/*

native_midi_mac: Native Midi support on MacOS for the SDL_mixer library

Copyright (C) 2001 Max Horn

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 of the License, or (at your option) any later version.

This library 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Max Horn

max@quendi.de

*/

#include "native_midi.h"

#include "native_midi_common.h"

#ifdef MACOSX

#include <QuickTime/QuickTimeMusic.h>

#else

#include <assert.h>

#include <stdlib.h>

#include <string.h>

/* Native Midi song */

struct _NativeMidiSong

{

Uint32 *tuneSequence;

Uint32 *tuneHeader;

};

enum

{

/* number of (32-bit) long words in a note request event */

kNoteRequestEventLength = ((sizeof(NoteRequest)/sizeof(long)) + 2),

/* number of (32-bit) long words in a marker event */

kMarkerEventLength = 1,

/* number of (32-bit) long words in a general event, minus its data */

kGeneralEventLength = 2

};

#define ERROR_BUF_SIZE 256

#define BUFFER_INCREMENT 5000

#define REST_IF_NECESSARY() do {\

int timeDiff = eventPos->time - lastEventTime; \

if(timeDiff) \

{ \

timeDiff = (int)(timeDiff*tick); \

qtma_StuffRestEvent(*tunePos, timeDiff); \

tunePos++; \

lastEventTime = eventPos->time; \

} \

} while(0)

static Uint32 *BuildTuneSequence(MIDIEvent *evntlist, int ppqn, int part_poly_max[32], int part_to_inst[32], int *numParts);

static Uint32 *BuildTuneHeader(int part_poly_max[32], int part_to_inst[32], int numParts);

/* The global TunePlayer instance */

static TunePlayer gTunePlayer = NULL;

static int gInstaceCount = 0;

static Uint32 *gCurrentTuneSequence = NULL;

static char gErrorBuffer[ERROR_BUF_SIZE] = "";

/* Check whether QuickTime is available */

int native_midi_detect()

{

/* TODO */

return 1;

}

NativeMidiSong *native_midi_loadsong(char *midifile)

{

NativeMidiSong *song = NULL;

MIDIEvent *evntlist = NULL;

int part_to_inst[32];

int part_poly_max[32];

int numParts = 0;

Uint16 ppqn;

/* Init the arrays */

memset(part_poly_max,0,sizeof(part_poly_max));

memset(part_to_inst,-1,sizeof(part_to_inst));

/* Attempt to load the midi file */

evntlist = CreateMIDIEventList(midifile, &ppqn);

if (!evntlist)

goto bail;

/* Allocate memory for the song struct */

song = malloc(sizeof(NativeMidiSong));

if (!song)

goto bail;

/* Build a tune sequence from the event list */

song->tuneSequence = BuildTuneSequence(evntlist, ppqn, part_poly_max, part_to_inst, &numParts);

if(!song->tuneSequence)

goto bail;

/* Now build a tune header from the data we collect above, create

all parts as needed and assign them the correct instrument.

*/

song->tuneHeader = BuildTuneHeader(part_poly_max, part_to_inst, numParts);

if(!song->tuneHeader)

goto bail;

/* Increment the instance count */

gInstaceCount++;

gTunePlayer = OpenDefaultComponent(kTunePlayerComponentType, 0);

/* Finally, free the event list */

FreeMIDIEventList(evntlist);

return song;

bail:

if (evntlist)

FreeMIDIEventList(evntlist);

if (song)

{

if(song->tuneSequence)

free(song->tuneSequence);

if(song->tuneHeader)

DisposePtr((Ptr)song->tuneHeader);

free(song);

}

return NULL;

}

void native_midi_freesong(NativeMidiSong *song)

{

if(!song || !song->tuneSequence)

return;

/* If this is the currently playing song, stop it now */

if (song->tuneSequence == gCurrentTuneSequence)

native_midi_stop();

/* Finally, free the data storage */

free(song->tuneSequence);

DisposePtr((Ptr)song->tuneHeader);

free(song);

/* Increment the instance count */

gInstaceCount--;

{

CloseComponent(gTunePlayer);

gTunePlayer = NULL;

}

}

void native_midi_start(NativeMidiSong *song)

{

UInt32 queueFlags = 0;

ComponentResult tpError;

assert (gTunePlayer != NULL);

SDL_PauseAudio(1);

SDL_UnlockAudio();

/* First, stop the currently playing music */

native_midi_stop();

/* Set up the queue flags */

queueFlags = kTuneStartNow;

