This page hosts a formal specification of Microsoft AVI file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for JavaScript generated by Kaitai Struct depends on the JavaScript runtime library. You have to install it before you can parse data.
The JavaScript runtime library is available at npm:
npm install kaitai-structSee the usage examples in the JavaScript notes.
Parse structure from an ArrayBuffer:
var arrayBuffer = ...;
var data = new Avi(new KaitaiStream(arrayBuffer));
After that, one can get various attributes from the structure by accessing fields or properties like:
data.magic1 // => get magic1
// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
define(['exports', 'kaitai-struct/KaitaiStream'], factory);
} else if (typeof exports === 'object' && exports !== null && typeof exports.nodeType !== 'number') {
factory(exports, require('kaitai-struct/KaitaiStream'));
} else {
factory(root.Avi || (root.Avi = {}), root.KaitaiStream);
}
})(typeof self !== 'undefined' ? self : this, function (Avi_, KaitaiStream) {
/**
* @see {@link https://learn.microsoft.com/en-us/previous-versions/ms779636(v=vs.85)|Source}
*/
var Avi = (function() {
Avi.ChunkType = Object.freeze({
IDX1: 829973609,
JUNK: 1263424842,
INFO: 1330007625,
ISFT: 1413894985,
LIST: 1414744396,
STRF: 1718776947,
AVIH: 1751742049,
STRH: 1752331379,
MOVI: 1769369453,
HDRL: 1819436136,
STRL: 1819440243,
829973609: "IDX1",
1263424842: "JUNK",
1330007625: "INFO",
1413894985: "ISFT",
1414744396: "LIST",
1718776947: "STRF",
1751742049: "AVIH",
1752331379: "STRH",
1769369453: "MOVI",
1819436136: "HDRL",
1819440243: "STRL",
});
Avi.HandlerType = Object.freeze({
MP3: 85,
AC3: 8192,
DTS: 8193,
CVID: 1684633187,
XVID: 1684633208,
85: "MP3",
8192: "AC3",
8193: "DTS",
1684633187: "CVID",
1684633208: "XVID",
});
Avi.StreamType = Object.freeze({
MIDS: 1935960429,
VIDS: 1935960438,
AUDS: 1935963489,
TXTS: 1937012852,
1935960429: "MIDS",
1935960438: "VIDS",
1935963489: "AUDS",
1937012852: "TXTS",
});
function Avi(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root || this;
this._read();
}
Avi.prototype._read = function() {
this.magic1 = this._io.readBytes(4);
if (!((KaitaiStream.byteArrayCompare(this.magic1, new Uint8Array([82, 73, 70, 70])) == 0))) {
throw new KaitaiStream.ValidationNotEqualError(new Uint8Array([82, 73, 70, 70]), this.magic1, this._io, "/seq/0");
}
this.fileSize = this._io.readU4le();
this.magic2 = this._io.readBytes(4);
if (!((KaitaiStream.byteArrayCompare(this.magic2, new Uint8Array([65, 86, 73, 32])) == 0))) {
throw new KaitaiStream.ValidationNotEqualError(new Uint8Array([65, 86, 73, 32]), this.magic2, this._io, "/seq/2");
}
this._raw_data = this._io.readBytes(this.fileSize - 4);
var _io__raw_data = new KaitaiStream(this._raw_data);
this.data = new Blocks(_io__raw_data, this, this._root);
}
/**
* Main header of an AVI file, defined as AVIMAINHEADER structure
* @see {@link https://learn.microsoft.com/en-us/previous-versions/ms779632(v=vs.85)|Source}
*/
var AvihBody = Avi.AvihBody = (function() {
function AvihBody(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
AvihBody.prototype._read = function() {
this.microSecPerFrame = this._io.readU4le();
this.maxBytesPerSec = this._io.readU4le();
this.paddingGranularity = this._io.readU4le();
this.flags = this._io.readU4le();
this.totalFrames = this._io.readU4le();
this.initialFrames = this._io.readU4le();
this.streams = this._io.readU4le();
this.suggestedBufferSize = this._io.readU4le();
this.width = this._io.readU4le();
this.height = this._io.readU4le();
this.reserved = this._io.readBytes(16);
}
return AvihBody;
})();
var Block = Avi.Block = (function() {
function Block(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
Block.prototype._read = function() {
this.fourCc = this._io.readU4le();
this.blockSize = this._io.readU4le();
switch (this.fourCc) {
case Avi.ChunkType.AVIH:
this._raw_data = this._io.readBytes(this.blockSize);
var _io__raw_data = new KaitaiStream(this._raw_data);
this.data = new AvihBody(_io__raw_data, this, this._root);
break;
case Avi.ChunkType.LIST:
this._raw_data = this._io.readBytes(this.blockSize);
var _io__raw_data = new KaitaiStream(this._raw_data);
this.data = new ListBody(_io__raw_data, this, this._root);
break;
case Avi.ChunkType.STRH:
this._raw_data = this._io.readBytes(this.blockSize);
var _io__raw_data = new KaitaiStream(this._raw_data);
this.data = new StrhBody(_io__raw_data, this, this._root);
break;
default:
this.data = this._io.readBytes(this.blockSize);
break;
}
}
return Block;
})();
var Blocks = Avi.Blocks = (function() {
function Blocks(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
Blocks.prototype._read = function() {
this.entries = [];
var i = 0;
while (!this._io.isEof()) {
this.entries.push(new Block(this._io, this, this._root));
i++;
}
}
return Blocks;
})();
var ListBody = Avi.ListBody = (function() {
function ListBody(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
ListBody.prototype._read = function() {
this.listType = this._io.readU4le();
this.data = new Blocks(this._io, this, this._root);
}
return ListBody;
})();
var Rect = Avi.Rect = (function() {
function Rect(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
Rect.prototype._read = function() {
this.left = this._io.readS2le();
this.top = this._io.readS2le();
this.right = this._io.readS2le();
this.bottom = this._io.readS2le();
}
return Rect;
})();
/**
* Stream format description
*/
var StrfBody = Avi.StrfBody = (function() {
function StrfBody(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
StrfBody.prototype._read = function() {
}
return StrfBody;
})();
/**
* Stream header (one header per stream), defined as AVISTREAMHEADER structure
* @see {@link https://learn.microsoft.com/en-us/previous-versions/ms779638(v=vs.85)|Source}
*/
var StrhBody = Avi.StrhBody = (function() {
function StrhBody(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root;
this._read();
}
StrhBody.prototype._read = function() {
this.fccType = this._io.readU4le();
this.fccHandler = this._io.readU4le();
this.flags = this._io.readU4le();
this.priority = this._io.readU2le();
this.language = this._io.readU2le();
this.initialFrames = this._io.readU4le();
this.scale = this._io.readU4le();
this.rate = this._io.readU4le();
this.start = this._io.readU4le();
this.length = this._io.readU4le();
this.suggestedBufferSize = this._io.readU4le();
this.quality = this._io.readU4le();
this.sampleSize = this._io.readU4le();
this.frame = new Rect(this._io, this, this._root);
}
/**
* Type of the data contained in the stream
*/
/**
* Type of preferred data handler for the stream (specifies codec for audio / video streams)
*/
return StrhBody;
})();
return Avi;
})();
Avi_.Avi = Avi;
});