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 2022 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 = void 0;
  27. var _util = require("../shared/util.js");
  28. var _core_utils = require("./core_utils.js");
  29. class JpegError extends _util.BaseException {
  30. constructor(msg) {
  31. super(`JPEG error: ${msg}`, "JpegError");
  32. }
  33. }
  34. class DNLMarkerError extends _util.BaseException {
  35. constructor(message, scanLines) {
  36. super(message, "DNLMarkerError");
  37. this.scanLines = scanLines;
  38. }
  39. }
  40. class EOIMarkerError extends _util.BaseException {
  41. constructor(msg) {
  42. super(msg, "EOIMarkerError");
  43. }
  44. }
  45. 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]);
  46. const dctCos1 = 4017;
  47. const dctSin1 = 799;
  48. const dctCos3 = 3406;
  49. const dctSin3 = 2276;
  50. const dctCos6 = 1567;
  51. const dctSin6 = 3784;
  52. const dctSqrt2 = 5793;
  53. const dctSqrt1d2 = 2896;
  54. function buildHuffmanTable(codeLengths, values) {
  55. let k = 0,
  56. i,
  57. j,
  58. length = 16;
  59. while (length > 0 && !codeLengths[length - 1]) {
  60. length--;
  61. }
  62. const code = [{
  63. children: [],
  64. index: 0
  65. }];
  66. let p = code[0],
  67. q;
  68. for (i = 0; i < length; i++) {
  69. for (j = 0; j < codeLengths[i]; j++) {
  70. p = code.pop();
  71. p.children[p.index] = values[k];
  72. while (p.index > 0) {
  73. p = code.pop();
  74. }
  75. p.index++;
  76. code.push(p);
  77. while (code.length <= i) {
  78. code.push(q = {
  79. children: [],
  80. index: 0
  81. });
  82. p.children[p.index] = q.children;
  83. p = q;
  84. }
  85. k++;
  86. }
  87. if (i + 1 < length) {
  88. code.push(q = {
  89. children: [],
  90. index: 0
  91. });
  92. p.children[p.index] = q.children;
  93. p = q;
  94. }
  95. }
  96. return code[0].children;
  97. }
  98. function getBlockBufferOffset(component, row, col) {
  99. return 64 * ((component.blocksPerLine + 1) * row + col);
  100. }
  101. function decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successivePrev, successive, parseDNLMarker = false) {
  102. const mcusPerLine = frame.mcusPerLine;
  103. const progressive = frame.progressive;
  104. const startOffset = offset;
  105. let bitsData = 0,
  106. bitsCount = 0;
  107. function readBit() {
  108. if (bitsCount > 0) {
  109. bitsCount--;
  110. return bitsData >> bitsCount & 1;
  111. }
  112. bitsData = data[offset++];
  113. if (bitsData === 0xff) {
  114. const nextByte = data[offset++];
  115. if (nextByte) {
  116. if (nextByte === 0xdc && parseDNLMarker) {
  117. offset += 2;
  118. const scanLines = (0, _core_utils.readUint16)(data, offset);
  119. offset += 2;
  120. if (scanLines > 0 && scanLines !== frame.scanLines) {
  121. throw new DNLMarkerError("Found DNL marker (0xFFDC) while parsing scan data", scanLines);
  122. }
  123. } else if (nextByte === 0xd9) {
  124. if (parseDNLMarker) {
  125. const maybeScanLines = blockRow * (frame.precision === 8 ? 8 : 0);
  126. if (maybeScanLines > 0 && Math.round(frame.scanLines / maybeScanLines) >= 5) {
  127. throw new DNLMarkerError("Found EOI marker (0xFFD9) while parsing scan data, " + "possibly caused by incorrect `scanLines` parameter", maybeScanLines);
  128. }
  129. }
  130. throw new EOIMarkerError("Found EOI marker (0xFFD9) while parsing scan data");
  131. }
  132. throw new JpegError(`unexpected marker ${(bitsData << 8 | nextByte).toString(16)}`);
  133. }
  134. }
  135. bitsCount = 7;
  136. return bitsData >>> 7;
  137. }
  138. function decodeHuffman(tree) {
  139. let node = tree;
  140. while (true) {
  141. node = node[readBit()];
  142. switch (typeof node) {
  143. case "number":
  144. return node;
  145. case "object":
  146. continue;
  147. }
  148. throw new JpegError("invalid huffman sequence");
  149. }
  150. }
