lerc.js 78 KB

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  1. /* This file is automatically rebuilt by the Cesium build process. */
  2. import { c as createCommonjsModule } from './_commonjsHelpers-3aae1032.js';
  3. var LercDecode = createCommonjsModule(function (module) {
  4. /* jshint forin: false, bitwise: false */
  5. /*
  6. Copyright 2015-2018 Esri
  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. http://www.apache.org/licenses/LICENSE-2.0
  11. Unless required by applicable law or agreed to in writing, software
  12. distributed under the License is distributed on an "AS IS" BASIS,
  13. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14. See the License for the specific language governing permissions and
  15. limitations under the License.
  16. A copy of the license and additional notices are located with the
  17. source distribution at:
  18. http://github.com/Esri/lerc/
  19. Contributors: Johannes Schmid, (LERC v1)
  20. Chayanika Khatua, (LERC v1)
  21. Wenxue Ju (LERC v1, v2.x)
  22. */
  23. /* Copyright 2015-2018 Esri. 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 @preserve */
  24. /**
  25. * a module for decoding LERC blobs
  26. * @module Lerc
  27. */
  28. (function() {
  29. //the original LercDecode for Version 1
  30. var LercDecode = (function() {
  31. // WARNING: This decoder version can only read old version 1 Lerc blobs. Use with caution.
  32. // Note: currently, this module only has an implementation for decoding LERC data, not encoding. The name of
  33. // the class was chosen to be future proof.
  34. var CntZImage = {};
  35. CntZImage.defaultNoDataValue = -3.4027999387901484e+38; // smallest Float32 value
  36. /**
  37. * Decode a LERC byte stream and return an object containing the pixel data and some required and optional
  38. * information about it, such as the image's width and height.
  39. *
  40. * @param {ArrayBuffer} input The LERC input byte stream
  41. * @param {object} [options] Decoding options, containing any of the following properties:
  42. * @config {number} [inputOffset = 0]
  43. * Skip the first inputOffset bytes of the input byte stream. A valid LERC file is expected at that position.
  44. * @config {Uint8Array} [encodedMask = null]
  45. * If specified, the decoder will not read mask information from the input and use the specified encoded
  46. * mask data instead. Mask header/data must not be present in the LERC byte stream in this case.
  47. * @config {number} [noDataValue = LercCode.defaultNoDataValue]
  48. * Pixel value to use for masked pixels.
  49. * @config {ArrayBufferView|Array} [pixelType = Float32Array]
  50. * The desired type of the pixelData array in the return value. Note that it is the caller's responsibility to
  51. * provide an appropriate noDataValue if the default pixelType is overridden.
  52. * @config {boolean} [returnMask = false]
  53. * If true, the return value will contain a maskData property of type Uint8Array which has one element per
  54. * pixel, the value of which is 1 or 0 depending on whether that pixel's data is present or masked. If the
  55. * input LERC data does not contain a mask, maskData will not be returned.
  56. * @config {boolean} [returnEncodedMask = false]
  57. * If true, the return value will contain a encodedMaskData property, which can be passed into encode() as
  58. * encodedMask.
  59. * @config {boolean} [returnFileInfo = false]
  60. * If true, the return value will have a fileInfo property that contains metadata obtained from the
  61. * LERC headers and the decoding process.
  62. * @config {boolean} [computeUsedBitDepths = false]
  63. * If true, the fileInfo property in the return value will contain the set of all block bit depths
  64. * encountered during decoding. Will only have an effect if returnFileInfo option is true.
  65. * @returns {{width, height, pixelData, minValue, maxValue, noDataValue, maskData, encodedMaskData, fileInfo}}
  66. */
  67. CntZImage.decode = function(input, options) {
  68. options = options || {};
  69. var skipMask = options.encodedMaskData || (options.encodedMaskData === null);
  70. var parsedData = parse(input, options.inputOffset || 0, skipMask);
  71. var noDataValue = (options.noDataValue !== null) ? options.noDataValue : CntZImage.defaultNoDataValue;
  72. var uncompressedData = uncompressPixelValues(parsedData, options.pixelType || Float32Array,
  73. options.encodedMaskData, noDataValue, options.returnMask);
  74. var result = {
  75. width: parsedData.width,
  76. height: parsedData.height,
  77. pixelData: uncompressedData.resultPixels,
  78. minValue: uncompressedData.minValue,
  79. maxValue: parsedData.pixels.maxValue,
  80. noDataValue: noDataValue
  81. };
  82. if (uncompressedData.resultMask) {
  83. result.maskData = uncompressedData.resultMask;
  84. }
  85. if (options.returnEncodedMask && parsedData.mask) {
  86. result.encodedMaskData = parsedData.mask.bitset ? parsedData.mask.bitset : null;
  87. }
  88. if (options.returnFileInfo) {
  89. result.fileInfo = formatFileInfo(parsedData);
  90. if (options.computeUsedBitDepths) {
  91. result.fileInfo.bitDepths = computeUsedBitDepths(parsedData);
  92. }
  93. }
  94. return result;
  95. };
  96. var uncompressPixelValues = function(data, TypedArrayClass, maskBitset, noDataValue, storeDecodedMask) {
  97. var blockIdx = 0;
  98. var numX = data.pixels.numBlocksX;
  99. var numY = data.pixels.numBlocksY;
  100. var blockWidth = Math.floor(data.width / numX);
  101. var blockHeight = Math.floor(data.height / numY);
  102. var scale = 2 * data.maxZError;
  103. var minValue = Number.MAX_VALUE, currentValue;
  104. maskBitset = maskBitset || ((data.mask) ? data.mask.bitset : null);
  105. var resultPixels, resultMask;
  106. resultPixels = new TypedArrayClass(data.width * data.height);
  107. if (storeDecodedMask && maskBitset) {
  108. resultMask = new Uint8Array(data.width * data.height);
  109. }
  110. var blockDataBuffer = new Float32Array(blockWidth * blockHeight);
  111. var xx, yy;
  112. for (var y = 0; y <= numY; y++) {
  113. var thisBlockHeight = (y !== numY) ? blockHeight : (data.height % numY);
  114. if (thisBlockHeight === 0) {
  115. continue;
  116. }
  117. for (var x = 0; x <= numX; x++) {
  118. var thisBlockWidth = (x !== numX) ? blockWidth : (data.width % numX);
  119. if (thisBlockWidth === 0) {
  120. continue;
  121. }
  122. var outPtr = y * data.width * blockHeight + x * blockWidth;
  123. var outStride = data.width - thisBlockWidth;
  124. var block = data.pixels.blocks[blockIdx];
  125. var blockData, blockPtr, constValue;
  126. if (block.encoding < 2) {
  127. // block is either uncompressed or bit-stuffed (encodings 0 and 1)
  128. if (block.encoding === 0) {
  129. // block is uncompressed
  130. blockData = block.rawData;
  131. } else {
  132. // block is bit-stuffed
  133. unstuff(block.stuffedData, block.bitsPerPixel, block.numValidPixels, block.offset, scale, blockDataBuffer, data.pixels.maxValue);
  134. blockData = blockDataBuffer;
  135. }
  136. blockPtr = 0;
  137. }
  138. else if (block.encoding === 2) {
  139. // block is all 0
  140. constValue = 0;
  141. }
  142. else {
  143. // block has constant value (encoding === 3)
  144. constValue = block.offset;
  145. }
  146. var maskByte;
  147. if (maskBitset) {
  148. for (yy = 0; yy < thisBlockHeight; yy++) {
  149. if (outPtr & 7) {
  150. //
  151. maskByte = maskBitset[outPtr >> 3];
  152. maskByte <<= outPtr & 7;
  153. }
  154. for (xx = 0; xx < thisBlockWidth; xx++) {
  155. if (!(outPtr & 7)) {
  156. // read next byte from mask
  157. maskByte = maskBitset[outPtr >> 3];
  158. }
  159. if (maskByte & 128) {
  160. // pixel data present
  161. if (resultMask) {
  162. resultMask[outPtr] = 1;
  163. }
  164. currentValue = (block.encoding < 2) ? blockData[blockPtr++] : constValue;
  165. minValue = minValue > currentValue ? currentValue : minValue;
  166. resultPixels[outPtr++] = currentValue;
  167. } else {
  168. // pixel data not present
  169. if (resultMask) {
  170. resultMask[outPtr] = 0;
  171. }
  172. resultPixels[outPtr++] = noDataValue;
  173. }
  174. maskByte <<= 1;
  175. }
  176. outPtr += outStride;
  177. }
  178. } else {
  179. // mask not present, simply copy block over
  180. if (block.encoding < 2) {
  181. // duplicating this code block for performance reasons
  182. // blockData case:
  183. for (yy = 0; yy < thisBlockHeight; yy++) {
  184. for (xx = 0; xx < thisBlockWidth; xx++) {
  185. currentValue = blockData[blockPtr++];
  186. minValue = minValue > currentValue ? currentValue : minValue;
  187. resultPixels[outPtr++] = currentValue;
  188. }
  189. outPtr += outStride;
  190. }
  191. }
  192. else {
  193. // constValue case:
  194. minValue = minValue > constValue ? constValue : minValue;
  195. for (yy = 0; yy < thisBlockHeight; yy++) {
