.dcx file format: JavaScript parsing library

DCX is a simple extension of PCX image format allowing to bundle many PCX images (typically, pages of a document) in one file. It saw some limited use in DOS-era fax software, but was largely superseded with multi-page TIFFs and PDFs since then.

File extension

dcx

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of .dcx file format using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime 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-struct

Code

See the usage examples in the JavaScript notes.

Parse structure from an ArrayBuffer:

var arrayBuffer = ...;
var data = new PcxDcx(new KaitaiStream(arrayBuffer));

After that, one can get various attributes from the structure by accessing fields or properties like:

data.magic // => get magic

JavaScript source code to parse .dcx file format

PcxDcx.js

// 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(['kaitai-struct/KaitaiStream', './Pcx'], factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(require('kaitai-struct/KaitaiStream'), require('./Pcx'));
  } else {
    root.PcxDcx = factory(root.KaitaiStream, root.Pcx);
  }
}(this, function (KaitaiStream, Pcx) {
/**
 * DCX is a simple extension of PCX image format allowing to bundle
 * many PCX images (typically, pages of a document) in one file. It saw
 * some limited use in DOS-era fax software, but was largely
 * superseded with multi-page TIFFs and PDFs since then.
 */

var PcxDcx = (function() {
  function PcxDcx(_io, _parent, _root) {
    this._io = _io;
    this._parent = _parent;
    this._root = _root || this;

    this._read();
  }
  PcxDcx.prototype._read = function() {
    this.magic = this._io.readBytes(4);
    if (!((KaitaiStream.byteArrayCompare(this.magic, [177, 104, 222, 58]) == 0))) {
      throw new KaitaiStream.ValidationNotEqualError([177, 104, 222, 58], this.magic, this._io, "/seq/0");
    }
    this.files = []
    var i = 0;
    do {
      var _ = new PcxOffset(this._io, this, this._root);
      this.files.push(_);
      i++;
    } while (!(_.ofsBody == 0));
  }

  var PcxOffset = PcxDcx.PcxOffset = (function() {
    function PcxOffset(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    PcxOffset.prototype._read = function() {
      this.ofsBody = this._io.readU4le();
    }
    Object.defineProperty(PcxOffset.prototype, 'body', {
      get: function() {
        if (this._m_body !== undefined)
          return this._m_body;
        if (this.ofsBody != 0) {
          var _pos = this._io.pos;
          this._io.seek(this.ofsBody);
          this._m_body = new Pcx(this._io, this, null);
          this._io.seek(_pos);
        }
        return this._m_body;
      }
    });

    return PcxOffset;
  })();

  return PcxDcx;
})();
return PcxDcx;
}));