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jpg.js 35 KB

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  1. /**
  2. * @licstart The following is the entire license notice for the
  3. * Javascript code in this page
  4. *
  5. * Copyright 2017 Mozilla Foundation
  6. *
  7. * Licensed under the Apache License, Version 2.0 (the "License");
  8. * you may not use this file except in compliance with the License.
  9. * You may obtain a copy of the License at
  10. *
  11. * http://www.apache.org/licenses/LICENSE-2.0
  12. *
  13. * Unless required by applicable law or agreed to in writing, software
  14. * distributed under the License is distributed on an "AS IS" BASIS,
  15. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16. * See the License for the specific language governing permissions and
  17. * limitations under the License.
  18. *
  19. * @licend The above is the entire license notice for the
  20. * Javascript code in this page
  21. */
  22. 'use strict';
  23. Object.defineProperty(exports, "__esModule", {
  24. value: true
  25. });
  26. exports.JpegImage = undefined;
  27. var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };
  28. var _util = require('../shared/util');
  29. var JpegError = function JpegErrorClosure() {
  30. function JpegError(msg) {
  31. this.message = 'JPEG error: ' + msg;
  32. }
  33. JpegError.prototype = new Error();
  34. JpegError.prototype.name = 'JpegError';
  35. JpegError.constructor = JpegError;
  36. return JpegError;
  37. }();
  38. var DNLMarkerError = function DNLMarkerErrorClosure() {
  39. function DNLMarkerError(message, scanLines) {
  40. this.message = message;
  41. this.scanLines = scanLines;
  42. }
  43. DNLMarkerError.prototype = new Error();
  44. DNLMarkerError.prototype.name = 'DNLMarkerError';
  45. DNLMarkerError.constructor = DNLMarkerError;
  46. return DNLMarkerError;
  47. }();
  48. var JpegImage = function JpegImageClosure() {
  49. var 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]);
  50. var dctCos1 = 4017;
  51. var dctSin1 = 799;
  52. var dctCos3 = 3406;
  53. var dctSin3 = 2276;
  54. var dctCos6 = 1567;
  55. var dctSin6 = 3784;
  56. var dctSqrt2 = 5793;
  57. var dctSqrt1d2 = 2896;
  58. function JpegImage() {
  59. this.decodeTransform = null;
  60. this.colorTransform = -1;
  61. }
  62. function buildHuffmanTable(codeLengths, values) {
  63. var k = 0,
  64. code = [],
  65. i,
  66. j,
  67. length = 16;
  68. while (length > 0 && !codeLengths[length - 1]) {
  69. length--;
  70. }
  71. code.push({
  72. children: [],
  73. index: 0
  74. });
  75. var p = code[0],
  76. q;
  77. for (i = 0; i < length; i++) {
  78. for (j = 0; j < codeLengths[i]; j++) {
  79. p = code.pop();
  80. p.children[p.index] = values[k];
  81. while (p.index > 0) {
  82. p = code.pop();
  83. }
  84. p.index++;
  85. code.push(p);
  86. while (code.length <= i) {
  87. code.push(q = {
  88. children: [],
  89. index: 0
  90. });
  91. p.children[p.index] = q.children;
  92. p = q;
  93. }
  94. k++;
  95. }
  96. if (i + 1 < length) {
  97. code.push(q = {
  98. children: [],
  99. index: 0
  100. });
  101. p.children[p.index] = q.children;
  102. p = q;
  103. }
  104. }
  105. return code[0].children;
  106. }
  107. function getBlockBufferOffset(component, row, col) {
  108. return 64 * ((component.blocksPerLine + 1) * row + col);
  109. }
  110. function decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successivePrev, successive) {
  111. var parseDNLMarker = arguments.length > 9 && arguments[9] !== undefined ? arguments[9] : false;
  112. var mcusPerLine = frame.mcusPerLine;
  113. var progressive = frame.progressive;
  114. var startOffset = offset,
  115. bitsData = 0,
  116. bitsCount = 0;
  117. function readBit() {
  118. if (bitsCount > 0) {
  119. bitsCount--;
  120. return bitsData >> bitsCount & 1;
  121. }
  122. bitsData = data[offset++];
  123. if (bitsData === 0xFF) {
  124. var nextByte = data[offset++];
  125. if (nextByte) {
  126. if (nextByte === 0xDC && parseDNLMarker) {
  127. offset += 2;
  128. var scanLines = data[offset++] << 8 | data[offset++];
  129. if (scanLines > 0 && scanLines !== frame.scanLines) {