  196. for (xx = 0; xx < thisBlockWidth; xx++) {
  197. resultPixels[outPtr++] = constValue;
  198. }
  199. outPtr += outStride;
  200. }
  201. }
  202. }
  203. if ((block.encoding === 1) && (blockPtr !== block.numValidPixels)) {
  204. throw "Block and Mask do not match";
  205. }
  206. blockIdx++;
  207. }
  208. }
  209. return {
  210. resultPixels: resultPixels,
  211. resultMask: resultMask,
  212. minValue: minValue
  213. };
  214. };
  215. var formatFileInfo = function(data) {
  216. return {
  217. "fileIdentifierString": data.fileIdentifierString,
  218. "fileVersion": data.fileVersion,
  219. "imageType": data.imageType,
  220. "height": data.height,
  221. "width": data.width,
  222. "maxZError": data.maxZError,
  223. "eofOffset": data.eofOffset,
  224. "mask": data.mask ? {
  225. "numBlocksX": data.mask.numBlocksX,
  226. "numBlocksY": data.mask.numBlocksY,
  227. "numBytes": data.mask.numBytes,
  228. "maxValue": data.mask.maxValue
  229. } : null,
  230. "pixels": {
  231. "numBlocksX": data.pixels.numBlocksX,
  232. "numBlocksY": data.pixels.numBlocksY,
  233. "numBytes": data.pixels.numBytes,
  234. "maxValue": data.pixels.maxValue,
  235. "noDataValue": data.noDataValue
  236. }
  237. };
  238. };
  239. var computeUsedBitDepths = function(data) {
  240. var numBlocks = data.pixels.numBlocksX * data.pixels.numBlocksY;
  241. var bitDepths = {};
  242. for (var i = 0; i < numBlocks; i++) {
  243. var block = data.pixels.blocks[i];
  244. if (block.encoding === 0) {
  245. bitDepths.float32 = true;
  246. } else if (block.encoding === 1) {
  247. bitDepths[block.bitsPerPixel] = true;
  248. } else {
  249. bitDepths[0] = true;
  250. }
  251. }
  252. return Object.keys(bitDepths);
  253. };
  254. var parse = function(input, fp, skipMask) {
  255. var data = {};
  256. // File header
  257. var fileIdView = new Uint8Array(input, fp, 10);
  258. data.fileIdentifierString = String.fromCharCode.apply(null, fileIdView);
  259. if (data.fileIdentifierString.trim() !== "CntZImage") {
  260. throw "Unexpected file identifier string: " + data.fileIdentifierString;
  261. }
  262. fp += 10;
  263. var view = new DataView(input, fp, 24);
  264. data.fileVersion = view.getInt32(0, true);
  265. data.imageType = view.getInt32(4, true);
  266. data.height = view.getUint32(8, true);
  267. data.width = view.getUint32(12, true);
  268. data.maxZError = view.getFloat64(16, true);
  269. fp += 24;
  270. // Mask Header
  271. if (!skipMask) {
  272. view = new DataView(input, fp, 16);
  273. data.mask = {};
  274. data.mask.numBlocksY = view.getUint32(0, true);
  275. data.mask.numBlocksX = view.getUint32(4, true);
  276. data.mask.numBytes = view.getUint32(8, true);
  277. data.mask.maxValue = view.getFloat32(12, true);
  278. fp += 16;
  279. // Mask Data
  280. if (data.mask.numBytes > 0) {
  281. var bitset = new Uint8Array(Math.ceil(data.width * data.height / 8));
  282. view = new DataView(input, fp, data.mask.numBytes);
  283. var cnt = view.getInt16(0, true);
  284. var ip = 2, op = 0;
  285. do {
  286. if (cnt > 0) {
  287. while (cnt--) { bitset[op++] = view.getUint8(ip++); }
  288. } else {
  289. var val = view.getUint8(ip++);
  290. cnt = -cnt;
  291. while (cnt--) { bitset[op++] = val; }
  292. }
  293. cnt = view.getInt16(ip, true);
  294. ip += 2;
  295. } while (ip < data.mask.numBytes);
  296. if ((cnt !== -32768) || (op < bitset.length)) {
  297. throw "Unexpected end of mask RLE encoding";
  298. }
  299. data.mask.bitset = bitset;
  300. fp += data.mask.numBytes;
  301. }
  302. else if ((data.mask.numBytes | data.mask.numBlocksY | data.mask.maxValue) === 0) { // Special case, all nodata
  303. data.mask.bitset = new Uint8Array(Math.ceil(data.width * data.height / 8));
  304. }
  305. }
  306. // Pixel Header
  307. view = new DataView(input, fp, 16);
  308. data.pixels = {};
  309. data.pixels.numBlocksY = view.getUint32(0, true);
  310. data.pixels.numBlocksX = view.getUint32(4, true);
  311. data.pixels.numBytes = view.getUint32(8, true);
  312. data.pixels.maxValue = view.getFloat32(12, true);
  313. fp += 16;
  314. var numBlocksX = data.pixels.numBlocksX;
  315. var numBlocksY = data.pixels.numBlocksY;
  316. // the number of blocks specified in the header does not take into account the blocks at the end of
  317. // each row/column with a special width/height that make the image complete in case the width is not
  318. // evenly divisible by the number of blocks.
  319. var actualNumBlocksX = numBlocksX + ((data.width % numBlocksX) > 0 ? 1 : 0);
  320. var actualNumBlocksY = numBlocksY + ((data.height % numBlocksY) > 0 ? 1 : 0);
  321. data.pixels.blocks = new Array(actualNumBlocksX * actualNumBlocksY);
  322. var blockI = 0;
  323. for (var blockY = 0; blockY < actualNumBlocksY; blockY++) {
  324. for (var blockX = 0; blockX < actualNumBlocksX; blockX++) {
  325. // Block
  326. var size = 0;
  327. var bytesLeft = input.byteLength - fp;
  328. view = new DataView(input, fp, Math.min(10, bytesLeft));
  329. var block = {};
  330. data.pixels.blocks[blockI++] = block;
  331. var headerByte = view.getUint8(0); size++;
  332. block.encoding = headerByte & 63;
  333. if (block.encoding > 3) {
  334. throw "Invalid block encoding (" + block.encoding + ")";
  335. }
  336. if (block.encoding === 2) {
  337. fp++;
  338. continue;
  339. }
  340. if ((headerByte !== 0) && (headerByte !== 2)) {
  341. headerByte >>= 6;
  342. block.offsetType = headerByte;
  343. if (headerByte === 2) {
  344. block.offset = view.getInt8(1); size++;
  345. } else if (headerByte === 1) {
  346. block.offset = view.getInt16(1, true); size += 2;
  347. } else if (headerByte === 0) {
  348. block.offset = view.getFloat32(1, true); size += 4;
  349. } else {
  350. throw "Invalid block offset type";
  351. }
  352. if (block.encoding === 1) {
  353. headerByte = view.getUint8(size); size++;
  354. block.bitsPerPixel = headerByte & 63;
  355. headerByte >>= 6;
  356. block.numValidPixelsType = headerByte;
  357. if (headerByte === 2) {
  358. block.numValidPixels = view.getUint8(size); size++;
  359. } else if (headerByte === 1) {
  360. block.numValidPixels = view.getUint16(size, true); size += 2;
  361. } else if (headerByte === 0) {
  362. block.numValidPixels = view.getUint32(size, true); size += 4;
  363. } else {
  364. throw "Invalid valid pixel count type";
  365. }
  366. }
  367. }
  368. fp += size;
  369. if (block.encoding === 3) {
  370. continue;
  371. }
  372. var arrayBuf, store8;
  373. if (block.encoding === 0) {
  374. var numPixels = (data.pixels.numBytes - 1) / 4;
  375. if (numPixels !== Math.floor(numPixels)) {
  376. throw "uncompressed block has invalid length";
  377. }
  378. arrayBuf = new ArrayBuffer(numPixels * 4);
  379. store8 = new Uint8Array(arrayBuf);
  380. store8.set(new Uint8Array(input, fp, numPixels * 4));
  381. var rawData = new Float32Array(arrayBuf);
  382. block.rawData = rawData;
  383. fp += numPixels * 4;
  384. } else if (block.encoding === 1) {
  385. var dataBytes = Math.ceil(block.numValidPixels * block.bitsPerPixel / 8);
  386. var dataWords = Math.ceil(dataBytes / 4);
  387. arrayBuf = new ArrayBuffer(dataWords * 4);
  388. store8 = new Uint8Array(arrayBuf);
  389. store8.set(new Uint8Array(input, fp, dataBytes));
  390. block.stuffedData = new Uint32Array(arrayBuf);
  391. fp += dataBytes;
  392. }
  393. }
  394. }
  395. data.eofOffset = fp;
  396. return data;
  397. };
  398. var unstuff = function(src, bitsPerPixel, numPixels, offset, scale, dest, maxValue) {
  399. var bitMask = (1 << bitsPerPixel) - 1;
  400. var i = 0, o;
  401. var bitsLeft = 0;
  402. var n, buffer;
  403. var nmax = Math.ceil((maxValue - offset) / scale);
  404. // get rid of trailing bytes that are already part of next block
  405. var numInvalidTailBytes = src.length * 4 - Math.ceil(bitsPerPixel * numPixels / 8);
  406. src[src.length - 1] <<= 8 * numInvalidTailBytes;
  407. for (o = 0; o < numPixels; o++) {
  408. if (bitsLeft === 0) {
  409. buffer = src[i++];
  410. bitsLeft = 32;
  411. }
  412. if (bitsLeft >= bitsPerPixel) {
  413. n = (buffer >>> (bitsLeft - bitsPerPixel)) & bitMask;
  414. bitsLeft -= bitsPerPixel;
  415. } else {
  416. var missingBits = (bitsPerPixel - bitsLeft);
  417. n = ((buffer & bitMask) << missingBits) & bitMask;
  418. buffer = src[i++];
  419. bitsLeft = 32 - missingBits;
  420. n += (buffer >>> bitsLeft);
  421. }
  422. //pixel values may exceed max due to quantization
  423. dest[o] = n < nmax ? offset + n * scale : maxValue;
  424. }
  425. return dest;
  426. };
  427. return CntZImage;
  428. })();
  429. //version 2. Supports 2.1, 2.2, 2.3
  430. var Lerc2Decode = (function() {
  431. // Note: currently, this module only has an implementation for decoding LERC data, not encoding. The name of
  432. // the class was chosen to be future proof, following LercDecode.
