deac/MIDI.js
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

let there be midi

Browse source
This commit is contained in:
Michael Deal 2012-02-15 20:46:03 -08:00
commit d338706cec
139 changed files with 12537 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

80
js/lib/base64binary.js Normal file
View file

@ -0,0 +1,80 @@
/*
Copyright (c) 2011, Daniel Guerrero
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of the Daniel Guerrero nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL DANIEL GUERRERO BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
var Base64Binary = {
_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
/* will return a Uint8Array type */
decodeArrayBuffer: function(input) {
var bytes = Math.ceil( (3*input.length) / 4.0);
var ab = new ArrayBuffer(bytes);
this.decode(input, ab);
return ab;
},
decode: function(input, arrayBuffer) {
//get last chars to see if are valid
var lkey1 = this._keyStr.indexOf(input.charAt(input.length-1));
var lkey2 = this._keyStr.indexOf(input.charAt(input.length-1));
var bytes = Math.ceil( (3*input.length) / 4.0);
if (lkey1 == 64) bytes--; //padding chars, so skip
if (lkey2 == 64) bytes--; //padding chars, so skip
var uarray;
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0;
var j = 0;
if (arrayBuffer)
uarray = new Uint8Array(arrayBuffer);
else
uarray = new Uint8Array(bytes);
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
for (i=0; i<bytes; i+=3) {
//get the 3 octects in 4 ascii chars
enc1 = this._keyStr.indexOf(input.charAt(j++));
enc2 = this._keyStr.indexOf(input.charAt(j++));
enc3 = this._keyStr.indexOf(input.charAt(j++));
enc4 = this._keyStr.indexOf(input.charAt(j++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
uarray[i] = chr1;
if (enc3 != 64) uarray[i+1] = chr2;
if (enc4 != 64) uarray[i+2] = chr3;
}
return uarray;
}
};

24
js/lib/jasmid/LICENSE Normal file
View file

@ -0,0 +1,24 @@
Copyright (c) 2010, Matt Westcott & Ben Firshman
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* The names of its contributors may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

24
js/lib/jasmid/jasmid/LICENSE Normal file
View file

@ -0,0 +1,24 @@
Copyright (c) 2010, Matt Westcott & Ben Firshman
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* The names of its contributors may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

