diff --git a/atom/atom.go b/atom/atom.go
index 8cf5f58..b97bac0 100644
--- a/atom/atom.go
+++ b/atom/atom.go
@@ -1,116 +1,3 @@
 
 package atom
 
-import (
-	"log"
-)
-
-type Atom interface {
-	CC4() string
-	Read(Reader) error
-}
-
-type Ftyp struct {
-}
-
-func (self Ftyp) CC4() string {
-	return "ftyp"
-}
-
-func (self Ftyp) Read(r Reader) (err error) {
-	log.Println("read ftyp")
-	return
-}
-
-type Moov struct {
-	*Mvhd
-	Trak []*Trak
-}
-
-func (self Moov) CC4() string {
-	return "moov"
-}
-
-func (self *Moov) Read(r Reader) (err error) {
-	var atom Atom
-	if atom, err = r.ReadAtom(&Mvhd{}); err != nil {
-		return
-	}
-	self.Mvhd = atom.(*Mvhd)
-
-	for {
-		if atom, err := r.ReadAtom(&Trak{}); err != nil {
-			break
-		} else {
-			self.Trak = append(self.Trak, atom.(*Trak))
-		}
-	}
-	return
-}
-
-type Mvhd struct {
-}
-
-func (self Mvhd) CC4() string {
-	return "mvhd"
-}
-
-func (self Mvhd) Read(r Reader) (err error) {
-	return
-}
-
-type Tkhd struct {
-}
-
-func (self Tkhd) CC4() string {
-	return "tkhd"
-}
-
-func (self *Tkhd) Read(r Reader) (err error) {
-	return
-}
-
-type Minf struct {
-}
-
-type Mdia struct {
-	*Minf
-}
-
-type Trak struct {
-	Tkhd []*Tkhd
-	*Mdia
-}
-
-func (self Trak) CC4() string {
-	return "tkhd"
-}
-
-func (self *Trak) Read(r Reader) (err error) {
-	return
-}
-
-// Time-to-Sample Atoms
-type Stts struct {
-}
-
-// Composition Offset Atom
-type Ctts struct {
-}
-
-// Sync Sample Atoms (Keyframe)
-type Stss struct {
-}
-
-// Sample-to-Chunk Atoms
-type Stsc struct {
-}
-
-// Sample Size Atoms
-type Stsz struct {
-}
-
-// Chunk Offset Atoms
-type Stco struct {
-}
-
diff --git a/atom/genAtomStruct.js b/atom/genAtomStruct.js
deleted file mode 100644
index 4431b5b..0000000
--- a/atom/genAtomStruct.js
+++ /dev/null
@@ -1,294 +0,0 @@
-
-var ucfirst = x => x.substr(0,1).toUpperCase() + x.slice(1);
-
-var D = (cls, prop, ...fields) => {
-	var ctor = function (args) {
-		this.cls = cls;
-		Object.assign(this, prop);
-		fields.forEach((f, i) => this[f] = typeof(args[i]) == 'string' ? ucfirst(args[i]) : args[i]);
-		if (cls == 'Atom' || cls == 'AtomPtr')
-			this.type = this.type + 'Atom';
-	};
-	global[cls] = (...args) => new ctor(args);
-}
-
-D('Int', {basic: true, type: 'int'}, 'name', 'len');
-D('Str', {basic: true, type: 'string'}, 'name', 'len');
-D('TimeStamp', {basic: true, type: 'TimeStamp'}, 'name', 'len');
-D('Bytes', {basic: true, type: '[]byte'}, 'name', 'len');
-D('Fixed32', {basic: true, type: 'Fixed32'}, 'name', 'len');
-
-D('Atom', {}, 'type', 'name');
-D('AtomPtr', {}, 'type', 'name');
-D('Struct', {}, 'type', 'name');
-D('StructPtr', {}, 'type', 'name');
-
-D('Arr', {}, 'name', 'elem', 'count');
-D('LenArr', {}, 'len', 'name', 'elem', 'isptr');
-
-D('Size', {hide: true}, 'len');
-D('_', {type: 'Dummy', hide: true}, 'len');
-
-var atoms = {
-	fileType: [
-		'ftyp',
-		AtomPtr('movie', 'movie'),
-	],
-
-	movie: [
-		'moov',
-		AtomPtr('movieHeader', 'header'),
-		Arr('tracks', AtomPtr('track')),
-	],
-
-	movieHeader: [
-		'mvhd',
-		Int('version', 1),
-		Int('flags', 3),
-		TimeStamp('cTime', 4),
-		TimeStamp('mTime', 4),
-		Int('timeScale', 4),
-		Int('duration', 4),
-		Int('preferredRate', 4),
-		Int('preferredVolume', 2),
-		_(10),
-		Bytes('matrix', 36),
-		TimeStamp('previewTime', 4),
-		TimeStamp('previewDuration', 4),
-		TimeStamp('posterTime', 4),
-		TimeStamp('selectionTime', 4),
-		TimeStamp('selectionDuration', 4),
-		TimeStamp('currentTime', 4),
