pdfjs-dist/lib/core/jpg.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 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.
 *
 * @licend The above is the entire license notice for the
 * Javascript code in this page
 */
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.JpegImage = void 0;

var _util = require("../shared/util.js");

var _core_utils = require("./core_utils.js");

class JpegError extends _util.BaseException {
  constructor(msg) {
    super(`JPEG error: ${msg}`);
  }

}

class DNLMarkerError extends _util.BaseException {
  constructor(message, scanLines) {
    super(message);
    this.scanLines = scanLines;
  }

}

class EOIMarkerError extends _util.BaseException {}

const dctZigZag = new Uint8Array([0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18, 11, 4, 5, 12, 19, 26, 33, 40, 48, 41, 34, 27, 20, 13, 6, 7, 14, 21, 28, 35, 42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, 30, 37, 44, 51, 58, 59, 52, 45, 38, 31, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63]);
const dctCos1 = 4017;
const dctSin1 = 799;
const dctCos3 = 3406;
const dctSin3 = 2276;
const dctCos6 = 1567;
const dctSin6 = 3784;
const dctSqrt2 = 5793;
const dctSqrt1d2 = 2896;

function buildHuffmanTable(codeLengths, values) {
  let k = 0,
      i,
      j,
      length = 16;

  while (length > 0 && !codeLengths[length - 1]) {
    length--;
  }

  const code = [{
    children: [],
    index: 0
  }];
  let p = code[0],
      q;

  for (i = 0; i < length; i++) {
    for (j = 0; j < codeLengths[i]; j++) {
      p = code.pop();
      p.children[p.index] = values[k];

      while (p.index > 0) {
        p = code.pop();
      }

      p.index++;
      code.push(p);

      while (code.length <= i) {
        code.push(q = {
          children: [],
          index: 0
        });
        p.children[p.index] = q.children;
        p = q;
      }

      k++;
    }

    if (i + 1 < length) {
      code.push(q = {
        children: [],
        index: 0
      });
      p.children[p.index] = q.children;
      p = q;
    }
  }

  return code[0].children;
}

function getBlockBufferOffset(component, row, col) {
  return 64 * ((component.blocksPerLine + 1) * row + col);
}

function decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successivePrev, successive, parseDNLMarker = false) {
  const mcusPerLine = frame.mcusPerLine;
  const progressive = frame.progressive;
  const startOffset = offset;
  let bitsData = 0,
      bitsCount = 0;

  function readBit() {
    if (bitsCount > 0) {
      bitsCount--;
      return bitsData >> bitsCount & 1;
    }

    bitsData = data[offset++];

    if (bitsData === 0xff) {
      const nextByte = data[offset++];

      if (nextByte) {
        if (nextByte === 0xdc && parseDNLMarker) {
          offset += 2;
          const scanLines = (0, _core_utils.readUint16)(data, offset);
          offset += 2;

          if (scanLines > 0 && scanLines !== frame.scanLines) {
            throw new DNLMarkerError("Found DNL marker (0xFFDC) while parsing scan data", scanLines);
          }
        } else if (nextByte === 0xd9) {
          if (parseDNLMarker) {
            const maybeScanLines = blockRow * (frame.precision === 8 ? 8 : 0);

            if (maybeScanLines > 0 && Math.round(frame.scanLines / maybeScanLines) >= 10) {
              throw new DNLMarkerError("Found EOI marker (0xFFD9) while parsing scan data, " + "possibly caused by incorrect `scanLines` parameter", maybeScanLines);
            }
          }

          throw new EOIMarkerError("Found EOI marker (0xFFD9) while parsing scan data");
        }

        throw new JpegError(`unexpected marker ${(bitsData << 8 | nextByte).toString(16)}`);
      }
    }

    bitsCount = 7;
    return bitsData >>> 7;
  }

  function decodeHuffman(tree) {
    let node = tree;

    while (true) {
      node = node[readBit()];

      switch (typeof node) {
        case "number":
          return node;

        case "object":
          continue;
      }

      throw new JpegError("invalid huffman sequence");
    }
  }

  function receive(length) {
    let n = 0;

    while (length > 0) {
      n = n << 1 | readBit();
      length--;
    }

    return n;
  }

  function receiveAndExtend(length) {
    if (length === 1) {
      return readBit() === 1 ? 1 : -1;
    }

    const n = receive(length);

    if (n >= 1 << length - 1) {
      return n;
    }

    return n + (-1 << length) + 1;
  }

  function decodeBaseline(component, blockOffset) {
    const t = decodeHuffman(component.huffmanTableDC);
    const diff = t === 0 ? 0 : receiveAndExtend(t);
    component.blockData[blockOffset] = component.pred += diff;
    let k = 1;

