jsmediatags/build2/ID3v2TagReader.js

Media Tags Reader (ID3, MP4)

'use strict';

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function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }

function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }

function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function _createSuperInternal() { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }

function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }

function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }

function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {})); return true; } catch (e) { return false; } }

function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }

var MediaTagReader = require('./MediaTagReader');

var MediaFileReader = require('./MediaFileReader');

var ID3v2FrameReader = require('./ID3v2FrameReader');

var ID3_HEADER_SIZE = 10;

var ID3v2TagReader = /*#__PURE__*/function (_MediaTagReader) {
  _inherits(ID3v2TagReader, _MediaTagReader);

  var _super = _createSuper(ID3v2TagReader);

  function ID3v2TagReader() {
    _classCallCheck(this, ID3v2TagReader);

    return _super.apply(this, arguments);
  }

  _createClass(ID3v2TagReader, [{
    key: "_loadData",
    value: function _loadData(mediaFileReader, callbacks) {
      mediaFileReader.loadRange([6, 9], {
        onSuccess: function onSuccess() {
          mediaFileReader.loadRange( // The tag size does not include the header size.
          [0, ID3_HEADER_SIZE + mediaFileReader.getSynchsafeInteger32At(6) - 1], callbacks);
        },
        onError: callbacks.onError
      });
    }
  }, {
    key: "_parseData",
    value: function _parseData(data, tags) {
      var offset = 0;
      var major = data.getByteAt(offset + 3);

      if (major > 4) {
        return {
          "type": "ID3",
          "version": ">2.4",
          "tags": {}
        };
      }

      var revision = data.getByteAt(offset + 4);
      var unsynch = data.isBitSetAt(offset + 5, 7);
      var xheader = data.isBitSetAt(offset + 5, 6);
      var xindicator = data.isBitSetAt(offset + 5, 5);
      var size = data.getSynchsafeInteger32At(offset + 6);
      offset += 10;

      if (xheader) {
        // We skip the extended header and don't offer support for it right now.
        if (major === 4) {
          var xheadersize = data.getSynchsafeInteger32At(offset);
          offset += xheadersize;
        } else {
          var xheadersize = data.getLongAt(offset, true); // The 'Extended header size', currently 6 or 10 bytes, excludes itself.

          offset += xheadersize + 4;
        }
      }

      var id3 = {
        "type": "ID3",
        "version": '2.' + major + '.' + revision,
        "major": major,
        "revision": revision,
        "flags": {
          "unsynchronisation": unsynch,
          "extended_header": xheader,
          "experimental_indicator": xindicator,
          // TODO: footer_present
          "footer_present": false
        },
        "size": size,
        "tags": {}
      };

      if (tags) {
        var expandedTags = this._expandShortcutTags(tags);
      }

      var offsetEnd = size + 10
      /*header size*/
      ; // When this flag is set the entire tag needs to be un-unsynchronised
      // before parsing each individual frame. Individual frame sizes might not
      // take unsynchronisation into consideration when it's set on the tag
      // header.

      if (id3.flags.unsynchronisation) {
        data = ID3v2FrameReader.getUnsyncFileReader(data, offset, size);
        offset = 0;
        offsetEnd = data.getSize();
      }

      var frames = ID3v2FrameReader.readFrames(offset, offsetEnd, data, id3, expandedTags); // create shortcuts for most common data.

      for (var name in SHORTCUTS) {
        if (SHORTCUTS.hasOwnProperty(name)) {
          var frameData = this._getFrameData(frames, SHORTCUTS[name]);

          if (frameData) {
            id3.tags[name] = frameData;
          }
        }
      }

      for (var frame in frames) {
        if (frames.hasOwnProperty(frame)) {
          id3.tags[frame] = frames[frame];
        }
      }

      return id3;
    }
  }, {
    key: "_getFrameData",
    value: function _getFrameData(frames, ids) {
      var frame;

      for (var i = 0, id; id = ids[i]; i++) {
        if (id in frames) {
          if (frames[id] instanceof Array) {
            frame = frames[id][0];
          } else {
            frame = frames[id];
          }

          return frame.data;
        }
      }
    }
  }, {
    key: "getShortcuts",
    value: function getShortcuts() {
      return SHORTCUTS;
    }
  }], [{
    key: "getTagIdentifierByteRange",
    value: function getTagIdentifierByteRange() {
      // ID3 header
      return {
        offset: 0,
        length: ID3_HEADER_SIZE
      };
    }
  }, {
    key: "canReadTagFormat",
    value: function canReadTagFormat(tagIdentifier) {
      var id = String.fromCharCode.apply(String, tagIdentifier.slice(0, 3));
      return id === 'ID3';
    }
  }]);

  return ID3v2TagReader;
}(MediaTagReader);

var SHORTCUTS = {
  "title": ["TIT2", "TT2"],
  "artist": ["TPE1", "TP1"],
  "album": ["TALB", "TAL"],
  "year": ["TYER", "TYE"],
  "comment": ["COMM", "COM"],
  "track": ["TRCK", "TRK"],
  "genre": ["TCON", "TCO"],
  "picture": ["APIC", "PIC"],
  "lyrics": ["USLT", "ULT"]
};
module.exports = ID3v2TagReader;