From: Jer Noble <jer.noble@apple.com>
Date: Fri, 7 Dec 2012 21:47:14 +0000 (-0800)
Subject: Added SyncSampleAtom, TimeToSampleAtom, and a new base Atom, VersionFlagsAtom, on... 
X-Git-Url: http://id.pley.net/movie_parser.git/commitdiff_plain/550e6dfa3c752008d9241f9617d41551f68b4827

Added SyncSampleAtom, TimeToSampleAtom, and a new base Atom, VersionFlagsAtom, on which other atoms are derived. Fixed a bunch of whitespace issues.
'
---

diff --git a/Atom.js b/Atom.js
index c7507db..7d15c3e 100644
--- a/Atom.js
+++ b/Atom.js
@@ -3,8 +3,7 @@ var Atom = function(buffer, offset) {
     return this.parse(buffer, offset) ? this : null;
 };
 
-Atom.create = function(buffer, offset)
-{
+Atom.create = function(buffer, offset) {
     // 'offset' is optional.
     if (arguments.length < 2)
         offset = 0;
@@ -14,10 +13,10 @@ Atom.create = function(buffer, offset)
 
     var typeArrayView = new Uint8Array(buffer, offset + 4, 4);
     var type = String.fromCharCode.apply(null, typeArrayView);
-    
+
     switch (type) {
         case 'ftyp':
-            return new FtypAtom(buffer, offset);
+            return new FileTypeAtom(buffer, offset);
         case 'moov':
         case 'trak':
         case 'mdia':
@@ -25,31 +24,34 @@ Atom.create = function(buffer, offset)
         case 'stbl':
             return new ContainerAtom(buffer, offset);
         case 'mvhd':
-            return new MvhdAtom(buffer, offset);
+            return new MovieHeaderAtom(buffer, offset);
         case 'tkhd':
-            return new TkhdAtom(buffer, offset);
+            return new TrackHeaderAtom(buffer, offset);
         case 'mdhd':
-            return new MdhdAtom(buffer, offset);
+            return new MediaHeaderAtom(buffer, offset);
+        case 'stss':
+            return new SyncSampleAtom(buffer, offset);
+        case 'stts':
+            return new TimeToSampleAtom(buffer, offset);
         default:
             return new Atom(buffer, offset);
     }
 }
 
-Atom.prototype.setDefaults = function()
-{
-    Object.defineProperty(this, "is64bit", { 
+Atom.prototype.setDefaults = function() {
+    Object.defineProperty(this, "is64bit", {
             value: false,
             writable: true,
             enumerable: false,
             configurable: true,
         });
-    Object.defineProperty(this, "minimumSize", { 
+    Object.defineProperty(this, "minimumSize", {
             value: 8,
             writable: true,
             enumerable: false,
             configurable: true,
         });
-    Object.defineProperty(this, "parent", { 
+    Object.defineProperty(this, "parent", {
             value: null,
             writable: true,
             enumerable: false,
@@ -59,39 +61,39 @@ Atom.prototype.setDefaults = function()
     this.type = '';
 }
 
-Atom.prototype.parse = function(buffer, offset)
-{
+Atom.prototype.parse = function(buffer, offset) {
     // 'offset' is optional.
-    if (arguments.length < 2)
+    if (typeof(offset) == 'undefined')
         offset = 0;
 
-    // Atoms are 8 bytes minimum.
-    if (buffer.byteLength - offset < 8)
-        return false;
+    if (buffer.byteLength - offset < this.minimumSize)
+        return 0;
 
     var view = new DataView(buffer, offset, 4);
-    offset += 4;
+    headerOffset = 0;
+
     this.size = view.getUint32(0);
+    headerOffset += 4;
 
-    var typeArrayView = new Uint8Array(buffer, offset, 4);
-    offset += 4;
+    var typeArrayView = new Uint8Array(buffer, offset + headerOffset, 4);
     this.type = String.fromCharCode.apply(null, typeArrayView);
+    headerOffset += 4;
 
     if (this.size == 1) {
         this.is64bit = true;
         if (buffer.byteLength - offset < 8)
             return false;
 
-        // NOTE: JavaScript can only represent up to 2^53 as precise integer. 
+        // NOTE: JavaScript can only represent up to 2^53 as precise integer.
         // This calculation may result in incorrect values.
-        var view = new DataView(buffer, offset, 8);
-        offset += 8;
+        var view = new DataView(buffer, offset + headerOffset, 8);
         var upper = view.getUint32(0);
         var lower = view.getUint32(4);
         this.size = (upper << 32)  + lower;
+        headerOffset += 8;
     }
-    
-    return true;
+
+    return headerOffset;
 };
 
 Atom.prototype.getAtomByType = function(type) {
@@ -130,84 +132,106 @@ Atom.prototype.getAtomsByType = function(type) {
     return result;
 };
 