238
js/lib/jasmid/jasmid/midifile.js Normal file
View file

@ -0,0 +1,238 @@
/*
class to parse the .mid file format
(depends on stream.js)
*/
function MidiFile(data) {
function readChunk(stream) {
var id = stream.read(4);
var length = stream.readInt32();
return {
'id': id,
'length': length,
'data': stream.read(length)
};
}
var lastEventTypeByte;
function readEvent(stream) {
var event = {};
event.deltaTime = stream.readVarInt();
var eventTypeByte = stream.readInt8();
if ((eventTypeByte & 0xf0) == 0xf0) {
/* system / meta event */
if (eventTypeByte == 0xff) {
/* meta event */
event.type = 'meta';
var subtypeByte = stream.readInt8();
var length = stream.readVarInt();
switch(subtypeByte) {
case 0x00:
event.subtype = 'sequenceNumber';
if (length != 2) throw "Expected length for sequenceNumber event is 2, got " + length;
event.number = stream.readInt16();
return event;
case 0x01:
event.subtype = 'text';
event.text = stream.read(length);
return event;
case 0x02:
event.subtype = 'copyrightNotice';
event.text = stream.read(length);
return event;
case 0x03:
event.subtype = 'trackName';
event.text = stream.read(length);
return event;
case 0x04:
event.subtype = 'instrumentName';
event.text = stream.read(length);
return event;
case 0x05:
event.subtype = 'lyrics';
event.text = stream.read(length);
return event;
case 0x06:
event.subtype = 'marker';
event.text = stream.read(length);
return event;
case 0x07:
event.subtype = 'cuePoint';
event.text = stream.read(length);
return event;
case 0x20:
event.subtype = 'midiChannelPrefix';
if (length != 1) throw "Expected length for midiChannelPrefix event is 1, got " + length;
event.channel = stream.readInt8();
return event;
case 0x2f:
event.subtype = 'endOfTrack';
if (length != 0) throw "Expected length for endOfTrack event is 0, got " + length;
return event;
case 0x51:
event.subtype = 'setTempo';
if (length != 3) throw "Expected length for setTempo event is 3, got " + length;
event.microsecondsPerBeat = (
(stream.readInt8() << 16)
+ (stream.readInt8() << 8)
+ stream.readInt8()
)
return event;
case 0x54:
event.subtype = 'smpteOffset';
if (length != 5) throw "Expected length for smpteOffset event is 5, got " + length;
var hourByte = stream.readInt8();
event.frameRate = {
0x00: 24, 0x20: 25, 0x40: 29, 0x60: 30
}[hourByte & 0x60];
event.hour = hourByte & 0x1f;
event.min = stream.readInt8();
event.sec = stream.readInt8();
event.frame = stream.readInt8();
event.subframe = stream.readInt8();
return event;
case 0x58:
event.subtype = 'timeSignature';
if (length != 4) throw "Expected length for timeSignature event is 4, got " + length;
event.numerator = stream.readInt8();
event.denominator = Math.pow(2, stream.readInt8());
event.metronome = stream.readInt8();
event.thirtyseconds = stream.readInt8();
return event;
case 0x59:
event.subtype = 'keySignature';
if (length != 2) throw "Expected length for keySignature event is 2, got " + length;
event.key = stream.readInt8();
event.scale = stream.readInt8();
return event;
case 0x7f:
event.subtype = 'sequencerSpecific';
event.data = stream.read(length);
return event;
default:
// console.log("Unrecognised meta event subtype: " + subtypeByte);
event.subtype = 'unknown'
event.data = stream.read(length);
return event;
}
event.data = stream.read(length);
return event;
} else if (eventTypeByte == 0xf0) {
event.type = 'sysEx';
var length = stream.readVarInt();
event.data = stream.read(length);
return event;
} else if (eventTypeByte == 0xf7) {
event.type = 'dividedSysEx';
var length = stream.readVarInt();
event.data = stream.read(length);
return event;
} else {
throw "Unrecognised MIDI event type byte: " + eventTypeByte;
}
} else {
/* channel event */
var param1;
if ((eventTypeByte & 0x80) == 0) {
/* running status - reuse lastEventTypeByte as the event type.
eventTypeByte is actually the first parameter
*/
param1 = eventTypeByte;
eventTypeByte = lastEventTypeByte;
} else {
param1 = stream.readInt8();
lastEventTypeByte = eventTypeByte;
}
var eventType = eventTypeByte >> 4;
event.channel = eventTypeByte & 0x0f;
event.type = 'channel';
switch (eventType) {
case 0x08:
event.subtype = 'noteOff';
event.noteNumber = param1;
event.velocity = stream.readInt8();
return event;
case 0x09:
event.noteNumber = param1;
event.velocity = stream.readInt8();
if (event.velocity == 0) {
event.subtype = 'noteOff';
} else {
event.subtype = 'noteOn';
}
return event;
case 0x0a:
event.subtype = 'noteAftertouch';
event.noteNumber = param1;
event.amount = stream.readInt8();
return event;
case 0x0b:
event.subtype = 'controller';
event.controllerType = param1;
event.value = stream.readInt8();
return event;
case 0x0c:
event.subtype = 'programChange';
event.programNumber = param1;
return event;
case 0x0d:
event.subtype = 'channelAftertouch';
event.amount = param1;
return event;
case 0x0e:
event.subtype = 'pitchBend';
event.value = param1 + (stream.readInt8() << 7);
return event;
default:
throw "Unrecognised MIDI event type: " + eventType
/*
console.log("Unrecognised MIDI event type: " + eventType);
stream.readInt8();
event.subtype = 'unknown';
return event;
*/
}
}
}
stream = Stream(data);
var headerChunk = readChunk(stream);
if (headerChunk.id != 'MThd' || headerChunk.length != 6) {
throw "Bad .mid file - header not found";
}
var headerStream = Stream(headerChunk.data);
var formatType = headerStream.readInt16();
var trackCount = headerStream.readInt16();
var timeDivision = headerStream.readInt16();
if (timeDivision & 0x8000) {
throw "Expressing time division in SMTPE frames is not supported yet"
} else {
ticksPerBeat = timeDivision;
}
var header = {
'formatType': formatType,
'trackCount': trackCount,
'ticksPerBeat': ticksPerBeat
}
var tracks = [];
for (var i = 0; i < header.trackCount; i++) {
tracks[i] = [];
var trackChunk = readChunk(stream);
if (trackChunk.id != 'MTrk') {
throw "Unexpected chunk - expected MTrk, got "+ trackChunk.id;
}
var trackStream = Stream(trackChunk.data);
while (!trackStream.eof()) {
var event = readEvent(trackStream);
tracks[i].push(event);
//console.log(event);
}
}
return {
'header': header,
'tracks': tracks
}
}

