pdf.js/src/core/stream.js

/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* globals bytesToString, ColorSpace, Dict, EOF, error, info, isArray,
           Jbig2Image, JpegImage, JpxImage, Lexer, PDFJS, shadow, Util, warn */

'use strict';

var Stream = (function StreamClosure() {
  function Stream(arrayBuffer, start, length, dict) {
    this.bytes = (arrayBuffer instanceof Uint8Array ?
                  arrayBuffer : new Uint8Array(arrayBuffer));
    this.start = start || 0;
    this.pos = this.start;
    this.end = (start + length) || this.bytes.length;
    this.dict = dict;
  }

  // required methods for a stream. if a particular stream does not
  // implement these, an error should be thrown
  Stream.prototype = {
    get length() {
      return this.end - this.start;
    },
    get isEmpty() {
      return this.length === 0;
    },
    getByte: function Stream_getByte() {
      if (this.pos >= this.end) {
        return -1;
      }
      return this.bytes[this.pos++];
    },
    getUint16: function Stream_getUint16() {
      var b0 = this.getByte();
      var b1 = this.getByte();
      if (b0 === -1 || b1 === -1) {
        return -1;
      }
      return (b0 << 8) + b1;
    },
    getInt32: function Stream_getInt32() {
      var b0 = this.getByte();
      var b1 = this.getByte();
      var b2 = this.getByte();
      var b3 = this.getByte();
      return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
    },
    // returns subarray of original buffer
    // should only be read
    getBytes: function Stream_getBytes(length) {
      var bytes = this.bytes;
      var pos = this.pos;
      var strEnd = this.end;

      if (!length) {
        return bytes.subarray(pos, strEnd);
      }
      var end = pos + length;
      if (end > strEnd) {
        end = strEnd;
      }
      this.pos = end;
      return bytes.subarray(pos, end);
    },
    peekByte: function Stream_peekByte() {
      var peekedByte = this.getByte();
      this.pos--;
      return peekedByte;
    },
    peekBytes: function Stream_peekBytes(length) {
      var bytes = this.getBytes(length);
      this.pos -= bytes.length;
      return bytes;
    },
    skip: function Stream_skip(n) {
      if (!n) {
        n = 1;
      }
      this.pos += n;
    },
    reset: function Stream_reset() {
      this.pos = this.start;
    },
    moveStart: function Stream_moveStart() {
      this.start = this.pos;
    },
    makeSubStream: function Stream_makeSubStream(start, length, dict) {
      return new Stream(this.bytes.buffer, start, length, dict);
    },
    isStream: true
  };

  return Stream;
})();

var StringStream = (function StringStreamClosure() {
  function StringStream(str) {
    var length = str.length;
    var bytes = new Uint8Array(length);
    for (var n = 0; n < length; ++n) {
      bytes[n] = str.charCodeAt(n);
    }
    Stream.call(this, bytes);
  }

  StringStream.prototype = Stream.prototype;

  return StringStream;
})();

// super class for the decoding streams
var DecodeStream = (function DecodeStreamClosure() {
  // Lots of DecodeStreams are created whose buffers are never used.  For these
  // we share a single empty buffer. This is (a) space-efficient and (b) avoids
  // having special cases that would be required if we used |null| for an empty
  // buffer.
  var emptyBuffer = new Uint8Array(0);

  function DecodeStream(maybeMinBufferLength) {
    this.pos = 0;
    this.bufferLength = 0;
    this.eof = false;
    this.buffer = emptyBuffer;
    this.minBufferLength = 512;
    if (maybeMinBufferLength) {
      // Compute the first power of two that is as big as maybeMinBufferLength.
      while (this.minBufferLength < maybeMinBufferLength) {
        this.minBufferLength *= 2;
      }
    }
  }

  DecodeStream.prototype = {
    get isEmpty() {
      while (!this.eof && this.bufferLength === 0) {
        this.readBlock();
      }
      return this.bufferLength === 0;
    },
    ensureBuffer: function DecodeStream_ensureBuffer(requested) {
      var buffer = this.buffer;
      if (requested <= buffer.byteLength) {
        return buffer;
      }
      var size = this.minBufferLength;
      while (size < requested) {
        size *= 2;
      }
      var buffer2 = new Uint8Array(size);
      buffer2.set(buffer);
      return (this.buffer = buffer2);
    },
    getByte: function DecodeStream_getByte() {
      var pos = this.pos;
      while (this.bufferLength <= pos) {
        if (this.eof) {
          return -1;
        }
        this.readBlock();
      }
      return this.buffer[this.pos++];
    },
    getUint16: function DecodeStream_getUint16() {
      var b0 = this.getByte();
      var b1 = this.getByte();
      if (b0 === -1 || b1 === -1) {
        return -1;
      }
      return (b0 << 8) + b1;
    },
    getInt32: function DecodeStream_getInt32() {
      var b0 = this.getByte();
      var b1 = this.getByte();
      var b2 = this.getByte();
      var b3 = this.getByte();
      return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
    },
    getBytes: function DecodeStream_getBytes(length) {
      var end, pos = this.pos;

      if (length) {
        this.ensureBuffer(pos + length);
        end = pos + length;

        while (!this.eof && this.bufferLength < end) {
          this.readBlock();
        }
        var bufEnd = this.bufferLength;
        if (end > bufEnd) {
          end = bufEnd;
        }
      } else {
        while (!this.eof) {
          this.readBlock();
        }
        end = this.bufferLength;
      }

      this.pos = end;
      return this.buffer.subarray(pos, end);
    },
    peekByte: function DecodeStream_peekByte() {
      var peekedByte = this.getByte();
      this.pos--;
      return peekedByte;
    },
    peekBytes: function DecodeStream_peekBytes(length) {
      var bytes = this.getBytes(length);
      this.pos -= bytes.length;
      return bytes;
    },
    makeSubStream: function DecodeStream_makeSubStream(start, length, dict) {
      var end = start + length;
      while (this.bufferLength <= end && !this.eof) {
        this.readBlock();
      }
      return new Stream(this.buffer, start, length, dict);
    },
    skip: function DecodeStream_skip(n) {
      if (!n) {
        n = 1;
      }
      this.pos += n;
    },
    reset: function DecodeStream_reset() {
      this.pos = 0;
    },
    getBaseStreams: function DecodeStream_getBaseStreams() {
      if (this.str && this.str.getBaseStreams) {
        return this.str.getBaseStreams();
      }
      return [];
    }
  };

  return DecodeStream;
})();

var StreamsSequenceStream = (function StreamsSequenceStreamClosure() {
  function StreamsSequenceStream(streams) {
    this.streams = streams;
    DecodeStream.call(this, /* maybeLength = */ null);
  }

  StreamsSequenceStream.prototype = Object.create(DecodeStream.prototype);

  StreamsSequenceStream.prototype.readBlock =
      function streamSequenceStreamReadBlock() {

    var streams = this.streams;
    if (streams.length === 0) {
      this.eof = true;
      return;
    }
    var stream = streams.shift();
    var chunk = stream.getBytes();
    var bufferLength = this.bufferLength;
    var newLength = bufferLength + chunk.length;
    var buffer = this.ensureBuffer(newLength);
    buffer.set(chunk, bufferLength);
    this.bufferLength = newLength;
  };

  StreamsSequenceStream.prototype.getBaseStreams =
    function StreamsSequenceStream_getBaseStreams() {

    var baseStreams = [];
    for (var i = 0, ii = this.streams.length; i < ii; i++) {
      var stream = this.streams[i];
      if (stream.getBaseStreams) {
        Util.appendToArray(baseStreams, stream.getBaseStreams());
      }
    }
    return baseStreams;
  };

  return StreamsSequenceStream;
})();

var FlateStream = (function FlateStreamClosure() {
  var codeLenCodeMap = new Int32Array([
    16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
  ]);

  var lengthDecode = new Int32Array([
    0x00003, 0x00004, 0x00005, 0x00006, 0x00007, 0x00008, 0x00009, 0x0000a,
    0x1000b, 0x1000d, 0x1000f, 0x10011, 0x20013, 0x20017, 0x2001b, 0x2001f,
    0x30023, 0x3002b, 0x30033, 0x3003b, 0x40043, 0x40053, 0x40063, 0x40073,
    0x50083, 0x500a3, 0x500c3, 0x500e3, 0x00102, 0x00102, 0x00102
  ]);

  var distDecode = new Int32Array([
    0x00001, 0x00002, 0x00003, 0x00004, 0x10005, 0x10007, 0x20009, 0x2000d,
    0x30011, 0x30019, 0x40021, 0x40031, 0x50041, 0x50061, 0x60081, 0x600c1,
    0x70101, 0x70181, 0x80201, 0x80301, 0x90401, 0x90601, 0xa0801, 0xa0c01,
    0xb1001, 0xb1801, 0xc2001, 0xc3001, 0xd4001, 0xd6001
  ]);