/* Set the time scale (units per second), we want milliseconds */

tpError = TuneSetTimeScale(gTunePlayer, 1000);

if (tpError != noErr)

{

strncpy (gErrorBuffer, "MIDI error during TuneSetTimeScale", ERROR_BUF_SIZE);

}

/* Set the header, to tell what instruments are used */

tpError = TuneSetHeader(gTunePlayer, (UInt32 *)song->tuneHeader);

if (tpError != noErr)

{

strncpy (gErrorBuffer, "MIDI error during TuneSetHeader", ERROR_BUF_SIZE);

}

/* Have it allocate whatever resources are needed */

tpError = TunePreroll(gTunePlayer);

if (tpError != noErr)

{

strncpy (gErrorBuffer, "MIDI error during TunePreroll", ERROR_BUF_SIZE);

}

/* We want to play at normal volume */

tpError = TuneSetVolume(gTunePlayer, 0x00010000);

if (tpError != noErr)

{

strncpy (gErrorBuffer, "MIDI error during TuneSetVolume", ERROR_BUF_SIZE);

}

/* Finally, start playing the full song */

gCurrentTuneSequence = song->tuneSequence;

tpError = TuneQueue(gTunePlayer, (UInt32 *)song->tuneSequence, 0x00010000, 0, 0xFFFFFFFF, queueFlags, NULL, 0);

if (tpError != noErr)

{

strncpy (gErrorBuffer, "MIDI error during TuneQueue", ERROR_BUF_SIZE);

done:

SDL_LockAudio();

SDL_PauseAudio(0);

}

void native_midi_stop()

{

return;

/* Stop music */

TuneStop(gTunePlayer, 0);

/* Deallocate all instruments */

TuneUnroll(gTunePlayer);

}

int native_midi_active()

{

{

TuneStatus ts;

TuneGetStatus(gTunePlayer,&ts);

return ts.queueTime != 0;

}

else

return 0;

}

void native_midi_setvolume(int volume)

{

return;

/* QTMA olume may range from 0.0 to 1.0 (in 16.16 fixed point encoding) */

TuneSetVolume(gTunePlayer, (0x00010000 * volume)/SDL_MIX_MAXVOLUME);

}

char *native_midi_error()

{

return gErrorBuffer;

}

Uint32 *BuildTuneSequence(MIDIEvent *evntlist, int ppqn, int part_poly_max[32], int part_to_inst[32], int *numParts)

{

int part_poly[32];

int channel_to_part[16];

int channel_pan[16];

int channel_vol[16];

int channel_pitch_bend[16];

int lastEventTime = 0;

int tempo = 500000;

double Ippqn = 1.0 / (1000*ppqn);

double tick = tempo * Ippqn;

MIDIEvent *eventPos = evntlist;

MIDIEvent *noteOffPos;

Uint32 *tunePos, *endPos;

Uint32 *tuneSequence;

size_t tuneSize;

/* allocate space for the tune header */

tuneSize = 5000;

tuneSequence = (Uint32 *)malloc(tuneSize * sizeof(Uint32));

if (tuneSequence == NULL)

return NULL;

/* Set starting position in our tune memory */

tunePos = tuneSequence;

endPos = tuneSequence + tuneSize;

/* Initialise the arrays */

memset(part_poly,0,sizeof(part_poly));

memset(channel_to_part,-1,sizeof(channel_to_part));

memset(channel_pan,-1,sizeof(channel_pan));

memset(channel_vol,-1,sizeof(channel_vol));

memset(channel_pitch_bend,-1,sizeof(channel_pitch_bend));

*numParts = 0;

/*

* Now the major work - iterate over all GM events,

* and turn them into QuickTime Music format.

* At the same time, calculate the max. polyphony for each part,

* and also the part->instrument mapping.

*/

while(eventPos)

{

int status = (eventPos->status&0xF0)>>4;

int channel = eventPos->status&0x0F;

int part = channel_to_part[channel];

int velocity, pitch;

int value, controller;

int bend;

int newInst;

/* Check if we are running low on space... */

if((tunePos+16) > endPos)

{

/* Resize our data storage. */

Uint32 *oldTuneSequence = tuneSequence;

tuneSize += BUFFER_INCREMENT;

tuneSequence = (Uint32 *)realloc(tuneSequence, tuneSize * sizeof(Uint32));

if(oldTuneSequence != tuneSequence)

tunePos += tuneSequence - oldTuneSequence;

endPos = tuneSequence + tuneSize;