    while (k < 64) {
      const rs = decodeHuffman(component.huffmanTableAC);
      const s = rs & 15,
            r = rs >> 4;

      if (s === 0) {
        if (r < 15) {
          break;
        }

        k += 16;
        continue;
      }

      k += r;
      const z = dctZigZag[k];
      component.blockData[blockOffset + z] = receiveAndExtend(s);
      k++;
    }
  }

  function decodeDCFirst(component, blockOffset) {
    const t = decodeHuffman(component.huffmanTableDC);
    const diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
    component.blockData[blockOffset] = component.pred += diff;
  }

  function decodeDCSuccessive(component, blockOffset) {
    component.blockData[blockOffset] |= readBit() << successive;
  }

  let eobrun = 0;

  function decodeACFirst(component, blockOffset) {
    if (eobrun > 0) {
      eobrun--;
      return;
    }

    let k = spectralStart;
    const e = spectralEnd;

    while (k <= e) {
      const rs = decodeHuffman(component.huffmanTableAC);
      const s = rs & 15,
            r = rs >> 4;

      if (s === 0) {
        if (r < 15) {
          eobrun = receive(r) + (1 << r) - 1;
          break;
        }

        k += 16;
        continue;
      }

      k += r;
      const z = dctZigZag[k];
      component.blockData[blockOffset + z] = receiveAndExtend(s) * (1 << successive);
      k++;
    }
  }

  let successiveACState = 0,
      successiveACNextValue;

  function decodeACSuccessive(component, blockOffset) {
    let k = spectralStart;
    const e = spectralEnd;
    let r = 0;
    let s;
    let rs;

    while (k <= e) {
      const offsetZ = blockOffset + dctZigZag[k];
      const sign = component.blockData[offsetZ] < 0 ? -1 : 1;

      switch (successiveACState) {
        case 0:
          rs = decodeHuffman(component.huffmanTableAC);
          s = rs & 15;
          r = rs >> 4;

          if (s === 0) {
            if (r < 15) {
              eobrun = receive(r) + (1 << r);
              successiveACState = 4;
            } else {
              r = 16;
              successiveACState = 1;
            }
          } else {
            if (s !== 1) {
              throw new JpegError("invalid ACn encoding");
            }

            successiveACNextValue = receiveAndExtend(s);
            successiveACState = r ? 2 : 3;
          }

          continue;

        case 1:
        case 2:
          if (component.blockData[offsetZ]) {
            component.blockData[offsetZ] += sign * (readBit() << successive);
          } else {
            r--;

            if (r === 0) {
              successiveACState = successiveACState === 2 ? 3 : 0;
            }
          }

          break;

        case 3:
          if (component.blockData[offsetZ]) {
            component.blockData[offsetZ] += sign * (readBit() << successive);
          } else {
            component.blockData[offsetZ] = successiveACNextValue << successive;
            successiveACState = 0;
          }

          break;

        case 4:
          if (component.blockData[offsetZ]) {
            component.blockData[offsetZ] += sign * (readBit() << successive);
          }

          break;
      }

      k++;
    }

    if (successiveACState === 4) {
      eobrun--;

      if (eobrun === 0) {
        successiveACState = 0;
      }
    }
  }

  let blockRow = 0;

  function decodeMcu(component, decode, mcu, row, col) {
    const mcuRow = mcu / mcusPerLine | 0;
    const mcuCol = mcu % mcusPerLine;
    blockRow = mcuRow * component.v + row;
    const blockCol = mcuCol * component.h + col;
    const blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
    decode(component, blockOffset);
  }

  function decodeBlock(component, decode, mcu) {
    blockRow = mcu / component.blocksPerLine | 0;
    const blockCol = mcu % component.blocksPerLine;
    const blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
    decode(component, blockOffset);
  }

  const componentsLength = components.length;
  let component, i, j, k, n;
  let decodeFn;

  if (progressive) {
    if (spectralStart === 0) {
      decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
    } else {
      decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive;
    }
  } else {
    decodeFn = decodeBaseline;
  }

  let mcu = 0,
      fileMarker;
  let mcuExpected;

  if (componentsLength === 1) {
    mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
  } else {
    mcuExpected = mcusPerLine * frame.mcusPerColumn;
  }

  let h, v;

  while (mcu <= mcuExpected) {
    const mcuToRead = resetInterval ? Math.min(mcuExpected - mcu, resetInterval) : mcuExpected;

    if (mcuToRead > 0) {
      for (i = 0; i < componentsLength; i++) {
        components[i].pred = 0;
      }

      eobrun = 0;

      if (componentsLength === 1) {
        component = components[0];