  130. throw new DNLMarkerError('Found DNL marker (0xFFDC) while parsing scan data', scanLines);
  131. }
  132. }
  133. throw new JpegError('unexpected marker ' + (bitsData << 8 | nextByte).toString(16));
  134. }
  135. }
  136. bitsCount = 7;
  137. return bitsData >>> 7;
  138. }
  139. function decodeHuffman(tree) {
  140. var node = tree;
  141. while (true) {
  142. node = node[readBit()];
  143. if (typeof node === 'number') {
  144. return node;
  145. }
  146. if ((typeof node === 'undefined' ? 'undefined' : _typeof(node)) !== 'object') {
  147. throw new JpegError('invalid huffman sequence');
  148. }
  149. }
  150. }
  151. function receive(length) {
  152. var n = 0;
  153. while (length > 0) {
  154. n = n << 1 | readBit();
  155. length--;
  156. }
  157. return n;
  158. }
  159. function receiveAndExtend(length) {
  160. if (length === 1) {
  161. return readBit() === 1 ? 1 : -1;
  162. }
  163. var n = receive(length);
  164. if (n >= 1 << length - 1) {
  165. return n;
  166. }
  167. return n + (-1 << length) + 1;
  168. }
  169. function decodeBaseline(component, offset) {
  170. var t = decodeHuffman(component.huffmanTableDC);
  171. var diff = t === 0 ? 0 : receiveAndExtend(t);
  172. component.blockData[offset] = component.pred += diff;
  173. var k = 1;
  174. while (k < 64) {
  175. var rs = decodeHuffman(component.huffmanTableAC);
  176. var s = rs & 15,
  177. r = rs >> 4;
  178. if (s === 0) {
  179. if (r < 15) {
  180. break;
  181. }
  182. k += 16;
  183. continue;
  184. }
  185. k += r;
  186. var z = dctZigZag[k];
  187. component.blockData[offset + z] = receiveAndExtend(s);
  188. k++;
  189. }
  190. }
  191. function decodeDCFirst(component, offset) {
  192. var t = decodeHuffman(component.huffmanTableDC);
  193. var diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
  194. component.blockData[offset] = component.pred += diff;
  195. }
  196. function decodeDCSuccessive(component, offset) {
  197. component.blockData[offset] |= readBit() << successive;
  198. }
  199. var eobrun = 0;
  200. function decodeACFirst(component, offset) {
  201. if (eobrun > 0) {
  202. eobrun--;
  203. return;
  204. }
  205. var k = spectralStart,
  206. e = spectralEnd;
  207. while (k <= e) {
  208. var rs = decodeHuffman(component.huffmanTableAC);
  209. var s = rs & 15,
  210. r = rs >> 4;
  211. if (s === 0) {
  212. if (r < 15) {
  213. eobrun = receive(r) + (1 << r) - 1;
  214. break;
  215. }
  216. k += 16;
  217. continue;
  218. }
  219. k += r;
  220. var z = dctZigZag[k];
  221. component.blockData[offset + z] = receiveAndExtend(s) * (1 << successive);
  222. k++;
  223. }
  224. }
  225. var successiveACState = 0,
  226. successiveACNextValue;
  227. function decodeACSuccessive(component, offset) {
  228. var k = spectralStart;
  229. var e = spectralEnd;
  230. var r = 0;
  231. var s;
  232. var rs;
  233. while (k <= e) {
  234. var offsetZ = offset + dctZigZag[k];
  235. var sign = component.blockData[offsetZ] < 0 ? -1 : 1;
  236. switch (successiveACState) {
  237. case 0:
  238. rs = decodeHuffman(component.huffmanTableAC);
  239. s = rs & 15;
  240. r = rs >> 4;
  241. if (s === 0) {
  242. if (r < 15) {
  243. eobrun = receive(r) + (1 << r);
  244. successiveACState = 4;
  245. } else {
  246. r = 16;
  247. successiveACState = 1;
  248. }
  249. } else {
  250. if (s !== 1) {
  251. throw new JpegError('invalid ACn encoding');
  252. }
  253. successiveACNextValue = receiveAndExtend(s);
  254. successiveACState = r ? 2 : 3;
  255. }
  256. continue;
  257. case 1:
  258. case 2:
  259. if (component.blockData[offsetZ]) {
  260. component.blockData[offsetZ] += sign * (readBit() << successive);
  261. } else {
  262. r--;
  263. if (r === 0) {
  264. successiveACState = successiveACState === 2 ? 3 : 0;
  265. }
  266. }
  267. break;
  268. case 3:
  269. if (component.blockData[offsetZ]) {
  270. component.blockData[offsetZ] += sign * (readBit() << successive);
  271. } else {
  272. component.blockData[offsetZ] = successiveACNextValue << successive;
  273. successiveACState = 0;
  274. }
  275. break;
  276. case 4:
  277. if (component.blockData[offsetZ]) {
  278. component.blockData[offsetZ] += sign * (readBit() << successive);
  279. }
  280. break;
  281. }
  282. k++;
  283. }
  284. if (successiveACState === 4) {
  285. eobrun--;
  286. if (eobrun === 0) {
  287. successiveACState = 0;
  288. }
  289. }
  290. }
  291. function decodeMcu(component, decode, mcu, row, col) {
  292. var mcuRow = mcu / mcusPerLine | 0;
  293. var mcuCol = mcu % mcusPerLine;
  294. var blockRow = mcuRow * component.v + row;
  295. var blockCol = mcuCol * component.h + col;
  296. var offset = getBlockBufferOffset(component, blockRow, blockCol);
  297. decode(component, offset);
  298. }
  299. function decodeBlock(component, decode, mcu) {
  300. var blockRow = mcu / component.blocksPerLine | 0;
  301. var blockCol = mcu % component.blocksPerLine;
  302. var offset = getBlockBufferOffset(component, blockRow, blockCol);
  303. decode(component, offset);
  304. }
  305. var componentsLength = components.length;
  306. var component, i, j, k, n;
  307. var decodeFn;
  308. if (progressive) {
  309. if (spectralStart === 0) {
  310. decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
  311. } else {
  312. decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive;
  313. }
  314. } else {
  315. decodeFn = decodeBaseline;
  316. }
  317. var mcu = 0,
  318. fileMarker;
  319. var mcuExpected;
  320. if (componentsLength === 1) {
  321. mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
  322. } else {
  323. mcuExpected = mcusPerLine * frame.mcusPerColumn;
  324. }
  325. var h, v;
  326. while (mcu < mcuExpected) {
  327. var mcuToRead = resetInterval ? Math.min(mcuExpected - mcu, resetInterval) : mcuExpected;
  328. for (i = 0; i < componentsLength; i++) {
  329. components[i].pred = 0;
  330. }
  331. eobrun = 0;
  332. if (componentsLength === 1) {
  333. component = components[0];
  334. for (n = 0; n < mcuToRead; n++) {
  335. decodeBlock(component, decodeFn, mcu);
  336. mcu++;
  337. }
  338. } else {
  339. for (n = 0; n < mcuToRead; n++) {
  340. for (i = 0; i < componentsLength; i++) {
  341. component = components[i];
  342. h = component.h;
  343. v = component.v;
  344. for (j = 0; j < v; j++) {
  345. for (k = 0; k < h; k++) {
  346. decodeMcu(component, decodeFn, mcu, j, k);
  347. }
  348. }
  349. }
  350. mcu++;
  351. }
  352. }
  353. bitsCount = 0;
  354. fileMarker = findNextFileMarker(data, offset);
  355. if (fileMarker && fileMarker.invalid) {
  356. (0, _util.warn)('decodeScan - unexpected MCU data, current marker is: ' + fileMarker.invalid);
  357. offset = fileMarker.offset;
  358. }
  359. var marker = fileMarker && fileMarker.marker;
  360. if (!marker || marker <= 0xFF00) {
  361. throw new JpegError('marker was not found');
  362. }
  363. if (marker >= 0xFFD0 && marker <= 0xFFD7) {
  364. offset += 2;
  365. } else {
  366. break;
  367. }
  368. }
  369. fileMarker = findNextFileMarker(data, offset);
  370. if (fileMarker && fileMarker.invalid) {
  371. (0, _util.warn)('decodeScan - unexpected Scan data, current marker is: ' + fileMarker.invalid);
  372. offset = fileMarker.offset;
  373. }
  374. return offset - startOffset;
  375. }
  376. function quantizeAndInverse(component, blockBufferOffset, p) {
  377. var qt = component.quantizationTable,
  378. blockData = component.blockData;
  379. var v0, v1, v2, v3, v4, v5, v6, v7;
  380. var p0, p1, p2, p3, p4, p5, p6, p7;
  381. var t;
  382. if (!qt) {
  383. throw new JpegError('missing required Quantization Table.');
  384. }
  385. for (var row = 0; row < 64; row += 8) {
  386. p0 = blockData[blockBufferOffset + row];
  387. p1 = blockData[blockBufferOffset + row + 1];
  388. p2 = blockData[blockBufferOffset + row + 2];
  389. p3 = blockData[blockBufferOffset + row + 3];
  390. p4 = blockData[blockBufferOffset + row + 4];
  391. p5 = blockData[blockBufferOffset + row + 5];
  392. p6 = blockData[blockBufferOffset + row + 6];
  393. p7 = blockData[blockBufferOffset + row + 7];
  394. p0 *= qt[row];
  395. if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
  396. t = dctSqrt2 * p0 + 512 >> 10;
  397. p[row] = t;
  398. p[row + 1] = t;
  399. p[row + 2] = t;