  433. /*****************************************
  434. * private static class bitsutffer used by Lerc2Decode
  435. *******************************************/
  436. var BitStuffer = {
  437. //methods ending with 2 are for the new byte order used by Lerc2.3 and above.
  438. //originalUnstuff is used to unpack Huffman code table. code is duplicated to unstuffx for performance reasons.
  439. unstuff: function(src, dest, bitsPerPixel, numPixels, lutArr, offset, scale, maxValue) {
  440. var bitMask = (1 << bitsPerPixel) - 1;
  441. var i = 0, o;
  442. var bitsLeft = 0;
  443. var n, buffer, missingBits, nmax;
  444. // get rid of trailing bytes that are already part of next block
  445. var numInvalidTailBytes = src.length * 4 - Math.ceil(bitsPerPixel * numPixels / 8);
  446. src[src.length - 1] <<= 8 * numInvalidTailBytes;
  447. if (lutArr) {
  448. for (o = 0; o < numPixels; o++) {
  449. if (bitsLeft === 0) {
  450. buffer = src[i++];
  451. bitsLeft = 32;
  452. }
  453. if (bitsLeft >= bitsPerPixel) {
  454. n = (buffer >>> (bitsLeft - bitsPerPixel)) & bitMask;
  455. bitsLeft -= bitsPerPixel;
  456. }
  457. else {
  458. missingBits = (bitsPerPixel - bitsLeft);
  459. n = ((buffer & bitMask) << missingBits) & bitMask;
  460. buffer = src[i++];
  461. bitsLeft = 32 - missingBits;
  462. n += (buffer >>> bitsLeft);
  463. }
  464. dest[o] = lutArr[n];//offset + lutArr[n] * scale;
  465. }
  466. }
  467. else {
  468. nmax = Math.ceil((maxValue - offset) / scale);
  469. for (o = 0; o < numPixels; o++) {
  470. if (bitsLeft === 0) {
  471. buffer = src[i++];
  472. bitsLeft = 32;
  473. }
  474. if (bitsLeft >= bitsPerPixel) {
  475. n = (buffer >>> (bitsLeft - bitsPerPixel)) & bitMask;
  476. bitsLeft -= bitsPerPixel;
  477. }
  478. else {
  479. missingBits = (bitsPerPixel - bitsLeft);
  480. n = ((buffer & bitMask) << missingBits) & bitMask;
  481. buffer = src[i++];
  482. bitsLeft = 32 - missingBits;
  483. n += (buffer >>> bitsLeft);
  484. }
  485. //pixel values may exceed max due to quantization
  486. dest[o] = n < nmax ? offset + n * scale : maxValue;
  487. }
  488. }
  489. },
  490. unstuffLUT: function(src, bitsPerPixel, numPixels, offset, scale, maxValue) {
  491. var bitMask = (1 << bitsPerPixel) - 1;
  492. var i = 0, o = 0, missingBits = 0, bitsLeft = 0, n = 0;
  493. var buffer;
  494. var dest = [];
  495. // get rid of trailing bytes that are already part of next block
  496. var numInvalidTailBytes = src.length * 4 - Math.ceil(bitsPerPixel * numPixels / 8);
  497. src[src.length - 1] <<= 8 * numInvalidTailBytes;
  498. var nmax = Math.ceil((maxValue - offset) / scale);
  499. for (o = 0; o < numPixels; o++) {
  500. if (bitsLeft === 0) {
  501. buffer = src[i++];
  502. bitsLeft = 32;
  503. }
  504. if (bitsLeft >= bitsPerPixel) {
  505. n = (buffer >>> (bitsLeft - bitsPerPixel)) & bitMask;
  506. bitsLeft -= bitsPerPixel;
  507. } else {
  508. missingBits = (bitsPerPixel - bitsLeft);
  509. n = ((buffer & bitMask) << missingBits) & bitMask;
  510. buffer = src[i++];
  511. bitsLeft = 32 - missingBits;
  512. n += (buffer >>> bitsLeft);
  513. }
  514. //dest.push(n);
  515. dest[o] = n < nmax ? offset + n * scale : maxValue;
  516. }
  517. dest.unshift(offset);//1st one
  518. return dest;
  519. },
  520. unstuff2: function(src, dest, bitsPerPixel, numPixels, lutArr, offset, scale, maxValue) {
  521. var bitMask = (1 << bitsPerPixel) - 1;
  522. var i = 0, o;
  523. var bitsLeft = 0, bitPos = 0;
  524. var n, buffer, missingBits;
  525. if (lutArr) {
  526. for (o = 0; o < numPixels; o++) {
  527. if (bitsLeft === 0) {
  528. buffer = src[i++];
  529. bitsLeft = 32;
  530. bitPos = 0;
  531. }
  532. if (bitsLeft >= bitsPerPixel) {
  533. n = ((buffer >>> bitPos) & bitMask);
  534. bitsLeft -= bitsPerPixel;
  535. bitPos += bitsPerPixel;
  536. } else {
  537. missingBits = (bitsPerPixel - bitsLeft);
  538. n = (buffer >>> bitPos) & bitMask;
  539. buffer = src[i++];
  540. bitsLeft = 32 - missingBits;
  541. n |= (buffer & ((1 << missingBits) - 1)) << (bitsPerPixel - missingBits);
  542. bitPos = missingBits;
  543. }
  544. dest[o] = lutArr[n];
  545. }
  546. }
  547. else {
  548. var nmax = Math.ceil((maxValue - offset) / scale);
  549. for (o = 0; o < numPixels; o++) {
  550. if (bitsLeft === 0) {
  551. buffer = src[i++];
  552. bitsLeft = 32;
  553. bitPos = 0;
  554. }
  555. if (bitsLeft >= bitsPerPixel) {
  556. //no unsigned left shift
  557. n = ((buffer >>> bitPos) & bitMask);
  558. bitsLeft -= bitsPerPixel;
  559. bitPos += bitsPerPixel;
  560. } else {
  561. missingBits = (bitsPerPixel - bitsLeft);
  562. n = (buffer >>> bitPos) & bitMask;//((buffer & bitMask) << missingBits) & bitMask;
  563. buffer = src[i++];
  564. bitsLeft = 32 - missingBits;
  565. n |= (buffer & ((1 << missingBits) - 1)) << (bitsPerPixel - missingBits);
  566. bitPos = missingBits;
  567. }
  568. //pixel values may exceed max due to quantization
  569. dest[o] = n < nmax ? offset + n * scale : maxValue;
  570. }
  571. }
  572. return dest;
  573. },
  574. unstuffLUT2: function(src, bitsPerPixel, numPixels, offset, scale, maxValue) {
  575. var bitMask = (1 << bitsPerPixel) - 1;
  576. var i = 0, o = 0, missingBits = 0, bitsLeft = 0, n = 0, bitPos = 0;
  577. var buffer;
  578. var dest = [];
  579. var nmax = Math.ceil((maxValue - offset) / scale);
  580. for (o = 0; o < numPixels; o++) {
  581. if (bitsLeft === 0) {
  582. buffer = src[i++];
  583. bitsLeft = 32;
  584. bitPos = 0;
  585. }
  586. if (bitsLeft >= bitsPerPixel) {
  587. //no unsigned left shift
  588. n = ((buffer >>> bitPos) & bitMask);
  589. bitsLeft -= bitsPerPixel;
  590. bitPos += bitsPerPixel;
  591. } else {
  592. missingBits = (bitsPerPixel - bitsLeft);
  593. n = (buffer >>> bitPos) & bitMask;//((buffer & bitMask) << missingBits) & bitMask;
  594. buffer = src[i++];
  595. bitsLeft = 32 - missingBits;
  596. n |= (buffer & ((1 << missingBits) - 1)) << (bitsPerPixel - missingBits);
  597. bitPos = missingBits;
  598. }
  599. //dest.push(n);
  600. dest[o] = n < nmax ? offset + n * scale : maxValue;
  601. }
  602. dest.unshift(offset);
  603. return dest;
  604. },
  605. originalUnstuff: function(src, dest, bitsPerPixel, numPixels) {
  606. var bitMask = (1 << bitsPerPixel) - 1;
  607. var i = 0, o;
  608. var bitsLeft = 0;
  609. var n, buffer, missingBits;
  610. // get rid of trailing bytes that are already part of next block
  611. var numInvalidTailBytes = src.length * 4 - Math.ceil(bitsPerPixel * numPixels / 8);
  612. src[src.length - 1] <<= 8 * numInvalidTailBytes;
  613. for (o = 0; o < numPixels; o++) {
  614. if (bitsLeft === 0) {
  615. buffer = src[i++];
  616. bitsLeft = 32;
  617. }
  618. if (bitsLeft >= bitsPerPixel) {
  619. n = (buffer >>> (bitsLeft - bitsPerPixel)) & bitMask;
  620. bitsLeft -= bitsPerPixel;
  621. }
  622. else {
  623. missingBits = (bitsPerPixel - bitsLeft);
  624. n = ((buffer & bitMask) << missingBits) & bitMask;
  625. buffer = src[i++];
  626. bitsLeft = 32 - missingBits;
  627. n += (buffer >>> bitsLeft);
  628. }
  629. dest[o] = n;
  630. }
  631. return dest;
  632. },
  633. originalUnstuff2: function(src, dest, bitsPerPixel, numPixels) {
  634. var bitMask = (1 << bitsPerPixel) - 1;
  635. var i = 0, o;
  636. var bitsLeft = 0, bitPos = 0;
  637. var n, buffer, missingBits;
  638. //micro-optimizations
  639. for (o = 0; o < numPixels; o++) {
  640. if (bitsLeft === 0) {
  641. buffer = src[i++];
  642. bitsLeft = 32;
  643. bitPos = 0;
  644. }
  645. if (bitsLeft >= bitsPerPixel) {
  646. //no unsigned left shift
  647. n = ((buffer >>> bitPos) & bitMask);
  648. bitsLeft -= bitsPerPixel;
  649. bitPos += bitsPerPixel;
  650. } else {