83
js/lib/jasmid/jasmid/replayer.js Normal file
View file

@ -0,0 +1,83 @@
var clone = function (o) {
if (typeof o != 'object') return (o);
if (o == null) return (o);
var ret = (typeof o.length == 'number') ? [] : {};
for (var key in o) ret[key] = clone(o[key]);
return ret;
};
function Replayer(midiFile, timeWarp, eventProcessor) {
//console.log(midiFile)
var trackStates = [];
var beatsPerMinute = 120;
var ticksPerBeat = midiFile.header.ticksPerBeat;
for (var i = 0; i < midiFile.tracks.length; i++) {
trackStates[i] = {
"nextEventIndex": 0,
"ticksToNextEvent": (
midiFile.tracks[i].length ? midiFile.tracks[i][0].deltaTime : null
)
};
}
function getNextEvent() {
var ticksToNextEvent = null;
var nextEventTrack = null;
var nextEventIndex = null;
for (var i = 0; i < trackStates.length; i++) {
if (trackStates[i].ticksToNextEvent != null && (ticksToNextEvent == null || trackStates[i].ticksToNextEvent < ticksToNextEvent)) {
ticksToNextEvent = trackStates[i].ticksToNextEvent;
nextEventTrack = i;
nextEventIndex = trackStates[i].nextEventIndex;
}
}
if (nextEventTrack != null) {
/// consume event from that track
var nextEvent = midiFile.tracks[nextEventTrack][nextEventIndex];
if (midiFile.tracks[nextEventTrack][nextEventIndex + 1]) {
trackStates[nextEventTrack].ticksToNextEvent += midiFile.tracks[nextEventTrack][nextEventIndex + 1].deltaTime;
} else {
trackStates[nextEventTrack].ticksToNextEvent = null;
}
trackStates[nextEventTrack].nextEventIndex += 1;
/// advance timings on all tracks by ticksToNextEvent
for (var i = 0; i < trackStates.length; i++) {
if (trackStates[i].ticksToNextEvent != null) {
trackStates[i].ticksToNextEvent -= ticksToNextEvent
}
}
return {
"ticksToEvent": ticksToNextEvent,
"event": nextEvent,
"track": nextEventTrack
}
} else {
return null;
}
};
//
var midiEvent;
var temporal = [];
//
function processEvents() {
function processNext() {
if (midiEvent.ticksToEvent > 0) {
var beatsToGenerate = midiEvent.ticksToEvent / ticksPerBeat;
var secondsToGenerate = beatsToGenerate / (beatsPerMinute / 60);
}
var time = secondsToGenerate * 1000 * timeWarp || 0;
temporal.push([ midiEvent, time]);
midiEvent = getNextEvent();
};
//
if (midiEvent = getNextEvent()) {
while(midiEvent) processNext(true);
}
};
processEvents();
return {
"getData": function() {
// console.log(temporal)
return clone(temporal);
}
};
};