-		Int('nextTrackId', 4),
-	],
-
-	track: [
-		'trak',
-		AtomPtr('trackHeader', 'header'),
-		AtomPtr('media', 'media'),
-	],
-
-	trackHeader: [
-		'tkhd',
-		Int('version', 1),
-		Int('flags', 3),
-		TimeStamp('cTime', 4),
-		TimeStamp('mTime', 4),
-		Int('trackId', 4),
-		_(4),
-		Int('duration', 4),
-		_(8),
-		Int('layer', 2),
-		Int('alternateGroup', 2),
-		Int('volume', 2),
-		_(2),
-		Bytes('matrix', 36),
-		Fixed32('trackWidth', 4),
-		Fixed32('trackHeight', 4),
-	],
-
-	media: [
-		'mdia',
-		AtomPtr('mediaHeader', 'header'),
-		AtomPtr('mediaInfo', 'info'),
-	],
-
-	mediaHeader: [
-		'mdhd',
-		Int('version', 1),
-		Int('flags', 3),
-		TimeStamp('cTime', 4),
-		TimeStamp('mTime', 4),
-		Int('timeScale', 4),
-		Int('duration', 4),
-		Int('language', 2),
-		Int('quality', 2),
-	],
-
-	mediaInfo: [
-		'minf',
-		AtomPtr('videoMediaInfo', 'video'),
-		AtomPtr('sampleTable', 'sample'),
-	],
-
-	videoMediaInfo: [
-		'vmhd',
-		Int('version', 1),
-		Int('flags', 3),
-		Int('graphicsMode', 2),
-		Arr('opcolor', Int('', 2), 3),
-	],
-
-	sampleTable: [
-		'stbl',
-		AtomPtr('sampleDesc', 'sampleDesc'),
-		AtomPtr('timeToSample', 'timeToSample'),
-		AtomPtr('compositionOffset', 'compositionOffset'),
-		AtomPtr('syncSample', 'syncSample'),
-		AtomPtr('sampleSize', 'sampleSize'),
-		AtomPtr('chunkOffset', 'chunkOffset'),
-	],
-
-	sampleDesc: [
-		'stsd',
-		Int('version', 1),
-		Int('flags', 3),
-		LenArr(4, 'entries', Struct('sampleDescEntry')),
-	],
-
-	timeToSample: [
-		'stts',
-		Int('version', 1),
-		Int('flags', 3),
-		LenArr(4, 'entries', Struct('timeToSampleEntry')),
-	],
-
-	compositionOffset: [
-		'ctts',
-		Int('version', 1),
-		Int('flags', 3),
-		LenArr(4, 'entries', Struct('compositionOffsetEntry')),
-	],
-
-	syncSample: [
-		'stss',
-		Int('version', 1),
-		Int('flags', 3),
-		LenArr(4, 'entries', Int('', 4)),
-	],
-
-	sampleSize: [
-		'stsz',
-		Int('version', 1),
-		Int('flags', 3),
-		LenArr(4, 'entries', Int('', 4)),
-	],
-
-	chunkOffset: [
-		'stco',
-		Int('version', 1),
-		Int('flags', 3),
-		LenArr(4, 'entries', Int('', 4)),
-	],
-};
-
-var structs = {
-	sampleDescEntry: [
-		Size(4),
-		Str('format', 4),
-		_(6),
-		Int('dataRefIdx', 2),
-		Bytes('data'),
-	],
-
-	timeToSampleEntry: [
-		Int('count', 4),
-		Int('duration', 4),
-	],
-
-	compositionOffsetEntry: [
-		Int('count', 4),
-		Int('offset', 4),
-	],
-};
-
-var typeStr = field => (
-	field.cls == 'AtomPtr' || field.cls == 'StructPtr') ? '*'+field.type : field.type;
-
-var dumpStruct = (name, list) => {
-	console.log(`type ${name} struct {
-		%s
-	}`, list
-		.filter(field => !field.hide)
-		.map(field => {
-			if (field.cls == 'Arr' || field.cls == 'LenArr')
-				return field.name +' []'+typeStr(field.elem);
-			return field.name+' '+typeStr(field)
-		}).join('\n')
-	);
-
-	dumpReadFn(name, null, false, list);
-};
-
-var dumpReadFn = (type, cc4, retptr, list) => {
-	var useSize;
-
-	if (retptr) {
-		console.log(`func Read${type}(r io.LimitedReader) (res *${type}, err error) {`);
-		console.log(`self := &${type}{}`);
-	} else {
-		console.log(`func Read${type}(r io.LimitedReader) (self ${type}, err error) {`);
-	}
-
-	list.forEach(field => {
-		if (field.cls == 'Size') {
-			useSize = true;
-			console.log(`size := ReadInt(r, ${field.len})`);
-		} else if (field.cls == 'Arr') {
-			var cond = field.count ? `i := 0; i < ${field.count}; i++` : `r.N > 0`;
-			console.log(`for ${cond} {`);
-			console.log(`var item ${typeStr(field.elem)}`);