        for (n = 0; n < mcuToRead; n++) {
          decodeBlock(component, decodeFn, mcu);
          mcu++;
        }
      } else {
        for (n = 0; n < mcuToRead; n++) {
          for (i = 0; i < componentsLength; i++) {
            component = components[i];
            h = component.h;
            v = component.v;

            for (j = 0; j < v; j++) {
              for (k = 0; k < h; k++) {
                decodeMcu(component, decodeFn, mcu, j, k);
              }
            }
          }

          mcu++;
        }
      }
    }

    bitsCount = 0;
    fileMarker = findNextFileMarker(data, offset);

    if (!fileMarker) {
      break;
    }

    if (fileMarker.invalid) {
      const partialMsg = mcuToRead > 0 ? "unexpected" : "excessive";
      (0, _util.warn)(`decodeScan - ${partialMsg} MCU data, current marker is: ${fileMarker.invalid}`);
      offset = fileMarker.offset;
    }

    if (fileMarker.marker >= 0xffd0 && fileMarker.marker <= 0xffd7) {
      offset += 2;
    } else {
      break;
    }
  }

  return offset - startOffset;
}

function quantizeAndInverse(component, blockBufferOffset, p) {
  const qt = component.quantizationTable,
        blockData = component.blockData;
  let v0, v1, v2, v3, v4, v5, v6, v7;
  let p0, p1, p2, p3, p4, p5, p6, p7;
  let t;

  if (!qt) {
    throw new JpegError("missing required Quantization Table.");
  }

  for (let row = 0; row < 64; row += 8) {
    p0 = blockData[blockBufferOffset + row];
    p1 = blockData[blockBufferOffset + row + 1];
    p2 = blockData[blockBufferOffset + row + 2];
    p3 = blockData[blockBufferOffset + row + 3];
    p4 = blockData[blockBufferOffset + row + 4];
    p5 = blockData[blockBufferOffset + row + 5];
    p6 = blockData[blockBufferOffset + row + 6];
    p7 = blockData[blockBufferOffset + row + 7];
    p0 *= qt[row];

    if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
      t = dctSqrt2 * p0 + 512 >> 10;
      p[row] = t;
      p[row + 1] = t;
      p[row + 2] = t;
      p[row + 3] = t;
      p[row + 4] = t;
      p[row + 5] = t;
      p[row + 6] = t;
      p[row + 7] = t;
      continue;
    }

    p1 *= qt[row + 1];
    p2 *= qt[row + 2];
    p3 *= qt[row + 3];
    p4 *= qt[row + 4];
    p5 *= qt[row + 5];
    p6 *= qt[row + 6];
    p7 *= qt[row + 7];
    v0 = dctSqrt2 * p0 + 128 >> 8;
    v1 = dctSqrt2 * p4 + 128 >> 8;
    v2 = p2;
    v3 = p6;
    v4 = dctSqrt1d2 * (p1 - p7) + 128 >> 8;
    v7 = dctSqrt1d2 * (p1 + p7) + 128 >> 8;
    v5 = p3 << 4;
    v6 = p5 << 4;
    v0 = v0 + v1 + 1 >> 1;
    v1 = v0 - v1;
    t = v2 * dctSin6 + v3 * dctCos6 + 128 >> 8;
    v2 = v2 * dctCos6 - v3 * dctSin6 + 128 >> 8;
    v3 = t;
    v4 = v4 + v6 + 1 >> 1;
    v6 = v4 - v6;
    v7 = v7 + v5 + 1 >> 1;
    v5 = v7 - v5;
    v0 = v0 + v3 + 1 >> 1;
    v3 = v0 - v3;
    v1 = v1 + v2 + 1 >> 1;
    v2 = v1 - v2;
    t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
    v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
    v7 = t;
    t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
    v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
    v6 = t;
    p[row] = v0 + v7;
    p[row + 7] = v0 - v7;
    p[row + 1] = v1 + v6;
    p[row + 6] = v1 - v6;
    p[row + 2] = v2 + v5;
    p[row + 5] = v2 - v5;
    p[row + 3] = v3 + v4;
    p[row + 4] = v3 - v4;
  }

  for (let col = 0; col < 8; ++col) {
    p0 = p[col];
    p1 = p[col + 8];
    p2 = p[col + 16];
    p3 = p[col + 24];
    p4 = p[col + 32];
    p5 = p[col + 40];
    p6 = p[col + 48];
    p7 = p[col + 56];

    if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
      t = dctSqrt2 * p0 + 8192 >> 14;

      if (t < -2040) {
        t = 0;
      } else if (t >= 2024) {
        t = 255;
      } else {
        t = t + 2056 >> 4;
      }