68
js/lib/jasmid/jasmid/stream.js Normal file
View file

@ -0,0 +1,68 @@
/* Wrapper for accessing strings through sequential reads */
function Stream(str) {
var position = 0;
function read(length) {
var result = str.substr(position, length);
position += length;
return result;
}
/* read a big-endian 32-bit integer */
function readInt32() {
var result = (
(str.charCodeAt(position) << 24)
+ (str.charCodeAt(position + 1) << 16)
+ (str.charCodeAt(position + 2) << 8)
+ str.charCodeAt(position + 3));
position += 4;
return result;
}
/* read a big-endian 16-bit integer */
function readInt16() {
var result = (
(str.charCodeAt(position) << 8)
+ str.charCodeAt(position + 1));
position += 2;
return result;
}
/* read an 8-bit integer */
function readInt8() {
var result = str.charCodeAt(position);
position += 1;
return result;
}
function eof() {
return position >= str.length;
}
/* read a MIDI-style variable-length integer
(big-endian value in groups of 7 bits,
with top bit set to signify that another byte follows)
*/
function readVarInt() {
var result = 0;
while (true) {
var b = readInt8();
if (b & 0x80) {
result += (b & 0x7f);
result <<= 7;
} else {
/* b is the last byte */
return result + b;
}
}
}
return {
'eof': eof,
'read': read,
'readInt32': readInt32,
'readInt16': readInt16,
'readInt8': readInt8,
'readVarInt': readVarInt
}
}