  651. missingBits = (bitsPerPixel - bitsLeft);
  652. n = (buffer >>> bitPos) & bitMask;//((buffer & bitMask) << missingBits) & bitMask;
  653. buffer = src[i++];
  654. bitsLeft = 32 - missingBits;
  655. n |= (buffer & ((1 << missingBits) - 1)) << (bitsPerPixel - missingBits);
  656. bitPos = missingBits;
  657. }
  658. dest[o] = n;
  659. }
  660. return dest;
  661. }
  662. };
  663. /*****************************************
  664. *private static class used by Lerc2Decode
  665. ******************************************/
  666. var Lerc2Helpers = {
  667. HUFFMAN_LUT_BITS_MAX: 12, //use 2^12 lut, treat it like constant
  668. computeChecksumFletcher32: function(input) {
  669. var sum1 = 0xffff, sum2 = 0xffff;
  670. var len = input.length;
  671. var words = Math.floor(len / 2);
  672. var i = 0;
  673. while (words) {
  674. var tlen = (words >= 359) ? 359 : words;
  675. words -= tlen;
  676. do {
  677. sum1 += (input[i++] << 8);
  678. sum2 += sum1 += input[i++];
  679. } while (--tlen);
  680. sum1 = (sum1 & 0xffff) + (sum1 >>> 16);
  681. sum2 = (sum2 & 0xffff) + (sum2 >>> 16);
  682. }
  683. // add the straggler byte if it exists
  684. if (len & 1) {
  685. sum2 += sum1 += (input[i] << 8);
  686. }
  687. // second reduction step to reduce sums to 16 bits
  688. sum1 = (sum1 & 0xffff) + (sum1 >>> 16);
  689. sum2 = (sum2 & 0xffff) + (sum2 >>> 16);
  690. return (sum2 << 16 | sum1) >>> 0;
  691. },
  692. readHeaderInfo: function(input, data) {
  693. var ptr = data.ptr;
  694. var fileIdView = new Uint8Array(input, ptr, 6);
  695. var headerInfo = {};
  696. headerInfo.fileIdentifierString = String.fromCharCode.apply(null, fileIdView);
  697. if (headerInfo.fileIdentifierString.lastIndexOf("Lerc2", 0) !== 0) {
  698. throw "Unexpected file identifier string (expect Lerc2 ): " + headerInfo.fileIdentifierString;
  699. }
  700. ptr += 6;
  701. var view = new DataView(input, ptr, 8);
  702. var fileVersion = view.getInt32(0, true);
  703. headerInfo.fileVersion = fileVersion;
  704. ptr += 4;
  705. if (fileVersion >= 3) {
  706. headerInfo.checksum = view.getUint32(4, true); //nrows
  707. ptr += 4;
  708. }
  709. //keys start from here
  710. view = new DataView(input, ptr, 12);
  711. headerInfo.height = view.getUint32(0, true); //nrows
  712. headerInfo.width = view.getUint32(4, true); //ncols
  713. ptr += 8;
  714. if (fileVersion >= 4) {
  715. headerInfo.numDims = view.getUint32(8, true);
  716. ptr += 4;
  717. }
  718. else {
  719. headerInfo.numDims = 1;
  720. }
  721. view = new DataView(input, ptr, 40);
  722. headerInfo.numValidPixel = view.getUint32(0, true);
  723. headerInfo.microBlockSize = view.getInt32(4, true);
  724. headerInfo.blobSize = view.getInt32(8, true);
  725. headerInfo.imageType = view.getInt32(12, true);
  726. headerInfo.maxZError = view.getFloat64(16, true);
  727. headerInfo.zMin = view.getFloat64(24, true);
  728. headerInfo.zMax = view.getFloat64(32, true);
  729. ptr += 40;
  730. data.headerInfo = headerInfo;
  731. data.ptr = ptr;
  732. var checksum, keyLength;
  733. if (fileVersion >= 3) {
  734. keyLength = fileVersion >= 4 ? 52 : 48;
  735. checksum = this.computeChecksumFletcher32(new Uint8Array(input, ptr - keyLength, headerInfo.blobSize - 14));
  736. if (checksum !== headerInfo.checksum) {
  737. throw "Checksum failed.";
  738. }
  739. }
  740. return true;
  741. },
  742. checkMinMaxRanges: function(input, data) {
  743. var headerInfo = data.headerInfo;
  744. var OutPixelTypeArray = this.getDataTypeArray(headerInfo.imageType);
  745. var rangeBytes = headerInfo.numDims * this.getDataTypeSize(headerInfo.imageType);
  746. var minValues = this.readSubArray(input, data.ptr, OutPixelTypeArray, rangeBytes);
  747. var maxValues = this.readSubArray(input, data.ptr + rangeBytes, OutPixelTypeArray, rangeBytes);
  748. data.ptr += (2 * rangeBytes);
  749. var i, equal = true;
  750. for (i = 0; i < headerInfo.numDims; i++) {
  751. if (minValues[i] !== maxValues[i]) {
  752. equal = false;
  753. break;
  754. }
  755. }
  756. headerInfo.minValues = minValues;
  757. headerInfo.maxValues = maxValues;
  758. return equal;
  759. },
  760. readSubArray: function(input, ptr, OutPixelTypeArray, numBytes) {
  761. var rawData;
  762. if (OutPixelTypeArray === Uint8Array) {
  763. rawData = new Uint8Array(input, ptr, numBytes);
  764. }
  765. else {
  766. var arrayBuf = new ArrayBuffer(numBytes);
  767. var store8 = new Uint8Array(arrayBuf);
  768. store8.set(new Uint8Array(input, ptr, numBytes));
  769. rawData = new OutPixelTypeArray(arrayBuf);
  770. }
  771. return rawData;
  772. },
  773. readMask: function(input, data) {
  774. var ptr = data.ptr;
  775. var headerInfo = data.headerInfo;
  776. var numPixels = headerInfo.width * headerInfo.height;
  777. var numValidPixel = headerInfo.numValidPixel;
  778. var view = new DataView(input, ptr, 4);
  779. var mask = {};
  780. mask.numBytes = view.getUint32(0, true);
  781. ptr += 4;
  782. // Mask Data
  783. if ((0 === numValidPixel || numPixels === numValidPixel) && 0 !== mask.numBytes) {
  784. throw ("invalid mask");
  785. }
  786. var bitset, resultMask;
  787. if (numValidPixel === 0) {
  788. bitset = new Uint8Array(Math.ceil(numPixels / 8));
  789. mask.bitset = bitset;
  790. resultMask = new Uint8Array(numPixels);
  791. data.pixels.resultMask = resultMask;
  792. ptr += mask.numBytes;
  793. }// ????? else if (data.mask.numBytes > 0 && data.mask.numBytes< data.numValidPixel) {
  794. else if (mask.numBytes > 0) {
  795. bitset = new Uint8Array(Math.ceil(numPixels / 8));
  796. view = new DataView(input, ptr, mask.numBytes);
  797. var cnt = view.getInt16(0, true);
  798. var ip = 2, op = 0, val = 0;
  799. do {
  800. if (cnt > 0) {
  801. while (cnt--) { bitset[op++] = view.getUint8(ip++); }
  802. } else {
  803. val = view.getUint8(ip++);
  804. cnt = -cnt;
  805. while (cnt--) { bitset[op++] = val; }
  806. }
  807. cnt = view.getInt16(ip, true);
  808. ip += 2;
  809. } while (ip < mask.numBytes);
  810. if ((cnt !== -32768) || (op < bitset.length)) {
  811. throw "Unexpected end of mask RLE encoding";
  812. }
  813. resultMask = new Uint8Array(numPixels);
  814. var mb = 0, k = 0;
  815. for (k = 0; k < numPixels; k++) {
  816. if (k & 7) {
  817. mb = bitset[k >> 3];
  818. mb <<= k & 7;
  819. }
  820. else {
  821. mb = bitset[k >> 3];
  822. }
  823. if (mb & 128) {
  824. resultMask[k] = 1;
  825. }
  826. }
  827. data.pixels.resultMask = resultMask;
  828. mask.bitset = bitset;
  829. ptr += mask.numBytes;
  830. }
  831. data.ptr = ptr;
  832. data.mask = mask;
  833. return true;
  834. },
  835. readDataOneSweep: function(input, data, OutPixelTypeArray) {
  836. var ptr = data.ptr;
  837. var headerInfo = data.headerInfo;
  838. var numDims = headerInfo.numDims;
  839. var numPixels = headerInfo.width * headerInfo.height;
  840. var imageType = headerInfo.imageType;
  841. var numBytes = headerInfo.numValidPixel * Lerc2Helpers.getDataTypeSize(imageType) * numDims;
  842. //data.pixels.numBytes = numBytes;
  843. var rawData;
  844. var mask = data.pixels.resultMask;
  845. if (OutPixelTypeArray === Uint8Array) {
  846. rawData = new Uint8Array(input, ptr, numBytes);
  847. }
  848. else {
  849. var arrayBuf = new ArrayBuffer(numBytes);
  850. var store8 = new Uint8Array(arrayBuf);
  851. store8.set(new Uint8Array(input, ptr, numBytes));
  852. rawData = new OutPixelTypeArray(arrayBuf);
  853. }
  854. if (rawData.length === numPixels * numDims) {
  855. data.pixels.resultPixels = rawData;
  856. }
  857. else //mask
  858. {
  859. data.pixels.resultPixels = new OutPixelTypeArray(numPixels * numDims);
  860. var z = 0, k = 0, i = 0, nStart = 0;
