kontainer-js/Matroska/index.js

A media file format generator/parser that exposes a React-like API.

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _slicedToArray2 = require('babel-runtime/helpers/slicedToArray');

var _slicedToArray3 = _interopRequireDefault(_slicedToArray2);

var _Element = require('./EBMLElement/Element');

var _Element2 = _interopRequireDefault(_Element);

var _ElementLookup = require('./ElementLookup');

var _ElementLookup2 = _interopRequireDefault(_ElementLookup);

var _Reader = require('../core/Reader');

var _Reader2 = _interopRequireDefault(_Reader);

var _Util = require('../core/Util');

var _Error = require('../core/Error');

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function getComponentClass(name) {
  return _ElementLookup2.default.lookupByName(name);
}

function parseTypeAndSize(buffer, offset) {
  var options = arguments.length <= 2 || arguments[2] === undefined ? {} : arguments[2];

  var _Element$parse = _Element2.default.parse(buffer, offset);

  var _Element$parse2 = (0, _slicedToArray3.default)(_Element$parse, 2);

  var readBytesNum = _Element$parse2[0];
  var props = _Element$parse2[1];

  var elementClass = _ElementLookup2.default.lookupById(props.elementId, !!options.ignoreUnknown);
  return [readBytesNum, elementClass, props.size === -1 ? -1 : readBytesNum + props.size];
}

function getRootWrapperClass() {
  return _ElementLookup2.default.lookupByName('File');
}

function skipBytes(buffer, offset) {
  for (var i = offset; i < buffer.length; i++) {
    try {
      var _Element$parse3 = _Element2.default.parse(buffer, i);

      var _Element$parse4 = (0, _slicedToArray3.default)(_Element$parse3, 2);

      var readBytesNum = _Element$parse4[0];
      var props = _Element$parse4[1];

      var elementClass = _ElementLookup2.default.lookupById(props.elementId, true);
      return i - offset;
    } catch (e) {
      continue;
    }
  }
  (0, _Util.throwException)('Matroska.skipBytes: Reached the end of buffer.');
}

function canParse(buffer, offset) {
  var readBytesNum = void 0,
      componentClass = void 0;

  try {
    var _parseTypeAndSize = parseTypeAndSize(buffer, offset);

    var _parseTypeAndSize2 = (0, _slicedToArray3.default)(_parseTypeAndSize, 2);

    readBytesNum = _parseTypeAndSize2[0];
    componentClass = _parseTypeAndSize2[1];

    if (componentClass) {
      var _componentClass$parse = componentClass.parse(buffer, offset);

      var _componentClass$parse2 = (0, _slicedToArray3.default)(_componentClass$parse, 1);

      readBytesNum = _componentClass$parse2[0];

      return true;
    }
  } catch (err) {
    if (componentClass && err.message === _Error.BufferReadError.ERROR_MESSAGE) {
      return true;
    }
  }
  return false;
}

exports.default = {
  name: 'webm',
  getComponentClass: getComponentClass,
  parseTypeAndSize: parseTypeAndSize,
  getRootWrapperClass: getRootWrapperClass,
  skipBytes: skipBytes,
  canParse: canParse
};