-			console.log(`if item, err = Read${field.elem.type}(r); err != nil {
-				return
-			} else {
-				self.${field.name} = append(self.${field.name}, item)
-			}`);
-			console.log(`}`);
-		} else if (field.cls == 'LenArr') {
-			console.log(`if n, err := ReadInt(r, ${field.len}); err != nil {
-				return nil, err
-			} else {
-				for i := 0; i < n; i++ {
-					self.${field.name} = append(self.${field.name}, item)
-				}
-			}`);
-		} else {
-			var fn = field.basic ? field.cls : field.type;
-			var args = field.basic ? 'r, ' + field.len : 'r';
-			console.log(`if self.${field.name}, err = Read${fn}(${args}); err != nil {
-				return
-			}`);
-		}
-	});
-
-	if (retptr) {
-		console.log(`res = self`);
-	}
-	console.log(`return`);
-	console.log(`}`);
-};
-
-var dumpWriteFn = (name, list) => {
-	var useSize;
-
-	console.log(`func Write${name}(w Writer, atom ${name}) (err error) {`);
-
-	list.map(x => {
-		if (x.type == 'size') {
-			useSize = true;
-			return `ReadInt(r, ${x.len})`;
-		}
-	});
-
-	console.log(`}`);
-};
-
-console.log('// THIS FILE IS AUTO GENERATED');
-console.log('');
-console.log('package atom');
-
-for (var k in atoms) {
-	var list = atoms[k];
-	var name = ucfirst(k)+'Atom';
-
-	var cc4 = list[0];
-	list = list.slice(1);
-	dumpStruct(name, list);
-	dumpReadFn(name, cc4, true, list);
-}
-
-for (var k in structs) {
-	var list = structs[k];
-	dumpStruct(ucfirst(k), list)
-}
-
diff --git a/atom/genStruct.js b/atom/genStruct.js
new file mode 100644
index 0000000..94b2fa2
--- /dev/null
+++ b/atom/genStruct.js
@@ -0,0 +1,354 @@
+
+var uc = x => x && x.substr(0,1).toUpperCase()+x.slice(1);
+Array.prototype.nonull = function () {
+	return this.filter(x => x);
+};
+
+var Int = (name,len) => {return {name:uc(name),len,type:'int',fn:'Int'}};
+var Str = (name,len) => {return {name:uc(name),len,type:'string',fn:'String'}};
+var TimeStamp = (name,len) => {return {name:uc(name),len,type:'TimeStamp',fn:'TimeStamp'}};
+var Bytes = (name,len) => {return {name:uc(name),len,type:'[]byte',fn:'Bytes'}};
+var BytesLeft = (name) => {return {name:uc(name),type:'[]byte',fn:'BytesLeft'}};
+var Fixed32 = (name,len) => {return {name:uc(name),len,type:'Fixed32',fn:'Fixed32'}};
+
+var Atom = (type,name) => {return {name:uc(name),type:uc(type)+'Atom',fn:uc(type)+'Atom'}};
+var AtomPtr = (type,name) => {return {name:uc(name),type:'*'+uc(type)+'Atom',fn:uc(type)+'Atom'}};
+
+var Struct = (type,name) => {return {name:uc(name),type:uc(type),fn:uc(type)}};
+var StructPtr = (type,name) => {return {name:uc(name),type:'*'+uc(type),fn:uc(type)}};
+
+var Arr = (name,elem,count) => {return {name:uc(name),elem,count,type:'[]'+elem.type}};
+var LenArr = (sizelen,name,elem) => {return {sizelen,name:uc(name),elem,type:'[]'+elem.type}};
+
+var Size = (len) => {return {len,hide:true,fn:'Int'}};
+var _ = (len) => {return {len,hide:true,fn:'Dummy'}};
+
+var atoms = {
+	fileType: [
+		'ftyp',
+		AtomPtr('movie', 'movie'),
+	],
+
+	movie: [
+		'moov',
+		AtomPtr('movieHeader', 'header'),
+		Arr('tracks', AtomPtr('track')),
+	],
+
+	movieHeader: [
+		'mvhd',
+		Int('version', 1),
+		Int('flags', 3),
+		TimeStamp('cTime', 4),
+		TimeStamp('mTime', 4),
+		Int('timeScale', 4),
+		Int('duration', 4),
+		Int('preferredRate', 4),
+		Int('preferredVolume', 2),
+		_(10),
+		Bytes('matrix', 36),
+		TimeStamp('previewTime', 4),
+		TimeStamp('previewDuration', 4),
+		TimeStamp('posterTime', 4),
+		TimeStamp('selectionTime', 4),