  151. function receive(length) {
  152. let 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. const n = receive(length);
  164. if (n >= 1 << length - 1) {
  165. return n;
  166. }
  167. return n + (-1 << length) + 1;
  168. }
  169. function decodeBaseline(component, blockOffset) {
  170. const t = decodeHuffman(component.huffmanTableDC);
  171. const diff = t === 0 ? 0 : receiveAndExtend(t);
  172. component.blockData[blockOffset] = component.pred += diff;
  173. let k = 1;
  174. while (k < 64) {
  175. const rs = decodeHuffman(component.huffmanTableAC);
  176. const 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. const z = dctZigZag[k];
  187. component.blockData[blockOffset + z] = receiveAndExtend(s);
  188. k++;
  189. }
  190. }
  191. function decodeDCFirst(component, blockOffset) {
  192. const t = decodeHuffman(component.huffmanTableDC);
  193. const diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
  194. component.blockData[blockOffset] = component.pred += diff;
  195. }
  196. function decodeDCSuccessive(component, blockOffset) {
  197. component.blockData[blockOffset] |= readBit() << successive;
  198. }
  199. let eobrun = 0;
  200. function decodeACFirst(component, blockOffset) {
  201. if (eobrun > 0) {
  202. eobrun--;
  203. return;
  204. }
  205. let k = spectralStart;
  206. const e = spectralEnd;
  207. while (k <= e) {
  208. const rs = decodeHuffman(component.huffmanTableAC);
  209. const 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. const z = dctZigZag[k];
  221. component.blockData[blockOffset + z] = receiveAndExtend(s) * (1 << successive);
  222. k++;
  223. }
  224. }
  225. let successiveACState = 0,
  226. successiveACNextValue;
  227. function decodeACSuccessive(component, blockOffset) {
  228. let k = spectralStart;
  229. const e = spectralEnd;
  230. let r = 0;
  231. let s;
  232. let rs;
  233. while (k <= e) {
  234. const offsetZ = blockOffset + dctZigZag[k];
  235. const 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. let blockRow = 0;
  292. function decodeMcu(component, decode, mcu, row, col) {
  293. const mcuRow = mcu / mcusPerLine | 0;
  294. const mcuCol = mcu % mcusPerLine;
  295. blockRow = mcuRow * component.v + row;
  296. const blockCol = mcuCol * component.h + col;
  297. const blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
  298. decode(component, blockOffset);
  299. }
  300. function decodeBlock(component, decode, mcu) {
  301. blockRow = mcu / component.blocksPerLine | 0;
  302. const blockCol = mcu % component.blocksPerLine;
  303. const blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
  304. decode(component, blockOffset);
  305. }
  306. const componentsLength = components.length;
  307. let component, i, j, k, n;
  308. let decodeFn;
  309. if (progressive) {
  310. if (spectralStart === 0) {
  311. decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
  312. } else {
  313. decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive;
  314. }
  315. } else {
  316. decodeFn = decodeBaseline;
  317. }
  318. let mcu = 0,
  319. fileMarker;
  320. let mcuExpected;
  321. if (componentsLength === 1) {
  322. mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
  323. } else {
  324. mcuExpected = mcusPerLine * frame.mcusPerColumn;
  325. }
  326. let h, v;
  327. while (mcu <= mcuExpected) {
  328. const mcuToRead = resetInterval ? Math.min(mcuExpected - mcu, resetInterval) : mcuExpected;
  329. if (mcuToRead > 0) {
  330. for (i = 0; i < componentsLength; i++) {
  331. components[i].pred = 0;
  332. }
  333. eobrun = 0;
  334. if (componentsLength === 1) {
  335. component = components[0];
  336. for (n = 0; n < mcuToRead; n++) {
  337. decodeBlock(component, decodeFn, mcu);
  338. mcu++;
  339. }
  340. } else {
  341. for (n = 0; n < mcuToRead; n++) {
  342. for (i = 0; i < componentsLength; i++) {
  343. component = components[i];