}

switch (status)

{

case MIDI_STATUS_NOTE_OFF:

assert(part>=0 && part<=31);

/* Keep track of the polyphony of the current part */

part_poly[part]--;

break;

case MIDI_STATUS_NOTE_ON:

if (part < 0)

{

/* If no part is specified yet, we default to the first instrument, which

is piano (or the first drum kit if we are on the drum channel)

*/

int newInst;

if (channel == 9)

newInst = kFirstDrumkit + 1; /* the first drum kit is the "no drum" kit! */

else

newInst = kFirstGMInstrument;

part = channel_to_part[channel] = *numParts;

part_to_inst[(*numParts)++] = newInst;

}

/* TODO - add support for more than 32 parts using eXtended QTMA events */

assert(part<=31);

/* Decode pitch & velocity */

pitch = eventPos->data[0];

velocity = eventPos->data[1];

if (velocity == 0)

{

/* was a NOTE OFF in disguise, so we decrement the polyphony */

part_poly[part]--;

}

else

{

/* Keep track of the polyphony of the current part */

int foo = ++part_poly[part];

if (part_poly_max[part] < foo)

part_poly_max[part] = foo;

/* Now scan forward to find the matching NOTE OFF event */

for(noteOffPos = eventPos; noteOffPos; noteOffPos = noteOffPos->next)

{

if ((noteOffPos->status&0xF0)>>4 == MIDI_STATUS_NOTE_OFF

&& channel == (eventPos->status&0x0F)

&& pitch == noteOffPos->data[0])

break;

/* NOTE ON with velocity == 0 is the same as a NOTE OFF */

if ((noteOffPos->status&0xF0)>>4 == MIDI_STATUS_NOTE_ON

&& channel == (eventPos->status&0x0F)

&& pitch == noteOffPos->data[0]

&& 0 == noteOffPos->data[1])

break;

}

/* Did we find a note off? Should always be the case, but who knows... */

if (noteOffPos)

{

/* We found a NOTE OFF, now calculate the note duration */

int duration = (int)((noteOffPos->time - eventPos->time)*tick);

REST_IF_NECESSARY();

if (duration < 2048 && pitch>=32 && pitch<=95 && velocity>=0 && velocity<=127)

{

qtma_StuffNoteEvent(*tunePos, part, pitch, velocity, duration);

tunePos++;

}

else

{

qtma_StuffXNoteEvent(*tunePos, *(tunePos+1), part, pitch, velocity, duration);

tunePos+=2;

}

}

}

break;

case MIDI_STATUS_AFTERTOUCH:

break;

case MIDI_STATUS_CONTROLLER:

controller = eventPos->data[0];

value = eventPos->data[1];

switch(controller)

{

case 0: /* bank change - igore for now */

break;

case kControllerVolume:

if(channel_vol[channel] != value<<8)

{

channel_vol[channel] = value<<8;

if(part>=0 && part<=31)

{

REST_IF_NECESSARY();

qtma_StuffControlEvent(*tunePos, part, kControllerVolume, channel_vol[channel]);

tunePos++;

}

}

break;

case kControllerPan:

if(part>=0 && part<=31)

{

REST_IF_NECESSARY();

qtma_StuffControlEvent(*tunePos, part, kControllerPan, channel_pan[channel]);

tunePos++;

}

}

break;

default:

/* No other controllers implemented yet */;

break;

}

break;

case MIDI_STATUS_PROG_CHANGE:

/* Instrument changed */

newInst = eventPos->data[0];

/* Channel 9 (the 10th channel) is different, it indicates a drum kit */

if (channel == 9)

newInst += kFirstDrumkit;

else

newInst += kFirstGMInstrument;

/* Only if the instrument for this channel *really* changed, add a new part. */

if(newInst != part_to_inst[part])

{

/* TODO maybe make use of kGeneralEventPartChange here,

to help QT reuse note channels?

*/

part = channel_to_part[channel] = *numParts;

part_to_inst[(*numParts)++] = newInst;

if(channel_vol[channel] >= 0)

{

REST_IF_NECESSARY();

qtma_StuffControlEvent(*tunePos, part, kControllerVolume, channel_vol[channel]);

tunePos++;

}

if(channel_pan[channel] >= 0)

{

REST_IF_NECESSARY();

qtma_StuffControlEvent(*tunePos, part, kControllerPan, channel_pan[channel]);

tunePos++;

}

if(channel_pitch_bend[channel] >= 0)

{

REST_IF_NECESSARY();

qtma_StuffControlEvent(*tunePos, part, kControllerPitchBend, channel_pitch_bend[channel]);

tunePos++;

}

}

break;

case MIDI_STATUS_PRESSURE:

/* NYI */

break;

case MIDI_STATUS_PITCH_WHEEL:

/* In the midi spec, 0x2000 = center, 0x0000 = - 2 semitones, 0x3FFF = +2 semitones

but for QTMA, we specify it as a 8.8 fixed point of semitones

TODO: detect "pitch bend range changes" & honor them!