  var fixedLitCodeTab = [new Int32Array([
    0x70100, 0x80050, 0x80010, 0x80118, 0x70110, 0x80070, 0x80030, 0x900c0,
    0x70108, 0x80060, 0x80020, 0x900a0, 0x80000, 0x80080, 0x80040, 0x900e0,
    0x70104, 0x80058, 0x80018, 0x90090, 0x70114, 0x80078, 0x80038, 0x900d0,
    0x7010c, 0x80068, 0x80028, 0x900b0, 0x80008, 0x80088, 0x80048, 0x900f0,
    0x70102, 0x80054, 0x80014, 0x8011c, 0x70112, 0x80074, 0x80034, 0x900c8,
    0x7010a, 0x80064, 0x80024, 0x900a8, 0x80004, 0x80084, 0x80044, 0x900e8,
    0x70106, 0x8005c, 0x8001c, 0x90098, 0x70116, 0x8007c, 0x8003c, 0x900d8,
    0x7010e, 0x8006c, 0x8002c, 0x900b8, 0x8000c, 0x8008c, 0x8004c, 0x900f8,
    0x70101, 0x80052, 0x80012, 0x8011a, 0x70111, 0x80072, 0x80032, 0x900c4,
    0x70109, 0x80062, 0x80022, 0x900a4, 0x80002, 0x80082, 0x80042, 0x900e4,
    0x70105, 0x8005a, 0x8001a, 0x90094, 0x70115, 0x8007a, 0x8003a, 0x900d4,
    0x7010d, 0x8006a, 0x8002a, 0x900b4, 0x8000a, 0x8008a, 0x8004a, 0x900f4,
    0x70103, 0x80056, 0x80016, 0x8011e, 0x70113, 0x80076, 0x80036, 0x900cc,
    0x7010b, 0x80066, 0x80026, 0x900ac, 0x80006, 0x80086, 0x80046, 0x900ec,
    0x70107, 0x8005e, 0x8001e, 0x9009c, 0x70117, 0x8007e, 0x8003e, 0x900dc,
    0x7010f, 0x8006e, 0x8002e, 0x900bc, 0x8000e, 0x8008e, 0x8004e, 0x900fc,
    0x70100, 0x80051, 0x80011, 0x80119, 0x70110, 0x80071, 0x80031, 0x900c2,
    0x70108, 0x80061, 0x80021, 0x900a2, 0x80001, 0x80081, 0x80041, 0x900e2,
    0x70104, 0x80059, 0x80019, 0x90092, 0x70114, 0x80079, 0x80039, 0x900d2,
    0x7010c, 0x80069, 0x80029, 0x900b2, 0x80009, 0x80089, 0x80049, 0x900f2,
    0x70102, 0x80055, 0x80015, 0x8011d, 0x70112, 0x80075, 0x80035, 0x900ca,
    0x7010a, 0x80065, 0x80025, 0x900aa, 0x80005, 0x80085, 0x80045, 0x900ea,
    0x70106, 0x8005d, 0x8001d, 0x9009a, 0x70116, 0x8007d, 0x8003d, 0x900da,
    0x7010e, 0x8006d, 0x8002d, 0x900ba, 0x8000d, 0x8008d, 0x8004d, 0x900fa,
    0x70101, 0x80053, 0x80013, 0x8011b, 0x70111, 0x80073, 0x80033, 0x900c6,
    0x70109, 0x80063, 0x80023, 0x900a6, 0x80003, 0x80083, 0x80043, 0x900e6,
    0x70105, 0x8005b, 0x8001b, 0x90096, 0x70115, 0x8007b, 0x8003b, 0x900d6,
    0x7010d, 0x8006b, 0x8002b, 0x900b6, 0x8000b, 0x8008b, 0x8004b, 0x900f6,
    0x70103, 0x80057, 0x80017, 0x8011f, 0x70113, 0x80077, 0x80037, 0x900ce,
    0x7010b, 0x80067, 0x80027, 0x900ae, 0x80007, 0x80087, 0x80047, 0x900ee,
    0x70107, 0x8005f, 0x8001f, 0x9009e, 0x70117, 0x8007f, 0x8003f, 0x900de,
    0x7010f, 0x8006f, 0x8002f, 0x900be, 0x8000f, 0x8008f, 0x8004f, 0x900fe,
    0x70100, 0x80050, 0x80010, 0x80118, 0x70110, 0x80070, 0x80030, 0x900c1,
    0x70108, 0x80060, 0x80020, 0x900a1, 0x80000, 0x80080, 0x80040, 0x900e1,
    0x70104, 0x80058, 0x80018, 0x90091, 0x70114, 0x80078, 0x80038, 0x900d1,
    0x7010c, 0x80068, 0x80028, 0x900b1, 0x80008, 0x80088, 0x80048, 0x900f1,
    0x70102, 0x80054, 0x80014, 0x8011c, 0x70112, 0x80074, 0x80034, 0x900c9,
    0x7010a, 0x80064, 0x80024, 0x900a9, 0x80004, 0x80084, 0x80044, 0x900e9,
    0x70106, 0x8005c, 0x8001c, 0x90099, 0x70116, 0x8007c, 0x8003c, 0x900d9,
    0x7010e, 0x8006c, 0x8002c, 0x900b9, 0x8000c, 0x8008c, 0x8004c, 0x900f9,
    0x70101, 0x80052, 0x80012, 0x8011a, 0x70111, 0x80072, 0x80032, 0x900c5,
    0x70109, 0x80062, 0x80022, 0x900a5, 0x80002, 0x80082, 0x80042, 0x900e5,
    0x70105, 0x8005a, 0x8001a, 0x90095, 0x70115, 0x8007a, 0x8003a, 0x900d5,
    0x7010d, 0x8006a, 0x8002a, 0x900b5, 0x8000a, 0x8008a, 0x8004a, 0x900f5,
    0x70103, 0x80056, 0x80016, 0x8011e, 0x70113, 0x80076, 0x80036, 0x900cd,
    0x7010b, 0x80066, 0x80026, 0x900ad, 0x80006, 0x80086, 0x80046, 0x900ed,
    0x70107, 0x8005e, 0x8001e, 0x9009d, 0x70117, 0x8007e, 0x8003e, 0x900dd,
    0x7010f, 0x8006e, 0x8002e, 0x900bd, 0x8000e, 0x8008e, 0x8004e, 0x900fd,
    0x70100, 0x80051, 0x80011, 0x80119, 0x70110, 0x80071, 0x80031, 0x900c3,
    0x70108, 0x80061, 0x80021, 0x900a3, 0x80001, 0x80081, 0x80041, 0x900e3,
    0x70104, 0x80059, 0x80019, 0x90093, 0x70114, 0x80079, 0x80039, 0x900d3,
    0x7010c, 0x80069, 0x80029, 0x900b3, 0x80009, 0x80089, 0x80049, 0x900f3,
    0x70102, 0x80055, 0x80015, 0x8011d, 0x70112, 0x80075, 0x80035, 0x900cb,
    0x7010a, 0x80065, 0x80025, 0x900ab, 0x80005, 0x80085, 0x80045, 0x900eb,
    0x70106, 0x8005d, 0x8001d, 0x9009b, 0x70116, 0x8007d, 0x8003d, 0x900db,
    0x7010e, 0x8006d, 0x8002d, 0x900bb, 0x8000d, 0x8008d, 0x8004d, 0x900fb,
    0x70101, 0x80053, 0x80013, 0x8011b, 0x70111, 0x80073, 0x80033, 0x900c7,
    0x70109, 0x80063, 0x80023, 0x900a7, 0x80003, 0x80083, 0x80043, 0x900e7,
    0x70105, 0x8005b, 0x8001b, 0x90097, 0x70115, 0x8007b, 0x8003b, 0x900d7,
    0x7010d, 0x8006b, 0x8002b, 0x900b7, 0x8000b, 0x8008b, 0x8004b, 0x900f7,
    0x70103, 0x80057, 0x80017, 0x8011f, 0x70113, 0x80077, 0x80037, 0x900cf,
    0x7010b, 0x80067, 0x80027, 0x900af, 0x80007, 0x80087, 0x80047, 0x900ef,
    0x70107, 0x8005f, 0x8001f, 0x9009f, 0x70117, 0x8007f, 0x8003f, 0x900df,
    0x7010f, 0x8006f, 0x8002f, 0x900bf, 0x8000f, 0x8008f, 0x8004f, 0x900ff
  ]), 9];

  var fixedDistCodeTab = [new Int32Array([
    0x50000, 0x50010, 0x50008, 0x50018, 0x50004, 0x50014, 0x5000c, 0x5001c,
    0x50002, 0x50012, 0x5000a, 0x5001a, 0x50006, 0x50016, 0x5000e, 0x00000,
    0x50001, 0x50011, 0x50009, 0x50019, 0x50005, 0x50015, 0x5000d, 0x5001d,
    0x50003, 0x50013, 0x5000b, 0x5001b, 0x50007, 0x50017, 0x5000f, 0x00000
  ]), 5];

  function FlateStream(str, maybeLength) {
    this.str = str;
    this.dict = str.dict;

    var cmf = str.getByte();
    var flg = str.getByte();
    if (cmf === -1 || flg === -1) {
      error('Invalid header in flate stream: ' + cmf + ', ' + flg);
    }
    if ((cmf & 0x0f) !== 0x08) {
      error('Unknown compression method in flate stream: ' + cmf + ', ' + flg);
    }
    if ((((cmf << 8) + flg) % 31) !== 0) {
      error('Bad FCHECK in flate stream: ' + cmf + ', ' + flg);
    }
    if (flg & 0x20) {
      error('FDICT bit set in flate stream: ' + cmf + ', ' + flg);
    }

    this.codeSize = 0;
    this.codeBuf = 0;

    DecodeStream.call(this, maybeLength);
  }

  FlateStream.prototype = Object.create(DecodeStream.prototype);

  FlateStream.prototype.getBits = function FlateStream_getBits(bits) {
    var str = this.str;
    var codeSize = this.codeSize;
    var codeBuf = this.codeBuf;

    var b;
    while (codeSize < bits) {
      if ((b = str.getByte()) === -1) {
        error('Bad encoding in flate stream');
      }
      codeBuf |= b << codeSize;
      codeSize += 8;
    }
    b = codeBuf & ((1 << bits) - 1);
    this.codeBuf = codeBuf >> bits;
    this.codeSize = codeSize -= bits;

    return b;
  };

  FlateStream.prototype.getCode = function FlateStream_getCode(table) {
    var str = this.str;
    var codes = table[0];
    var maxLen = table[1];
    var codeSize = this.codeSize;
    var codeBuf = this.codeBuf;

    var b;
    while (codeSize < maxLen) {
      if ((b = str.getByte()) === -1) {
        // premature end of stream. code might however still be valid.
        // codeSize < codeLen check below guards against incomplete codeVal.
        break;
      }
      codeBuf |= (b << codeSize);
      codeSize += 8;
    }
    var code = codes[codeBuf & ((1 << maxLen) - 1)];
    var codeLen = code >> 16;
    var codeVal = code & 0xffff;
    if (codeLen < 1 || codeSize < codeLen) {
      error('Bad encoding in flate stream');
    }
    this.codeBuf = (codeBuf >> codeLen);
    this.codeSize = (codeSize - codeLen);
    return codeVal;
  };

  FlateStream.prototype.generateHuffmanTable =
      function flateStreamGenerateHuffmanTable(lengths) {
    var n = lengths.length;

    // find max code length
    var maxLen = 0;
    var i;
    for (i = 0; i < n; ++i) {
      if (lengths[i] > maxLen) {
        maxLen = lengths[i];
      }
    }

    // build the table
    var size = 1 << maxLen;
    var codes = new Int32Array(size);
    for (var len = 1, code = 0, skip = 2;
         len <= maxLen;
         ++len, code <<= 1, skip <<= 1) {
      for (var val = 0; val < n; ++val) {
        if (lengths[val] === len) {
          // bit-reverse the code
          var code2 = 0;
          var t = code;
          for (i = 0; i < len; ++i) {
            code2 = (code2 << 1) | (t & 1);
            t >>= 1;
          }

          // fill the table entries
          for (i = code2; i < size; i += skip) {
            codes[i] = (len << 16) | val;
          }
          ++code;
        }
      }
    }

    return [codes, maxLen];
  };