  344. h = component.h;
  345. v = component.v;
  346. for (j = 0; j < v; j++) {
  347. for (k = 0; k < h; k++) {
  348. decodeMcu(component, decodeFn, mcu, j, k);
  349. }
  350. }
  351. }
  352. mcu++;
  353. }
  354. }
  355. }
  356. bitsCount = 0;
  357. fileMarker = findNextFileMarker(data, offset);
  358. if (!fileMarker) {
  359. break;
  360. }
  361. if (fileMarker.invalid) {
  362. const partialMsg = mcuToRead > 0 ? "unexpected" : "excessive";
  363. (0, _util.warn)(`decodeScan - ${partialMsg} MCU data, current marker is: ${fileMarker.invalid}`);
  364. offset = fileMarker.offset;
  365. }
  366. if (fileMarker.marker >= 0xffd0 && fileMarker.marker <= 0xffd7) {
  367. offset += 2;
  368. } else {
  369. break;
  370. }
  371. }
  372. return offset - startOffset;
  373. }
  374. function quantizeAndInverse(component, blockBufferOffset, p) {
  375. const qt = component.quantizationTable,
  376. blockData = component.blockData;
  377. let v0, v1, v2, v3, v4, v5, v6, v7;
  378. let p0, p1, p2, p3, p4, p5, p6, p7;
  379. let t;
  380. if (!qt) {
  381. throw new JpegError("missing required Quantization Table.");
  382. }
  383. for (let row = 0; row < 64; row += 8) {
  384. p0 = blockData[blockBufferOffset + row];
  385. p1 = blockData[blockBufferOffset + row + 1];
  386. p2 = blockData[blockBufferOffset + row + 2];
  387. p3 = blockData[blockBufferOffset + row + 3];
  388. p4 = blockData[blockBufferOffset + row + 4];
  389. p5 = blockData[blockBufferOffset + row + 5];
  390. p6 = blockData[blockBufferOffset + row + 6];
  391. p7 = blockData[blockBufferOffset + row + 7];
  392. p0 *= qt[row];
  393. if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
  394. t = dctSqrt2 * p0 + 512 >> 10;
  395. p[row] = t;
  396. p[row + 1] = t;
  397. p[row + 2] = t;
  398. p[row + 3] = t;
  399. p[row + 4] = t;
  400. p[row + 5] = t;
  401. p[row + 6] = t;
  402. p[row + 7] = t;
  403. continue;
  404. }
  405. p1 *= qt[row + 1];
  406. p2 *= qt[row + 2];
  407. p3 *= qt[row + 3];
  408. p4 *= qt[row + 4];
  409. p5 *= qt[row + 5];
  410. p6 *= qt[row + 6];
  411. p7 *= qt[row + 7];
  412. v0 = dctSqrt2 * p0 + 128 >> 8;
  413. v1 = dctSqrt2 * p4 + 128 >> 8;
  414. v2 = p2;
  415. v3 = p6;
  416. v4 = dctSqrt1d2 * (p1 - p7) + 128 >> 8;
  417. v7 = dctSqrt1d2 * (p1 + p7) + 128 >> 8;
  418. v5 = p3 << 4;
  419. v6 = p5 << 4;
  420. v0 = v0 + v1 + 1 >> 1;
  421. v1 = v0 - v1;
  422. t = v2 * dctSin6 + v3 * dctCos6 + 128 >> 8;
  423. v2 = v2 * dctCos6 - v3 * dctSin6 + 128 >> 8;
  424. v3 = t;
  425. v4 = v4 + v6 + 1 >> 1;
  426. v6 = v4 - v6;
  427. v7 = v7 + v5 + 1 >> 1;
  428. v5 = v7 - v5;
  429. v0 = v0 + v3 + 1 >> 1;
  430. v3 = v0 - v3;
  431. v1 = v1 + v2 + 1 >> 1;
  432. v2 = v1 - v2;
  433. t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
  434. v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
  435. v7 = t;
  436. t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
  437. v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
  438. v6 = t;
  439. p[row] = v0 + v7;
  440. p[row + 7] = v0 - v7;
  441. p[row + 1] = v1 + v6;
  442. p[row + 6] = v1 - v6;
  443. p[row + 2] = v2 + v5;
  444. p[row + 5] = v2 - v5;
  445. p[row + 3] = v3 + v4;
  446. p[row + 4] = v3 - v4;
  447. }
  448. for (let col = 0; col < 8; ++col) {
  449. p0 = p[col];
  450. p1 = p[col + 8];
  451. p2 = p[col + 16];
  452. p3 = p[col + 24];
  453. p4 = p[col + 32];
  454. p5 = p[col + 40];
  455. p6 = p[col + 48];
  456. p7 = p[col + 56];
  457. if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
  458. t = dctSqrt2 * p0 + 8192 >> 14;
  459. if (t < -2040) {
  460. t = 0;
  461. } else if (t >= 2024) {
  462. t = 255;
  463. } else {
  464. t = t + 2056 >> 4;
  465. }
  466. blockData[blockBufferOffset + col] = t;
  467. blockData[blockBufferOffset + col + 8] = t;
  468. blockData[blockBufferOffset + col + 16] = t;