      blockData[blockBufferOffset + col] = t;
      blockData[blockBufferOffset + col + 8] = t;
      blockData[blockBufferOffset + col + 16] = t;
      blockData[blockBufferOffset + col + 24] = t;
      blockData[blockBufferOffset + col + 32] = t;
      blockData[blockBufferOffset + col + 40] = t;
      blockData[blockBufferOffset + col + 48] = t;
      blockData[blockBufferOffset + col + 56] = t;
      continue;
    }

    v0 = dctSqrt2 * p0 + 2048 >> 12;
    v1 = dctSqrt2 * p4 + 2048 >> 12;
    v2 = p2;
    v3 = p6;
    v4 = dctSqrt1d2 * (p1 - p7) + 2048 >> 12;
    v7 = dctSqrt1d2 * (p1 + p7) + 2048 >> 12;
    v5 = p3;
    v6 = p5;
    v0 = (v0 + v1 + 1 >> 1) + 4112;
    v1 = v0 - v1;
    t = v2 * dctSin6 + v3 * dctCos6 + 2048 >> 12;
    v2 = v2 * dctCos6 - v3 * dctSin6 + 2048 >> 12;
    v3 = t;
    v4 = v4 + v6 + 1 >> 1;
    v6 = v4 - v6;
    v7 = v7 + v5 + 1 >> 1;
    v5 = v7 - v5;
    v0 = v0 + v3 + 1 >> 1;
    v3 = v0 - v3;
    v1 = v1 + v2 + 1 >> 1;
    v2 = v1 - v2;
    t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
    v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
    v7 = t;
    t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
    v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
    v6 = t;
    p0 = v0 + v7;
    p7 = v0 - v7;
    p1 = v1 + v6;
    p6 = v1 - v6;
    p2 = v2 + v5;
    p5 = v2 - v5;
    p3 = v3 + v4;
    p4 = v3 - v4;

    if (p0 < 16) {
      p0 = 0;
    } else if (p0 >= 4080) {
      p0 = 255;
    } else {
      p0 >>= 4;
    }

    if (p1 < 16) {
      p1 = 0;
    } else if (p1 >= 4080) {
      p1 = 255;
    } else {
      p1 >>= 4;
    }

    if (p2 < 16) {
      p2 = 0;
    } else if (p2 >= 4080) {
      p2 = 255;
    } else {
      p2 >>= 4;
    }

    if (p3 < 16) {
      p3 = 0;
    } else if (p3 >= 4080) {
      p3 = 255;
    } else {
      p3 >>= 4;
    }

    if (p4 < 16) {
      p4 = 0;
    } else if (p4 >= 4080) {
      p4 = 255;
    } else {
      p4 >>= 4;
    }

    if (p5 < 16) {
      p5 = 0;
    } else if (p5 >= 4080) {
      p5 = 255;
    } else {
      p5 >>= 4;
    }

    if (p6 < 16) {
      p6 = 0;
    } else if (p6 >= 4080) {
      p6 = 255;
    } else {
      p6 >>= 4;
    }

    if (p7 < 16) {
      p7 = 0;
    } else if (p7 >= 4080) {
      p7 = 255;
    } else {
      p7 >>= 4;
    }

    blockData[blockBufferOffset + col] = p0;
    blockData[blockBufferOffset + col + 8] = p1;
    blockData[blockBufferOffset + col + 16] = p2;
    blockData[blockBufferOffset + col + 24] = p3;
    blockData[blockBufferOffset + col + 32] = p4;
    blockData[blockBufferOffset + col + 40] = p5;
    blockData[blockBufferOffset + col + 48] = p6;
    blockData[blockBufferOffset + col + 56] = p7;
  }
}

function buildComponentData(frame, component) {
  const blocksPerLine = component.blocksPerLine;
  const blocksPerColumn = component.blocksPerColumn;
  const computationBuffer = new Int16Array(64);

  for (let blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
    for (let blockCol = 0; blockCol < blocksPerLine; blockCol++) {
      const offset = getBlockBufferOffset(component, blockRow, blockCol);
      quantizeAndInverse(component, offset, computationBuffer);
    }
  }

  return component.blockData;
}

function findNextFileMarker(data, currentPos, startPos = currentPos) {
  const maxPos = data.length - 1;
  let newPos = startPos < currentPos ? startPos : currentPos;

  if (currentPos >= maxPos) {
    return null;
  }

  const currentMarker = (0, _core_utils.readUint16)(data, currentPos);

  if (currentMarker >= 0xffc0 && currentMarker <= 0xfffe) {
    return {
      invalid: null,
      marker: currentMarker,
      offset: currentPos
    };
  }

  let newMarker = (0, _core_utils.readUint16)(data, newPos);