  400. p[row + 3] = t;
  401. p[row + 4] = t;
  402. p[row + 5] = t;
  403. p[row + 6] = t;
  404. p[row + 7] = t;
  405. continue;
  406. }
  407. p1 *= qt[row + 1];
  408. p2 *= qt[row + 2];
  409. p3 *= qt[row + 3];
  410. p4 *= qt[row + 4];
  411. p5 *= qt[row + 5];
  412. p6 *= qt[row + 6];
  413. p7 *= qt[row + 7];
  414. v0 = dctSqrt2 * p0 + 128 >> 8;
  415. v1 = dctSqrt2 * p4 + 128 >> 8;
  416. v2 = p2;
  417. v3 = p6;
  418. v4 = dctSqrt1d2 * (p1 - p7) + 128 >> 8;
  419. v7 = dctSqrt1d2 * (p1 + p7) + 128 >> 8;
  420. v5 = p3 << 4;
  421. v6 = p5 << 4;
  422. v0 = v0 + v1 + 1 >> 1;
  423. v1 = v0 - v1;
  424. t = v2 * dctSin6 + v3 * dctCos6 + 128 >> 8;
  425. v2 = v2 * dctCos6 - v3 * dctSin6 + 128 >> 8;
  426. v3 = t;
  427. v4 = v4 + v6 + 1 >> 1;
  428. v6 = v4 - v6;
  429. v7 = v7 + v5 + 1 >> 1;
  430. v5 = v7 - v5;
  431. v0 = v0 + v3 + 1 >> 1;
  432. v3 = v0 - v3;
  433. v1 = v1 + v2 + 1 >> 1;
  434. v2 = v1 - v2;
  435. t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
  436. v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
  437. v7 = t;
  438. t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
  439. v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
  440. v6 = t;
  441. p[row] = v0 + v7;
  442. p[row + 7] = v0 - v7;
  443. p[row + 1] = v1 + v6;
  444. p[row + 6] = v1 - v6;
  445. p[row + 2] = v2 + v5;
  446. p[row + 5] = v2 - v5;
  447. p[row + 3] = v3 + v4;
  448. p[row + 4] = v3 - v4;
  449. }
  450. for (var col = 0; col < 8; ++col) {
  451. p0 = p[col];
  452. p1 = p[col + 8];
  453. p2 = p[col + 16];
  454. p3 = p[col + 24];
  455. p4 = p[col + 32];
  456. p5 = p[col + 40];
  457. p6 = p[col + 48];
  458. p7 = p[col + 56];
  459. if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
  460. t = dctSqrt2 * p0 + 8192 >> 14;
  461. t = t < -2040 ? 0 : t >= 2024 ? 255 : t + 2056 >> 4;
  462. blockData[blockBufferOffset + col] = t;
  463. blockData[blockBufferOffset + col + 8] = t;
  464. blockData[blockBufferOffset + col + 16] = t;
  465. blockData[blockBufferOffset + col + 24] = t;
  466. blockData[blockBufferOffset + col + 32] = t;
  467. blockData[blockBufferOffset + col + 40] = t;
  468. blockData[blockBufferOffset + col + 48] = t;
  469. blockData[blockBufferOffset + col + 56] = t;
  470. continue;
  471. }
  472. v0 = dctSqrt2 * p0 + 2048 >> 12;
  473. v1 = dctSqrt2 * p4 + 2048 >> 12;
  474. v2 = p2;
  475. v3 = p6;
  476. v4 = dctSqrt1d2 * (p1 - p7) + 2048 >> 12;
  477. v7 = dctSqrt1d2 * (p1 + p7) + 2048 >> 12;
  478. v5 = p3;
  479. v6 = p5;
  480. v0 = (v0 + v1 + 1 >> 1) + 4112;
  481. v1 = v0 - v1;
  482. t = v2 * dctSin6 + v3 * dctCos6 + 2048 >> 12;
  483. v2 = v2 * dctCos6 - v3 * dctSin6 + 2048 >> 12;
  484. v3 = t;
  485. v4 = v4 + v6 + 1 >> 1;
  486. v6 = v4 - v6;
  487. v7 = v7 + v5 + 1 >> 1;
  488. v5 = v7 - v5;
  489. v0 = v0 + v3 + 1 >> 1;
  490. v3 = v0 - v3;
  491. v1 = v1 + v2 + 1 >> 1;
  492. v2 = v1 - v2;
  493. t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
  494. v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
  495. v7 = t;
  496. t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
  497. v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
  498. v6 = t;
  499. p0 = v0 + v7;
  500. p7 = v0 - v7;
  501. p1 = v1 + v6;
  502. p6 = v1 - v6;
  503. p2 = v2 + v5;
  504. p5 = v2 - v5;
  505. p3 = v3 + v4;
  506. p4 = v3 - v4;
  507. p0 = p0 < 16 ? 0 : p0 >= 4080 ? 255 : p0 >> 4;
  508. p1 = p1 < 16 ? 0 : p1 >= 4080 ? 255 : p1 >> 4;
  509. p2 = p2 < 16 ? 0 : p2 >= 4080 ? 255 : p2 >> 4;
  510. p3 = p3 < 16 ? 0 : p3 >= 4080 ? 255 : p3 >> 4;
  511. p4 = p4 < 16 ? 0 : p4 >= 4080 ? 255 : p4 >> 4;
  512. p5 = p5 < 16 ? 0 : p5 >= 4080 ? 255 : p5 >> 4;
  513. p6 = p6 < 16 ? 0 : p6 >= 4080 ? 255 : p6 >> 4;
  514. p7 = p7 < 16 ? 0 : p7 >= 4080 ? 255 : p7 >> 4;
  515. blockData[blockBufferOffset + col] = p0;
  516. blockData[blockBufferOffset + col + 8] = p1;
  517. blockData[blockBufferOffset + col + 16] = p2;
  518. blockData[blockBufferOffset + col + 24] = p3;
  519. blockData[blockBufferOffset + col + 32] = p4;
  520. blockData[blockBufferOffset + col + 40] = p5;
  521. blockData[blockBufferOffset + col + 48] = p6;
  522. blockData[blockBufferOffset + col + 56] = p7;