  469. blockData[blockBufferOffset + col + 24] = t;
  470. blockData[blockBufferOffset + col + 32] = t;
  471. blockData[blockBufferOffset + col + 40] = t;
  472. blockData[blockBufferOffset + col + 48] = t;
  473. blockData[blockBufferOffset + col + 56] = t;
  474. continue;
  475. }
  476. v0 = dctSqrt2 * p0 + 2048 >> 12;
  477. v1 = dctSqrt2 * p4 + 2048 >> 12;
  478. v2 = p2;
  479. v3 = p6;
  480. v4 = dctSqrt1d2 * (p1 - p7) + 2048 >> 12;
  481. v7 = dctSqrt1d2 * (p1 + p7) + 2048 >> 12;
  482. v5 = p3;
  483. v6 = p5;
  484. v0 = (v0 + v1 + 1 >> 1) + 4112;
  485. v1 = v0 - v1;
  486. t = v2 * dctSin6 + v3 * dctCos6 + 2048 >> 12;
  487. v2 = v2 * dctCos6 - v3 * dctSin6 + 2048 >> 12;
  488. v3 = t;
  489. v4 = v4 + v6 + 1 >> 1;
  490. v6 = v4 - v6;
  491. v7 = v7 + v5 + 1 >> 1;
  492. v5 = v7 - v5;
  493. v0 = v0 + v3 + 1 >> 1;
  494. v3 = v0 - v3;
  495. v1 = v1 + v2 + 1 >> 1;
  496. v2 = v1 - v2;
  497. t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
  498. v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
  499. v7 = t;
  500. t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
  501. v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
  502. v6 = t;
  503. p0 = v0 + v7;
  504. p7 = v0 - v7;
  505. p1 = v1 + v6;
  506. p6 = v1 - v6;
  507. p2 = v2 + v5;
  508. p5 = v2 - v5;
  509. p3 = v3 + v4;
  510. p4 = v3 - v4;
  511. if (p0 < 16) {
  512. p0 = 0;
  513. } else if (p0 >= 4080) {
  514. p0 = 255;
  515. } else {
  516. p0 >>= 4;
  517. }
  518. if (p1 < 16) {
  519. p1 = 0;
  520. } else if (p1 >= 4080) {
  521. p1 = 255;
  522. } else {
  523. p1 >>= 4;
  524. }
  525. if (p2 < 16) {
  526. p2 = 0;
  527. } else if (p2 >= 4080) {
  528. p2 = 255;
  529. } else {
  530. p2 >>= 4;
  531. }
  532. if (p3 < 16) {
  533. p3 = 0;
  534. } else if (p3 >= 4080) {
  535. p3 = 255;
  536. } else {
  537. p3 >>= 4;
  538. }
  539. if (p4 < 16) {
  540. p4 = 0;
  541. } else if (p4 >= 4080) {
  542. p4 = 255;
  543. } else {
  544. p4 >>= 4;
  545. }
  546. if (p5 < 16) {
  547. p5 = 0;
  548. } else if (p5 >= 4080) {
  549. p5 = 255;
  550. } else {
  551. p5 >>= 4;
  552. }
  553. if (p6 < 16) {
  554. p6 = 0;
  555. } else if (p6 >= 4080) {
  556. p6 = 255;
  557. } else {
  558. p6 >>= 4;
  559. }
  560. if (p7 < 16) {
  561. p7 = 0;
  562. } else if (p7 >= 4080) {
  563. p7 = 255;
  564. } else {
  565. p7 >>= 4;
  566. }
  567. blockData[blockBufferOffset + col] = p0;
  568. blockData[blockBufferOffset + col + 8] = p1;
  569. blockData[blockBufferOffset + col + 16] = p2;
  570. blockData[blockBufferOffset + col + 24] = p3;
  571. blockData[blockBufferOffset + col + 32] = p4;
  572. blockData[blockBufferOffset + col + 40] = p5;
  573. blockData[blockBufferOffset + col + 48] = p6;
  574. blockData[blockBufferOffset + col + 56] = p7;
  575. }
  576. }
  577. function buildComponentData(frame, component) {
  578. const blocksPerLine = component.blocksPerLine;
  579. const blocksPerColumn = component.blocksPerColumn;
  580. const computationBuffer = new Int16Array(64);
  581. for (let blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
  582. for (let blockCol = 0; blockCol < blocksPerLine; blockCol++) {
  583. const offset = getBlockBufferOffset(component, blockRow, blockCol);
  584. quantizeAndInverse(component, offset, computationBuffer);
  585. }
  586. }
  587. return component.blockData;
  588. }
  589. function findNextFileMarker(data, currentPos, startPos = currentPos) {
  590. const maxPos = data.length - 1;
  591. let newPos = startPos < currentPos ? startPos : currentPos;
  592. if (currentPos >= maxPos) {
  593. return null;
  594. }
  595. const currentMarker = (0, _core_utils.readUint16)(data, currentPos);
  596. if (currentMarker >= 0xffc0 && currentMarker <= 0xfffe) {
  597. return {
  598. invalid: null,
  599. marker: currentMarker,
  600. offset: currentPos
  601. };
  602. }
