docs: function(segmentIndex, index, obj) {
        var file = obj;
  
        if (file.type === 'VIDEO' || file.type === 'AUDIO') {
          file = findSupportedSource(file);
        }
  
        if (file) {
          _bytesTotal += file.size;
          _files[segmentIndex].push(file);
        }
      }