  FlateStream.prototype.readBlock = function FlateStream_readBlock() {
    var buffer, len;
    var str = this.str;
    // read block header
    var hdr = this.getBits(3);
    if (hdr & 1) {
      this.eof = true;
    }
    hdr >>= 1;

    if (hdr === 0) { // uncompressed block
      var b;

      if ((b = str.getByte()) === -1) {
        error('Bad block header in flate stream');
      }
      var blockLen = b;
      if ((b = str.getByte()) === -1) {
        error('Bad block header in flate stream');
      }
      blockLen |= (b << 8);
      if ((b = str.getByte()) === -1) {
        error('Bad block header in flate stream');
      }
      var check = b;
      if ((b = str.getByte()) === -1) {
        error('Bad block header in flate stream');
      }
      check |= (b << 8);
      if (check !== (~blockLen & 0xffff) &&
          (blockLen !== 0 || check !== 0)) {
        // Ignoring error for bad "empty" block (see issue 1277)
        error('Bad uncompressed block length in flate stream');
      }

      this.codeBuf = 0;
      this.codeSize = 0;

      var bufferLength = this.bufferLength;
      buffer = this.ensureBuffer(bufferLength + blockLen);
      var end = bufferLength + blockLen;
      this.bufferLength = end;
      if (blockLen === 0) {
        if (str.peekByte() === -1) {
          this.eof = true;
        }
      } else {
        for (var n = bufferLength; n < end; ++n) {
          if ((b = str.getByte()) === -1) {
            this.eof = true;
            break;
          }
          buffer[n] = b;
        }
      }
      return;
    }

    var litCodeTable;
    var distCodeTable;
    if (hdr === 1) { // compressed block, fixed codes
      litCodeTable = fixedLitCodeTab;
      distCodeTable = fixedDistCodeTab;
    } else if (hdr === 2) { // compressed block, dynamic codes
      var numLitCodes = this.getBits(5) + 257;
      var numDistCodes = this.getBits(5) + 1;
      var numCodeLenCodes = this.getBits(4) + 4;

      // build the code lengths code table
      var codeLenCodeLengths = new Uint8Array(codeLenCodeMap.length);

      var i;
      for (i = 0; i < numCodeLenCodes; ++i) {
        codeLenCodeLengths[codeLenCodeMap[i]] = this.getBits(3);
      }
      var codeLenCodeTab = this.generateHuffmanTable(codeLenCodeLengths);

      // build the literal and distance code tables
      len = 0;
      i = 0;
      var codes = numLitCodes + numDistCodes;
      var codeLengths = new Uint8Array(codes);
      var bitsLength, bitsOffset, what;
      while (i < codes) {
        var code = this.getCode(codeLenCodeTab);
        if (code === 16) {
          bitsLength = 2; bitsOffset = 3; what = len;
        } else if (code === 17) {
          bitsLength = 3; bitsOffset = 3; what = (len = 0);
        } else if (code === 18) {
          bitsLength = 7; bitsOffset = 11; what = (len = 0);
        } else {
          codeLengths[i++] = len = code;
          continue;
        }

        var repeatLength = this.getBits(bitsLength) + bitsOffset;
        while (repeatLength-- > 0) {
          codeLengths[i++] = what;
        }
      }

      litCodeTable =
        this.generateHuffmanTable(codeLengths.subarray(0, numLitCodes));
      distCodeTable =
        this.generateHuffmanTable(codeLengths.subarray(numLitCodes, codes));
    } else {
      error('Unknown block type in flate stream');
    }

    buffer = this.buffer;
    var limit = buffer ? buffer.length : 0;
    var pos = this.bufferLength;
    while (true) {
      var code1 = this.getCode(litCodeTable);
      if (code1 < 256) {
        if (pos + 1 >= limit) {
          buffer = this.ensureBuffer(pos + 1);
          limit = buffer.length;
        }
        buffer[pos++] = code1;
        continue;
      }
      if (code1 === 256) {
        this.bufferLength = pos;
        return;
      }
      code1 -= 257;
      code1 = lengthDecode[code1];
      var code2 = code1 >> 16;
      if (code2 > 0) {
        code2 = this.getBits(code2);
      }
      len = (code1 & 0xffff) + code2;
      code1 = this.getCode(distCodeTable);
      code1 = distDecode[code1];
      code2 = code1 >> 16;
      if (code2 > 0) {
        code2 = this.getBits(code2);
      }
      var dist = (code1 & 0xffff) + code2;
      if (pos + len >= limit) {
        buffer = this.ensureBuffer(pos + len);
        limit = buffer.length;
      }
      for (var k = 0; k < len; ++k, ++pos) {
        buffer[pos] = buffer[pos - dist];
      }
    }
  };

  return FlateStream;
})();

var PredictorStream = (function PredictorStreamClosure() {
  function PredictorStream(str, maybeLength, params) {
    var predictor = this.predictor = params.get('Predictor') || 1;

    if (predictor <= 1) {
      return str; // no prediction
    }
    if (predictor !== 2 && (predictor < 10 || predictor > 15)) {
      error('Unsupported predictor: ' + predictor);
    }

    if (predictor === 2) {
      this.readBlock = this.readBlockTiff;
    } else {
      this.readBlock = this.readBlockPng;
    }

    this.str = str;
    this.dict = str.dict;

    var colors = this.colors = params.get('Colors') || 1;
    var bits = this.bits = params.get('BitsPerComponent') || 8;
    var columns = this.columns = params.get('Columns') || 1;

    this.pixBytes = (colors * bits + 7) >> 3;
    this.rowBytes = (columns * colors * bits + 7) >> 3;

    DecodeStream.call(this, maybeLength);
    return this;
  }

  PredictorStream.prototype = Object.create(DecodeStream.prototype);

  PredictorStream.prototype.readBlockTiff =
      function predictorStreamReadBlockTiff() {
    var rowBytes = this.rowBytes;

    var bufferLength = this.bufferLength;
    var buffer = this.ensureBuffer(bufferLength + rowBytes);

    var bits = this.bits;
    var colors = this.colors;

    var rawBytes = this.str.getBytes(rowBytes);
    this.eof = !rawBytes.length;
    if (this.eof) {
      return;
    }

    var inbuf = 0, outbuf = 0;
    var inbits = 0, outbits = 0;
    var pos = bufferLength;
    var i;

    if (bits === 1) {
      for (i = 0; i < rowBytes; ++i) {
        var c = rawBytes[i];
        inbuf = (inbuf << 8) | c;
        // bitwise addition is exclusive or
        // first shift inbuf and then add
        buffer[pos++] = (c ^ (inbuf >> colors)) & 0xFF;
        // truncate inbuf (assumes colors < 16)
        inbuf &= 0xFFFF;
      }
    } else if (bits === 8) {
      for (i = 0; i < colors; ++i) {
        buffer[pos++] = rawBytes[i];
      }
      for (; i < rowBytes; ++i) {
        buffer[pos] = buffer[pos - colors] + rawBytes[i];
        pos++;
      }
    } else {
      var compArray = new Uint8Array(colors + 1);
      var bitMask = (1 << bits) - 1;
      var j = 0, k = bufferLength;
      var columns = this.columns;
      for (i = 0; i < columns; ++i) {
        for (var kk = 0; kk < colors; ++kk) {
          if (inbits < bits) {
            inbuf = (inbuf << 8) | (rawBytes[j++] & 0xFF);
            inbits += 8;
          }
          compArray[kk] = (compArray[kk] +
                           (inbuf >> (inbits - bits))) & bitMask;
          inbits -= bits;
          outbuf = (outbuf << bits) | compArray[kk];
          outbits += bits;
          if (outbits >= 8) {
            buffer[k++] = (outbuf >> (outbits - 8)) & 0xFF;
            outbits -= 8;
          }
        }
      }
      if (outbits > 0) {
        buffer[k++] = (outbuf << (8 - outbits)) +
                      (inbuf & ((1 << (8 - outbits)) - 1));
      }
    }
    this.bufferLength += rowBytes;
  };

  PredictorStream.prototype.readBlockPng =
      function predictorStreamReadBlockPng() {

    var rowBytes = this.rowBytes;
    var pixBytes = this.pixBytes;

    var predictor = this.str.getByte();
    var rawBytes = this.str.getBytes(rowBytes);
    this.eof = !rawBytes.length;
    if (this.eof) {
      return;
    }

    var bufferLength = this.bufferLength;
    var buffer = this.ensureBuffer(bufferLength + rowBytes);

    var prevRow = buffer.subarray(bufferLength - rowBytes, bufferLength);
    if (prevRow.length === 0) {
      prevRow = new Uint8Array(rowBytes);
    }

    var i, j = bufferLength, up, c;
    switch (predictor) {
      case 0:
        for (i = 0; i < rowBytes; ++i) {
          buffer[j++] = rawBytes[i];
        }
        break;
      case 1:
        for (i = 0; i < pixBytes; ++i) {
          buffer[j++] = rawBytes[i];
        }
        for (; i < rowBytes; ++i) {
          buffer[j] = (buffer[j - pixBytes] + rawBytes[i]) & 0xFF;
          j++;
        }
        break;
      case 2:
        for (i = 0; i < rowBytes; ++i) {
          buffer[j++] = (prevRow[i] + rawBytes[i]) & 0xFF;
        }
        break;
      case 3:
        for (i = 0; i < pixBytes; ++i) {
          buffer[j++] = (prevRow[i] >> 1) + rawBytes[i];
        }
        for (; i < rowBytes; ++i) {
          buffer[j] = (((prevRow[i] + buffer[j - pixBytes]) >> 1) +
                           rawBytes[i]) & 0xFF;
          j++;
        }
        break;
      case 4:
        // we need to save the up left pixels values. the simplest way
        // is to create a new buffer
        for (i = 0; i < pixBytes; ++i) {
          up = prevRow[i];
          c = rawBytes[i];
          buffer[j++] = up + c;
        }
        for (; i < rowBytes; ++i) {
          up = prevRow[i];
          var upLeft = prevRow[i - pixBytes];
          var left = buffer[j - pixBytes];
          var p = left + up - upLeft;

          var pa = p - left;
          if (pa < 0) {
            pa = -pa;
          }
          var pb = p - up;
          if (pb < 0) {
            pb = -pb;
          }
          var pc = p - upLeft;
          if (pc < 0) {
            pc = -pc;
          }

          c = rawBytes[i];
          if (pa <= pb && pa <= pc) {
            buffer[j++] = left + c;
          } else if (pb <= pc) {
            buffer[j++] = up + c;
          } else {
            buffer[j++] = upLeft + c;
          }
        }
        break;
      default:
        error('Unsupported predictor: ' + predictor);
    }
    this.bufferLength += rowBytes;
  };

  return PredictorStream;
})();

/**
 * Depending on the type of JPEG a JpegStream is handled in different ways. For
 * JPEG's that are supported natively such as DeviceGray and DeviceRGB the image
 * data is stored and then loaded by the browser.  For unsupported JPEG's we use
 * a library to decode these images and the stream behaves like all the other
 * DecodeStreams.
 */
var JpegStream = (function JpegStreamClosure() {
  function JpegStream(stream, maybeLength, dict, xref) {
    // Some images may contain 'junk' before the SOI (start-of-image) marker.
    // Note: this seems to mainly affect inline images.
    var ch;
    while ((ch = stream.getByte()) !== -1) {
      if (ch === 0xFF) { // Find the first byte of the SOI marker (0xFFD8).
        stream.skip(-1); // Reset the stream position to the SOI.
        break;
      }
    }
    this.stream = stream;
    this.maybeLength = maybeLength;
    this.dict = dict;