  603. let newMarker = (0, _core_utils.readUint16)(data, newPos);
  604. while (!(newMarker >= 0xffc0 && newMarker <= 0xfffe)) {
  605. if (++newPos >= maxPos) {
  606. return null;
  607. }
  608. newMarker = (0, _core_utils.readUint16)(data, newPos);
  609. }
  610. return {
  611. invalid: currentMarker.toString(16),
  612. marker: newMarker,
  613. offset: newPos
  614. };
  615. }
  616. class JpegImage {
  617. constructor({
  618. decodeTransform = null,
  619. colorTransform = -1
  620. } = {}) {
  621. this._decodeTransform = decodeTransform;
  622. this._colorTransform = colorTransform;
  623. }
  624. parse(data, {
  625. dnlScanLines = null
  626. } = {}) {
  627. function readDataBlock() {
  628. const length = (0, _core_utils.readUint16)(data, offset);
  629. offset += 2;
  630. let endOffset = offset + length - 2;
  631. const fileMarker = findNextFileMarker(data, endOffset, offset);
  632. if (fileMarker && fileMarker.invalid) {
  633. (0, _util.warn)("readDataBlock - incorrect length, current marker is: " + fileMarker.invalid);
  634. endOffset = fileMarker.offset;
  635. }
  636. const array = data.subarray(offset, endOffset);
  637. offset += array.length;
  638. return array;
  639. }
  640. function prepareComponents(frame) {
  641. const mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
  642. const mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
  643. for (const component of frame.components) {
  644. const blocksPerLine = Math.ceil(Math.ceil(frame.samplesPerLine / 8) * component.h / frame.maxH);
  645. const blocksPerColumn = Math.ceil(Math.ceil(frame.scanLines / 8) * component.v / frame.maxV);
  646. const blocksPerLineForMcu = mcusPerLine * component.h;
  647. const blocksPerColumnForMcu = mcusPerColumn * component.v;
  648. const blocksBufferSize = 64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
  649. component.blockData = new Int16Array(blocksBufferSize);
  650. component.blocksPerLine = blocksPerLine;
  651. component.blocksPerColumn = blocksPerColumn;
  652. }
  653. frame.mcusPerLine = mcusPerLine;
  654. frame.mcusPerColumn = mcusPerColumn;
  655. }
  656. let offset = 0;
  657. let jfif = null;
  658. let adobe = null;
  659. let frame, resetInterval;
  660. let numSOSMarkers = 0;
  661. const quantizationTables = [];
  662. const huffmanTablesAC = [],
  663. huffmanTablesDC = [];
  664. let fileMarker = (0, _core_utils.readUint16)(data, offset);
  665. offset += 2;
  666. if (fileMarker !== 0xffd8) {
  667. throw new JpegError("SOI not found");
  668. }
  669. fileMarker = (0, _core_utils.readUint16)(data, offset);
  670. offset += 2;
  671. markerLoop: while (fileMarker !== 0xffd9) {
  672. let i, j, l;
  673. switch (fileMarker) {
  674. case 0xffe0:
  675. case 0xffe1:
  676. case 0xffe2:
  677. case 0xffe3:
  678. case 0xffe4:
  679. case 0xffe5:
  680. case 0xffe6:
  681. case 0xffe7:
  682. case 0xffe8:
  683. case 0xffe9:
  684. case 0xffea:
  685. case 0xffeb:
  686. case 0xffec:
  687. case 0xffed:
  688. case 0xffee:
  689. case 0xffef:
  690. case 0xfffe:
  691. const appData = readDataBlock();
  692. if (fileMarker === 0xffe0) {
  693. if (appData[0] === 0x4a && appData[1] === 0x46 && appData[2] === 0x49 && appData[3] === 0x46 && appData[4] === 0) {
  694. jfif = {
  695. version: {
  696. major: appData[5],
  697. minor: appData[6]
  698. },
  699. densityUnits: appData[7],
  700. xDensity: appData[8] << 8 | appData[9],
  701. yDensity: appData[10] << 8 | appData[11],
  702. thumbWidth: appData[12],
  703. thumbHeight: appData[13],
  704. thumbData: appData.subarray(14, 14 + 3 * appData[12] * appData[13])
  705. };
  706. }
  707. }
  708. if (fileMarker === 0xffee) {
  709. if (appData[0] === 0x41 && appData[1] === 0x64 && appData[2] === 0x6f && appData[3] === 0x62 && appData[4] === 0x65) {
  710. adobe = {
  711. version: appData[5] << 8 | appData[6],
