
*/		
// this shows you how you should dispose of everything
		FailIf ((result = DisposeMusicPlayer (player)), fail, "DisposeMusicPlayer");
		FailIf ((result = DisposeMusicSequence(sequence)), fail, "DisposeMusicSequence");
		// don't own the graph so don't dispose it (the seq owns it as we never set it ourselves, we just got it....)
	}
	else {
		FailIf ((result = DisposeMusicSequence(sequence)), fail, "DisposeMusicSequence");
	}
	
	while (waitAtEnd)
		CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.25, false);
		
    return 0;
	
fail:
	if (shouldPrint) printf ("Error = %ld\n", (long)result);
	return result;
}
Example #6
0
int main (int argc, const char * argv[]) 
{
	if (argc == 1) {
		fprintf (stderr, "%s\n", usageStr);
		exit(0);
	}
	
	char* filePath = 0;
	bool shouldPlay = false;
	bool shouldSetBank = false;
    bool shouldUseMIDIEndpoint = false;
	bool shouldPrint = true;
	bool waitAtEnd = false;
	bool diskStream = false;
	
	OSType dataFormat = 0;
	Float64 srate = 0;
	const char* outputFilePath = 0;
	
	MusicSequenceLoadFlags	loadFlags = 0;
	
	char* bankPath = 0;
	Float32 startTime = 0;
	UInt32 numFrames = 512;
	
	for (int i = 1; i < argc; ++i)
	{
		if (!strcmp ("-p", argv[i]))
		{
			shouldPlay = true;
		}
		else if (!strcmp ("-w", argv[i]))
		{
			waitAtEnd = true;
		}
		else if (!strcmp ("-d", argv[i]))
		{
			diskStream = true;
		}
		else if (!strcmp ("-b", argv[i])) 
		{
			shouldSetBank = true;
			if (++i == argc) goto malformedInput;
			bankPath = const_cast<char*>(argv[i]);
		}
		else if (!strcmp ("-n", argv[i]))
		{
			shouldPrint = false;
		}
		else if ((filePath == 0) && (argv[i][0] == '/' || argv[i][0] == '~'))
		{
			filePath = const_cast<char*>(argv[i]);
		}
		else if (!strcmp ("-t", argv[i])) 
		{
			if (++i == argc) goto malformedInput;
			sscanf (argv[i], "%f", &startTime);
		}
		else if (!strcmp("-e", argv[i]))
        {
            shouldUseMIDIEndpoint = true;
        }
		else if (!strcmp("-c", argv[i]))
        {
            loadFlags = kMusicSequenceLoadSMF_ChannelsToTracks;
        }
        else if (!strcmp ("-i", argv[i])) 
		{
			if (++i == argc) goto malformedInput;
			sscanf (argv[i], "%ld", &numFrames);
		}
        else if (!strcmp ("-f", argv[i])) 
		{
			if (i + 3 >= argc) goto malformedInput;
			outputFilePath = argv[++i];
			str2OSType (argv[++i], dataFormat);
			sscanf (argv[++i], "%lf", &srate);
		}
		else
		{
malformedInput:
			fprintf (stderr, "%s\n", usageStr);
			exit (1);
		}
	}
	
	if (filePath == 0) {
		fprintf (stderr, "You have to specify a MIDI file to print or play\n");
		fprintf (stderr, "%s\n", usageStr);
		exit (1);
	}
	
	if (shouldUseMIDIEndpoint && outputFilePath) {
		printf ("can't write a file when you try to play out to a MIDI Endpoint\n");
		exit (1);
	}
	
	MusicSequence sequence;
	OSStatus result;
	
	require_noerr (result = LoadSMF (filePath, sequence, loadFlags), fail);
			
	if (shouldPrint) 
		CAShow (sequence);
	
	if (shouldPlay)
	{
        AUGraph graph = 0;
        AudioUnit theSynth = 0;
		
		require_noerr (result = MusicSequenceGetAUGraph (sequence, &graph), fail);
		require_noerr (result = AUGraphOpen (graph), fail);     
		  
		require_noerr (result = GetSynthFromGraph (graph, theSynth), fail);
		require_noerr (result = AudioUnitSetProperty (theSynth,
										kAudioUnitProperty_CPULoad,
										kAudioUnitScope_Global, 0,
										&maxCPULoad, sizeof(maxCPULoad)), fail);

        if (shouldUseMIDIEndpoint) 
		{
			MIDIClientRef	theMidiClient;
			MIDIClientCreate(CFSTR("Play Sequence"), NULL, NULL, &theMidiClient);		
            