    DecodeStream.call(this, maybeLength);
  }

  JpegStream.prototype = Object.create(DecodeStream.prototype);

  Object.defineProperty(JpegStream.prototype, 'bytes', {
    get: function JpegStream_bytes() {
      // If this.maybeLength is null, we'll get the entire stream.
      return shadow(this, 'bytes', this.stream.getBytes(this.maybeLength));
    },
    configurable: true
  });

  JpegStream.prototype.ensureBuffer = function JpegStream_ensureBuffer(req) {
    if (this.bufferLength) {
      return;
    }
    try {
      var jpegImage = new JpegImage();

      // checking if values needs to be transformed before conversion
      if (this.forceRGB && this.dict && isArray(this.dict.get('Decode'))) {
        var decodeArr = this.dict.get('Decode');
        var bitsPerComponent = this.dict.get('BitsPerComponent') || 8;
        var decodeArrLength = decodeArr.length;
        var transform = new Int32Array(decodeArrLength);
        var transformNeeded = false;
        var maxValue = (1 << bitsPerComponent) - 1;
        for (var i = 0; i < decodeArrLength; i += 2) {
          transform[i] = ((decodeArr[i + 1] - decodeArr[i]) * 256) | 0;
          transform[i + 1] = (decodeArr[i] * maxValue) | 0;
          if (transform[i] !== 256 || transform[i + 1] !== 0) {
            transformNeeded = true;
          }
        }
        if (transformNeeded) {
          jpegImage.decodeTransform = transform;
        }
      }

      jpegImage.parse(this.bytes);
      var data = jpegImage.getData(this.drawWidth, this.drawHeight,
                                   this.forceRGB);
      this.buffer = data;
      this.bufferLength = data.length;
      this.eof = true;
    } catch (e) {
      error('JPEG error: ' + e);
    }
  };

  JpegStream.prototype.getBytes = function JpegStream_getBytes(length) {
    this.ensureBuffer();
    return this.buffer;
  };

  JpegStream.prototype.getIR = function JpegStream_getIR() {
    return PDFJS.createObjectURL(this.bytes, 'image/jpeg');
  };
  /**
   * Checks if the image can be decoded and displayed by the browser without any
   * further processing such as color space conversions.
   */
  JpegStream.prototype.isNativelySupported =
      function JpegStream_isNativelySupported(xref, res) {
    var cs = ColorSpace.parse(this.dict.get('ColorSpace', 'CS'), xref, res);
    return (cs.name === 'DeviceGray' || cs.name === 'DeviceRGB') &&
           cs.isDefaultDecode(this.dict.get('Decode', 'D'));
  };
  /**
   * Checks if the image can be decoded by the browser.
   */
  JpegStream.prototype.isNativelyDecodable =
      function JpegStream_isNativelyDecodable(xref, res) {
    var cs = ColorSpace.parse(this.dict.get('ColorSpace', 'CS'), xref, res);
    return (cs.numComps === 1 || cs.numComps === 3) &&
           cs.isDefaultDecode(this.dict.get('Decode', 'D'));
  };

  return JpegStream;
})();

/**
 * For JPEG 2000's we use a library to decode these images and
 * the stream behaves like all the other DecodeStreams.
 */
var JpxStream = (function JpxStreamClosure() {
  function JpxStream(stream, maybeLength, dict) {
    this.stream = stream;
    this.maybeLength = maybeLength;
    this.dict = dict;

    DecodeStream.call(this, maybeLength);
  }

  JpxStream.prototype = Object.create(DecodeStream.prototype);

  Object.defineProperty(JpxStream.prototype, 'bytes', {
    get: function JpxStream_bytes() {
      // If this.maybeLength is null, we'll get the entire stream.
      return shadow(this, 'bytes', this.stream.getBytes(this.maybeLength));
    },
    configurable: true
  });

  JpxStream.prototype.ensureBuffer = function JpxStream_ensureBuffer(req) {
    if (this.bufferLength) {
      return;
    }

    var jpxImage = new JpxImage();
    jpxImage.parse(this.bytes);

    var width = jpxImage.width;
    var height = jpxImage.height;
    var componentsCount = jpxImage.componentsCount;
    var tileCount = jpxImage.tiles.length;
    if (tileCount === 1) {
      this.buffer = jpxImage.tiles[0].items;
    } else {
      var data = new Uint8Array(width * height * componentsCount);

      for (var k = 0; k < tileCount; k++) {
        var tileComponents = jpxImage.tiles[k];
        var tileWidth = tileComponents.width;
        var tileHeight = tileComponents.height;
        var tileLeft = tileComponents.left;
        var tileTop = tileComponents.top;

        var src = tileComponents.items;
        var srcPosition = 0;
        var dataPosition = (width * tileTop + tileLeft) * componentsCount;
        var imgRowSize = width * componentsCount;
        var tileRowSize = tileWidth * componentsCount;

        for (var j = 0; j < tileHeight; j++) {
          var rowBytes = src.subarray(srcPosition, srcPosition + tileRowSize);
          data.set(rowBytes, dataPosition);
          srcPosition += tileRowSize;
          dataPosition += imgRowSize;
        }
      }
      this.buffer = data;
    }
    this.bufferLength = this.buffer.length;
    this.eof = true;
  };

  return JpxStream;
})();

/**
 * For JBIG2's we use a library to decode these images and
 * the stream behaves like all the other DecodeStreams.
 */
var Jbig2Stream = (function Jbig2StreamClosure() {
  function Jbig2Stream(stream, maybeLength, dict) {
    this.stream = stream;
    this.maybeLength = maybeLength;
    this.dict = dict;

    DecodeStream.call(this, maybeLength);
  }

  Jbig2Stream.prototype = Object.create(DecodeStream.prototype);

  Object.defineProperty(Jbig2Stream.prototype, 'bytes', {
    get: function Jbig2Stream_bytes() {
      // If this.maybeLength is null, we'll get the entire stream.
      return shadow(this, 'bytes', this.stream.getBytes(this.maybeLength));
    },
    configurable: true
  });

  Jbig2Stream.prototype.ensureBuffer = function Jbig2Stream_ensureBuffer(req) {
    if (this.bufferLength) {
      return;
    }

    var jbig2Image = new Jbig2Image();

    var chunks = [], xref = this.dict.xref;
    var decodeParams = xref.fetchIfRef(this.dict.get('DecodeParms'));

    // According to the PDF specification, DecodeParms can be either
    // a dictionary, or an array whose elements are dictionaries.
    if (isArray(decodeParams)) {
      if (decodeParams.length > 1) {
        warn('JBIG2 - \'DecodeParms\' array with multiple elements ' +
             'not supported.');
      }
      decodeParams = xref.fetchIfRef(decodeParams[0]);
    }
    if (decodeParams && decodeParams.has('JBIG2Globals')) {
      var globalsStream = decodeParams.get('JBIG2Globals');
      var globals = globalsStream.getBytes();
      chunks.push({data: globals, start: 0, end: globals.length});
    }
    chunks.push({data: this.bytes, start: 0, end: this.bytes.length});
    var data = jbig2Image.parseChunks(chunks);
    var dataLength = data.length;

    // JBIG2 had black as 1 and white as 0, inverting the colors
    for (var i = 0; i < dataLength; i++) {
      data[i] ^= 0xFF;
    }

    this.buffer = data;
    this.bufferLength = dataLength;
    this.eof = true;
  };

  return Jbig2Stream;
})();

var DecryptStream = (function DecryptStreamClosure() {
  function DecryptStream(str, maybeLength, decrypt) {
    this.str = str;
    this.dict = str.dict;
    this.decrypt = decrypt;
    this.nextChunk = null;
    this.initialized = false;

    DecodeStream.call(this, maybeLength);
  }

  var chunkSize = 512;

  DecryptStream.prototype = Object.create(DecodeStream.prototype);

  DecryptStream.prototype.readBlock = function DecryptStream_readBlock() {
    var chunk;
    if (this.initialized) {
      chunk = this.nextChunk;
    } else {
      chunk = this.str.getBytes(chunkSize);
      this.initialized = true;
    }
    if (!chunk || chunk.length === 0) {
      this.eof = true;
      return;
    }
    this.nextChunk = this.str.getBytes(chunkSize);
    var hasMoreData = this.nextChunk && this.nextChunk.length > 0;

    var decrypt = this.decrypt;
    chunk = decrypt(chunk, !hasMoreData);

    var bufferLength = this.bufferLength;
    var i, n = chunk.length;
    var buffer = this.ensureBuffer(bufferLength + n);
    for (i = 0; i < n; i++) {
      buffer[bufferLength++] = chunk[i];
    }
    this.bufferLength = bufferLength;
  };

  return DecryptStream;
})();

var Ascii85Stream = (function Ascii85StreamClosure() {
  function Ascii85Stream(str, maybeLength) {
    this.str = str;
    this.dict = str.dict;
    this.input = new Uint8Array(5);

    // Most streams increase in size when decoded, but Ascii85 streams
    // typically shrink by ~20%.
    if (maybeLength) {
      maybeLength = 0.8 * maybeLength;
    }
    DecodeStream.call(this, maybeLength);
  }

  Ascii85Stream.prototype = Object.create(DecodeStream.prototype);

  Ascii85Stream.prototype.readBlock = function Ascii85Stream_readBlock() {
    var TILDA_CHAR = 0x7E; // '~'
    var Z_LOWER_CHAR = 0x7A; // 'z'
    var EOF = -1;

    var str = this.str;

    var c = str.getByte();
    while (Lexer.isSpace(c)) {
      c = str.getByte();
    }

    if (c === EOF || c === TILDA_CHAR) {
      this.eof = true;
      return;
    }

    var bufferLength = this.bufferLength, buffer;
    var i;

    // special code for z
    if (c === Z_LOWER_CHAR) {
      buffer = this.ensureBuffer(bufferLength + 4);
      for (i = 0; i < 4; ++i) {
        buffer[bufferLength + i] = 0;
      }
      this.bufferLength += 4;
    } else {
      var input = this.input;
      input[0] = c;
      for (i = 1; i < 5; ++i) {
        c = str.getByte();
        while (Lexer.isSpace(c)) {
          c = str.getByte();
        }

        input[i] = c;

        if (c === EOF || c === TILDA_CHAR) {
          break;
        }
      }
      buffer = this.ensureBuffer(bufferLength + i - 1);
      this.bufferLength += i - 1;