+		TimeStamp('selectionDuration', 4),
+		TimeStamp('currentTime', 4),
+		Int('nextTrackId', 4),
+	],
+
+	track: [
+		'trak',
+		AtomPtr('trackHeader', 'header'),
+		AtomPtr('media', 'media'),
+	],
+
+	trackHeader: [
+		'tkhd',
+		Int('version', 1),
+		Int('flags', 3),
+		TimeStamp('cTime', 4),
+		TimeStamp('mTime', 4),
+		Int('trackId', 4),
+		_(4),
+		Int('duration', 4),
+		_(8),
+		Int('layer', 2),
+		Int('alternateGroup', 2),
+		Int('volume', 2),
+		_(2),
+		Bytes('matrix', 36),
+		Fixed32('trackWidth', 4),
+		Fixed32('trackHeight', 4),
+	],
+
+	media: [
+		'mdia',
+		AtomPtr('mediaHeader', 'header'),
+		AtomPtr('mediaInfo', 'info'),
+	],
+
+	mediaHeader: [
+		'mdhd',
+		Int('version', 1),
+		Int('flags', 3),
+		TimeStamp('cTime', 4),
+		TimeStamp('mTime', 4),
+		Int('timeScale', 4),
+		Int('duration', 4),
+		Int('language', 2),
+		Int('quality', 2),
+	],
+
+	mediaInfo: [
+		'minf',
+		AtomPtr('videoMediaInfo', 'video'),
+		AtomPtr('sampleTable', 'sample'),
+	],
+
+	videoMediaInfo: [
+		'vmhd',
+		Int('version', 1),
+		Int('flags', 3),
+		Int('graphicsMode', 2),
+		Arr('opcolor', Int('', 2), 3),
+	],
+
+	sampleTable: [
+		'stbl',
+		AtomPtr('sampleDesc', 'sampleDesc'),
+		AtomPtr('timeToSample', 'timeToSample'),
+		AtomPtr('compositionOffset', 'compositionOffset'),
+		AtomPtr('syncSample', 'syncSample'),
+		AtomPtr('sampleSize', 'sampleSize'),
+		AtomPtr('chunkOffset', 'chunkOffset'),
+	],
+
+	sampleDesc: [
+		'stsd',
+		Int('version', 1),
+		Int('flags', 3),
+		LenArr(4, 'entries', Struct('sampleDescEntry')),
+	],
+
+	timeToSample: [
+		'stts',
+		Int('version', 1),
+		Int('flags', 3),
+		LenArr(4, 'entries', Struct('timeToSampleEntry')),
+	],
+
+	compositionOffset: [
+		'ctts',
+		Int('version', 1),
+		Int('flags', 3),
+		LenArr(4, 'entries', Struct('compositionOffsetEntry')),
+	],
+
+	syncSample: [
+		'stss',
+		Int('version', 1),
+		Int('flags', 3),
+		LenArr(4, 'entries', Int('', 4)),
+	],
+
+	sampleSize: [
+		'stsz',
+		Int('version', 1),
+		Int('flags', 3),
+		LenArr(4, 'entries', Int('', 4)),
+	],
+
+	chunkOffset: [
+		'stco',
+		Int('version', 1),
+		Int('flags', 3),
+		LenArr(4, 'entries', Int('', 4)),
+	],
+};
+
+var structs = {
+	sampleDescEntry: [
+		Size(4),
+		Str('format', 4),
+		_(6),
+		Int('dataRefIdx', 2),
+		BytesLeft('data'),
+	],
+
+	timeToSampleEntry: [
+		Int('count', 4),
+		Int('duration', 4),
+	],
+
+	compositionOffsetEntry: [
+		Int('count', 4),
+		Int('offset', 4),
+	],
+};
+
+var genReadStmts = (opts) => {
+	var stmts = [];
+
+	if (opts.resIsPtr)
+		stmts = stmts.concat([StrStmt(`self := &${opts.atomType}{}`)]);
+
+	var readElemStmts = field => {
+		var arr = 'self.'+field.name;
+		return [
+			DeclVar('item', field.elem.type),
+			CallCheckAssign('Read'+field.elem.fn, ['r', field.elem.len].nonull(), ['item']),
+			StrStmt(`${arr} = append(${arr}, item)`),
+		]
+	};
+
+	stmts = stmts.concat(opts.fields.map(field => {
+		if (field.sizelen) {
+			var arr = 'self.'+field.name;
+			return [
+				DeclVar('count', 'int'),
+				CallCheckAssign('ReadInt', ['r', field.sizelen], ['count']),
+				For(RangeN('i', 'count'), readElemStmts(field)),
+			];
+		} else if (field.elem) {
+			var cond = field.count ? RangeN('i', field.count) : StrStmt('r.N > 0');
+			return For(cond, readElemStmts(field));
+		} else if (!field.hide) {
+			return CallCheckAssign('Read'+field.fn, ['r', field.len].nonull(), ['self.'+field.name]);
+		}
+	}).nonull());
+
+	if (opts.resIsPtr)
+		stmts = stmts.concat([StrStmt(`res = self`)]);