  while (!(newMarker >= 0xffc0 && newMarker <= 0xfffe)) {
    if (++newPos >= maxPos) {
      return null;
    }

    newMarker = (0, _core_utils.readUint16)(data, newPos);
  }

  return {
    invalid: currentMarker.toString(16),
    marker: newMarker,
    offset: newPos
  };
}

class JpegImage {
  constructor({
    decodeTransform = null,
    colorTransform = -1
  } = {}) {
    this._decodeTransform = decodeTransform;
    this._colorTransform = colorTransform;
  }

  parse(data, {
    dnlScanLines = null
  } = {}) {
    function readDataBlock() {
      const length = (0, _core_utils.readUint16)(data, offset);
      offset += 2;
      let endOffset = offset + length - 2;
      const fileMarker = findNextFileMarker(data, endOffset, offset);

      if (fileMarker && fileMarker.invalid) {
        (0, _util.warn)("readDataBlock - incorrect length, current marker is: " + fileMarker.invalid);
        endOffset = fileMarker.offset;
      }

      const array = data.subarray(offset, endOffset);
      offset += array.length;
      return array;
    }

    function prepareComponents(frame) {
      const mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
      const mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);

      for (let i = 0, ii = frame.components.length; i < ii; i++) {
        const component = frame.components[i];
        const blocksPerLine = Math.ceil(Math.ceil(frame.samplesPerLine / 8) * component.h / frame.maxH);
        const blocksPerColumn = Math.ceil(Math.ceil(frame.scanLines / 8) * component.v / frame.maxV);
        const blocksPerLineForMcu = mcusPerLine * component.h;
        const blocksPerColumnForMcu = mcusPerColumn * component.v;
        const blocksBufferSize = 64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
        component.blockData = new Int16Array(blocksBufferSize);
        component.blocksPerLine = blocksPerLine;
        component.blocksPerColumn = blocksPerColumn;
      }

      frame.mcusPerLine = mcusPerLine;
      frame.mcusPerColumn = mcusPerColumn;
    }

    let offset = 0;
    let jfif = null;
    let adobe = null;
    let frame, resetInterval;
    let numSOSMarkers = 0;
    const quantizationTables = [];
    const huffmanTablesAC = [],
          huffmanTablesDC = [];
    let fileMarker = (0, _core_utils.readUint16)(data, offset);
    offset += 2;

    if (fileMarker !== 0xffd8) {
      throw new JpegError("SOI not found");
    }

    fileMarker = (0, _core_utils.readUint16)(data, offset);
    offset += 2;

    markerLoop: while (fileMarker !== 0xffd9) {
      let i, j, l;

      switch (fileMarker) {
        case 0xffe0:
        case 0xffe1:
        case 0xffe2:
        case 0xffe3:
        case 0xffe4:
        case 0xffe5:
        case 0xffe6:
        case 0xffe7:
        case 0xffe8:
        case 0xffe9:
        case 0xffea:
        case 0xffeb:
        case 0xffec:
        case 0xffed:
        case 0xffee:
        case 0xffef:
        case 0xfffe:
          const appData = readDataBlock();

          if (fileMarker === 0xffe0) {
            if (appData[0] === 0x4a && appData[1] === 0x46 && appData[2] === 0x49 && appData[3] === 0x46 && appData[4] === 0) {
              jfif = {
                version: {
                  major: appData[5],
                  minor: appData[6]
                },
                densityUnits: appData[7],
                xDensity: appData[8] << 8 | appData[9],
                yDensity: appData[10] << 8 | appData[11],
                thumbWidth: appData[12],
                thumbHeight: appData[13],
                thumbData: appData.subarray(14, 14 + 3 * appData[12] * appData[13])
              };
            }
          }

          if (fileMarker === 0xffee) {
            if (appData[0] === 0x41 && appData[1] === 0x64 && appData[2] === 0x6f && appData[3] === 0x62 && appData[4] === 0x65) {
              adobe = {
                version: appData[5] << 8 | appData[6],
                flags0: appData[7] << 8 | appData[8],
                flags1: appData[9] << 8 | appData[10],
                transformCode: appData[11]
              };
            }
          }

          break;

        case 0xffdb:
          const quantizationTablesLength = (0, _core_utils.readUint16)(data, offset);
          offset += 2;
          const quantizationTablesEnd = quantizationTablesLength + offset - 2;
          let z;

          while (offset < quantizationTablesEnd) {
            const quantizationTableSpec = data[offset++];
            const tableData = new Uint16Array(64);