      // partial ending;
      if (i < 5) {
        for (; i < 5; ++i) {
          input[i] = 0x21 + 84;
        }
        this.eof = true;
      }
      var t = 0;
      for (i = 0; i < 5; ++i) {
        t = t * 85 + (input[i] - 0x21);
      }

      for (i = 3; i >= 0; --i) {
        buffer[bufferLength + i] = t & 0xFF;
        t >>= 8;
      }
    }
  };

  return Ascii85Stream;
})();

var AsciiHexStream = (function AsciiHexStreamClosure() {
  function AsciiHexStream(str, maybeLength) {
    this.str = str;
    this.dict = str.dict;

    this.firstDigit = -1;

    // Most streams increase in size when decoded, but AsciiHex streams shrink
    // by 50%.
    if (maybeLength) {
      maybeLength = 0.5 * maybeLength;
    }
    DecodeStream.call(this, maybeLength);
  }

  AsciiHexStream.prototype = Object.create(DecodeStream.prototype);

  AsciiHexStream.prototype.readBlock = function AsciiHexStream_readBlock() {
    var UPSTREAM_BLOCK_SIZE = 8000;
    var bytes = this.str.getBytes(UPSTREAM_BLOCK_SIZE);
    if (!bytes.length) {
      this.eof = true;
      return;
    }

    var maxDecodeLength = (bytes.length + 1) >> 1;
    var buffer = this.ensureBuffer(this.bufferLength + maxDecodeLength);
    var bufferLength = this.bufferLength;

    var firstDigit = this.firstDigit;
    for (var i = 0, ii = bytes.length; i < ii; i++) {
      var ch = bytes[i], digit;
      if (ch >= 0x30 && ch <= 0x39) { // '0'-'9'
        digit = ch & 0x0F;
      } else if ((ch >= 0x41 && ch <= 0x46) || (ch >= 0x61 && ch <= 0x66)) {
        // 'A'-'Z', 'a'-'z'
        digit = (ch & 0x0F) + 9;
      } else if (ch === 0x3E) { // '>'
        this.eof = true;
        break;
      } else { // probably whitespace
        continue; // ignoring
      }
      if (firstDigit < 0) {
        firstDigit = digit;
      } else {
        buffer[bufferLength++] = (firstDigit << 4) | digit;
        firstDigit = -1;
      }
    }
    if (firstDigit >= 0 && this.eof) {
      // incomplete byte
      buffer[bufferLength++] = (firstDigit << 4);
      firstDigit = -1;
    }
    this.firstDigit = firstDigit;
    this.bufferLength = bufferLength;
  };

  return AsciiHexStream;
})();

var RunLengthStream = (function RunLengthStreamClosure() {
  function RunLengthStream(str, maybeLength) {
    this.str = str;
    this.dict = str.dict;

    DecodeStream.call(this, maybeLength);
  }

  RunLengthStream.prototype = Object.create(DecodeStream.prototype);

  RunLengthStream.prototype.readBlock = function RunLengthStream_readBlock() {
    // The repeatHeader has following format. The first byte defines type of run
    // and amount of bytes to repeat/copy: n = 0 through 127 - copy next n bytes
    // (in addition to the second byte from the header), n = 129 through 255 -
    // duplicate the second byte from the header (257 - n) times, n = 128 - end.
    var repeatHeader = this.str.getBytes(2);
    if (!repeatHeader || repeatHeader.length < 2 || repeatHeader[0] === 128) {
      this.eof = true;
      return;
    }

    var buffer;
    var bufferLength = this.bufferLength;
    var n = repeatHeader[0];
    if (n < 128) {
      // copy n bytes
      buffer = this.ensureBuffer(bufferLength + n + 1);
      buffer[bufferLength++] = repeatHeader[1];
      if (n > 0) {
        var source = this.str.getBytes(n);
        buffer.set(source, bufferLength);
        bufferLength += n;
      }
    } else {
      n = 257 - n;
      var b = repeatHeader[1];
      buffer = this.ensureBuffer(bufferLength + n + 1);
      for (var i = 0; i < n; i++) {
        buffer[bufferLength++] = b;
      }
    }
    this.bufferLength = bufferLength;
  };

  return RunLengthStream;
})();

var CCITTFaxStream = (function CCITTFaxStreamClosure() {

  var ccittEOL = -2;
  var twoDimPass = 0;
  var twoDimHoriz = 1;
  var twoDimVert0 = 2;
  var twoDimVertR1 = 3;
  var twoDimVertL1 = 4;
  var twoDimVertR2 = 5;
  var twoDimVertL2 = 6;
  var twoDimVertR3 = 7;
  var twoDimVertL3 = 8;

  var twoDimTable = [
    [-1, -1], [-1, -1],                   // 000000x
    [7, twoDimVertL3],                    // 0000010
    [7, twoDimVertR3],                    // 0000011
    [6, twoDimVertL2], [6, twoDimVertL2], // 000010x
    [6, twoDimVertR2], [6, twoDimVertR2], // 000011x
    [4, twoDimPass], [4, twoDimPass],     // 0001xxx
    [4, twoDimPass], [4, twoDimPass],
    [4, twoDimPass], [4, twoDimPass],
    [4, twoDimPass], [4, twoDimPass],
    [3, twoDimHoriz], [3, twoDimHoriz],   // 001xxxx
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimHoriz], [3, twoDimHoriz],
    [3, twoDimVertL1], [3, twoDimVertL1], // 010xxxx
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertL1], [3, twoDimVertL1],
    [3, twoDimVertR1], [3, twoDimVertR1], // 011xxxx
    [3, twoDimVertR1], [3, twoDimVertR1],
    [3, twoDimVertR1], [3, twoDimVertR1],
    [3, twoDimVertR1], [3, twoDimVertR1],
    [3, twoDimVertR1], [3, twoDimVertR1],
    [3, twoDimVertR1], [3, twoDimVertR1],
    [3, twoDimVertR1], [3, twoDimVertR1],
    [3, twoDimVertR1], [3, twoDimVertR1],
    [1, twoDimVert0], [1, twoDimVert0],   // 1xxxxxx
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0],
    [1, twoDimVert0], [1, twoDimVert0]
  ];

  var whiteTable1 = [
    [-1, -1],                               // 00000
    [12, ccittEOL],                         // 00001
    [-1, -1], [-1, -1],                     // 0001x
    [-1, -1], [-1, -1], [-1, -1], [-1, -1], // 001xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1], // 010xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1], // 011xx
    [11, 1792], [11, 1792],                 // 1000x
    [12, 1984],                             // 10010
    [12, 2048],                             // 10011
    [12, 2112],                             // 10100
    [12, 2176],                             // 10101
    [12, 2240],                             // 10110
    [12, 2304],                             // 10111
    [11, 1856], [11, 1856],                 // 1100x
    [11, 1920], [11, 1920],                 // 1101x
    [12, 2368],                             // 11100
    [12, 2432],                             // 11101
    [12, 2496],                             // 11110
    [12, 2560]                              // 11111
  ];