-var FtypAtom = function(buffer, offset) {
-    return Atom.prototype.constructor.call(this, buffer, offset);
+var FileTypeAtom = function(buffer, offset) {
+    Object.getPrototypeOf(FileTypeAtom.prototype).constructor.call(this, buffer, offset);
 }
 
-FtypAtom.prototype = Object.create(Atom.prototype);
+FileTypeAtom.prototype = Object.create(Atom.prototype);
 
-FtypAtom.prototype.setDefaults = function() {
-    Atom.prototype.setDefaults.call(this);
+FileTypeAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(FileTypeAtom.prototype).setDefaults.call(this);
     this.minimumSize = 16;
     this.brand = "";
     this.version = 0;
     this.compatible_brands = [];
 }
 
-FtypAtom.prototype.parse = function(buffer, offset) {
-    if (!Atom.prototype.parse.call(this, buffer, offset))
-        return false;
+FileTypeAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(FileTypeAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
 
-    var begin = offset;
-    var end = begin + this.size;
-    offset += this.is64bit ? 16 : 8;
+    var view = new DataView(buffer, offset, this.size);
 
-    var brandArrayView = new Uint8Array(buffer, offset, 4);
-    offset += 4;
+    var brandArrayView = new Uint8Array(buffer, offset + headerOffset, 4);
     this.brand = String.fromCharCode.apply(null, brandArrayView);
+    headerOffset += 4;
 
-    var view = new DataView(buffer, offset, 4);
-    offset += 4;
-    this.version = view.getUint32(0);
+    this.version = view.getUint32(headerOffset);
+    headerOffset += 4;
 
-    while (offset <= end - 4) {
-        var brandArrayView = new Uint8Array(buffer, offset, 4);
-        offset += 4;
+    while (headerOffset < this.size - 4) {
+        var brandArrayView = new Uint8Array(buffer, offset + headerOffset, 4);
         this.compatible_brands.push(String.fromCharCode.apply(null, brandArrayView));
+        headerOffset += 4;
     }
-    
+
     return true;
 }
 
 var ContainerAtom = function(buffer, offset) {
-    return Atom.prototype.constructor.call(this, buffer, offset);
+    Object.getPrototypeOf(ContainerAtom.prototype).constructor.call(this, buffer, offset);
 }
 
 ContainerAtom.prototype = Object.create(Atom.prototype);
 
-ContainerAtom.prototype.setDefaults = function()
-{
-    Atom.prototype.setDefaults.call(this);
+ContainerAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(ContainerAtom.prototype).setDefaults.call(this);
     this.childAtoms = [];
 }
 
 ContainerAtom.prototype.parse = function(buffer, offset) {
-    if (!Atom.prototype.parse.call(this, buffer, offset))
-        return false;
+    var headerOffset = Object.getPrototypeOf(ContainerAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
 
-    var begin = offset;
-    var end = begin + this.size;
-    offset += this.is64bit ? 16 : 8;
-
-    while (offset < end) {
-        var childAtom = Atom.create(buffer, offset);
+    while (headerOffset < this.size) {
+        var childAtom = Atom.create(buffer, offset + headerOffset);
         if (!childAtom)
             break;
-        offset += childAtom.size;
+        headerOffset += childAtom.size;
         this.childAtoms.push(childAtom);
         childAtom.parent = this;
     }
 }
 
-var MvhdAtom = function(buffer, offset) {
-    return Atom.prototype.constructor.call(this, buffer, offset);
+var VersionFlagsAtom = function(buffer, offset) {
+    Object.getPrototypeOf(VersionFlagsAtom.prototype).constructor.call(this, buffer, offset);
 }
 
-MvhdAtom.prototype = Object.create(Atom.prototype);
+VersionFlagsAtom.prototype = Object.create(Atom.prototype);
 
-MvhdAtom.prototype.setDefaults = function() {
-    Atom.prototype.setDefaults.call(this);
+VersionFlagsAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(VersionFlagsAtom.prototype).setDefaults.call(this);
     this.version = 0;
+    this.flags = 0;
+}
+
+VersionFlagsAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(VersionFlagsAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
+
+    var view = new DataView(buffer, offset);
+
+    this.version = view.getUint8(headerOffset);
+    headerOffset += 1;
+
+    // 'flags' is a 3-byte field, so retrieve from one extra byte and concatenate
+    this.flags = (view.getUint8(headerOffset) << 8) + view.getUint16(headerOffset + 1);
+    headerOffset += 3;
+
+    return headerOffset;
+}
+
+var MovieHeaderAtom = function(buffer, offset) {
+    return Object.getPrototypeOf(MovieHeaderAtom.prototype).constructor.call(this, buffer, offset);
+}
+
+MovieHeaderAtom.prototype = Object.create(VersionFlagsAtom.prototype);
+
+MovieHeaderAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(MovieHeaderAtom.prototype).setDefaults.call(this);
     this.creationTime = 0;
     this.modificationTime = 0;
     this.timeScale = 0;
@@ -222,18 +246,13 @@ MvhdAtom.prototype.setDefaults = function() {
     this.nextTrackID = 0;
 }
 