+
+	return Func(
+		'Read'+opts.fnName,
+		[['r', '*io.LimitedReader']],
+		[[opts.resIsPtr?'res':'self', (opts.resIsPtr?'*':'')+opts.atomType], ['err', 'error']],
+		stmts
+	);
+};
+
+var D = (cls, ...fields) => {
+	global[cls] = (...args) => {
+		var obj = {cls: cls};
+		fields.forEach((k, i) => obj[k] = args[i]);
+		return obj;
+	};
+};
+
+D('Func', 'name', 'args', 'rets', 'body');
+D('CallCheckAssign', 'fn', 'args', 'rets');
+D('DeclVar', 'name', 'type');
+D('For', 'cond', 'body');
+D('RangeN', 'i', 'n');
+D('DeclStruct', 'name', 'body');
+D('StrStmt', 'content');
+
+var dumpFn = f => {
+	var dumpArgs = x => x.map(x => x.join(' ')).join(',');
+	return `func ${f.name}(${dumpArgs(f.args)}) (${dumpArgs(f.rets)}) {
+		${dumpStmts(f.body)}
+		return
+	}`;
+};
+
+var dumpStmts = stmts => {
+	var dumpStmt = stmt => {
+		if (stmt instanceof Array) {
+			return dumpStmts(stmt);
+		} if (stmt.cls == 'CallCheckAssign') {
+			return `if ${stmt.rets.concat(['err']).join(',')} = ${stmt.fn}(${stmt.args.join(',')}); err != nil {
+				return
+			}`;
+		} else if (stmt.cls == 'DeclVar') {
+			return `var ${stmt.name} ${stmt.type}`;
+		} else if (stmt.cls == 'For') {
+			return `for ${dumpStmt(stmt.cond)} {
+				${dumpStmts(stmt.body)}
+			}`;
+		} else if (stmt.cls == 'RangeN') {
+			return `${stmt.i} := 0; ${stmt.i} < ${stmt.n}; ${stmt.i}++`;
+		} else if (stmt.cls == 'DeclStruct') {
+			return `type ${stmt.name} struct {
+				${stmt.body.map(line => line.join(' ')).join('\n')}
+			}`;
+		} else if (stmt.cls == 'Func') {
+			return dumpFn(stmt);
+		} else if (stmt.cls == 'StrStmt') {
+			return stmt.content;
+		}
+	};
+	return stmts.map(dumpStmt).join('\n')
+};
+
+(() => {
+	var len = 3;
+	var f = Func('Readxx', [['f', '*io.LimitedReader']], [['res', '*xx'], ['err', 'error']], [
+		CallCheckAssign('ReadInt', ['f', len], ['self.xx']),
+		CallCheckAssign('WriteInt', ['f', len], ['self.xx']),
+		DeclVar('n', 'int'),
+		For(RangeN('i', 'n'), [
+			CallCheckAssign('WriteInt', ['f', len], ['self.xx']),
+			DeclStruct('hi', [['a', 'b'], ['c', 'd'], ['e', 'f']]),
+		]),
+	]);
+	console.log(dumpFn(f));
+});
+
+var allStmts = () => {
+	var stmts = [];
+
+	var convStructFields = fields => {
+		var typeStr = field => (
+			field.cls == 'AtomPtr' || field.cls == 'StructPtr') ? '*'+field.type : field.type;
+
+		return fields.filter(field => !field.hide)
+		.map(field => {
+			if (field.cls == 'Arr' || field.cls == 'LenArr')
+				return [field.name, '[]'+typeStr(field.elem)];
+			return [field.name, typeStr(field)];
+		});
+	};
+
+	for (var k in atoms) {
+		var list = atoms[k];
+		var name = uc(k)+'Atom';
+		var cc4 = list[0];
+		var fields = list.slice(1);
+
+		stmts = stmts.concat([
+			DeclStruct(name, convStructFields(fields)),
+			genReadStmts({
+				cc4: cc4,
+				fields: fields,
+				fnName: name,
+				atomType: name,
+				resIsPtr: true,
+			}),
+		]);
+	}
+
+	for (var k in structs) {
+		var fields = structs[k];
+		var name = uc(k);
+
+		stmts = stmts.concat([
+			DeclStruct(name, convStructFields(fields)),
+			genReadStmts({
+				fields: fields,
+				fnName: name,
+				atomType: name,
+			}),
+		]);
+	}
+
+	return stmts;
+};
+
+console.log(`// THIS FILE IS AUTO GENERATED
+package atom
+import (
+	"io"
+)
+`, dumpStmts(allStmts()));
+
diff --git a/atom/reader.go b/atom/reader.go
index 188fd9f..4af4a3a 100644
--- a/atom/reader.go
+++ b/atom/reader.go
@@ -6,15 +6,24 @@ import (
 	"io/ioutil"
 )
 