238
js/lib/jasmid/midifile.js Normal file
View file

@ -0,0 +1,238 @@
/*
class to parse the .mid file format
(depends on stream.js)
*/
function MidiFile(data) {
function readChunk(stream) {
var id = stream.read(4);
var length = stream.readInt32();
return {
'id': id,
'length': length,
'data': stream.read(length)
};
}
var lastEventTypeByte;
function readEvent(stream) {
var event = {};
event.deltaTime = stream.readVarInt();
var eventTypeByte = stream.readInt8();
if ((eventTypeByte & 0xf0) == 0xf0) {
/* system / meta event */
if (eventTypeByte == 0xff) {
/* meta event */
event.type = 'meta';
var subtypeByte = stream.readInt8();
var length = stream.readVarInt();
switch(subtypeByte) {
case 0x00:
event.subtype = 'sequenceNumber';
if (length != 2) throw "Expected length for sequenceNumber event is 2, got " + length;
event.number = stream.readInt16();
return event;
case 0x01:
event.subtype = 'text';
event.text = stream.read(length);
return event;
case 0x02:
event.subtype = 'copyrightNotice';
event.text = stream.read(length);
return event;
case 0x03:
event.subtype = 'trackName';
event.text = stream.read(length);
return event;
case 0x04:
event.subtype = 'instrumentName';
event.text = stream.read(length);
return event;
case 0x05:
event.subtype = 'lyrics';
event.text = stream.read(length);
return event;
case 0x06:
event.subtype = 'marker';
event.text = stream.read(length);
return event;
case 0x07:
event.subtype = 'cuePoint';
event.text = stream.read(length);
return event;
case 0x20:
event.subtype = 'midiChannelPrefix';
if (length != 1) throw "Expected length for midiChannelPrefix event is 1, got " + length;
event.channel = stream.readInt8();
return event;
case 0x2f:
event.subtype = 'endOfTrack';
if (length != 0) throw "Expected length for endOfTrack event is 0, got " + length;
return event;
case 0x51:
event.subtype = 'setTempo';
if (length != 3) throw "Expected length for setTempo event is 3, got " + length;
event.microsecondsPerBeat = (
(stream.readInt8() << 16)
+ (stream.readInt8() << 8)
+ stream.readInt8()
)
return event;
case 0x54:
event.subtype = 'smpteOffset';
if (length != 5) throw "Expected length for smpteOffset event is 5, got " + length;
var hourByte = stream.readInt8();
event.frameRate = {
0x00: 24, 0x20: 25, 0x40: 29, 0x60: 30
}[hourByte & 0x60];
event.hour = hourByte & 0x1f;
event.min = stream.readInt8();
event.sec = stream.readInt8();
event.frame = stream.readInt8();
event.subframe = stream.readInt8();
return event;
case 0x58:
event.subtype = 'timeSignature';
if (length != 4) throw "Expected length for timeSignature event is 4, got " + length;
event.numerator = stream.readInt8();
event.denominator = Math.pow(2, stream.readInt8());
event.metronome = stream.readInt8();
event.thirtyseconds = stream.readInt8();
return event;
case 0x59:
event.subtype = 'keySignature';
if (length != 2) throw "Expected length for keySignature event is 2, got " + length;
event.key = stream.readInt8();
event.scale = stream.readInt8();
return event;
case 0x7f:
event.subtype = 'sequencerSpecific';
event.data = stream.read(length);
return event;
default:
// console.log("Unrecognised meta event subtype: " + subtypeByte);
event.subtype = 'unknown'
event.data = stream.read(length);
return event;
}
event.data = stream.read(length);
return event;
} else if (eventTypeByte == 0xf0) {
event.type = 'sysEx';
var length = stream.readVarInt();
event.data = stream.read(length);
return event;
} else if (eventTypeByte == 0xf7) {
event.type = 'dividedSysEx';
var length = stream.readVarInt();
event.data = stream.read(length);
return event;
} else {
throw "Unrecognised MIDI event type byte: " + eventTypeByte;
}
} else {
/* channel event */
var param1;
if ((eventTypeByte & 0x80) == 0) {
/* running status - reuse lastEventTypeByte as the event type.
eventTypeByte is actually the first parameter
*/
param1 = eventTypeByte;
eventTypeByte = lastEventTypeByte;
} else {
param1 = stream.readInt8();
lastEventTypeByte = eventTypeByte;
}
var eventType = eventTypeByte >> 4;
event.channel = eventTypeByte & 0x0f;
event.type = 'channel';
switch (eventType) {
case 0x08:
event.subtype = 'noteOff';
event.noteNumber = param1;
event.velocity = stream.readInt8();
return event;
case 0x09:
event.noteNumber = param1;
event.velocity = stream.readInt8();
if (event.velocity == 0) {
event.subtype = 'noteOff';
} else {
event.subtype = 'noteOn';
}
return event;
case 0x0a:
event.subtype = 'noteAftertouch';
event.noteNumber = param1;
event.amount = stream.readInt8();
return event;
case 0x0b:
event.subtype = 'controller';
event.controllerType = param1;
event.value = stream.readInt8();
return event;
case 0x0c:
event.subtype = 'programChange';
event.programNumber = param1;
return event;
case 0x0d:
event.subtype = 'channelAftertouch';
event.amount = param1;
return event;
case 0x0e:
event.subtype = 'pitchBend';
event.value = param1 + (stream.readInt8() << 7);
return event;
default:
throw "Unrecognised MIDI event type: " + eventType
/*
console.log("Unrecognised MIDI event type: " + eventType);
stream.readInt8();
event.subtype = 'unknown';
return event;
*/
}
}
}
stream = Stream(data);
var headerChunk = readChunk(stream);
if (headerChunk.id != 'MThd' || headerChunk.length != 6) {
throw "Bad .mid file - header not found";
}
var headerStream = Stream(headerChunk.data);
var formatType = headerStream.readInt16();
var trackCount = headerStream.readInt16();
var timeDivision = headerStream.readInt16();
if (timeDivision & 0x8000) {
throw "Expressing time division in SMTPE frames is not supported yet"
} else {
ticksPerBeat = timeDivision;
}
var header = {
'formatType': formatType,
'trackCount': trackCount,
'ticksPerBeat': ticksPerBeat
}
var tracks = [];
for (var i = 0; i < header.trackCount; i++) {
tracks[i] = [];
var trackChunk = readChunk(stream);
if (trackChunk.id != 'MTrk') {
throw "Unexpected chunk - expected MTrk, got "+ trackChunk.id;
}
var trackStream = Stream(trackChunk.data);
while (!trackStream.eof()) {
var event = readEvent(trackStream);
tracks[i].push(event);
//console.log(event);
}
}
return {
'header': header,
'tracks': tracks
}
}