-MvhdAtom.prototype.parse = function(buffer, offset) {
-    if (!Atom.prototype.parse.call(this, buffer, offset))
-        return false;
+MovieHeaderAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(MovieHeaderAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
 
-    offset += this.is64bit ? 16 : 8;
-
-    var headerOffset = 0;
     var view = new DataView(buffer, offset);
 
-    this.version = view.getUint8(headerOffset);
-    headerOffset += 4;
-
     this.creationTime = new Date(view.getUint32(headerOffset)*1000 + Date.UTC(1904, 0, 1));
     headerOffset += 4;
 
@@ -242,10 +261,10 @@ MvhdAtom.prototype.parse = function(buffer, offset) {
 
     this.timeScale = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.duration  = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.preferredRate = view.getUint32(headerOffset) / (1 << 16);
     headerOffset += 4;
 
@@ -286,36 +305,34 @@ MvhdAtom.prototype.parse = function(buffer, offset) {
 
     this.previewTime = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.previewDuration = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.posterTime = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.selectionTime = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.selectionDuration = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.nextTrackID = view.getUint32(headerOffset);
     headerOffset += 4;
 
     return true;
 }
 
-var TkhdAtom = function(buffer, offset) {
-    return Atom.prototype.constructor.call(this, buffer, offset);
+var TrackHeaderAtom = function(buffer, offset) {
+    Object.getPrototypeOf(TrackHeaderAtom.prototype).constructor.call(this, buffer, offset);
 }
 
-TkhdAtom.prototype = Object.create(Atom.prototype);
+TrackHeaderAtom.prototype = Object.create(Atom.prototype);
+
+TrackHeaderAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(TrackHeaderAtom.prototype).setDefaults.call(this);
 
-TkhdAtom.prototype.setDefaults = function() {
-    Atom.prototype.setDefaults.call(this);
-    
-    this.version = 0;
-    this.flags = 0;
     this.creationTime = 0;
     this.modificationTime = 0;
     this.trackID = 0;
@@ -328,23 +345,13 @@ TkhdAtom.prototype.setDefaults = function() {
     this.height = 0;
 }
 
-TkhdAtom.prototype.parse = function(buffer, offset)
-{
-    if (!Atom.prototype.parse.call(this, buffer, offset))
-        return false;
+TrackHeaderAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(TrackHeaderAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
 
-    offset += this.is64bit ? 16 : 8;
-
-    var headerOffset = 0;
     var view = new DataView(buffer, offset);
 
-    this.version = view.getUint8(headerOffset);
-    headerOffset += 1;
-    
-    // 'flags' is a 3-byte field, so retrieve from one extra byte and concatenate
-    this.flags = (view.getUint8(headerOffset) << 8) + view.getUint16(headerOffset + 1);
-    headerOffset += 3;
-    
     this.creationTime = new Date(view.getUint32(headerOffset)*1000 + Date.UTC(1904, 0, 1));
     headerOffset += 4;
 
@@ -353,31 +360,31 @@ TkhdAtom.prototype.parse = function(buffer, offset)
 
     this.trackID = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     // Reserved
     // A 32-bit integer that is reserved for use by Apple. Set this field to 0.
     headerOffset += 4;
 
     this.duration = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     // Reserved
     // An 8-byte value that is reserved for use by Apple. Set this field to 0.
     headerOffset += 8;
-    
+
     this.layer = view.getUint16(headerOffset);
     headerOffset += 2;
-    
+
     this.alternateGroup = view.getUint16(headerOffset);
     headerOffset += 2;
 
     this.volume = view.getUint16(headerOffset) / (1 << 8);
     headerOffset += 2;
-    
+
     // Reserved
     // A 16-bit integer that is reserved for use by Apple. Set this field to 0.
     headerOffset += 2;
-    
+
     this.trackMatrix = new Array(3);
     // a, b, u:
     this.trackMatrix[0] = new Array(3);
@@ -405,25 +412,23 @@ TkhdAtom.prototype.parse = function(buffer, offset)
     headerOffset += 4;
     this.trackMatrix[2][2] = view.getUint32(headerOffset) / (1 << 30);
     headerOffset += 4;
-    
+
     this.width = view.getUint32(headerOffset) / (1 << 16);
     headerOffset += 4;
-    
+
     this.height = view.getUint32(headerOffset) / (1 << 16);
     headerOffset += 4;
 }
 