  523. }
  524. }
  525. function buildComponentData(frame, component) {
  526. var blocksPerLine = component.blocksPerLine;
  527. var blocksPerColumn = component.blocksPerColumn;
  528. var computationBuffer = new Int16Array(64);
  529. for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
  530. for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
  531. var offset = getBlockBufferOffset(component, blockRow, blockCol);
  532. quantizeAndInverse(component, offset, computationBuffer);
  533. }
  534. }
  535. return component.blockData;
  536. }
  537. function findNextFileMarker(data, currentPos) {
  538. var startPos = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : currentPos;
  539. function peekUint16(pos) {
  540. return data[pos] << 8 | data[pos + 1];
  541. }
  542. var maxPos = data.length - 1;
  543. var newPos = startPos < currentPos ? startPos : currentPos;
  544. if (currentPos >= maxPos) {
  545. return null;
  546. }
  547. var currentMarker = peekUint16(currentPos);
  548. if (currentMarker >= 0xFFC0 && currentMarker <= 0xFFFE) {
  549. return {
  550. invalid: null,
  551. marker: currentMarker,
  552. offset: currentPos
  553. };
  554. }
  555. var newMarker = peekUint16(newPos);
  556. while (!(newMarker >= 0xFFC0 && newMarker <= 0xFFFE)) {
  557. if (++newPos >= maxPos) {
  558. return null;
  559. }
  560. newMarker = peekUint16(newPos);
  561. }
  562. return {
  563. invalid: currentMarker.toString(16),
  564. marker: newMarker,
  565. offset: newPos
  566. };
  567. }
  568. JpegImage.prototype = {
  569. parse: function parse(data) {
  570. var _ref = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
  571. _ref$dnlScanLines = _ref.dnlScanLines,
  572. dnlScanLines = _ref$dnlScanLines === undefined ? null : _ref$dnlScanLines;
  573. function readUint16() {
  574. var value = data[offset] << 8 | data[offset + 1];
  575. offset += 2;
  576. return value;
  577. }
  578. function readDataBlock() {
  579. var length = readUint16();
  580. var endOffset = offset + length - 2;
  581. var fileMarker = findNextFileMarker(data, endOffset, offset);
  582. if (fileMarker && fileMarker.invalid) {
  583. (0, _util.warn)('readDataBlock - incorrect length, current marker is: ' + fileMarker.invalid);
  584. endOffset = fileMarker.offset;
  585. }
  586. var array = data.subarray(offset, endOffset);
  587. offset += array.length;
  588. return array;
  589. }
  590. function prepareComponents(frame) {
  591. var mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
  592. var mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
  593. for (var i = 0; i < frame.components.length; i++) {
  594. component = frame.components[i];
  595. var blocksPerLine = Math.ceil(Math.ceil(frame.samplesPerLine / 8) * component.h / frame.maxH);
  596. var blocksPerColumn = Math.ceil(Math.ceil(frame.scanLines / 8) * component.v / frame.maxV);
  597. var blocksPerLineForMcu = mcusPerLine * component.h;
  598. var blocksPerColumnForMcu = mcusPerColumn * component.v;
  599. var blocksBufferSize = 64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
  600. component.blockData = new Int16Array(blocksBufferSize);
  601. component.blocksPerLine = blocksPerLine;
  602. component.blocksPerColumn = blocksPerColumn;
  603. }
  604. frame.mcusPerLine = mcusPerLine;
  605. frame.mcusPerColumn = mcusPerColumn;
  606. }
  607. var offset = 0;
  608. var jfif = null;
  609. var adobe = null;
  610. var frame, resetInterval;
  611. var numSOSMarkers = 0;
  612. var quantizationTables = [];
  613. var huffmanTablesAC = [],
  614. huffmanTablesDC = [];
  615. var fileMarker = readUint16();
  616. if (fileMarker !== 0xFFD8) {
  617. throw new JpegError('SOI not found');
  618. }
  619. fileMarker = readUint16();
  620. while (fileMarker !== 0xFFD9) {
  621. var i, j, l;
  622. switch (fileMarker) {
  623. case 0xFFE0:
  624. case 0xFFE1:
  625. case 0xFFE2:
  626. case 0xFFE3:
  627. case 0xFFE4:
  628. case 0xFFE5:
  629. case 0xFFE6:
  630. case 0xFFE7:
  631. case 0xFFE8:
  632. case 0xFFE9:
  633. case 0xFFEA:
  634. case 0xFFEB:
  635. case 0xFFEC:
  636. case 0xFFED:
  637. case 0xFFEE:
  638. case 0xFFEF:
  639. case 0xFFFE:
  640. var appData = readDataBlock();
  641. if (fileMarker === 0xFFE0) {
  642. if (appData[0] === 0x4A && appData[1] === 0x46 && appData[2] === 0x49 && appData[3] === 0x46 && appData[4] === 0) {
  643. jfif = {
  644. version: {
  645. major: appData[5],
  646. minor: appData[6]
  647. },
  648. densityUnits: appData[7],
  649. xDensity: appData[8] << 8 | appData[9],
  650. yDensity: appData[10] << 8 | appData[11],
  651. thumbWidth: appData[12],
  652. thumbHeight: appData[13],
  653. thumbData: appData.subarray(14, 14 + 3 * appData[12] * appData[13])
  654. };
  655. }
  656. }
  657. if (fileMarker === 0xFFEE) {
  658. if (appData[0] === 0x41 && appData[1] === 0x64 && appData[2] === 0x6F && appData[3] === 0x62 && appData[4] === 0x65) {
  659. adobe = {
  660. version: appData[5] << 8 | appData[6],
  661. flags0: appData[7] << 8 | appData[8],
  662. flags1: appData[9] << 8 | appData[10],
  663. transformCode: appData[11]
  664. };
  665. }
  666. }
  667. break;
  668. case 0xFFDB:
  669. var quantizationTablesLength = readUint16();
  670. var quantizationTablesEnd = quantizationTablesLength + offset - 2;
  671. var z;
  672. while (offset < quantizationTablesEnd) {
  673. var quantizationTableSpec = data[offset++];
  674. var tableData = new Uint16Array(64);
  675. if (quantizationTableSpec >> 4 === 0) {
  676. for (j = 0; j < 64; j++) {
  677. z = dctZigZag[j];
  678. tableData[z] = data[offset++];
  679. }
  680. } else if (quantizationTableSpec >> 4 === 1) {
  681. for (j = 0; j < 64; j++) {
  682. z = dctZigZag[j];
  683. tableData[z] = readUint16();
  684. }
  685. } else {
  686. throw new JpegError('DQT - invalid table spec');
  687. }
  688. quantizationTables[quantizationTableSpec & 15] = tableData;
  689. }
  690. break;
  691. case 0xFFC0:
  692. case 0xFFC1:
  693. case 0xFFC2:
  694. if (frame) {
  695. throw new JpegError('Only single frame JPEGs supported');
  696. }
  697. readUint16();
  698. frame = {};
  699. frame.extended = fileMarker === 0xFFC1;
  700. frame.progressive = fileMarker === 0xFFC2;
  701. frame.precision = data[offset++];
  702. var sofScanLines = readUint16();
  703. frame.scanLines = dnlScanLines || sofScanLines;
  704. frame.samplesPerLine = readUint16();
  705. frame.components = [];
  706. frame.componentIds = {};
  707. var componentsCount = data[offset++],
  708. componentId;
  709. var maxH = 0,
  710. maxV = 0;
  711. for (i = 0; i < componentsCount; i++) {
  712. componentId = data[offset];
  713. var h = data[offset + 1] >> 4;
  714. var v = data[offset + 1] & 15;
  715. if (maxH < h) {
  716. maxH = h;
  717. }
  718. if (maxV < v) {
  719. maxV = v;
  720. }
  721. var qId = data[offset + 2];
  722. l = frame.components.push({
  723. h: h,
  724. v: v,
  725. quantizationId: qId,
  726. quantizationTable: null
  727. });
  728. frame.componentIds[componentId] = l - 1;
  729. offset += 3;
  730. }
  731. frame.maxH = maxH;
  732. frame.maxV = maxV;
  733. prepareComponents(frame);
  734. break;
  735. case 0xFFC4:
  736. var huffmanLength = readUint16();
  737. for (i = 2; i < huffmanLength;) {
  738. var huffmanTableSpec = data[offset++];
  739. var codeLengths = new Uint8Array(16);
  740. var codeLengthSum = 0;
  741. for (j = 0; j < 16; j++, offset++) {
  742. codeLengthSum += codeLengths[j] = data[offset];
  743. }
  744. var huffmanValues = new Uint8Array(codeLengthSum);
  745. for (j = 0; j < codeLengthSum; j++, offset++) {
  746. huffmanValues[j] = data[offset];
  747. }
  748. i += 17 + codeLengthSum;
  749. (huffmanTableSpec >> 4 === 0 ? huffmanTablesDC : huffmanTablesAC)[huffmanTableSpec & 15] = buildHuffmanTable(codeLengths, huffmanValues);
  750. }
  751. break;
  752. case 0xFFDD:
  753. readUint16();
  754. resetInterval = readUint16();
  755. break;
  756. case 0xFFDA:
  757. var parseDNLMarker = ++numSOSMarkers === 1 && !dnlScanLines;
  758. readUint16();
  759. var selectorsCount = data[offset++];
  760. var components = [],
  761. component;
  762. for (i = 0; i < selectorsCount; i++) {
  763. var componentIndex = frame.componentIds[data[offset++]];
  764. component = frame.components[componentIndex];