83
js/lib/jasmid/replayer.js Normal file
View file

@ -0,0 +1,83 @@
var clone = function (o) {
if (typeof o != 'object') return (o);
if (o == null) return (o);
var ret = (typeof o.length == 'number') ? [] : {};
for (var key in o) ret[key] = clone(o[key]);
return ret;
};
function Replayer(midiFile, timeWarp, eventProcessor) {
//console.log(midiFile)
var trackStates = [];
var beatsPerMinute = 120;
var ticksPerBeat = midiFile.header.ticksPerBeat;
for (var i = 0; i < midiFile.tracks.length; i++) {
trackStates[i] = {
"nextEventIndex": 0,
"ticksToNextEvent": (
midiFile.tracks[i].length ? midiFile.tracks[i][0].deltaTime : null
)
};
}
function getNextEvent() {
var ticksToNextEvent = null;
var nextEventTrack = null;
var nextEventIndex = null;
for (var i = 0; i < trackStates.length; i++) {
if (trackStates[i].ticksToNextEvent != null && (ticksToNextEvent == null || trackStates[i].ticksToNextEvent < ticksToNextEvent)) {
ticksToNextEvent = trackStates[i].ticksToNextEvent;
nextEventTrack = i;
nextEventIndex = trackStates[i].nextEventIndex;
}
}
if (nextEventTrack != null) {
/// consume event from that track
var nextEvent = midiFile.tracks[nextEventTrack][nextEventIndex];
if (midiFile.tracks[nextEventTrack][nextEventIndex + 1]) {
trackStates[nextEventTrack].ticksToNextEvent += midiFile.tracks[nextEventTrack][nextEventIndex + 1].deltaTime;
} else {
trackStates[nextEventTrack].ticksToNextEvent = null;
}
trackStates[nextEventTrack].nextEventIndex += 1;
/// advance timings on all tracks by ticksToNextEvent
for (var i = 0; i < trackStates.length; i++) {
if (trackStates[i].ticksToNextEvent != null) {
trackStates[i].ticksToNextEvent -= ticksToNextEvent
}
}
return {
"ticksToEvent": ticksToNextEvent,
"event": nextEvent,
"track": nextEventTrack
}
} else {
return null;
}
};
//
var midiEvent;
var temporal = [];
//
function processEvents() {
function processNext() {
if (midiEvent.ticksToEvent > 0) {
var beatsToGenerate = midiEvent.ticksToEvent / ticksPerBeat;
var secondsToGenerate = beatsToGenerate / (beatsPerMinute / 60);
}
var time = secondsToGenerate * 1000 * timeWarp || 0;
temporal.push([ midiEvent, time]);
midiEvent = getNextEvent();
};
//
if (midiEvent = getNextEvent()) {
while(midiEvent) processNext(true);
}
};
processEvents();
return {
"getData": function() {
// console.log(temporal)
return clone(temporal);
}
};
};

68
js/lib/jasmid/stream.js Normal file
View file

@ -0,0 +1,68 @@
/* Wrapper for accessing strings through sequential reads */
function Stream(str) {
var position = 0;
function read(length) {
var result = str.substr(position, length);
position += length;
return result;
}
/* read a big-endian 32-bit integer */
function readInt32() {
var result = (
(str.charCodeAt(position) << 24)
+ (str.charCodeAt(position + 1) << 16)
+ (str.charCodeAt(position + 2) << 8)
+ str.charCodeAt(position + 3));
position += 4;
return result;
}
/* read a big-endian 16-bit integer */
function readInt16() {
var result = (
(str.charCodeAt(position) << 8)
+ str.charCodeAt(position + 1));
position += 2;
return result;
}
/* read an 8-bit integer */
function readInt8() {
var result = str.charCodeAt(position);
position += 1;
return result;
}
function eof() {
return position >= str.length;
}
/* read a MIDI-style variable-length integer
(big-endian value in groups of 7 bits,
with top bit set to signify that another byte follows)
*/
function readVarInt() {
var result = 0;
while (true) {
var b = readInt8();
if (b & 0x80) {
result += (b & 0x7f);
result <<= 7;
} else {
/* b is the last byte */
return result + b;
}
}
}
return {
'eof': eof,
'read': read,
'readInt32': readInt32,
'readInt16': readInt16,
'readInt8': readInt8,
'readVarInt': readVarInt
}
}