  712. flags0: appData[7] << 8 | appData[8],
  713. flags1: appData[9] << 8 | appData[10],
  714. transformCode: appData[11]
  715. };
  716. }
  717. }
  718. break;
  719. case 0xffdb:
  720. const quantizationTablesLength = (0, _core_utils.readUint16)(data, offset);
  721. offset += 2;
  722. const quantizationTablesEnd = quantizationTablesLength + offset - 2;
  723. let z;
  724. while (offset < quantizationTablesEnd) {
  725. const quantizationTableSpec = data[offset++];
  726. const tableData = new Uint16Array(64);
  727. if (quantizationTableSpec >> 4 === 0) {
  728. for (j = 0; j < 64; j++) {
  729. z = dctZigZag[j];
  730. tableData[z] = data[offset++];
  731. }
  732. } else if (quantizationTableSpec >> 4 === 1) {
  733. for (j = 0; j < 64; j++) {
  734. z = dctZigZag[j];
  735. tableData[z] = (0, _core_utils.readUint16)(data, offset);
  736. offset += 2;
  737. }
  738. } else {
  739. throw new JpegError("DQT - invalid table spec");
  740. }
  741. quantizationTables[quantizationTableSpec & 15] = tableData;
  742. }
  743. break;
  744. case 0xffc0:
  745. case 0xffc1:
  746. case 0xffc2:
  747. if (frame) {
  748. throw new JpegError("Only single frame JPEGs supported");
  749. }
  750. offset += 2;
  751. frame = {};
  752. frame.extended = fileMarker === 0xffc1;
  753. frame.progressive = fileMarker === 0xffc2;
  754. frame.precision = data[offset++];
  755. const sofScanLines = (0, _core_utils.readUint16)(data, offset);
  756. offset += 2;
  757. frame.scanLines = dnlScanLines || sofScanLines;
  758. frame.samplesPerLine = (0, _core_utils.readUint16)(data, offset);
  759. offset += 2;
  760. frame.components = [];
  761. frame.componentIds = {};
  762. const componentsCount = data[offset++];
  763. let maxH = 0,
  764. maxV = 0;
  765. for (i = 0; i < componentsCount; i++) {
  766. const componentId = data[offset];
  767. const h = data[offset + 1] >> 4;
  768. const v = data[offset + 1] & 15;
  769. if (maxH < h) {
  770. maxH = h;
  771. }
  772. if (maxV < v) {
  773. maxV = v;
  774. }
  775. const qId = data[offset + 2];
  776. l = frame.components.push({
  777. h,
  778. v,
  779. quantizationId: qId,
  780. quantizationTable: null
  781. });
  782. frame.componentIds[componentId] = l - 1;
  783. offset += 3;
  784. }
  785. frame.maxH = maxH;
  786. frame.maxV = maxV;
  787. prepareComponents(frame);
  788. break;
  789. case 0xffc4:
  790. const huffmanLength = (0, _core_utils.readUint16)(data, offset);
  791. offset += 2;
  792. for (i = 2; i < huffmanLength;) {
  793. const huffmanTableSpec = data[offset++];
  794. const codeLengths = new Uint8Array(16);
  795. let codeLengthSum = 0;
  796. for (j = 0; j < 16; j++, offset++) {
  797. codeLengthSum += codeLengths[j] = data[offset];
  798. }
  799. const huffmanValues = new Uint8Array(codeLengthSum);
  800. for (j = 0; j < codeLengthSum; j++, offset++) {
  801. huffmanValues[j] = data[offset];
  802. }
  803. i += 17 + codeLengthSum;
  804. (huffmanTableSpec >> 4 === 0 ? huffmanTablesDC : huffmanTablesAC)[huffmanTableSpec & 15] = buildHuffmanTable(codeLengths, huffmanValues);
  805. }
  806. break;
  807. case 0xffdd:
  808. offset += 2;
  809. resetInterval = (0, _core_utils.readUint16)(data, offset);
  810. offset += 2;
  811. break;
  812. case 0xffda:
  813. const parseDNLMarker = ++numSOSMarkers === 1 && !dnlScanLines;
  814. offset += 2;
  815. const selectorsCount = data[offset++],
  816. components = [];
  817. for (i = 0; i < selectorsCount; i++) {
  818. const index = data[offset++];
  819. const componentIndex = frame.componentIds[index];
  820. const component = frame.components[componentIndex];
  821. component.index = index;
  822. const tableSpec = data[offset++];
  823. component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
  824. component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
  825. components.push(component);