  861. if (numDims > 1) {
  862. for (i=0; i < numDims; i++) {
  863. nStart = i * numPixels;
  864. for (k = 0; k < numPixels; k++) {
  865. if (mask[k]) {
  866. data.pixels.resultPixels[nStart + k] = rawData[z++];
  867. }
  868. }
  869. }
  870. }
  871. else {
  872. for (k = 0; k < numPixels; k++) {
  873. if (mask[k]) {
  874. data.pixels.resultPixels[k] = rawData[z++];
  875. }
  876. }
  877. }
  878. }
  879. ptr += numBytes;
  880. data.ptr = ptr; //return data;
  881. return true;
  882. },
  883. readHuffmanTree: function(input, data) {
  884. var BITS_MAX = this.HUFFMAN_LUT_BITS_MAX; //8 is slow for the large test image
  885. //var size_max = 1 << BITS_MAX;
  886. /* ************************
  887. * reading code table
  888. *************************/
  889. var view = new DataView(input, data.ptr, 16);
  890. data.ptr += 16;
  891. var version = view.getInt32(0, true);
  892. if (version < 2) {
  893. throw "unsupported Huffman version";
  894. }
  895. var size = view.getInt32(4, true);
  896. var i0 = view.getInt32(8, true);
  897. var i1 = view.getInt32(12, true);
  898. if (i0 >= i1) {
  899. return false;
  900. }
  901. var blockDataBuffer = new Uint32Array(i1 - i0);
  902. Lerc2Helpers.decodeBits(input, data, blockDataBuffer);
  903. var codeTable = []; //size
  904. var i, j, k, len;
  905. for (i = i0; i < i1; i++) {
  906. j = i - (i < size ? 0 : size);//wrap around
  907. codeTable[j] = { first: blockDataBuffer[i - i0], second: null };
  908. }
  909. var dataBytes = input.byteLength - data.ptr;
  910. var dataWords = Math.ceil(dataBytes / 4);
  911. var arrayBuf = new ArrayBuffer(dataWords * 4);
  912. var store8 = new Uint8Array(arrayBuf);
  913. store8.set(new Uint8Array(input, data.ptr, dataBytes));
  914. var stuffedData = new Uint32Array(arrayBuf); //must start from x*4
  915. var bitPos = 0, word, srcPtr = 0;
  916. word = stuffedData[0];
  917. for (i = i0; i < i1; i++) {
  918. j = i - (i < size ? 0 : size);//wrap around
  919. len = codeTable[j].first;
  920. if (len > 0) {
  921. codeTable[j].second = (word << bitPos) >>> (32 - len);
  922. if (32 - bitPos >= len) {
  923. bitPos += len;
  924. if (bitPos === 32) {
  925. bitPos = 0;
  926. srcPtr++;
  927. word = stuffedData[srcPtr];
  928. }
  929. }
  930. else {
  931. bitPos += len - 32;
  932. srcPtr++;
  933. word = stuffedData[srcPtr];
  934. codeTable[j].second |= word >>> (32 - bitPos);
  935. }
  936. }
  937. }
  938. //finished reading code table
  939. /* ************************
  940. * building lut
  941. *************************/
  942. var numBitsLUT = 0, numBitsLUTQick = 0;
  943. var tree = new TreeNode();
  944. for (i = 0; i < codeTable.length; i++) {
  945. if (codeTable[i] !== undefined) {
  946. numBitsLUT = Math.max(numBitsLUT, codeTable[i].first);
  947. }
  948. }
  949. if (numBitsLUT >= BITS_MAX) {
  950. numBitsLUTQick = BITS_MAX;
  951. }
  952. else {
  953. numBitsLUTQick = numBitsLUT;
  954. }
  955. if (numBitsLUT >= 30) {
  956. console.log("WARning, large NUM LUT BITS IS " + numBitsLUT);
  957. }
  958. var decodeLut = [], entry, code, numEntries, jj, currentBit, node;
  959. for (i = i0; i < i1; i++) {
  960. j = i - (i < size ? 0 : size);//wrap around
  961. len = codeTable[j].first;
  962. if (len > 0) {
  963. entry = [len, j];
  964. if (len <= numBitsLUTQick) {
  965. code = codeTable[j].second << (numBitsLUTQick - len);
  966. numEntries = 1 << (numBitsLUTQick - len);
  967. for (k = 0; k < numEntries; k++) {
  968. decodeLut[code | k] = entry;
  969. }
  970. }
  971. else {
  972. //build tree
  973. code = codeTable[j].second;
  974. node = tree;
  975. for (jj = len - 1; jj >= 0; jj--) {
  976. currentBit = code >>> jj & 1; //no left shift as length could be 30,31
  977. if (currentBit) {
  978. if (!node.right) {
  979. node.right = new TreeNode();
  980. }
  981. node = node.right;
  982. }
  983. else {
  984. if (!node.left) {
  985. node.left = new TreeNode();
  986. }
  987. node = node.left;
  988. }
  989. if (jj === 0 && !node.val) {
  990. node.val = entry[1];
  991. }
  992. }
  993. }
  994. }
  995. }
  996. return {
  997. decodeLut: decodeLut,
  998. numBitsLUTQick: numBitsLUTQick,
  999. numBitsLUT: numBitsLUT,
  1000. tree: tree,
  1001. stuffedData: stuffedData,
  1002. srcPtr: srcPtr,
  1003. bitPos: bitPos
  1004. };
  1005. },
  1006. readHuffman: function(input, data, OutPixelTypeArray) {
  1007. var headerInfo = data.headerInfo;
  1008. var numDims = headerInfo.numDims;
  1009. var height = data.headerInfo.height;
  1010. var width = data.headerInfo.width;
  1011. var numPixels = width * height;
  1012. //var size_max = 1 << BITS_MAX;
  1013. /* ************************
  1014. * reading huffman structure info
  1015. *************************/
  1016. var huffmanInfo = this.readHuffmanTree(input, data);
  1017. var decodeLut = huffmanInfo.decodeLut;
  1018. var tree = huffmanInfo.tree;
  1019. //stuffedData includes huffman headers
  1020. var stuffedData = huffmanInfo.stuffedData;
  1021. var srcPtr = huffmanInfo.srcPtr;
  1022. var bitPos = huffmanInfo.bitPos;
  1023. var numBitsLUTQick = huffmanInfo.numBitsLUTQick;
  1024. var numBitsLUT = huffmanInfo.numBitsLUT;
  1025. var offset = data.headerInfo.imageType === 0 ? 128 : 0;
  1026. /*************************
  1027. * decode
  1028. ***************************/
  1029. var node, val, delta, mask = data.pixels.resultMask, valTmp, valTmpQuick, currentBit;
  1030. var i, j, k, ii;
  1031. var prevVal = 0;
  1032. if (bitPos > 0) {
  1033. srcPtr++;
  1034. bitPos = 0;
  1035. }
  1036. var word = stuffedData[srcPtr];
  1037. var deltaEncode = data.encodeMode === 1;
  1038. var resultPixelsAllDim = new OutPixelTypeArray(numPixels * numDims);
  1039. var resultPixels = resultPixelsAllDim;
  1040. var iDim;
  1041. for (iDim = 0; iDim < headerInfo.numDims; iDim++) {
  1042. if (numDims > 1) {
  1043. //get the mem block of current dimension
  1044. resultPixels = new OutPixelTypeArray(resultPixelsAllDim.buffer, numPixels * iDim, numPixels);
  1045. prevVal = 0;
  1046. }
  1047. if (data.headerInfo.numValidPixel === width * height) { //all valid
  1048. for (k = 0, i = 0; i < height; i++) {
  1049. for (j = 0; j < width; j++, k++) {
  1050. val = 0;
  1051. valTmp = (word << bitPos) >>> (32 - numBitsLUTQick);
  1052. valTmpQuick = valTmp;// >>> deltaBits;
  1053. if (32 - bitPos < numBitsLUTQick) {
  1054. valTmp |= ((stuffedData[srcPtr + 1]) >>> (64 - bitPos - numBitsLUTQick));
  1055. valTmpQuick = valTmp;// >>> deltaBits;
  1056. }
  1057. if (decodeLut[valTmpQuick]) // if there, move the correct number of bits and done
  1058. {
  1059. val = decodeLut[valTmpQuick][1];
  1060. bitPos += decodeLut[valTmpQuick][0];
  1061. }
  1062. else {
  1063. valTmp = (word << bitPos) >>> (32 - numBitsLUT);
  1064. valTmpQuick = valTmp;// >>> deltaBits;
  1065. if (32 - bitPos < numBitsLUT) {
  1066. valTmp |= ((stuffedData[srcPtr + 1]) >>> (64 - bitPos - numBitsLUT));
  1067. valTmpQuick = valTmp;// >>> deltaBits;
  1068. }
  1069. node = tree;
  1070. for (ii = 0; ii < numBitsLUT; ii++) {
  1071. currentBit = valTmp >>> (numBitsLUT - ii - 1) & 1;
  1072. node = currentBit ? node.right : node.left;
  1073. if (!(node.left || node.right)) {
  1074. val = node.val;
  1075. bitPos = bitPos + ii + 1;
  1076. break;
  1077. }
  1078. }
  1079. }
  1080. if (bitPos >= 32) {
  1081. bitPos -= 32;
  1082. srcPtr++;
  1083. word = stuffedData[srcPtr];
  1084. }
  1085. delta = val - offset;
  1086. if (deltaEncode) {
  1087. if (j > 0) {
  1088. delta += prevVal; // use overflow
  1089. }
  1090. else if (i > 0) {
  1091. delta += resultPixels[k - width];
  1092. }
  1093. else {
  1094. delta += prevVal;
  1095. }