*/

/* "Center" the bend */

bend -= 0x2000;

/* Move it to our format: */

bend <<= 4;

/* If it turns out the pitch bend didn't change, stop here */

if(channel_pitch_bend[channel] == bend)

break;

channel_pitch_bend[channel] = bend;

if(part>=0 && part<=31)

{

/* Stuff a control event */

REST_IF_NECESSARY();

qtma_StuffControlEvent(*tunePos, part, kControllerPitchBend, bend);

tunePos++;

}

break;

case MIDI_STATUS_SYSEX:

if (eventPos->status == 0xFF && eventPos->data[0] == 0x51) /* Tempo change */

{

tempo = (eventPos->extraData[0] << 16) +

(eventPos->extraData[1] << 8) +

eventPos->extraData[2];

tick = tempo * Ippqn;

}

break;

}

/* on to the next event */

eventPos = eventPos->next;

}

/* Finally, place an end marker */

*tunePos = kEndMarkerValue;

return tuneSequence;

}

Uint32 *BuildTuneHeader(int part_poly_max[32], int part_to_inst[32], int numParts)

{

Uint32 *myHeader;

Uint32 *myPos1, *myPos2; /* pointers to the head and tail long words of a music event */

NoteRequest *myNoteRequest;

NoteAllocator myNoteAllocator; /* for the NAStuffToneDescription call */

ComponentResult myErr = noErr;

int part;

myHeader = NULL;

myNoteAllocator = NULL;

/*

* Open up the Note Allocator

*/

myNoteAllocator = OpenDefaultComponent(kNoteAllocatorComponentType,0);

if (myNoteAllocator == NULL)

goto bail;

/*

* Allocate space for the tune header

*/

myHeader = (Uint32 *)

NewPtrClear((numParts * kNoteRequestEventLength + kMarkerEventLength) * sizeof(Uint32));

if (myHeader == NULL)

goto bail;

myPos1 = myHeader;

/*

* Loop over all parts

*/

for(part = 0; part < numParts; ++part)

{

/*

* Stuff request for the instrument with the given polyphony

*/

myPos2 = myPos1 + (kNoteRequestEventLength - 1); /* last longword of general event */

qtma_StuffGeneralEvent(*myPos1, *myPos2, part, kGeneralEventNoteRequest, kNoteRequestEventLength);

myNoteRequest = (NoteRequest *)(myPos1 + 1);

myNoteRequest->info.flags = 0;

/* I'm told by the Apple people that the Quicktime types were poorly designed and it was

* too late to change them. On little endian, the BigEndian(Short|Fixed) types are structs

* while on big endian they are primitive types. Furthermore, Quicktime failed to

* provide setter and getter functions. To get this to work, we need to case the

* code for the two possible situations.

* My assumption is that the right-side value was always expected to be BigEndian

* as it was written way before the Universal Binary transition. So in the little endian

* case, OSSwap is used.

*/

#if __LITTLE_ENDIAN__

myNoteRequest->info.polyphony.bigEndianValue = OSSwapHostToBigInt16(part_poly_max[part]);

myNoteRequest->info.typicalPolyphony.bigEndianValue = OSSwapHostToBigInt32(0x00010000);

#else

myNoteRequest->info.polyphony = part_poly_max[part];

myNoteRequest->info.typicalPolyphony = 0x00010000;

myErr = NAStuffToneDescription(myNoteAllocator,part_to_inst[part],&myNoteRequest->tone);

if (myErr != noErr)

goto bail;

/* move pointer to beginning of next event */

myPos1 += kNoteRequestEventLength;

}

*myPos1 = kEndMarkerValue; /* end of sequence marker */

bail:

if(myNoteAllocator)

CloseComponent(myNoteAllocator);

/* if we encountered an error, dispose of the storage we allocated and return NULL */

if (myErr != noErr) {

DisposePtr((Ptr)myHeader);

myHeader = NULL;

}

return myHeader;

}

#endif /* MacOS native MIDI support */