  var whiteTable2 = [
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],     // 0000000xx
    [8, 29], [8, 29],                           // 00000010x
    [8, 30], [8, 30],                           // 00000011x
    [8, 45], [8, 45],                           // 00000100x
    [8, 46], [8, 46],                           // 00000101x
    [7, 22], [7, 22], [7, 22], [7, 22],         // 0000011xx
    [7, 23], [7, 23], [7, 23], [7, 23],         // 0000100xx
    [8, 47], [8, 47],                           // 00001010x
    [8, 48], [8, 48],                           // 00001011x
    [6, 13], [6, 13], [6, 13], [6, 13],         // 000011xxx
    [6, 13], [6, 13], [6, 13], [6, 13],
    [7, 20], [7, 20], [7, 20], [7, 20],         // 0001000xx
    [8, 33], [8, 33],                           // 00010010x
    [8, 34], [8, 34],                           // 00010011x
    [8, 35], [8, 35],                           // 00010100x
    [8, 36], [8, 36],                           // 00010101x
    [8, 37], [8, 37],                           // 00010110x
    [8, 38], [8, 38],                           // 00010111x
    [7, 19], [7, 19], [7, 19], [7, 19],         // 0001100xx
    [8, 31], [8, 31],                           // 00011010x
    [8, 32], [8, 32],                           // 00011011x
    [6, 1], [6, 1], [6, 1], [6, 1],             // 000111xxx
    [6, 1], [6, 1], [6, 1], [6, 1],
    [6, 12], [6, 12], [6, 12], [6, 12],         // 001000xxx
    [6, 12], [6, 12], [6, 12], [6, 12],
    [8, 53], [8, 53],                           // 00100100x
    [8, 54], [8, 54],                           // 00100101x
    [7, 26], [7, 26], [7, 26], [7, 26],         // 0010011xx
    [8, 39], [8, 39],                           // 00101000x
    [8, 40], [8, 40],                           // 00101001x
    [8, 41], [8, 41],                           // 00101010x
    [8, 42], [8, 42],                           // 00101011x
    [8, 43], [8, 43],                           // 00101100x
    [8, 44], [8, 44],                           // 00101101x
    [7, 21], [7, 21], [7, 21], [7, 21],         // 0010111xx
    [7, 28], [7, 28], [7, 28], [7, 28],         // 0011000xx
    [8, 61], [8, 61],                           // 00110010x
    [8, 62], [8, 62],                           // 00110011x
    [8, 63], [8, 63],                           // 00110100x
    [8, 0], [8, 0],                             // 00110101x
    [8, 320], [8, 320],                         // 00110110x
    [8, 384], [8, 384],                         // 00110111x
    [5, 10], [5, 10], [5, 10], [5, 10],         // 00111xxxx
    [5, 10], [5, 10], [5, 10], [5, 10],
    [5, 10], [5, 10], [5, 10], [5, 10],
    [5, 10], [5, 10], [5, 10], [5, 10],
    [5, 11], [5, 11], [5, 11], [5, 11],         // 01000xxxx
    [5, 11], [5, 11], [5, 11], [5, 11],
    [5, 11], [5, 11], [5, 11], [5, 11],
    [5, 11], [5, 11], [5, 11], [5, 11],
    [7, 27], [7, 27], [7, 27], [7, 27],         // 0100100xx
    [8, 59], [8, 59],                           // 01001010x
    [8, 60], [8, 60],                           // 01001011x
    [9, 1472],                                  // 010011000
    [9, 1536],                                  // 010011001
    [9, 1600],                                  // 010011010
    [9, 1728],                                  // 010011011
    [7, 18], [7, 18], [7, 18], [7, 18],         // 0100111xx
    [7, 24], [7, 24], [7, 24], [7, 24],         // 0101000xx
    [8, 49], [8, 49],                           // 01010010x
    [8, 50], [8, 50],                           // 01010011x
    [8, 51], [8, 51],                           // 01010100x
    [8, 52], [8, 52],                           // 01010101x
    [7, 25], [7, 25], [7, 25], [7, 25],         // 0101011xx
    [8, 55], [8, 55],                           // 01011000x
    [8, 56], [8, 56],                           // 01011001x
    [8, 57], [8, 57],                           // 01011010x
    [8, 58], [8, 58],                           // 01011011x
    [6, 192], [6, 192], [6, 192], [6, 192],     // 010111xxx
    [6, 192], [6, 192], [6, 192], [6, 192],
    [6, 1664], [6, 1664], [6, 1664], [6, 1664], // 011000xxx
    [6, 1664], [6, 1664], [6, 1664], [6, 1664],
    [8, 448], [8, 448],                         // 01100100x
    [8, 512], [8, 512],                         // 01100101x
    [9, 704],                                   // 011001100
    [9, 768],                                   // 011001101
    [8, 640], [8, 640],                         // 01100111x
    [8, 576], [8, 576],                         // 01101000x
    [9, 832],                                   // 011010010
    [9, 896],                                   // 011010011
    [9, 960],                                   // 011010100
    [9, 1024],                                  // 011010101
    [9, 1088],                                  // 011010110
    [9, 1152],                                  // 011010111
    [9, 1216],                                  // 011011000
    [9, 1280],                                  // 011011001
    [9, 1344],                                  // 011011010
    [9, 1408],                                  // 011011011
    [7, 256], [7, 256], [7, 256], [7, 256],     // 0110111xx
    [4, 2], [4, 2], [4, 2], [4, 2],             // 0111xxxxx
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 2], [4, 2], [4, 2], [4, 2],
    [4, 3], [4, 3], [4, 3], [4, 3],             // 1000xxxxx
    [4, 3], [4, 3], [4, 3], [4, 3],
    [4, 3], [4, 3], [4, 3], [4, 3],
    [4, 3], [4, 3], [4, 3], [4, 3],
    [4, 3], [4, 3], [4, 3], [4, 3],
    [4, 3], [4, 3], [4, 3], [4, 3],
    [4, 3], [4, 3], [4, 3], [4, 3],
    [4, 3], [4, 3], [4, 3], [4, 3],
    [5, 128], [5, 128], [5, 128], [5, 128],     // 10010xxxx
    [5, 128], [5, 128], [5, 128], [5, 128],
    [5, 128], [5, 128], [5, 128], [5, 128],
    [5, 128], [5, 128], [5, 128], [5, 128],
    [5, 8], [5, 8], [5, 8], [5, 8],             // 10011xxxx
    [5, 8], [5, 8], [5, 8], [5, 8],
    [5, 8], [5, 8], [5, 8], [5, 8],
    [5, 8], [5, 8], [5, 8], [5, 8],
    [5, 9], [5, 9], [5, 9], [5, 9],             // 10100xxxx
    [5, 9], [5, 9], [5, 9], [5, 9],
    [5, 9], [5, 9], [5, 9], [5, 9],
    [5, 9], [5, 9], [5, 9], [5, 9],
    [6, 16], [6, 16], [6, 16], [6, 16],         // 101010xxx
    [6, 16], [6, 16], [6, 16], [6, 16],
    [6, 17], [6, 17], [6, 17], [6, 17],         // 101011xxx
    [6, 17], [6, 17], [6, 17], [6, 17],
    [4, 4], [4, 4], [4, 4], [4, 4],             // 1011xxxxx
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 4], [4, 4], [4, 4], [4, 4],
    [4, 5], [4, 5], [4, 5], [4, 5],             // 1100xxxxx
    [4, 5], [4, 5], [4, 5], [4, 5],
    [4, 5], [4, 5], [4, 5], [4, 5],
    [4, 5], [4, 5], [4, 5], [4, 5],
    [4, 5], [4, 5], [4, 5], [4, 5],
    [4, 5], [4, 5], [4, 5], [4, 5],
    [4, 5], [4, 5], [4, 5], [4, 5],
    [4, 5], [4, 5], [4, 5], [4, 5],
    [6, 14], [6, 14], [6, 14], [6, 14],         // 110100xxx
    [6, 14], [6, 14], [6, 14], [6, 14],
    [6, 15], [6, 15], [6, 15], [6, 15],         // 110101xxx
    [6, 15], [6, 15], [6, 15], [6, 15],
    [5, 64], [5, 64], [5, 64], [5, 64],         // 11011xxxx
    [5, 64], [5, 64], [5, 64], [5, 64],
    [5, 64], [5, 64], [5, 64], [5, 64],
    [5, 64], [5, 64], [5, 64], [5, 64],
    [4, 6], [4, 6], [4, 6], [4, 6],             // 1110xxxxx
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 6], [4, 6], [4, 6], [4, 6],
    [4, 7], [4, 7], [4, 7], [4, 7],             // 1111xxxxx
    [4, 7], [4, 7], [4, 7], [4, 7],
    [4, 7], [4, 7], [4, 7], [4, 7],
    [4, 7], [4, 7], [4, 7], [4, 7],
    [4, 7], [4, 7], [4, 7], [4, 7],
    [4, 7], [4, 7], [4, 7], [4, 7],
    [4, 7], [4, 7], [4, 7], [4, 7],
    [4, 7], [4, 7], [4, 7], [4, 7]
  ];

  var blackTable1 = [
    [-1, -1], [-1, -1],                             // 000000000000x
    [12, ccittEOL], [12, ccittEOL],                 // 000000000001x
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000001xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000010xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000011xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000100xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000101xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000110xx
    [-1, -1], [-1, -1], [-1, -1], [-1, -1],         // 00000000111xx
    [11, 1792], [11, 1792], [11, 1792], [11, 1792], // 00000001000xx
    [12, 1984], [12, 1984],                         // 000000010010x
    [12, 2048], [12, 2048],                         // 000000010011x
    [12, 2112], [12, 2112],                         // 000000010100x
    [12, 2176], [12, 2176],                         // 000000010101x
    [12, 2240], [12, 2240],                         // 000000010110x
    [12, 2304], [12, 2304],                         // 000000010111x
    [11, 1856], [11, 1856], [11, 1856], [11, 1856], // 00000001100xx
    [11, 1920], [11, 1920], [11, 1920], [11, 1920], // 00000001101xx
    [12, 2368], [12, 2368],                         // 000000011100x
    [12, 2432], [12, 2432],                         // 000000011101x
    [12, 2496], [12, 2496],                         // 000000011110x
    [12, 2560], [12, 2560],                         // 000000011111x
    [10, 18], [10, 18], [10, 18], [10, 18],         // 0000001000xxx
    [10, 18], [10, 18], [10, 18], [10, 18],
    [12, 52], [12, 52],                             // 000000100100x
    [13, 640],                                      // 0000001001010
    [13, 704],                                      // 0000001001011
    [13, 768],                                      // 0000001001100
    [13, 832],                                      // 0000001001101
    [12, 55], [12, 55],                             // 000000100111x
    [12, 56], [12, 56],                             // 000000101000x
    [13, 1280],                                     // 0000001010010
    [13, 1344],                                     // 0000001010011
    [13, 1408],                                     // 0000001010100
    [13, 1472],                                     // 0000001010101
    [12, 59], [12, 59],                             // 000000101011x
    [12, 60], [12, 60],                             // 000000101100x
    [13, 1536],                                     // 0000001011010
    [13, 1600],                                     // 0000001011011
    [11, 24], [11, 24], [11, 24], [11, 24],         // 00000010111xx
    [11, 25], [11, 25], [11, 25], [11, 25],         // 00000011000xx
    [13, 1664],                                     // 0000001100100
    [13, 1728],                                     // 0000001100101
    [12, 320], [12, 320],                           // 000000110011x
    [12, 384], [12, 384],                           // 000000110100x
    [12, 448], [12, 448],                           // 000000110101x
    [13, 512],                                      // 0000001101100
    [13, 576],                                      // 0000001101101
    [12, 53], [12, 53],                             // 000000110111x
    [12, 54], [12, 54],                             // 000000111000x
    [13, 896],                                      // 0000001110010
    [13, 960],                                      // 0000001110011
    [13, 1024],                                     // 0000001110100
    [13, 1088],                                     // 0000001110101
    [13, 1152],                                     // 0000001110110
    [13, 1216],                                     // 0000001110111
    [10, 64], [10, 64], [10, 64], [10, 64],         // 0000001111xxx
    [10, 64], [10, 64], [10, 64], [10, 64]
  ];

  var blackTable2 = [
    [8, 13], [8, 13], [8, 13], [8, 13],     // 00000100xxxx
    [8, 13], [8, 13], [8, 13], [8, 13],
    [8, 13], [8, 13], [8, 13], [8, 13],
    [8, 13], [8, 13], [8, 13], [8, 13],
    [11, 23], [11, 23],                     // 00000101000x
    [12, 50],                               // 000001010010
    [12, 51],                               // 000001010011
    [12, 44],                               // 000001010100
    [12, 45],                               // 000001010101
    [12, 46],                               // 000001010110
    [12, 47],                               // 000001010111
    [12, 57],                               // 000001011000
    [12, 58],                               // 000001011001
    [12, 61],                               // 000001011010
    [12, 256],                              // 000001011011
    [10, 16], [10, 16], [10, 16], [10, 16], // 0000010111xx
    [10, 17], [10, 17], [10, 17], [10, 17], // 0000011000xx
    [12, 48],                               // 000001100100
    [12, 49],                               // 000001100101
    [12, 62],                               // 000001100110
    [12, 63],                               // 000001100111
    [12, 30],                               // 000001101000
    [12, 31],                               // 000001101001
    [12, 32],                               // 000001101010
    [12, 33],                               // 000001101011
    [12, 40],                               // 000001101100
    [12, 41],                               // 000001101101
    [11, 22], [11, 22],                     // 00000110111x
    [8, 14], [8, 14], [8, 14], [8, 14],     // 00000111xxxx
    [8, 14], [8, 14], [8, 14], [8, 14],
    [8, 14], [8, 14], [8, 14], [8, 14],
    [8, 14], [8, 14], [8, 14], [8, 14],
    [7, 10], [7, 10], [7, 10], [7, 10],     // 0000100xxxxx
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 10], [7, 10], [7, 10], [7, 10],
    [7, 11], [7, 11], [7, 11], [7, 11],     // 0000101xxxxx
    [7, 11], [7, 11], [7, 11], [7, 11],
    [7, 11], [7, 11], [7, 11], [7, 11],
    [7, 11], [7, 11], [7, 11], [7, 11],
    [7, 11], [7, 11], [7, 11], [7, 11],
    [7, 11], [7, 11], [7, 11], [7, 11],
    [7, 11], [7, 11], [7, 11], [7, 11],
    [7, 11], [7, 11], [7, 11], [7, 11],
    [9, 15], [9, 15], [9, 15], [9, 15],     // 000011000xxx
    [9, 15], [9, 15], [9, 15], [9, 15],
    [12, 128],                              // 000011001000
    [12, 192],                              // 000011001001
    [12, 26],                               // 000011001010
    [12, 27],                               // 000011001011
    [12, 28],                               // 000011001100
    [12, 29],                               // 000011001101
    [11, 19], [11, 19],                     // 00001100111x
    [11, 20], [11, 20],                     // 00001101000x
    [12, 34],                               // 000011010010
    [12, 35],                               // 000011010011
    [12, 36],                               // 000011010100
    [12, 37],                               // 000011010101
    [12, 38],                               // 000011010110
    [12, 39],                               // 000011010111
    [11, 21], [11, 21],                     // 00001101100x
    [12, 42],                               // 000011011010
    [12, 43],                               // 000011011011
    [10, 0], [10, 0], [10, 0], [10, 0],     // 0000110111xx
    [7, 12], [7, 12], [7, 12], [7, 12],     // 0000111xxxxx
    [7, 12], [7, 12], [7, 12], [7, 12],
    [7, 12], [7, 12], [7, 12], [7, 12],
    [7, 12], [7, 12], [7, 12], [7, 12],
    [7, 12], [7, 12], [7, 12], [7, 12],
    [7, 12], [7, 12], [7, 12], [7, 12],
    [7, 12], [7, 12], [7, 12], [7, 12],
    [7, 12], [7, 12], [7, 12], [7, 12]
  ];