  1096. delta &= 0xFF; //overflow
  1097. resultPixels[k] = delta;//overflow
  1098. prevVal = delta;
  1099. }
  1100. else {
  1101. resultPixels[k] = delta;
  1102. }
  1103. }
  1104. }
  1105. }
  1106. else { //not all valid, use mask
  1107. for (k = 0, i = 0; i < height; i++) {
  1108. for (j = 0; j < width; j++, k++) {
  1109. if (mask[k]) {
  1110. val = 0;
  1111. valTmp = (word << bitPos) >>> (32 - numBitsLUTQick);
  1112. valTmpQuick = valTmp;// >>> deltaBits;
  1113. if (32 - bitPos < numBitsLUTQick) {
  1114. valTmp |= ((stuffedData[srcPtr + 1]) >>> (64 - bitPos - numBitsLUTQick));
  1115. valTmpQuick = valTmp;// >>> deltaBits;
  1116. }
  1117. if (decodeLut[valTmpQuick]) // if there, move the correct number of bits and done
  1118. {
  1119. val = decodeLut[valTmpQuick][1];
  1120. bitPos += decodeLut[valTmpQuick][0];
  1121. }
  1122. else {
  1123. valTmp = (word << bitPos) >>> (32 - numBitsLUT);
  1124. valTmpQuick = valTmp;// >>> deltaBits;
  1125. if (32 - bitPos < numBitsLUT) {
  1126. valTmp |= ((stuffedData[srcPtr + 1]) >>> (64 - bitPos - numBitsLUT));
  1127. valTmpQuick = valTmp;// >>> deltaBits;
  1128. }
  1129. node = tree;
  1130. for (ii = 0; ii < numBitsLUT; ii++) {
  1131. currentBit = valTmp >>> (numBitsLUT - ii - 1) & 1;
  1132. node = currentBit ? node.right : node.left;
  1133. if (!(node.left || node.right)) {
  1134. val = node.val;
  1135. bitPos = bitPos + ii + 1;
  1136. break;
  1137. }
  1138. }
  1139. }
  1140. if (bitPos >= 32) {
  1141. bitPos -= 32;
  1142. srcPtr++;
  1143. word = stuffedData[srcPtr];
  1144. }
  1145. delta = val - offset;
  1146. if (deltaEncode) {
  1147. if (j > 0 && mask[k - 1]) {
  1148. delta += prevVal; // use overflow
  1149. }
  1150. else if (i > 0 && mask[k - width]) {
  1151. delta += resultPixels[k - width];
  1152. }
  1153. else {
  1154. delta += prevVal;
  1155. }
  1156. delta &= 0xFF; //overflow
  1157. resultPixels[k] = delta;//overflow
  1158. prevVal = delta;
  1159. }
  1160. else {
  1161. resultPixels[k] = delta;
  1162. }
  1163. }
  1164. }
  1165. }
  1166. }
  1167. data.ptr = data.ptr + (srcPtr + 1) * 4 + (bitPos > 0 ? 4 : 0);
  1168. }
  1169. data.pixels.resultPixels = resultPixelsAllDim;
  1170. },
  1171. decodeBits: function(input, data, blockDataBuffer, offset, iDim) {
  1172. {
  1173. //bitstuff encoding is 3
  1174. var headerInfo = data.headerInfo;
  1175. var fileVersion = headerInfo.fileVersion;
  1176. //var block = {};
  1177. var blockPtr = 0;
  1178. var view = new DataView(input, data.ptr, 5);//to do
  1179. var headerByte = view.getUint8(0);
  1180. blockPtr++;
  1181. var bits67 = headerByte >> 6;
  1182. var n = (bits67 === 0) ? 4 : 3 - bits67;
  1183. var doLut = (headerByte & 32) > 0 ? true : false;//5th bit
  1184. var numBits = headerByte & 31;
  1185. var numElements = 0;
  1186. if (n === 1) {
  1187. numElements = view.getUint8(blockPtr); blockPtr++;
  1188. } else if (n === 2) {
  1189. numElements = view.getUint16(blockPtr, true); blockPtr += 2;
  1190. } else if (n === 4) {
  1191. numElements = view.getUint32(blockPtr, true); blockPtr += 4;
  1192. } else {
  1193. throw "Invalid valid pixel count type";
  1194. }
  1195. //fix: huffman codes are bit stuffed, but not bound by data's max value, so need to use originalUnstuff
  1196. //offset = offset || 0;
  1197. var scale = 2 * headerInfo.maxZError;
  1198. var stuffedData, arrayBuf, store8, dataBytes, dataWords;
  1199. var lutArr, lutData, lutBytes, bitsPerPixel;
  1200. var zMax = headerInfo.numDims > 1 ? headerInfo.maxValues[iDim] : headerInfo.zMax;
  1201. if (doLut) {
  1202. data.counter.lut++;
  1203. lutBytes = view.getUint8(blockPtr);
  1204. blockPtr++;
  1205. dataBytes = Math.ceil((lutBytes - 1) * numBits / 8);
  1206. dataWords = Math.ceil(dataBytes / 4);
  1207. arrayBuf = new ArrayBuffer(dataWords * 4);
  1208. store8 = new Uint8Array(arrayBuf);
  1209. data.ptr += blockPtr;
  1210. store8.set(new Uint8Array(input, data.ptr, dataBytes));
  1211. lutData = new Uint32Array(arrayBuf);
  1212. data.ptr += dataBytes;
  1213. bitsPerPixel = 0;
  1214. while ((lutBytes - 1) >>> bitsPerPixel) {
  1215. bitsPerPixel++;
  1216. }
  1217. dataBytes = Math.ceil(numElements * bitsPerPixel / 8);
  1218. dataWords = Math.ceil(dataBytes / 4);
  1219. arrayBuf = new ArrayBuffer(dataWords * 4);
  1220. store8 = new Uint8Array(arrayBuf);
  1221. store8.set(new Uint8Array(input, data.ptr, dataBytes));
  1222. stuffedData = new Uint32Array(arrayBuf);
  1223. data.ptr += dataBytes;
  1224. if (fileVersion >= 3) {
  1225. lutArr = BitStuffer.unstuffLUT2(lutData, numBits, lutBytes - 1, offset, scale, zMax);
  1226. }
  1227. else {
  1228. lutArr = BitStuffer.unstuffLUT(lutData, numBits, lutBytes - 1, offset, scale, zMax);
  1229. }
  1230. //lutArr.unshift(0);
  1231. if (fileVersion >= 3) {
  1232. //BitStuffer.unstuff2(block, blockDataBuffer, headerInfo.zMax);
  1233. BitStuffer.unstuff2(stuffedData, blockDataBuffer, bitsPerPixel, numElements, lutArr);
  1234. }
  1235. else {
  1236. BitStuffer.unstuff(stuffedData, blockDataBuffer, bitsPerPixel, numElements, lutArr);
  1237. }
  1238. }
  1239. else {
  1240. //console.debug("bitstuffer");
  1241. data.counter.bitstuffer++;
  1242. bitsPerPixel = numBits;
  1243. data.ptr += blockPtr;
  1244. if (bitsPerPixel > 0) {
  1245. dataBytes = Math.ceil(numElements * bitsPerPixel / 8);
  1246. dataWords = Math.ceil(dataBytes / 4);
  1247. arrayBuf = new ArrayBuffer(dataWords * 4);
  1248. store8 = new Uint8Array(arrayBuf);
  1249. store8.set(new Uint8Array(input, data.ptr, dataBytes));
  1250. stuffedData = new Uint32Array(arrayBuf);
  1251. data.ptr += dataBytes;
  1252. if (fileVersion >= 3) {
  1253. if (offset == null) {
  1254. BitStuffer.originalUnstuff2(stuffedData, blockDataBuffer, bitsPerPixel, numElements);
  1255. }
  1256. else {
  1257. BitStuffer.unstuff2(stuffedData, blockDataBuffer, bitsPerPixel, numElements, false, offset, scale, zMax);
  1258. }
  1259. }
  1260. else {
  1261. if (offset == null) {
  1262. BitStuffer.originalUnstuff(stuffedData, blockDataBuffer, bitsPerPixel, numElements);
  1263. }
  1264. else {
  1265. BitStuffer.unstuff(stuffedData, blockDataBuffer, bitsPerPixel, numElements, false, offset, scale, zMax);
  1266. }
  1267. }
  1268. }
  1269. }
  1270. }
  1271. },
  1272. readTiles: function(input, data, OutPixelTypeArray) {
  1273. var headerInfo = data.headerInfo;
  1274. var width = headerInfo.width;
  1275. var height = headerInfo.height;
  1276. var microBlockSize = headerInfo.microBlockSize;
  1277. var imageType = headerInfo.imageType;
  1278. var dataTypeSize = Lerc2Helpers.getDataTypeSize(imageType);
  1279. var numBlocksX = Math.ceil(width / microBlockSize);
  1280. var numBlocksY = Math.ceil(height / microBlockSize);
  1281. data.pixels.numBlocksY = numBlocksY;
  1282. data.pixels.numBlocksX = numBlocksX;
  1283. data.pixels.ptr = 0;
  1284. var row = 0, col = 0, blockY = 0, blockX = 0, thisBlockHeight = 0, thisBlockWidth = 0, bytesLeft = 0, headerByte = 0, bits67 = 0, testCode = 0, outPtr = 0, outStride = 0, numBytes = 0, bytesleft = 0, z = 0, blockPtr = 0;
  1285. var view, block, arrayBuf, store8, rawData;
  1286. var blockEncoding;
  1287. var blockDataBuffer = new OutPixelTypeArray(microBlockSize * microBlockSize);
  1288. var lastBlockHeight = (height % microBlockSize) || microBlockSize;
  1289. var lastBlockWidth = (width % microBlockSize) || microBlockSize;
  1290. var offsetType, offset;
  1291. var numDims = headerInfo.numDims, iDim;
  1292. var mask = data.pixels.resultMask;
  1293. var resultPixels = data.pixels.resultPixels;
  1294. for (blockY = 0; blockY < numBlocksY; blockY++) {
  1295. thisBlockHeight = (blockY !== numBlocksY - 1) ? microBlockSize : lastBlockHeight;