			ItemCount destCount = MIDIGetNumberOfDestinations();
            if (destCount == 0) {
                fprintf (stderr, "No MIDI Endpoints to play to.\n");
                exit(1);
            }
            
            require_noerr (result = MusicSequenceSetMIDIEndpoint (sequence, MIDIGetDestination(0)), fail);
        } 
		else 
		{   
			if (shouldSetBank) {                
				FSRef soundBankRef;
				require_noerr (result = FSPathMakeRef ((const UInt8*)bankPath, &soundBankRef, 0), fail);
								
				printf ("Setting Sound Bank:%s\n", bankPath);
					
				require_noerr (result = AudioUnitSetProperty (theSynth,
												kMusicDeviceProperty_SoundBankFSRef,
												kAudioUnitScope_Global, 0,
												&soundBankRef, sizeof(soundBankRef)), fail);
			}
						
			if (diskStream) {
				UInt32 value = diskStream;
				require_noerr (result = AudioUnitSetProperty (theSynth,
											kMusicDeviceProperty_StreamFromDisk,
											kAudioUnitScope_Global, 0,
											&value, sizeof(value)), fail);
			}

			if (outputFilePath) {
				// need to tell synth that is going to render a file.
				UInt32 value = 1;
				require_noerr (result = AudioUnitSetProperty (theSynth,
												kAudioUnitProperty_OfflineRender,
												kAudioUnitScope_Global, 0,
												&value, sizeof(value)), fail);
			}
			
			require_noerr (result = SetUpGraph (graph, numFrames, srate, (outputFilePath != NULL)), fail);
			
			if (shouldPrint) {
				printf ("Sample Rate: %.1f \n", srate);
				printf ("Disk Streaming is enabled: %c\n", (diskStream ? 'T' : 'F'));
			}
			
			require_noerr (result = AUGraphInitialize (graph), fail);

            if (shouldPrint)
				CAShow (graph);
        }
        
		MusicPlayer player;
		require_noerr (result = NewMusicPlayer (&player), fail);

		require_noerr (result = MusicPlayerSetSequence (player, sequence), fail);

	// figure out sequence length
		UInt32 ntracks;
		require_noerr(MusicSequenceGetTrackCount (sequence, &ntracks), fail);
		MusicTimeStamp sequenceLength = 0;
		for (UInt32 i = 0; i < ntracks; ++i) {
			MusicTrack track;
			MusicTimeStamp trackLength;
			UInt32 propsize = sizeof(MusicTimeStamp);
			require_noerr (result = MusicSequenceGetIndTrack(sequence, i, &track), fail);
			require_noerr (result = MusicTrackGetProperty(track, kSequenceTrackProperty_TrackLength,
							&trackLength, &propsize), fail);
			if (trackLength > sequenceLength)
				sequenceLength = trackLength;
		}
	
	// now I'm going to add 8 beats on the end for the reverb/long releases to tail off...
		sequenceLength += 8;
		
		require_noerr (result = MusicPlayerSetTime (player, startTime), fail);
		
		require_noerr (result = MusicPlayerPreroll (player), fail);
		
		if (shouldPrint) {
			printf ("Ready to play: %s, %.2f beats long\n\t<Enter> to continue: ", filePath, sequenceLength); 

			getc(stdin);
		}
		
		startRunningTime = AudioGetCurrentHostTime ();
		
		require_noerr (result = MusicPlayerStart (player), fail);
		
		if (outputFilePath) 
			WriteOutputFile (outputFilePath, dataFormat, srate, sequenceLength, shouldPrint, graph, numFrames, player);
		else
			PlayLoop (player, graph, sequenceLength, shouldPrint, waitAtEnd);
					
		require_noerr (result = MusicPlayerStop (player), fail);
		if (shouldPrint) printf ("finished playing\n");
			
// this shows you how you should dispose of everything
		require_noerr (result = DisposeMusicPlayer (player), fail);
		require_noerr (result = DisposeMusicSequence(sequence), fail);
		// don't own the graph so don't dispose it (the seq owns it as we never set it ourselves, we just got it....)
	}
	else {
		require_noerr (result = DisposeMusicSequence(sequence), fail);
	}
	
	while (waitAtEnd)
		CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.25, false);
		
    return 0;
	
fail:
	if (shouldPrint) printf ("Error = %ld\n", result);
	return result;
}