  826. }
  827. const spectralStart = data[offset++],
  828. spectralEnd = data[offset++],
  829. successiveApproximation = data[offset++];
  830. try {
  831. const processed = decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successiveApproximation >> 4, successiveApproximation & 15, parseDNLMarker);
  832. offset += processed;
  833. } catch (ex) {
  834. if (ex instanceof DNLMarkerError) {
  835. (0, _util.warn)(`${ex.message} -- attempting to re-parse the JPEG image.`);
  836. return this.parse(data, {
  837. dnlScanLines: ex.scanLines
  838. });
  839. } else if (ex instanceof EOIMarkerError) {
  840. (0, _util.warn)(`${ex.message} -- ignoring the rest of the image data.`);
  841. break markerLoop;
  842. }
  843. throw ex;
  844. }
  845. break;
  846. case 0xffdc:
  847. offset += 4;
  848. break;
  849. case 0xffff:
  850. if (data[offset] !== 0xff) {
  851. offset--;
  852. }
  853. break;
  854. default:
  855. const nextFileMarker = findNextFileMarker(data, offset - 2, offset - 3);
  856. if (nextFileMarker && nextFileMarker.invalid) {
  857. (0, _util.warn)("JpegImage.parse - unexpected data, current marker is: " + nextFileMarker.invalid);
  858. offset = nextFileMarker.offset;
  859. break;
  860. }
  861. if (!nextFileMarker || offset >= data.length - 1) {
  862. (0, _util.warn)("JpegImage.parse - reached the end of the image data " + "without finding an EOI marker (0xFFD9).");
  863. break markerLoop;
  864. }
  865. throw new JpegError("JpegImage.parse - unknown marker: " + fileMarker.toString(16));
  866. }
  867. fileMarker = (0, _core_utils.readUint16)(data, offset);
  868. offset += 2;
  869. }
  870. this.width = frame.samplesPerLine;
  871. this.height = frame.scanLines;
  872. this.jfif = jfif;
  873. this.adobe = adobe;
  874. this.components = [];
  875. for (const component of frame.components) {
  876. const quantizationTable = quantizationTables[component.quantizationId];
  877. if (quantizationTable) {
  878. component.quantizationTable = quantizationTable;
  879. }
  880. this.components.push({
  881. index: component.index,
  882. output: buildComponentData(frame, component),
  883. scaleX: component.h / frame.maxH,
  884. scaleY: component.v / frame.maxV,
  885. blocksPerLine: component.blocksPerLine,
  886. blocksPerColumn: component.blocksPerColumn
  887. });
  888. }
  889. this.numComponents = this.components.length;
  890. return undefined;
  891. }
  892. _getLinearizedBlockData(width, height, isSourcePDF = false) {
  893. const scaleX = this.width / width,
  894. scaleY = this.height / height;
  895. let component, componentScaleX, componentScaleY, blocksPerScanline;
  896. let x, y, i, j, k;
  897. let index;
  898. let offset = 0;
  899. let output;
  900. const numComponents = this.components.length;
  901. const dataLength = width * height * numComponents;
  902. const data = new Uint8ClampedArray(dataLength);
  903. const xScaleBlockOffset = new Uint32Array(width);
  904. const mask3LSB = 0xfffffff8;
  905. let lastComponentScaleX;
  906. for (i = 0; i < numComponents; i++) {
  907. component = this.components[i];
  908. componentScaleX = component.scaleX * scaleX;
  909. componentScaleY = component.scaleY * scaleY;
  910. offset = i;
  911. output = component.output;
  912. blocksPerScanline = component.blocksPerLine + 1 << 3;
  913. if (componentScaleX !== lastComponentScaleX) {
  914. for (x = 0; x < width; x++) {
  915. j = 0 | x * componentScaleX;
  916. xScaleBlockOffset[x] = (j & mask3LSB) << 3 | j & 7;
  917. }
  918. lastComponentScaleX = componentScaleX;
  919. }
  920. for (y = 0; y < height; y++) {
  921. j = 0 | y * componentScaleY;
  922. index = blocksPerScanline * (j & mask3LSB) | (j & 7) << 3;
  923. for (x = 0; x < width; x++) {
  924. data[offset] = output[index + xScaleBlockOffset[x]];
  925. offset += numComponents;
  926. }
  927. }
  928. }