  1296. for (blockX = 0; blockX < numBlocksX; blockX++) {
  1297. //console.debug("y" + blockY + " x" + blockX);
  1298. thisBlockWidth = (blockX !== numBlocksX - 1) ? microBlockSize : lastBlockWidth;
  1299. outPtr = blockY * width * microBlockSize + blockX * microBlockSize;
  1300. outStride = width - thisBlockWidth;
  1301. for (iDim = 0; iDim < numDims; iDim++) {
  1302. if (numDims > 1) {
  1303. resultPixels = new OutPixelTypeArray(data.pixels.resultPixels.buffer, width * height * iDim * dataTypeSize, width * height);
  1304. }
  1305. bytesLeft = input.byteLength - data.ptr;
  1306. view = new DataView(input, data.ptr, Math.min(10, bytesLeft));
  1307. block = {};
  1308. blockPtr = 0;
  1309. headerByte = view.getUint8(0);
  1310. blockPtr++;
  1311. bits67 = (headerByte >> 6) & 0xFF;
  1312. testCode = (headerByte >> 2) & 15; // use bits 2345 for integrity check
  1313. if (testCode !== (((blockX * microBlockSize) >> 3) & 15)) {
  1314. throw "integrity issue";
  1315. //return false;
  1316. }
  1317. blockEncoding = headerByte & 3;
  1318. if (blockEncoding > 3) {
  1319. data.ptr += blockPtr;
  1320. throw "Invalid block encoding (" + blockEncoding + ")";
  1321. }
  1322. else if (blockEncoding === 2) { //constant 0
  1323. data.counter.constant++;
  1324. data.ptr += blockPtr;
  1325. continue;
  1326. }
  1327. else if (blockEncoding === 0) { //uncompressed
  1328. data.counter.uncompressed++;
  1329. data.ptr += blockPtr;
  1330. numBytes = thisBlockHeight * thisBlockWidth * dataTypeSize;
  1331. bytesleft = input.byteLength - data.ptr;
  1332. numBytes = numBytes < bytesleft ? numBytes : bytesleft;
  1333. //bit alignment
  1334. arrayBuf = new ArrayBuffer((numBytes % dataTypeSize) === 0 ? numBytes : (numBytes + dataTypeSize - numBytes % dataTypeSize));
  1335. store8 = new Uint8Array(arrayBuf);
  1336. store8.set(new Uint8Array(input, data.ptr, numBytes));
  1337. rawData = new OutPixelTypeArray(arrayBuf);
  1338. z = 0;
  1339. if (mask) {
  1340. for (row = 0; row < thisBlockHeight; row++) {
  1341. for (col = 0; col < thisBlockWidth; col++) {
  1342. if (mask[outPtr]) {
  1343. resultPixels[outPtr] = rawData[z++];
  1344. }
  1345. outPtr++;
  1346. }
  1347. outPtr += outStride;
  1348. }
  1349. }
  1350. else {//all valid
  1351. for (row = 0; row < thisBlockHeight; row++) {
  1352. for (col = 0; col < thisBlockWidth; col++) {
  1353. resultPixels[outPtr++] = rawData[z++];
  1354. }
  1355. outPtr += outStride;
  1356. }
  1357. }
  1358. data.ptr += z * dataTypeSize;
  1359. }
  1360. else { //1 or 3
  1361. offsetType = Lerc2Helpers.getDataTypeUsed(imageType, bits67);
  1362. offset = Lerc2Helpers.getOnePixel(block, blockPtr, offsetType, view);
  1363. blockPtr += Lerc2Helpers.getDataTypeSize(offsetType);
  1364. if (blockEncoding === 3) //constant offset value
  1365. {
  1366. data.ptr += blockPtr;
  1367. data.counter.constantoffset++;
  1368. //you can delete the following resultMask case in favor of performance because val is constant and users use nodata mask, otherwise nodatavalue post processing handles it too.
  1369. //while the above statement is true, we're not doing it as we want to keep invalid pixel value at 0 rather than arbitrary values
  1370. if (mask) {
  1371. for (row = 0; row < thisBlockHeight; row++) {
  1372. for (col = 0; col < thisBlockWidth; col++) {
  1373. if (mask[outPtr]) {
  1374. resultPixels[outPtr] = offset;
  1375. }
  1376. outPtr++;
  1377. }
  1378. outPtr += outStride;
  1379. }
  1380. }
  1381. else {
  1382. for (row = 0; row < thisBlockHeight; row++) {
  1383. for (col = 0; col < thisBlockWidth; col++) {
  1384. resultPixels[outPtr++] = offset;
  1385. }
  1386. outPtr += outStride;
  1387. }
  1388. }
  1389. }
  1390. else { //bitstuff encoding is 3
  1391. data.ptr += blockPtr;
  1392. //heavy lifting
  1393. Lerc2Helpers.decodeBits(input, data, blockDataBuffer, offset, iDim);
  1394. blockPtr = 0;
  1395. if (mask) {
  1396. for (row = 0; row < thisBlockHeight; row++) {
  1397. for (col = 0; col < thisBlockWidth; col++) {
  1398. if (mask[outPtr]) {
  1399. resultPixels[outPtr] = blockDataBuffer[blockPtr++];
  1400. }
  1401. outPtr++;
  1402. }
  1403. outPtr += outStride;
  1404. }
  1405. }
  1406. else {
  1407. for (row = 0; row < thisBlockHeight; row++) {
  1408. for (col = 0; col < thisBlockWidth; col++) {
  1409. resultPixels[outPtr++] = blockDataBuffer[blockPtr++];
  1410. }
  1411. outPtr += outStride;
  1412. }
  1413. }
  1414. }
  1415. }
  1416. }
  1417. }
  1418. }
  1419. },
  1420. /*****************
  1421. * private methods (helper methods)
  1422. *****************/
  1423. formatFileInfo: function(data) {
  1424. return {
  1425. "fileIdentifierString": data.headerInfo.fileIdentifierString,
  1426. "fileVersion": data.headerInfo.fileVersion,
  1427. "imageType": data.headerInfo.imageType,
  1428. "height": data.headerInfo.height,
  1429. "width": data.headerInfo.width,
  1430. "numValidPixel": data.headerInfo.numValidPixel,
  1431. "microBlockSize": data.headerInfo.microBlockSize,
  1432. "blobSize": data.headerInfo.blobSize,
  1433. "maxZError": data.headerInfo.maxZError,
  1434. "pixelType": Lerc2Helpers.getPixelType(data.headerInfo.imageType),
  1435. "eofOffset": data.eofOffset,
  1436. "mask": data.mask ? {
  1437. "numBytes": data.mask.numBytes
  1438. } : null,
  1439. "pixels": {
  1440. "numBlocksX": data.pixels.numBlocksX,
  1441. "numBlocksY": data.pixels.numBlocksY,
  1442. //"numBytes": data.pixels.numBytes,
  1443. "maxValue": data.headerInfo.zMax,
  1444. "minValue": data.headerInfo.zMin,
  1445. "noDataValue": data.noDataValue
  1446. }
  1447. };
  1448. },
  1449. constructConstantSurface: function(data) {
  1450. var val = data.headerInfo.zMax;
  1451. var numDims = data.headerInfo.numDims;
  1452. var numPixels = data.headerInfo.height * data.headerInfo.width;
  1453. var numPixelAllDims = numPixels * numDims;
  1454. var i=0, k = 0, nStart=0;
  1455. var mask = data.pixels.resultMask;
  1456. if (mask) {
  1457. if (numDims > 1) {
  1458. for (i=0; i < numDims; i++) {
  1459. nStart = i * numPixels;
  1460. for (k = 0; k < numPixels; k++) {
  1461. if (mask[k]) {
  1462. data.pixels.resultPixels[nStart + k] = val;
  1463. }
  1464. }
  1465. }
  1466. }
  1467. else {
  1468. for (k = 0; k < numPixels; k++) {
  1469. if (mask[k]) {
  1470. data.pixels.resultPixels[k] = val;
  1471. }
  1472. }
  1473. }
  1474. }
  1475. else {
  1476. if (data.pixels.resultPixels.fill) {
  1477. data.pixels.resultPixels.fill(val);
  1478. }
  1479. else {
  1480. for (k = 0; k < numPixelAllDims; k++) {
  1481. data.pixels.resultPixels[k] = val;
  1482. }
  1483. }
  1484. }
  1485. return;
  1486. },
  1487. getDataTypeArray: function(t) {
  1488. var tp;
  1489. switch (t) {
  1490. case 0: //char
  1491. tp = Int8Array;
  1492. break;
  1493. case 1: //byte
  1494. tp = Uint8Array;
  1495. break;
  1496. case 2: //short
  1497. tp = Int16Array;
  1498. break;
  1499. case 3: //ushort
  1500. tp = Uint16Array;
  1501. break;
  1502. case 4:
  1503. tp = Int32Array;
  1504. break;
  1505. case 5:
  1506. tp = Uint32Array;
  1507. break;
  1508. case 6:
  1509. tp = Float32Array;
  1510. break;
  1511. case 7:
  1512. tp = Float64Array;
  1513. break;
  1514. default:
  1515. tp = Float32Array;
  1516. }
  1517. return tp;
  1518. },
  1519. getPixelType: function(t) {
  1520. var tp;
  1521. switch (t) {
  1522. case 0: //char
  1523. tp = "S8";
  1524. break;
  1525. case 1: //byte
  1526. tp = "U8";
  1527. break;
  1528. case 2: //short
  1529. tp = "S16";
  1530. break;
  1531. case 3: //ushort
  1532. tp = "U16";
  1533. break;
  1534. case 4:
  1535. tp = "S32";