  var blackTable3 = [
    [-1, -1], [-1, -1], [-1, -1], [-1, -1], // 0000xx
    [6, 9],                                 // 000100
    [6, 8],                                 // 000101
    [5, 7], [5, 7],                         // 00011x
    [4, 6], [4, 6], [4, 6], [4, 6],         // 0010xx
    [4, 5], [4, 5], [4, 5], [4, 5],         // 0011xx
    [3, 1], [3, 1], [3, 1], [3, 1],         // 010xxx
    [3, 1], [3, 1], [3, 1], [3, 1],
    [3, 4], [3, 4], [3, 4], [3, 4],         // 011xxx
    [3, 4], [3, 4], [3, 4], [3, 4],
    [2, 3], [2, 3], [2, 3], [2, 3],         // 10xxxx
    [2, 3], [2, 3], [2, 3], [2, 3],
    [2, 3], [2, 3], [2, 3], [2, 3],
    [2, 3], [2, 3], [2, 3], [2, 3],
    [2, 2], [2, 2], [2, 2], [2, 2],         // 11xxxx
    [2, 2], [2, 2], [2, 2], [2, 2],
    [2, 2], [2, 2], [2, 2], [2, 2],
    [2, 2], [2, 2], [2, 2], [2, 2]
  ];

  function CCITTFaxStream(str, maybeLength, params) {
    this.str = str;
    this.dict = str.dict;

    params = params || Dict.empty;

    this.encoding = params.get('K') || 0;
    this.eoline = params.get('EndOfLine') || false;
    this.byteAlign = params.get('EncodedByteAlign') || false;
    this.columns = params.get('Columns') || 1728;
    this.rows = params.get('Rows') || 0;
    var eoblock = params.get('EndOfBlock');
    if (eoblock === null || eoblock === undefined) {
      eoblock = true;
    }
    this.eoblock = eoblock;
    this.black = params.get('BlackIs1') || false;

    this.codingLine = new Uint32Array(this.columns + 1);
    this.refLine = new Uint32Array(this.columns + 2);

    this.codingLine[0] = this.columns;
    this.codingPos = 0;

    this.row = 0;
    this.nextLine2D = this.encoding < 0;
    this.inputBits = 0;
    this.inputBuf = 0;
    this.outputBits = 0;

    var code1;
    while ((code1 = this.lookBits(12)) === 0) {
      this.eatBits(1);
    }
    if (code1 === 1) {
      this.eatBits(12);
    }
    if (this.encoding > 0) {
      this.nextLine2D = !this.lookBits(1);
      this.eatBits(1);
    }

    DecodeStream.call(this, maybeLength);
  }

  CCITTFaxStream.prototype = Object.create(DecodeStream.prototype);

  CCITTFaxStream.prototype.readBlock = function CCITTFaxStream_readBlock() {
    while (!this.eof) {
      var c = this.lookChar();
      this.ensureBuffer(this.bufferLength + 1);
      this.buffer[this.bufferLength++] = c;
    }
  };

  CCITTFaxStream.prototype.addPixels =
      function ccittFaxStreamAddPixels(a1, blackPixels) {
    var codingLine = this.codingLine;
    var codingPos = this.codingPos;

    if (a1 > codingLine[codingPos]) {
      if (a1 > this.columns) {
        info('row is wrong length');
        this.err = true;
        a1 = this.columns;
      }
      if ((codingPos & 1) ^ blackPixels) {
        ++codingPos;
      }

      codingLine[codingPos] = a1;
    }
    this.codingPos = codingPos;
  };

  CCITTFaxStream.prototype.addPixelsNeg =
      function ccittFaxStreamAddPixelsNeg(a1, blackPixels) {
    var codingLine = this.codingLine;
    var codingPos = this.codingPos;

    if (a1 > codingLine[codingPos]) {
      if (a1 > this.columns) {
        info('row is wrong length');
        this.err = true;
        a1 = this.columns;
      }
      if ((codingPos & 1) ^ blackPixels) {
        ++codingPos;
      }

      codingLine[codingPos] = a1;
    } else if (a1 < codingLine[codingPos]) {
      if (a1 < 0) {
        info('invalid code');
        this.err = true;
        a1 = 0;
      }
      while (codingPos > 0 && a1 < codingLine[codingPos - 1]) {
        --codingPos;
      }
      codingLine[codingPos] = a1;
    }

    this.codingPos = codingPos;
  };

  CCITTFaxStream.prototype.lookChar = function CCITTFaxStream_lookChar() {
    var refLine = this.refLine;
    var codingLine = this.codingLine;
    var columns = this.columns;

    var refPos, blackPixels, bits, i;

    if (this.outputBits === 0) {
      if (this.eof) {
        return null;
      }
      this.err = false;

      var code1, code2, code3;
      if (this.nextLine2D) {
        for (i = 0; codingLine[i] < columns; ++i) {
          refLine[i] = codingLine[i];
        }
        refLine[i++] = columns;
        refLine[i] = columns;
        codingLine[0] = 0;
        this.codingPos = 0;
        refPos = 0;
        blackPixels = 0;

        while (codingLine[this.codingPos] < columns) {
          code1 = this.getTwoDimCode();
          switch (code1) {
            case twoDimPass:
              this.addPixels(refLine[refPos + 1], blackPixels);
              if (refLine[refPos + 1] < columns) {
                refPos += 2;
              }
              break;
            case twoDimHoriz:
              code1 = code2 = 0;
              if (blackPixels) {
                do {
                  code1 += (code3 = this.getBlackCode());
                } while (code3 >= 64);
                do {
                  code2 += (code3 = this.getWhiteCode());
                } while (code3 >= 64);
              } else {
                do {
                  code1 += (code3 = this.getWhiteCode());
                } while (code3 >= 64);
                do {
                  code2 += (code3 = this.getBlackCode());
                } while (code3 >= 64);
              }
              this.addPixels(codingLine[this.codingPos] +
                             code1, blackPixels);
              if (codingLine[this.codingPos] < columns) {
                this.addPixels(codingLine[this.codingPos] + code2,
                               blackPixels ^ 1);
              }
              while (refLine[refPos] <= codingLine[this.codingPos] &&
                     refLine[refPos] < columns) {
                refPos += 2;
              }
              break;
            case twoDimVertR3:
              this.addPixels(refLine[refPos] + 3, blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                ++refPos;
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case twoDimVertR2:
              this.addPixels(refLine[refPos] + 2, blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                ++refPos;
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case twoDimVertR1:
              this.addPixels(refLine[refPos] + 1, blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                ++refPos;
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case twoDimVert0:
              this.addPixels(refLine[refPos], blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                ++refPos;
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case twoDimVertL3:
              this.addPixelsNeg(refLine[refPos] - 3, blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                if (refPos > 0) {
                  --refPos;
                } else {
                  ++refPos;
                }
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case twoDimVertL2:
              this.addPixelsNeg(refLine[refPos] - 2, blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                if (refPos > 0) {
                  --refPos;
                } else {
                  ++refPos;
                }
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case twoDimVertL1:
              this.addPixelsNeg(refLine[refPos] - 1, blackPixels);
              blackPixels ^= 1;
              if (codingLine[this.codingPos] < columns) {
                if (refPos > 0) {
                  --refPos;
                } else {
                  ++refPos;
                }
                while (refLine[refPos] <= codingLine[this.codingPos] &&
                       refLine[refPos] < columns) {
                  refPos += 2;
                }
              }
              break;
            case EOF:
              this.addPixels(columns, 0);
              this.eof = true;
              break;
            default:
              info('bad 2d code');
              this.addPixels(columns, 0);
              this.err = true;
          }
        }
      } else {
        codingLine[0] = 0;
        this.codingPos = 0;
        blackPixels = 0;
        while (codingLine[this.codingPos] < columns) {
          code1 = 0;
          if (blackPixels) {
            do {
              code1 += (code3 = this.getBlackCode());
            } while (code3 >= 64);
          } else {
            do {
              code1 += (code3 = this.getWhiteCode());
            } while (code3 >= 64);
          }
          this.addPixels(codingLine[this.codingPos] + code1, blackPixels);
          blackPixels ^= 1;
        }
      }

      var gotEOL = false;

      if (this.byteAlign) {
        this.inputBits &= ~7;
      }

      if (!this.eoblock && this.row === this.rows - 1) {
        this.eof = true;
      } else {
        code1 = this.lookBits(12);
        if (this.eoline) {
          while (code1 !== EOF && code1 !== 1) {
            this.eatBits(1);
            code1 = this.lookBits(12);
          }
        } else {
          while (code1 === 0) {
            this.eatBits(1);
            code1 = this.lookBits(12);
          }
        }
        if (code1 === 1) {
          this.eatBits(12);
          gotEOL = true;
        } else if (code1 === EOF) {
          this.eof = true;
        }
      }

      if (!this.eof && this.encoding > 0) {
        this.nextLine2D = !this.lookBits(1);
        this.eatBits(1);
      }