  765. var tableSpec = data[offset++];
  766. component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
  767. component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
  768. components.push(component);
  769. }
  770. var spectralStart = data[offset++];
  771. var spectralEnd = data[offset++];
  772. var successiveApproximation = data[offset++];
  773. try {
  774. var processed = decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successiveApproximation >> 4, successiveApproximation & 15, parseDNLMarker);
  775. offset += processed;
  776. } catch (ex) {
  777. if (ex instanceof DNLMarkerError) {
  778. (0, _util.warn)('Attempting to re-parse JPEG image using "scanLines" ' + 'parameter found in DNL marker (0xFFDC) segment.');
  779. return this.parse(data, { dnlScanLines: ex.scanLines });
  780. }
  781. throw ex;
  782. }
  783. break;
  784. case 0xFFDC:
  785. offset += 4;
  786. break;
  787. case 0xFFFF:
  788. if (data[offset] !== 0xFF) {
  789. offset--;
  790. }
  791. break;
  792. default:
  793. if (data[offset - 3] === 0xFF && data[offset - 2] >= 0xC0 && data[offset - 2] <= 0xFE) {
  794. offset -= 3;
  795. break;
  796. }
  797. var nextFileMarker = findNextFileMarker(data, offset - 2);
  798. if (nextFileMarker && nextFileMarker.invalid) {
  799. (0, _util.warn)('JpegImage.parse - unexpected data, current marker is: ' + nextFileMarker.invalid);
  800. offset = nextFileMarker.offset;
  801. break;
  802. }
  803. throw new JpegError('unknown marker ' + fileMarker.toString(16));
  804. }
  805. fileMarker = readUint16();
  806. }
  807. this.width = frame.samplesPerLine;
  808. this.height = frame.scanLines;
  809. this.jfif = jfif;
  810. this.adobe = adobe;
  811. this.components = [];
  812. for (i = 0; i < frame.components.length; i++) {
  813. component = frame.components[i];
  814. var quantizationTable = quantizationTables[component.quantizationId];
  815. if (quantizationTable) {
  816. component.quantizationTable = quantizationTable;
  817. }
  818. this.components.push({
  819. output: buildComponentData(frame, component),
  820. scaleX: component.h / frame.maxH,
  821. scaleY: component.v / frame.maxV,
  822. blocksPerLine: component.blocksPerLine,
  823. blocksPerColumn: component.blocksPerColumn
  824. });
  825. }
  826. this.numComponents = this.components.length;
  827. },
  828. _getLinearizedBlockData: function getLinearizedBlockData(width, height) {
  829. var scaleX = this.width / width,
  830. scaleY = this.height / height;
  831. var component, componentScaleX, componentScaleY, blocksPerScanline;
  832. var x, y, i, j, k;
  833. var index;
  834. var offset = 0;
  835. var output;
  836. var numComponents = this.components.length;
  837. var dataLength = width * height * numComponents;
  838. var data = new Uint8ClampedArray(dataLength);
  839. var xScaleBlockOffset = new Uint32Array(width);
  840. var mask3LSB = 0xfffffff8;
  841. for (i = 0; i < numComponents; i++) {
  842. component = this.components[i];
  843. componentScaleX = component.scaleX * scaleX;
  844. componentScaleY = component.scaleY * scaleY;
  845. offset = i;
  846. output = component.output;
  847. blocksPerScanline = component.blocksPerLine + 1 << 3;
  848. for (x = 0; x < width; x++) {
  849. j = 0 | x * componentScaleX;
  850. xScaleBlockOffset[x] = (j & mask3LSB) << 3 | j & 7;
  851. }
  852. for (y = 0; y < height; y++) {
  853. j = 0 | y * componentScaleY;
  854. index = blocksPerScanline * (j & mask3LSB) | (j & 7) << 3;
  855. for (x = 0; x < width; x++) {
  856. data[offset] = output[index + xScaleBlockOffset[x]];
  857. offset += numComponents;
  858. }
  859. }
  860. }
  861. var transform = this.decodeTransform;
  862. if (transform) {
  863. for (i = 0; i < dataLength;) {
  864. for (j = 0, k = 0; j < numComponents; j++, i++, k += 2) {
  865. data[i] = (data[i] * transform[k] >> 8) + transform[k + 1];
  866. }
  867. }
  868. }
  869. return data;
  870. },
  871. _isColorConversionNeeded: function _isColorConversionNeeded() {
  872. if (this.adobe) {
  873. return !!this.adobe.transformCode;
  874. }
  875. if (this.numComponents === 3) {
  876. if (this.colorTransform === 0) {
  877. return false;