            if (quantizationTableSpec >> 4 === 0) {
              for (j = 0; j < 64; j++) {
                z = dctZigZag[j];
                tableData[z] = data[offset++];
              }
            } else if (quantizationTableSpec >> 4 === 1) {
              for (j = 0; j < 64; j++) {
                z = dctZigZag[j];
                tableData[z] = (0, _core_utils.readUint16)(data, offset);
                offset += 2;
              }
            } else {
              throw new JpegError("DQT - invalid table spec");
            }

            quantizationTables[quantizationTableSpec & 15] = tableData;
          }

          break;

        case 0xffc0:
        case 0xffc1:
        case 0xffc2:
          if (frame) {
            throw new JpegError("Only single frame JPEGs supported");
          }

          offset += 2;
          frame = {};
          frame.extended = fileMarker === 0xffc1;
          frame.progressive = fileMarker === 0xffc2;
          frame.precision = data[offset++];
          const sofScanLines = (0, _core_utils.readUint16)(data, offset);
          offset += 2;
          frame.scanLines = dnlScanLines || sofScanLines;
          frame.samplesPerLine = (0, _core_utils.readUint16)(data, offset);
          offset += 2;
          frame.components = [];
          frame.componentIds = {};
          const componentsCount = data[offset++];
          let maxH = 0,
              maxV = 0;

          for (i = 0; i < componentsCount; i++) {
            const componentId = data[offset];
            const h = data[offset + 1] >> 4;
            const v = data[offset + 1] & 15;

            if (maxH < h) {
              maxH = h;
            }

            if (maxV < v) {
              maxV = v;
            }

            const qId = data[offset + 2];
            l = frame.components.push({
              h,
              v,
              quantizationId: qId,
              quantizationTable: null
            });
            frame.componentIds[componentId] = l - 1;
            offset += 3;
          }

          frame.maxH = maxH;
          frame.maxV = maxV;
          prepareComponents(frame);
          break;

        case 0xffc4:
          const huffmanLength = (0, _core_utils.readUint16)(data, offset);
          offset += 2;

          for (i = 2; i < huffmanLength;) {
            const huffmanTableSpec = data[offset++];
            const codeLengths = new Uint8Array(16);
            let codeLengthSum = 0;

            for (j = 0; j < 16; j++, offset++) {
              codeLengthSum += codeLengths[j] = data[offset];
            }

            const huffmanValues = new Uint8Array(codeLengthSum);

            for (j = 0; j < codeLengthSum; j++, offset++) {
              huffmanValues[j] = data[offset];
            }

            i += 17 + codeLengthSum;
            (huffmanTableSpec >> 4 === 0 ? huffmanTablesDC : huffmanTablesAC)[huffmanTableSpec & 15] = buildHuffmanTable(codeLengths, huffmanValues);
          }

          break;

        case 0xffdd:
          offset += 2;
          resetInterval = (0, _core_utils.readUint16)(data, offset);
          offset += 2;
          break;

        case 0xffda:
          const parseDNLMarker = ++numSOSMarkers === 1 && !dnlScanLines;
          offset += 2;
          const selectorsCount = data[offset++],
                components = [];

          for (i = 0; i < selectorsCount; i++) {
            const index = data[offset++];
            const componentIndex = frame.componentIds[index];
            const component = frame.components[componentIndex];
            component.index = index;
            const tableSpec = data[offset++];
            component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
            component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
            components.push(component);
          }

          const spectralStart = data[offset++],
                spectralEnd = data[offset++],
                successiveApproximation = data[offset++];

          try {
            const processed = decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successiveApproximation >> 4, successiveApproximation & 15, parseDNLMarker);
            offset += processed;
          } catch (ex) {
            if (ex instanceof DNLMarkerError) {
              (0, _util.warn)(`${ex.message} -- attempting to re-parse the JPEG image.`);
              return this.parse(data, {
                dnlScanLines: ex.scanLines
              });
            } else if (ex instanceof EOIMarkerError) {
              (0, _util.warn)(`${ex.message} -- ignoring the rest of the image data.`);
              break markerLoop;
            }

            throw ex;
          }

          break;

        case 0xffdc:
          offset += 4;
          break;

        case 0xffff:
          if (data[offset] !== 0xff) {
            offset--;
          }

          break;

        default:
          const nextFileMarker = findNextFileMarker(data, offset - 2, offset - 3);

          if (nextFileMarker && nextFileMarker.invalid) {
            (0, _util.warn)("JpegImage.parse - unexpected data, current marker is: " + nextFileMarker.invalid);
            offset = nextFileMarker.offset;
            break;
          }

          if (!nextFileMarker || offset >= data.length - 1) {
            (0, _util.warn)("JpegImage.parse - reached the end of the image data " + "without finding an EOI marker (0xFFD9).");
            break markerLoop;
          }