-type Reader struct {
-	io.LimitedReader
+type Fixed32 uint32
+type TimeStamp uint32
+
+func ReadBytes(r io.Reader, n int) (res []byte, err error) {
+	res = make([]byte, n)
+	if n, err = r.Read(res); err != nil {
+		return
+	}
+	return
 }
 
-type Fixed32 uint32
+func ReadBytesLeft(r *io.LimitedReader) (res []byte, err error) {
+	return ReadBytes(r, int(r.N))
+}
 
-func (self Reader) ReadUInt(n int) (res uint, err error) {
-	b := make([]byte, n)
-	if n, err = self.Read(b); err != nil {
+func ReadUInt(r io.Reader, n int) (res uint, err error) {
+	var b []byte
+	if b, err = ReadBytes(r, n); err != nil {
 		return
 	}
 	for i := 0; i < n; i++ {
@@ -24,29 +33,48 @@ func (self Reader) ReadUInt(n int) (res uint, err error) {
 	return
 }
 
-func (self Reader) ReadInt(n int) (res int, err error) {
-	var resu uint
-	if resu, err = self.ReadUInt(n); err != nil {
+func ReadInt(r io.Reader, n int) (res int, err error) {
+	var ui uint
+	if ui, err = ReadUInt(r, n); err != nil {
 		return
 	}
-	res = int(resu)
+	res = int(ui)
 	return
 }
 
-func (self Reader) ReadString(n int) (res string, err error) {
-	b := make([]byte, n)
-	if n, err = self.Read(b); err != nil {
+func ReadFixed32(r io.Reader, n int) (res Fixed32, err error) {
+	var ui uint
+	if ui, err = ReadUInt(r, n); err != nil {
+		return
+	}
+	res = Fixed32(ui)
+	return
+}
+
+func ReadTimeStamp(r io.Reader, n int) (res TimeStamp, err error) {
+	var ui uint
+	if ui, err = ReadUInt(r, n); err != nil {
+		return
+	}
+	res = TimeStamp(ui)
+	return
+}
+
+func ReadString(r io.Reader, n int) (res string, err error) {
+	var b []byte
+	if b, err = ReadBytes(r, n); err != nil {
 		return
 	}
 	res = string(b)
 	return
 }
 
-func (self Reader) Skip(n int) (err error) {
-	_, err = io.CopyN(ioutil.Discard, self.Reader, int64(n))
+func ReadDummy(r io.Reader, n int) (res int, err error) {
+	_, err = io.CopyN(ioutil.Discard, r, int64(n))
 	return
 }
 
+/*
 func (self Reader) ReadAtom(atom Atom) (res Atom, err error) {
 	for {
 		var size int
@@ -83,4 +111,5 @@ func (self Reader) ReadAtom(atom Atom) (res Atom, err error) {
 		return
 	}
 }
+*/
 
diff --git a/atom/struct.go b/atom/struct.go
index 9a3fac8..f0a240f 100644
--- a/atom/struct.go
+++ b/atom/struct.go
@@ -1,134 +1,547 @@
+// THIS FILE IS AUTO GENERATED
 package atom
 
+import (
+	"io"
+)
+
 type FileTypeAtom struct {
-	Movie *Movie
+	Movie *MovieAtom
+}
+
+func ReadFileTypeAtom(r *io.LimitedReader) (res *FileTypeAtom, err error) {
+	self := &FileTypeAtom{}
+	if self.Movie, err = ReadMovieAtom(r); err != nil {
+		return
+	}
+	res = self
+	return
 }
 
 type MovieAtom struct {
-	MovieHeader *MovieHeader
+	Header *MovieHeaderAtom
+	Tracks []*TrackAtom
+}
+
+func ReadMovieAtom(r *io.LimitedReader) (res *MovieAtom, err error) {
+	self := &MovieAtom{}
+	if self.Header, err = ReadMovieHeaderAtom(r); err != nil {
+		return
+	}
+	for r.N > 0 {
+		var item *TrackAtom
+		if item, err = ReadTrackAtom(r); err != nil {
+			return
+		}
+		self.Tracks = append(self.Tracks, item)
+	}
+	res = self
+	return
 }
 
 type MovieHeaderAtom struct {
-	Version         int
-	Flags           int
-	CTime           Ts
-	MTime           Ts
-	TimeScale       int
-	Duration        int
-	PreferredRate   int
-	PreferredVolume int
-
+	Version           int
+	Flags             int
+	CTime             TimeStamp
+	MTime             TimeStamp
+	TimeScale         int
+	Duration          int
+	PreferredRate     int
+	PreferredVolume   int
 	Matrix            []byte
-	PreviewTime       Ts
-	PreviewDuration   Ts
-	PosterTime        Ts
-	SelectionTime     Ts
-	SelectionDuration Ts
-	CurrentTime       Ts
+	PreviewTime       TimeStamp
+	PreviewDuration   TimeStamp
+	PosterTime        TimeStamp
+	SelectionTime     TimeStamp
+	SelectionDuration TimeStamp
+	CurrentTime       TimeStamp
 	NextTrackId       int
 }
 