-var MdhdAtom = function(buffer, offset) {
-    return Atom.prototype.constructor.call(this, buffer, offset);
+var MediaHeaderAtom = function(buffer, offset) {
+    Object.getPrototypeOf(MediaHeaderAtom.prototype).constructor.call(this, buffer, offset);
 }
 
-MdhdAtom.prototype = Object.create(Atom.prototype);
+MediaHeaderAtom.prototype = Object.create(VersionFlagsAtom.prototype);
+
+MediaHeaderAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(MediaHeaderAtom.prototype).setDefaults.call(this);
 
-MdhdAtom.prototype.setDefaults = function() {
-    Atom.prototype.setDefaults.call(this);
-    
-    this.version = 0;
-    this.flags = 0;
     this.creationTime = 0;
     this.modificationTime = 0;
     this.timeScale = 0;
@@ -432,23 +437,13 @@ MdhdAtom.prototype.setDefaults = function() {
     this.quality = 0;
 }
 
-MdhdAtom.prototype.parse = function(buffer, offset)
-{
-    if (!Atom.prototype.parse.call(this, buffer, offset))
-        return false;
-
-    offset += this.is64bit ? 16 : 8;
+MediaHeaderAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(MediaHeaderAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
 
-    var headerOffset = 0;
     var view = new DataView(buffer, offset);
 
-    this.version = view.getUint8(headerOffset);
-    headerOffset += 1;
-    
-    // 'flags' is a 3-byte field, so retrieve from one extra byte and concatenate
-    this.flags = (view.getUint8(headerOffset) << 8) + view.getUint16(headerOffset + 1);
-    headerOffset += 3;
-    
     this.creationTime = new Date(view.getUint32(headerOffset)*1000 + Date.UTC(1904, 0, 1));
     headerOffset += 4;
 
@@ -457,13 +452,92 @@ MdhdAtom.prototype.parse = function(buffer, offset)
 
     this.timeScale = view.getUint32(headerOffset);
     headerOffset += 4;
-    
+
     this.duration = view.getUint32(headerOffset);
     headerOffset += 4;
-        
+
     this.language = view.getUint16(headerOffset);
     headerOffset += 2;
-    
+
     this.quality = view.getUint16(headerOffset);
     headerOffset += 2;
+}
+
+var SyncSampleAtom = function(buffer, offset) {
+    Object.getPrototypeOf(SyncSampleAtom.prototype).constructor.call(this, buffer, offset);
+}
+
+SyncSampleAtom.prototype = Object.create(Atom.prototype);
+
+SyncSampleAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(SyncSampleAtom.prototype).setDefaults.call(this);
+
+    this.version = 0;
+    this.flags = 0;
+    this.entries = 0;
+    this.syncSamples = [];
+}
+
+SyncSampleAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(SyncSampleAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
+
+    var view = new DataView(buffer, offset);
+
+    this.version = view.getUint8(headerOffset);
+    headerOffset += 1;
+
+    // 'flags' is a 3-byte field, so retrieve from one extra byte and concatenate
+    this.flags = (view.getUint8(headerOffset) << 8) + view.getUint16(headerOffset + 1);
+    headerOffset += 3;
+
+    this.entries = view.getUint32(headerOffset);
+    headerOffset += 4;
+
+    while (headerOffset < this.size) {
+        var sampleNumber = view.getUint32(headerOffset);
+        headerOffset += 4;
+        this.syncSamples.push(sampleNumber);
+    }
+}
+
+var TimeToSampleAtom = function(buffer, offset) {
+    Object.getPrototypeOf(TimeToSampleAtom.prototype).constructor.call(this, buffer, offset);
+}
+
+TimeToSampleAtom.prototype = Object.create(VersionFlagsAtom.prototype);
+
+TimeToSampleAtom.prototype.setDefaults = function() {
+    Object.getPrototypeOf(TimeToSampleAtom.prototype).setDefaults.call(this);
+
+    this.entries = 0;
+    
+    Object.defineProperty(this, "timeToSamples", {
+        value: [],
+        writable: true,
+        enumerable: false,
+        configurable: true,
+    });
+}
+
+TimeToSampleAtom.prototype.parse = function(buffer, offset) {
+    var headerOffset = Object.getPrototypeOf(TimeToSampleAtom.prototype).parse.call(this, buffer, offset);
+    if (!headerOffset)
+        return 0;
+
+    var view = new DataView(buffer, offset);
+
+    this.entries = view.getUint32(headerOffset);
+        headerOffset += 4;
+
+    while (headerOffset < this.size) {
+        var sampleCount = view.getUint32(headerOffset);
+        headerOffset += 4;
+
+        var sampleDuration = view.getUint32(headerOffset);
+        headerOffset += 4;
+
+        this.timeToSamples.push([sampleCount, sampleDuration]);
+    }
 }
\ No newline at end of file