          throw new JpegError("JpegImage.parse - unknown marker: " + fileMarker.toString(16));
      }

      fileMarker = (0, _core_utils.readUint16)(data, offset);
      offset += 2;
    }

    this.width = frame.samplesPerLine;
    this.height = frame.scanLines;
    this.jfif = jfif;
    this.adobe = adobe;
    this.components = [];

    for (let i = 0, ii = frame.components.length; i < ii; i++) {
      const component = frame.components[i];
      const quantizationTable = quantizationTables[component.quantizationId];

      if (quantizationTable) {
        component.quantizationTable = quantizationTable;
      }

      this.components.push({
        index: component.index,
        output: buildComponentData(frame, component),
        scaleX: component.h / frame.maxH,
        scaleY: component.v / frame.maxV,
        blocksPerLine: component.blocksPerLine,
        blocksPerColumn: component.blocksPerColumn
      });
    }

    this.numComponents = this.components.length;
    return undefined;
  }

  _getLinearizedBlockData(width, height, isSourcePDF = false) {
    const scaleX = this.width / width,
          scaleY = this.height / height;
    let component, componentScaleX, componentScaleY, blocksPerScanline;
    let x, y, i, j, k;
    let index;
    let offset = 0;
    let output;
    const numComponents = this.components.length;
    const dataLength = width * height * numComponents;
    const data = new Uint8ClampedArray(dataLength);
    const xScaleBlockOffset = new Uint32Array(width);
    const mask3LSB = 0xfffffff8;
    let lastComponentScaleX;

    for (i = 0; i < numComponents; i++) {
      component = this.components[i];
      componentScaleX = component.scaleX * scaleX;
      componentScaleY = component.scaleY * scaleY;
      offset = i;
      output = component.output;
      blocksPerScanline = component.blocksPerLine + 1 << 3;

      if (componentScaleX !== lastComponentScaleX) {
        for (x = 0; x < width; x++) {
          j = 0 | x * componentScaleX;
          xScaleBlockOffset[x] = (j & mask3LSB) << 3 | j & 7;
        }

        lastComponentScaleX = componentScaleX;
      }

      for (y = 0; y < height; y++) {
        j = 0 | y * componentScaleY;
        index = blocksPerScanline * (j & mask3LSB) | (j & 7) << 3;

        for (x = 0; x < width; x++) {
          data[offset] = output[index + xScaleBlockOffset[x]];
          offset += numComponents;
        }
      }
    }

    let transform = this._decodeTransform;

    if (!isSourcePDF && numComponents === 4 && !transform) {
      transform = new Int32Array([-256, 255, -256, 255, -256, 255, -256, 255]);
    }

    if (transform) {
      for (i = 0; i < dataLength;) {
        for (j = 0, k = 0; j < numComponents; j++, i++, k += 2) {
          data[i] = (data[i] * transform[k] >> 8) + transform[k + 1];
        }
      }
    }

    return data;
  }

  get _isColorConversionNeeded() {
    if (this.adobe) {
      return !!this.adobe.transformCode;
    }

    if (this.numComponents === 3) {
      if (this._colorTransform === 0) {
        return false;
      } else if (this.components[0].index === 0x52 && this.components[1].index === 0x47 && this.components[2].index === 0x42) {
        return false;
      }

      return true;
    }

    if (this._colorTransform === 1) {
      return true;
    }

    return false;
  }

  _convertYccToRgb(data) {
    let Y, Cb, Cr;

    for (let i = 0, length = data.length; i < length; i += 3) {
      Y = data[i];
      Cb = data[i + 1];
      Cr = data[i + 2];
      data[i] = Y - 179.456 + 1.402 * Cr;
      data[i + 1] = Y + 135.459 - 0.344 * Cb - 0.714 * Cr;
      data[i + 2] = Y - 226.816 + 1.772 * Cb;
    }

    return data;
  }

  _convertYcckToRgb(data) {
    let Y, Cb, Cr, k;
    let offset = 0;