+func ReadMovieHeaderAtom(r *io.LimitedReader) (res *MovieHeaderAtom, err error) {
+	self := &MovieHeaderAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	if self.CTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.MTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.TimeScale, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Duration, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.PreferredRate, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.PreferredVolume, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	if self.Matrix, err = ReadBytes(r, 36); err != nil {
+		return
+	}
+	if self.PreviewTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.PreviewDuration, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.PosterTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.SelectionTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.SelectionDuration, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.CurrentTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.NextTrackId, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	res = self
+	return
+}
+
 type TrackAtom struct {
-	TrackHeader *TrackHeader
-	Media       *Media
+	Header *TrackHeaderAtom
+	Media  *MediaAtom
+}
+
+func ReadTrackAtom(r *io.LimitedReader) (res *TrackAtom, err error) {
+	self := &TrackAtom{}
+	if self.Header, err = ReadTrackHeaderAtom(r); err != nil {
+		return
+	}
+	if self.Media, err = ReadMediaAtom(r); err != nil {
+		return
+	}
+	res = self
+	return
 }
 
 type TrackHeaderAtom struct {
-	Version int
-	Flags   int
-	CTime   Ts
-	MTime   Ts
-	TrackId int
-
-	Duration int
-
+	Version        int
+	Flags          int
+	CTime          TimeStamp
+	MTime          TimeStamp
+	TrackId        int
+	Duration       int
 	Layer          int
 	AlternateGroup int
 	Volume         int
+	Matrix         []byte
+	TrackWidth     Fixed32
+	TrackHeight    Fixed32
+}
 
-	Matrix      []byte
-	TrackWidth  fixed32
-	TrackHeight fixed32
+func ReadTrackHeaderAtom(r *io.LimitedReader) (res *TrackHeaderAtom, err error) {
+	self := &TrackHeaderAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	if self.CTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.MTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.TrackId, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Duration, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Layer, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	if self.AlternateGroup, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	if self.Volume, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	if self.Matrix, err = ReadBytes(r, 36); err != nil {
+		return
+	}
+	if self.TrackWidth, err = ReadFixed32(r, 4); err != nil {
+		return
+	}
+	if self.TrackHeight, err = ReadFixed32(r, 4); err != nil {
+		return
+	}
+	res = self
+	return
 }
 
 type MediaAtom struct {
-	MediaHeader *MediaHeader
-	MediaInfo   *MediaInfo
+	Header *MediaHeaderAtom
+	Info   *MediaInfoAtom
+}
+
+func ReadMediaAtom(r *io.LimitedReader) (res *MediaAtom, err error) {
+	self := &MediaAtom{}
+	if self.Header, err = ReadMediaHeaderAtom(r); err != nil {
+		return
+	}
+	if self.Info, err = ReadMediaInfoAtom(r); err != nil {
+		return
+	}
+	res = self
+	return
 }
 
 type MediaHeaderAtom struct {
 	Version   int
 	Flags     int
-	CTime     Ts
-	MTime     Ts
+	CTime     TimeStamp
+	MTime     TimeStamp
 	TimeScale int
 	Duration  int
 	Language  int
 	Quality   int
 }
 
+func ReadMediaHeaderAtom(r *io.LimitedReader) (res *MediaHeaderAtom, err error) {
+	self := &MediaHeaderAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	if self.CTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.MTime, err = ReadTimeStamp(r, 4); err != nil {
+		return
+	}
+	if self.TimeScale, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Duration, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Language, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	if self.Quality, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	res = self
+	return
+}
+
 type MediaInfoAtom struct {
-	VideoMediaInfo *VideoMediaInfo
+	Video  *VideoMediaInfoAtom
+	Sample *SampleTableAtom
+}
+
+func ReadMediaInfoAtom(r *io.LimitedReader) (res *MediaInfoAtom, err error) {
+	self := &MediaInfoAtom{}
+	if self.Video, err = ReadVideoMediaInfoAtom(r); err != nil {
+		return
+	}
+	if self.Sample, err = ReadSampleTableAtom(r); err != nil {
+		return
+	}
+	res = self
+	return
 }
 
 type VideoMediaInfoAtom struct {
 	Version      int
 	Flags        int
 	GraphicsMode int
+	Opcolor      []int
+}
+
+func ReadVideoMediaInfoAtom(r *io.LimitedReader) (res *VideoMediaInfoAtom, err error) {
+	self := &VideoMediaInfoAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	if self.GraphicsMode, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	for i := 0; i < 3; i++ {
+		var item int
+		if item, err = ReadInt(r, 2); err != nil {
+			return
+		}
+		self.Opcolor = append(self.Opcolor, item)
+	}
+	res = self
+	return
 }
 
 type SampleTableAtom struct {
-	SampleDesc        *SampleDesc
-	TimeToSample      *TimeToSample
-	CompositionOffset *CompositionOffset
-	SyncSample        *SyncSample
-	SampleSize        *SampleSize
-	ChunkOffset       *ChunkOffset
+	SampleDesc        *SampleDescAtom
+	TimeToSample      *TimeToSampleAtom
+	CompositionOffset *CompositionOffsetAtom
+	SyncSample        *SyncSampleAtom
+	SampleSize        *SampleSizeAtom
+	ChunkOffset       *ChunkOffsetAtom
+}
+
+func ReadSampleTableAtom(r *io.LimitedReader) (res *SampleTableAtom, err error) {
+	self := &SampleTableAtom{}
+	if self.SampleDesc, err = ReadSampleDescAtom(r); err != nil {
+		return
+	}
+	if self.TimeToSample, err = ReadTimeToSampleAtom(r); err != nil {
+		return
+	}
+	if self.CompositionOffset, err = ReadCompositionOffsetAtom(r); err != nil {
+		return
+	}
+	if self.SyncSample, err = ReadSyncSampleAtom(r); err != nil {
+		return
+	}
+	if self.SampleSize, err = ReadSampleSizeAtom(r); err != nil {
+		return
+	}
+	if self.ChunkOffset, err = ReadChunkOffsetAtom(r); err != nil {
+		return
+	}
+	res = self
+	return
 }
 