  878. }
  879. return true;
  880. }
  881. if (this.colorTransform === 1) {
  882. return true;
  883. }
  884. return false;
  885. },
  886. _convertYccToRgb: function convertYccToRgb(data) {
  887. var Y, Cb, Cr;
  888. for (var i = 0, length = data.length; i < length; i += 3) {
  889. Y = data[i];
  890. Cb = data[i + 1];
  891. Cr = data[i + 2];
  892. data[i] = Y - 179.456 + 1.402 * Cr;
  893. data[i + 1] = Y + 135.459 - 0.344 * Cb - 0.714 * Cr;
  894. data[i + 2] = Y - 226.816 + 1.772 * Cb;
  895. }
  896. return data;
  897. },
  898. _convertYcckToRgb: function convertYcckToRgb(data) {
  899. var Y, Cb, Cr, k;
  900. var offset = 0;
  901. for (var i = 0, length = data.length; i < length; i += 4) {
  902. Y = data[i];
  903. Cb = data[i + 1];
  904. Cr = data[i + 2];
  905. k = data[i + 3];
  906. 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);
  907. 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);
  908. 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);
  909. }
  910. return data.subarray(0, offset);
  911. },
  912. _convertYcckToCmyk: function convertYcckToCmyk(data) {
  913. var Y, Cb, Cr;
  914. for (var i = 0, length = data.length; i < length; i += 4) {
  915. Y = data[i];
  916. Cb = data[i + 1];
  917. Cr = data[i + 2];
  918. data[i] = 434.456 - Y - 1.402 * Cr;
  919. data[i + 1] = 119.541 - Y + 0.344 * Cb + 0.714 * Cr;
  920. data[i + 2] = 481.816 - Y - 1.772 * Cb;
  921. }
  922. return data;
  923. },
  924. _convertCmykToRgb: function convertCmykToRgb(data) {
  925. var c, m, y, k;
  926. var offset = 0;
  927. var scale = 1 / 255;
  928. for (var i = 0, length = data.length; i < length; i += 4) {
  929. c = data[i] * scale;
  930. m = data[i + 1] * scale;
  931. y = data[i + 2] * scale;
  932. k = data[i + 3] * scale;
  933. data[offset++] = 255 + c * (-4.387332384609988 * c + 54.48615194189176 * m + 18.82290502165302 * y + 212.25662451639585 * k - 285.2331026137004) + m * (1.7149763477362134 * m - 5.6096736904047315 * y - 17.873870861415444 * k - 5.497006427196366) + y * (-2.5217340131683033 * y - 21.248923337353073 * k + 17.5119270841813) - k * (21.86122147463605 * k + 189.48180835922747);
  934. data[offset++] = 255 + c * (8.841041422036149 * c + 60.118027045597366 * m + 6.871425592049007 * y + 31.159100130055922 * k - 79.2970844816548) + m * (-15.310361306967817 * m + 17.575251261109482 * y + 131.35250912493976 * k - 190.9453302588951) + y * (4.444339102852739 * y + 9.8632861493405 * k - 24.86741582555878) - k * (20.737325471181034 * k + 187.80453709719578);
  935. data[offset++] = 255 + c * (0.8842522430003296 * c + 8.078677503112928 * m + 30.89978309703729 * y - 0.23883238689178934 * k - 14.183576799673286) + m * (10.49593273432072 * m + 63.02378494754052 * y + 50.606957656360734 * k - 112.23884253719248) + y * (0.03296041114873217 * y + 115.60384449646641 * k - 193.58209356861505) - k * (22.33816807309886 * k + 180.12613974708367);
  936. }
  937. return data.subarray(0, offset);
  938. },
  939. getData: function getData(width, height, forceRGBoutput) {
  940. if (this.numComponents > 4) {
  941. throw new JpegError('Unsupported color mode');
  942. }
  943. var data = this._getLinearizedBlockData(width, height);
  944. if (this.numComponents === 1 && forceRGBoutput) {
  945. var dataLength = data.length;
  946. var rgbData = new Uint8ClampedArray(dataLength * 3);
  947. var offset = 0;
  948. for (var i = 0; i < dataLength; i++) {
  949. var grayColor = data[i];
  950. rgbData[offset++] = grayColor;
  951. rgbData[offset++] = grayColor;
  952. rgbData[offset++] = grayColor;
  953. }
  954. return rgbData;
  955. } else if (this.numComponents === 3 && this._isColorConversionNeeded()) {
  956. return this._convertYccToRgb(data);
  957. } else if (this.numComponents === 4) {
  958. if (this._isColorConversionNeeded()) {
  959. if (forceRGBoutput) {
  960. return this._convertYcckToRgb(data);
  961. }
  962. return this._convertYcckToCmyk(data);
  963. } else if (forceRGBoutput) {
  964. return this._convertCmykToRgb(data);
  965. }
  966. }
  967. return data;
  968. }
  969. };
  970. return JpegImage;
  971. }();
  972. exports.JpegImage = JpegImage;