    for (let i = 0, length = data.length; i < length; i += 4) {
      Y = data[i];
      Cb = data[i + 1];
      Cr = data[i + 2];
      k = data[i + 3];
      data[offset++] = -122.67195406894 + Cb * (-6.60635669420364e-5 * Cb + 0.000437130475926232 * Cr - 5.4080610064599e-5 * Y + 0.00048449797120281 * k - 0.154362151871126) + Cr * (-0.000957964378445773 * Cr + 0.000817076911346625 * Y - 0.00477271405408747 * k + 1.53380253221734) + Y * (0.000961250184130688 * Y - 0.00266257332283933 * k + 0.48357088451265) + k * (-0.000336197177618394 * k + 0.484791561490776);
      data[offset++] = 107.268039397724 + Cb * (2.19927104525741e-5 * Cb - 0.000640992018297945 * Cr + 0.000659397001245577 * Y + 0.000426105652938837 * k - 0.176491792462875) + Cr * (-0.000778269941513683 * Cr + 0.00130872261408275 * Y + 0.000770482631801132 * k - 0.151051492775562) + Y * (0.00126935368114843 * Y - 0.00265090189010898 * k + 0.25802910206845) + k * (-0.000318913117588328 * k - 0.213742400323665);
      data[offset++] = -20.810012546947 + Cb * (-0.000570115196973677 * Cb - 2.63409051004589e-5 * Cr + 0.0020741088115012 * Y - 0.00288260236853442 * k + 0.814272968359295) + Cr * (-1.53496057440975e-5 * Cr - 0.000132689043961446 * Y + 0.000560833691242812 * k - 0.195152027534049) + Y * (0.00174418132927582 * Y - 0.00255243321439347 * k + 0.116935020465145) + k * (-0.000343531996510555 * k + 0.24165260232407);
    }

    return data.subarray(0, offset);
  }

  _convertYcckToCmyk(data) {
    let Y, Cb, Cr;

    for (let i = 0, length = data.length; i < length; i += 4) {
      Y = data[i];
      Cb = data[i + 1];
      Cr = data[i + 2];
      data[i] = 434.456 - Y - 1.402 * Cr;
      data[i + 1] = 119.541 - Y + 0.344 * Cb + 0.714 * Cr;
      data[i + 2] = 481.816 - Y - 1.772 * Cb;
    }

    return data;
  }

  _convertCmykToRgb(data) {
    let c, m, y, k;
    let offset = 0;

    for (let i = 0, length = data.length; i < length; i += 4) {
      c = data[i];
      m = data[i + 1];
      y = data[i + 2];
      k = data[i + 3];
      data[offset++] = 255 + c * (-0.00006747147073602441 * c + 0.0008379262121013727 * m + 0.0002894718188643294 * y + 0.003264231057537806 * k - 1.1185611867203937) + m * (0.000026374107616089405 * m - 0.00008626949158638572 * y - 0.0002748769067499491 * k - 0.02155688794978967) + y * (-0.00003878099212869363 * y - 0.0003267808279485286 * k + 0.0686742238595345) - k * (0.0003361971776183937 * k + 0.7430659151342254);
      data[offset++] = 255 + c * (0.00013596372813588848 * c + 0.000924537132573585 * m + 0.00010567359618683593 * y + 0.0004791864687436512 * k - 0.3109689587515875) + m * (-0.00023545346108370344 * m + 0.0002702845253534714 * y + 0.0020200308977307156 * k - 0.7488052167015494) + y * (0.00006834815998235662 * y + 0.00015168452363460973 * k - 0.09751927774728933) - k * (0.00031891311758832814 * k + 0.7364883807733168);
      data[offset++] = 255 + c * (0.000013598650411385307 * c + 0.00012423956175490851 * m + 0.0004751985097583589 * y - 0.0000036729317476630422 * k - 0.05562186980264034) + m * (0.00016141380598724676 * m + 0.0009692239130725186 * y + 0.0007782692450036253 * k - 0.44015232367526463) + y * (5.068882914068769e-7 * y + 0.0017778369011375071 * k - 0.7591454649749609) - k * (0.0003435319965105553 * k + 0.7063770186160144);
    }

    return data.subarray(0, offset);
  }

  getData({
    width,
    height,
    forceRGB = false,
    isSourcePDF = false
  }) {
    if (this.numComponents > 4) {
      throw new JpegError("Unsupported color mode");
    }

    const data = this._getLinearizedBlockData(width, height, isSourcePDF);

    if (this.numComponents === 1 && forceRGB) {
      const dataLength = data.length;
      const rgbData = new Uint8ClampedArray(dataLength * 3);
      let offset = 0;

      for (let i = 0; i < dataLength; i++) {
        const grayColor = data[i];
        rgbData[offset++] = grayColor;
        rgbData[offset++] = grayColor;
        rgbData[offset++] = grayColor;
      }

      return rgbData;
    } else if (this.numComponents === 3 && this._isColorConversionNeeded) {
      return this._convertYccToRgb(data);
    } else if (this.numComponents === 4) {
      if (this._isColorConversionNeeded) {
        if (forceRGB) {
          return this._convertYcckToRgb(data);
        }

        return this._convertYcckToCmyk(data);
      } else if (forceRGB) {
        return this._convertCmykToRgb(data);
      }
    }

    return data;
  }

}

exports.JpegImage = JpegImage;