 type SampleDescAtom struct {
 	Version int
 	Flags   int
+	Entries []SampleDescEntry
+}
+
+func ReadSampleDescAtom(r *io.LimitedReader) (res *SampleDescAtom, err error) {
+	self := &SampleDescAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	var count int
+	if count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	for i := 0; i < count; i++ {
+		var item SampleDescEntry
+		if item, err = ReadSampleDescEntry(r); err != nil {
+			return
+		}
+		self.Entries = append(self.Entries, item)
+	}
+	res = self
+	return
 }
 
 type TimeToSampleAtom struct {
 	Version int
 	Flags   int
+	Entries []TimeToSampleEntry
+}
+
+func ReadTimeToSampleAtom(r *io.LimitedReader) (res *TimeToSampleAtom, err error) {
+	self := &TimeToSampleAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	var count int
+	if count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	for i := 0; i < count; i++ {
+		var item TimeToSampleEntry
+		if item, err = ReadTimeToSampleEntry(r); err != nil {
+			return
+		}
+		self.Entries = append(self.Entries, item)
+	}
+	res = self
+	return
 }
 
 type CompositionOffsetAtom struct {
 	Version int
 	Flags   int
+	Entries []CompositionOffsetEntry
+}
+
+func ReadCompositionOffsetAtom(r *io.LimitedReader) (res *CompositionOffsetAtom, err error) {
+	self := &CompositionOffsetAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	var count int
+	if count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	for i := 0; i < count; i++ {
+		var item CompositionOffsetEntry
+		if item, err = ReadCompositionOffsetEntry(r); err != nil {
+			return
+		}
+		self.Entries = append(self.Entries, item)
+	}
+	res = self
+	return
 }
 
 type SyncSampleAtom struct {
 	Version int
 	Flags   int
+	Entries []int
+}
+
+func ReadSyncSampleAtom(r *io.LimitedReader) (res *SyncSampleAtom, err error) {
+	self := &SyncSampleAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	var count int
+	if count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	for i := 0; i < count; i++ {
+		var item int
+		if item, err = ReadInt(r, 4); err != nil {
+			return
+		}
+		self.Entries = append(self.Entries, item)
+	}
+	res = self
+	return
 }
 
 type SampleSizeAtom struct {
 	Version int
 	Flags   int
+	Entries []int
+}
+
+func ReadSampleSizeAtom(r *io.LimitedReader) (res *SampleSizeAtom, err error) {
+	self := &SampleSizeAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	var count int
+	if count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	for i := 0; i < count; i++ {
+		var item int
+		if item, err = ReadInt(r, 4); err != nil {
+			return
+		}
+		self.Entries = append(self.Entries, item)
+	}
+	res = self
+	return
 }
 
 type ChunkOffsetAtom struct {
 	Version int
 	Flags   int
+	Entries []int
 }
 
-type sampleDescEntry struct {
-	Format string
+func ReadChunkOffsetAtom(r *io.LimitedReader) (res *ChunkOffsetAtom, err error) {
+	self := &ChunkOffsetAtom{}
+	if self.Version, err = ReadInt(r, 1); err != nil {
+		return
+	}
+	if self.Flags, err = ReadInt(r, 3); err != nil {
+		return
+	}
+	var count int
+	if count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	for i := 0; i < count; i++ {
+		var item int
+		if item, err = ReadInt(r, 4); err != nil {
+			return
+		}
+		self.Entries = append(self.Entries, item)
+	}
+	res = self
+	return
+}
 
+type SampleDescEntry struct {
+	Format     string
 	DataRefIdx int
 	Data       []byte
 }
 
-type timeToSampleEntry struct {
+func ReadSampleDescEntry(r *io.LimitedReader) (self SampleDescEntry, err error) {
+	if self.Format, err = ReadString(r, 4); err != nil {
+		return
+	}
+	if self.DataRefIdx, err = ReadInt(r, 2); err != nil {
+		return
+	}
+	if self.Data, err = ReadBytesLeft(r); err != nil {
+		return
+	}
+	return
+}
+
+type TimeToSampleEntry struct {
 	Count    int
 	Duration int
 }
 
-type compositionOffsetEntry struct {
+func ReadTimeToSampleEntry(r *io.LimitedReader) (self TimeToSampleEntry, err error) {
+	if self.Count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Duration, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	return
+}
+
+type CompositionOffsetEntry struct {
 	Count  int
 	Offset int
 }
+
+func ReadCompositionOffsetEntry(r *io.LimitedReader) (self CompositionOffsetEntry, err error) {
+	if self.Count, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	if self.Offset, err = ReadInt(r, 4); err != nil {
+		return
+	}
+	return
+}