  929. let transform = this._decodeTransform;
  930. if (!isSourcePDF && numComponents === 4 && !transform) {
  931. transform = new Int32Array([-256, 255, -256, 255, -256, 255, -256, 255]);
  932. }
  933. if (transform) {
  934. for (i = 0; i < dataLength;) {
  935. for (j = 0, k = 0; j < numComponents; j++, i++, k += 2) {
  936. data[i] = (data[i] * transform[k] >> 8) + transform[k + 1];
  937. }
  938. }
  939. }
  940. return data;
  941. }
  942. get _isColorConversionNeeded() {
  943. if (this.adobe) {
  944. return !!this.adobe.transformCode;
  945. }
  946. if (this.numComponents === 3) {
  947. if (this._colorTransform === 0) {
  948. return false;
  949. } else if (this.components[0].index === 0x52 && this.components[1].index === 0x47 && this.components[2].index === 0x42) {
  950. return false;
  951. }
  952. return true;
  953. }
  954. if (this._colorTransform === 1) {
  955. return true;
  956. }
  957. return false;
  958. }
  959. _convertYccToRgb(data) {
  960. let Y, Cb, Cr;
  961. for (let i = 0, length = data.length; i < length; i += 3) {
  962. Y = data[i];
  963. Cb = data[i + 1];
  964. Cr = data[i + 2];
  965. data[i] = Y - 179.456 + 1.402 * Cr;
  966. data[i + 1] = Y + 135.459 - 0.344 * Cb - 0.714 * Cr;
  967. data[i + 2] = Y - 226.816 + 1.772 * Cb;
  968. }
  969. return data;
  970. }
  971. _convertYcckToRgb(data) {
  972. let Y, Cb, Cr, k;
  973. let offset = 0;
  974. for (let i = 0, length = data.length; i < length; i += 4) {
  975. Y = data[i];
  976. Cb = data[i + 1];
  977. Cr = data[i + 2];
  978. k = data[i + 3];
  979. 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);
  980. 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);
  981. 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);
  982. }
  983. return data.subarray(0, offset);
  984. }
  985. _convertYcckToCmyk(data) {
  986. let Y, Cb, Cr;
  987. for (let i = 0, length = data.length; i < length; i += 4) {
  988. Y = data[i];
  989. Cb = data[i + 1];
  990. Cr = data[i + 2];
  991. data[i] = 434.456 - Y - 1.402 * Cr;
  992. data[i + 1] = 119.541 - Y + 0.344 * Cb + 0.714 * Cr;
  993. data[i + 2] = 481.816 - Y - 1.772 * Cb;
  994. }
  995. return data;
  996. }
  997. _convertCmykToRgb(data) {
  998. let c, m, y, k;
  999. let offset = 0;
  1000. for (let i = 0, length = data.length; i < length; i += 4) {
  1001. c = data[i];
  1002. m = data[i + 1];
  1003. y = data[i + 2];
  1004. k = data[i + 3];
  1005. 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);
  1006. 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 * (0.0003189131175883281 * k + 0.7364883807733168);
  1007. 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);
  1008. }
  1009. return data.subarray(0, offset);
  1010. }
  1011. getData({
  1012. width,
  1013. height,
  1014. forceRGB = false,
  1015. isSourcePDF = false
  1016. }) {
  1017. if (this.numComponents > 4) {
  1018. throw new JpegError("Unsupported color mode");
  1019. }
  1020. const data = this._getLinearizedBlockData(width, height, isSourcePDF);
  1021. if (this.numComponents === 1 && forceRGB) {
  1022. const rgbData = new Uint8ClampedArray(data.length * 3);
  1023. let offset = 0;
  1024. for (const grayColor of data) {
  1025. rgbData[offset++] = grayColor;
  1026. rgbData[offset++] = grayColor;
  1027. rgbData[offset++] = grayColor;
  1028. }
  1029. return rgbData;
  1030. } else if (this.numComponents === 3 && this._isColorConversionNeeded) {
  1031. return this._convertYccToRgb(data);
  1032. } else if (this.numComponents === 4) {
  1033. if (this._isColorConversionNeeded) {
  1034. if (forceRGB) {
  1035. return this._convertYcckToRgb(data);
  1036. }
  1037. return this._convertYcckToCmyk(data);
  1038. } else if (forceRGB) {
  1039. return this._convertCmykToRgb(data);
  1040. }
  1041. }
  1042. return data;
  1043. }
  1044. }
  1045. exports.JpegImage = JpegImage;