      if (this.eoblock && gotEOL && this.byteAlign) {
        code1 = this.lookBits(12);
        if (code1 === 1) {
          this.eatBits(12);
          if (this.encoding > 0) {
            this.lookBits(1);
            this.eatBits(1);
          }
          if (this.encoding >= 0) {
            for (i = 0; i < 4; ++i) {
              code1 = this.lookBits(12);
              if (code1 !== 1) {
                info('bad rtc code: ' + code1);
              }
              this.eatBits(12);
              if (this.encoding > 0) {
                this.lookBits(1);
                this.eatBits(1);
              }
            }
          }
          this.eof = true;
        }
      } else if (this.err && this.eoline) {
        while (true) {
          code1 = this.lookBits(13);
          if (code1 === EOF) {
            this.eof = true;
            return null;
          }
          if ((code1 >> 1) === 1) {
            break;
          }
          this.eatBits(1);
        }
        this.eatBits(12);
        if (this.encoding > 0) {
          this.eatBits(1);
          this.nextLine2D = !(code1 & 1);
        }
      }

      if (codingLine[0] > 0) {
        this.outputBits = codingLine[this.codingPos = 0];
      } else {
        this.outputBits = codingLine[this.codingPos = 1];
      }
      this.row++;
    }

    var c;
    if (this.outputBits >= 8) {
      c = (this.codingPos & 1) ? 0 : 0xFF;
      this.outputBits -= 8;
      if (this.outputBits === 0 && codingLine[this.codingPos] < columns) {
        this.codingPos++;
        this.outputBits = (codingLine[this.codingPos] -
                           codingLine[this.codingPos - 1]);
      }
    } else {
      bits = 8;
      c = 0;
      do {
        if (this.outputBits > bits) {
          c <<= bits;
          if (!(this.codingPos & 1)) {
            c |= 0xFF >> (8 - bits);
          }
          this.outputBits -= bits;
          bits = 0;
        } else {
          c <<= this.outputBits;
          if (!(this.codingPos & 1)) {
            c |= 0xFF >> (8 - this.outputBits);
          }
          bits -= this.outputBits;
          this.outputBits = 0;
          if (codingLine[this.codingPos] < columns) {
            this.codingPos++;
            this.outputBits = (codingLine[this.codingPos] -
                               codingLine[this.codingPos - 1]);
          } else if (bits > 0) {
            c <<= bits;
            bits = 0;
          }
        }
      } while (bits);
    }
    if (this.black) {
      c ^= 0xFF;
    }
    return c;
  };

  // This functions returns the code found from the table.
  // The start and end parameters set the boundaries for searching the table.
  // The limit parameter is optional. Function returns an array with three
  // values. The first array element indicates whether a valid code is being
  // returned. The second array element is the actual code. The third array
  // element indicates whether EOF was reached.
  CCITTFaxStream.prototype.findTableCode =
      function ccittFaxStreamFindTableCode(start, end, table, limit) {

    var limitValue = limit || 0;
    for (var i = start; i <= end; ++i) {
      var code = this.lookBits(i);
      if (code === EOF) {
        return [true, 1, false];
      }
      if (i < end) {
        code <<= end - i;
      }
      if (!limitValue || code >= limitValue) {
        var p = table[code - limitValue];
        if (p[0] === i) {
          this.eatBits(i);
          return [true, p[1], true];
        }
      }
    }
    return [false, 0, false];
  };

  CCITTFaxStream.prototype.getTwoDimCode =
      function ccittFaxStreamGetTwoDimCode() {

    var code = 0;
    var p;
    if (this.eoblock) {
      code = this.lookBits(7);
      p = twoDimTable[code];
      if (p && p[0] > 0) {
        this.eatBits(p[0]);
        return p[1];
      }
    } else {
      var result = this.findTableCode(1, 7, twoDimTable);
      if (result[0] && result[2]) {
        return result[1];
      }
    }
    info('Bad two dim code');
    return EOF;
  };

  CCITTFaxStream.prototype.getWhiteCode =
      function ccittFaxStreamGetWhiteCode() {

    var code = 0;
    var p;
    if (this.eoblock) {
      code = this.lookBits(12);
      if (code === EOF) {
        return 1;
      }

      if ((code >> 5) === 0) {
        p = whiteTable1[code];
      } else {
        p = whiteTable2[code >> 3];
      }

      if (p[0] > 0) {
        this.eatBits(p[0]);
        return p[1];
      }
    } else {
      var result = this.findTableCode(1, 9, whiteTable2);
      if (result[0]) {
        return result[1];
      }

      result = this.findTableCode(11, 12, whiteTable1);
      if (result[0]) {
        return result[1];
      }
    }
    info('bad white code');
    this.eatBits(1);
    return 1;
  };

  CCITTFaxStream.prototype.getBlackCode =
      function ccittFaxStreamGetBlackCode() {

    var code, p;
    if (this.eoblock) {
      code = this.lookBits(13);
      if (code === EOF) {
        return 1;
      }
      if ((code >> 7) === 0) {
        p = blackTable1[code];
      } else if ((code >> 9) === 0 && (code >> 7) !== 0) {
        p = blackTable2[(code >> 1) - 64];
      } else {
        p = blackTable3[code >> 7];
      }

      if (p[0] > 0) {
        this.eatBits(p[0]);
        return p[1];
      }
    } else {
      var result = this.findTableCode(2, 6, blackTable3);
      if (result[0]) {
        return result[1];
      }

      result = this.findTableCode(7, 12, blackTable2, 64);
      if (result[0]) {
        return result[1];
      }

      result = this.findTableCode(10, 13, blackTable1);
      if (result[0]) {
        return result[1];
      }
    }
    info('bad black code');
    this.eatBits(1);
    return 1;
  };

  CCITTFaxStream.prototype.lookBits = function CCITTFaxStream_lookBits(n) {
    var c;
    while (this.inputBits < n) {
      if ((c = this.str.getByte()) === -1) {
        if (this.inputBits === 0) {
          return EOF;
        }
        return ((this.inputBuf << (n - this.inputBits)) &
                (0xFFFF >> (16 - n)));
      }
      this.inputBuf = (this.inputBuf << 8) + c;
      this.inputBits += 8;
    }
    return (this.inputBuf >> (this.inputBits - n)) & (0xFFFF >> (16 - n));
  };

  CCITTFaxStream.prototype.eatBits = function CCITTFaxStream_eatBits(n) {
    if ((this.inputBits -= n) < 0) {
      this.inputBits = 0;
    }
  };

  return CCITTFaxStream;
})();

var LZWStream = (function LZWStreamClosure() {
  function LZWStream(str, maybeLength, earlyChange) {
    this.str = str;
    this.dict = str.dict;
    this.cachedData = 0;
    this.bitsCached = 0;

    var maxLzwDictionarySize = 4096;
    var lzwState = {
      earlyChange: earlyChange,
      codeLength: 9,
      nextCode: 258,
      dictionaryValues: new Uint8Array(maxLzwDictionarySize),
      dictionaryLengths: new Uint16Array(maxLzwDictionarySize),
      dictionaryPrevCodes: new Uint16Array(maxLzwDictionarySize),
      currentSequence: new Uint8Array(maxLzwDictionarySize),
      currentSequenceLength: 0
    };
    for (var i = 0; i < 256; ++i) {
      lzwState.dictionaryValues[i] = i;
      lzwState.dictionaryLengths[i] = 1;
    }
    this.lzwState = lzwState;

    DecodeStream.call(this, maybeLength);
  }

  LZWStream.prototype = Object.create(DecodeStream.prototype);

  LZWStream.prototype.readBits = function LZWStream_readBits(n) {
    var bitsCached = this.bitsCached;
    var cachedData = this.cachedData;
    while (bitsCached < n) {
      var c = this.str.getByte();
      if (c === -1) {
        this.eof = true;
        return null;
      }
      cachedData = (cachedData << 8) | c;
      bitsCached += 8;
    }
    this.bitsCached = (bitsCached -= n);
    this.cachedData = cachedData;
    this.lastCode = null;
    return (cachedData >>> bitsCached) & ((1 << n) - 1);
  };

  LZWStream.prototype.readBlock = function LZWStream_readBlock() {
    var blockSize = 512;
    var estimatedDecodedSize = blockSize * 2, decodedSizeDelta = blockSize;
    var i, j, q;

    var lzwState = this.lzwState;
    if (!lzwState) {
      return; // eof was found
    }

    var earlyChange = lzwState.earlyChange;
    var nextCode = lzwState.nextCode;
    var dictionaryValues = lzwState.dictionaryValues;
    var dictionaryLengths = lzwState.dictionaryLengths;
    var dictionaryPrevCodes = lzwState.dictionaryPrevCodes;
    var codeLength = lzwState.codeLength;
    var prevCode = lzwState.prevCode;
    var currentSequence = lzwState.currentSequence;
    var currentSequenceLength = lzwState.currentSequenceLength;

    var decodedLength = 0;
    var currentBufferLength = this.bufferLength;
    var buffer = this.ensureBuffer(this.bufferLength + estimatedDecodedSize);

    for (i = 0; i < blockSize; i++) {
      var code = this.readBits(codeLength);
      var hasPrev = currentSequenceLength > 0;
      if (code < 256) {
        currentSequence[0] = code;
        currentSequenceLength = 1;
      } else if (code >= 258) {
        if (code < nextCode) {
          currentSequenceLength = dictionaryLengths[code];
          for (j = currentSequenceLength - 1, q = code; j >= 0; j--) {
            currentSequence[j] = dictionaryValues[q];
            q = dictionaryPrevCodes[q];
          }
        } else {
          currentSequence[currentSequenceLength++] = currentSequence[0];
        }
      } else if (code === 256) {
        codeLength = 9;
        nextCode = 258;
        currentSequenceLength = 0;
        continue;
      } else {
        this.eof = true;
        delete this.lzwState;
        break;
      }

      if (hasPrev) {
        dictionaryPrevCodes[nextCode] = prevCode;
        dictionaryLengths[nextCode] = dictionaryLengths[prevCode] + 1;
        dictionaryValues[nextCode] = currentSequence[0];
        nextCode++;
        codeLength = (nextCode + earlyChange) & (nextCode + earlyChange - 1) ?
          codeLength : Math.min(Math.log(nextCode + earlyChange) /
          0.6931471805599453 + 1, 12) | 0;
      }
      prevCode = code;

      decodedLength += currentSequenceLength;
      if (estimatedDecodedSize < decodedLength) {
        do {
          estimatedDecodedSize += decodedSizeDelta;
        } while (estimatedDecodedSize < decodedLength);
        buffer = this.ensureBuffer(this.bufferLength + estimatedDecodedSize);
      }
      for (j = 0; j < currentSequenceLength; j++) {
        buffer[currentBufferLength++] = currentSequence[j];
      }
    }
    lzwState.nextCode = nextCode;
    lzwState.codeLength = codeLength;
    lzwState.prevCode = prevCode;
    lzwState.currentSequenceLength = currentSequenceLength;

    this.bufferLength = currentBufferLength;
  };

  return LZWStream;
})();

var NullStream = (function NullStreamClosure() {
  function NullStream() {
    Stream.call(this, new Uint8Array(0));
  }

  NullStream.prototype = Stream.prototype;

  return NullStream;
})();