  1536. break;
  1537. case 5:
  1538. tp = "U32";
  1539. break;
  1540. case 6:
  1541. tp = "F32";
  1542. break;
  1543. case 7:
  1544. tp = "F64"; //not supported
  1545. break;
  1546. default:
  1547. tp = "F32";
  1548. }
  1549. return tp;
  1550. },
  1551. isValidPixelValue: function(t, val) {
  1552. if (val == null) {
  1553. return false;
  1554. }
  1555. var isValid;
  1556. switch (t) {
  1557. case 0: //char
  1558. isValid = val >= -128 && val <= 127;
  1559. break;
  1560. case 1: //byte (unsigned char)
  1561. isValid = val >= 0 && val <= 255;
  1562. break;
  1563. case 2: //short
  1564. isValid = val >= -32768 && val <= 32767;
  1565. break;
  1566. case 3: //ushort
  1567. isValid = val >= 0 && val <= 65536;
  1568. break;
  1569. case 4: //int 32
  1570. isValid = val >= -2147483648 && val <= 2147483647;
  1571. break;
  1572. case 5: //uinit 32
  1573. isValid = val >= 0 && val <= 4294967296;
  1574. break;
  1575. case 6:
  1576. isValid = val >= -3.4027999387901484e+38 && val <= 3.4027999387901484e+38;
  1577. break;
  1578. case 7:
  1579. isValid = val >= 5e-324 && val <= 1.7976931348623157e+308;
  1580. break;
  1581. default:
  1582. isValid = false;
  1583. }
  1584. return isValid;
  1585. },
  1586. getDataTypeSize: function(t) {
  1587. var s = 0;
  1588. switch (t) {
  1589. case 0: //ubyte
  1590. case 1: //byte
  1591. s = 1;
  1592. break;
  1593. case 2: //short
  1594. case 3: //ushort
  1595. s = 2;
  1596. break;
  1597. case 4:
  1598. case 5:
  1599. case 6:
  1600. s = 4;
  1601. break;
  1602. case 7:
  1603. s = 8;
  1604. break;
  1605. default:
  1606. s = t;
  1607. }
  1608. return s;
  1609. },
  1610. getDataTypeUsed: function(dt, tc) {
  1611. var t = dt;
  1612. switch (dt) {
  1613. case 2: //short
  1614. case 4: //long
  1615. t = dt - tc;
  1616. break;
  1617. case 3: //ushort
  1618. case 5: //ulong
  1619. t = dt - 2 * tc;
  1620. break;
  1621. case 6: //float
  1622. if (0 === tc) {
  1623. t = dt;
  1624. }
  1625. else if (1 === tc) {
  1626. t = 2;
  1627. }
  1628. else {
  1629. t = 1;//byte
  1630. }
  1631. break;
  1632. case 7: //double
  1633. if (0 === tc) {
  1634. t = dt;
  1635. }
  1636. else {
  1637. t = dt - 2 * tc + 1;
  1638. }
  1639. break;
  1640. default:
  1641. t = dt;
  1642. break;
  1643. }
  1644. return t;
  1645. },
  1646. getOnePixel: function(block, blockPtr, offsetType, view) {
  1647. var temp = 0;
  1648. switch (offsetType) {
  1649. case 0: //char
  1650. temp = view.getInt8(blockPtr);
  1651. break;
  1652. case 1: //byte
  1653. temp = view.getUint8(blockPtr);
  1654. break;
  1655. case 2:
  1656. temp = view.getInt16(blockPtr, true);
  1657. break;
  1658. case 3:
  1659. temp = view.getUint16(blockPtr, true);
  1660. break;
  1661. case 4:
  1662. temp = view.getInt32(blockPtr, true);
  1663. break;
  1664. case 5:
  1665. temp = view.getUInt32(blockPtr, true);
  1666. break;
  1667. case 6:
  1668. temp = view.getFloat32(blockPtr, true);
  1669. break;
  1670. case 7:
  1671. //temp = view.getFloat64(blockPtr, true);
  1672. //blockPtr += 8;
  1673. //lerc2 encoding doesnt handle float 64, force to float32???
  1674. temp = view.getFloat64(blockPtr, true);
  1675. break;
  1676. default:
  1677. throw ("the decoder does not understand this pixel type");
  1678. }
  1679. return temp;
  1680. }
  1681. };
  1682. /***************************************************
  1683. *private class for a tree node. Huffman code is in Lerc2Helpers
  1684. ****************************************************/
  1685. var TreeNode = function(val, left, right) {
  1686. this.val = val;
  1687. this.left = left;
  1688. this.right = right;
  1689. };
  1690. var Lerc2Decode = {
  1691. /*
  1692. * ********removed options compared to LERC1. We can bring some of them back if needed.
  1693. * removed pixel type. LERC2 is typed and doesn't require user to give pixel type
  1694. * changed encodedMaskData to maskData. LERC2 's js version make it faster to use maskData directly.
  1695. * removed returnMask. mask is used by LERC2 internally and is cost free. In case of user input mask, it's returned as well and has neglible cost.
  1696. * removed nodatavalue. Because LERC2 pixels are typed, nodatavalue will sacrify a useful value for many types (8bit, 16bit) etc,
  1697. * user has to be knowledgable enough about raster and their data to avoid usability issues. so nodata value is simply removed now.
  1698. * We can add it back later if their's a clear requirement.
  1699. * removed encodedMask. This option was not implemented in LercDecode. It can be done after decoding (less efficient)
  1700. * removed computeUsedBitDepths.
  1701. *
  1702. *
  1703. * response changes compared to LERC1
  1704. * 1. encodedMaskData is not available
  1705. * 2. noDataValue is optional (returns only if user's noDataValue is with in the valid data type range)
  1706. * 3. maskData is always available
  1707. */
  1708. /*****************
  1709. * public properties
  1710. ******************/
  1711. //HUFFMAN_LUT_BITS_MAX: 12, //use 2^12 lut, not configurable
  1712. /*****************
  1713. * public methods
  1714. *****************/
  1715. /**
  1716. * Decode a LERC2 byte stream and return an object containing the pixel data and optional metadata.
  1717. *
  1718. * @param {ArrayBuffer} input The LERC input byte stream
  1719. * @param {object} [options] options Decoding options
  1720. * @param {number} [options.inputOffset] The number of bytes to skip in the input byte stream. A valid LERC file is expected at that position
  1721. * @param {boolean} [options.returnFileInfo] If true, the return value will have a fileInfo property that contains metadata obtained from the LERC headers and the decoding process
  1722. */
  1723. decode: function(/*byte array*/ input, /*object*/ options) {
  1724. //currently there's a bug in the sparse array, so please do not set to false
  1725. options = options || {};
  1726. var noDataValue = options.noDataValue;
  1727. //initialize
  1728. var i = 0, data = {};
  1729. data.ptr = options.inputOffset || 0;
  1730. data.pixels = {};
  1731. // File header
  1732. if (!Lerc2Helpers.readHeaderInfo(input, data)) ;
  1733. var headerInfo = data.headerInfo;
  1734. var fileVersion = headerInfo.fileVersion;
  1735. var OutPixelTypeArray = Lerc2Helpers.getDataTypeArray(headerInfo.imageType);
  1736. // Mask Header
  1737. Lerc2Helpers.readMask(input, data);
  1738. if (headerInfo.numValidPixel !== headerInfo.width * headerInfo.height && !data.pixels.resultMask) {
  1739. data.pixels.resultMask = options.maskData;
  1740. }
  1741. var numPixels = headerInfo.width * headerInfo.height;
  1742. data.pixels.resultPixels = new OutPixelTypeArray(numPixels * headerInfo.numDims);
  1743. data.counter = {
  1744. onesweep: 0,
  1745. uncompressed: 0,
  1746. lut: 0,
  1747. bitstuffer: 0,
  1748. constant: 0,
  1749. constantoffset: 0
  1750. };
  1751. if (headerInfo.numValidPixel !== 0) {
  1752. //not tested
  1753. if (headerInfo.zMax === headerInfo.zMin) //constant surface
  1754. {
  1755. Lerc2Helpers.constructConstantSurface(data);
  1756. }
  1757. else if (fileVersion >= 4 && Lerc2Helpers.checkMinMaxRanges(input, data)) {
  1758. Lerc2Helpers.constructConstantSurface(data);
  1759. }
  1760. else {
  1761. var view = new DataView(input, data.ptr, 2);
  1762. var bReadDataOneSweep = view.getUint8(0);
  1763. data.ptr++;
  1764. if (bReadDataOneSweep) {
  1765. //console.debug("OneSweep");
  1766. Lerc2Helpers.readDataOneSweep(input, data, OutPixelTypeArray);
  1767. }
  1768. else {
  1769. //lerc2.1: //bitstuffing + lut
  1770. //lerc2.2: //bitstuffing + lut + huffman
  1771. //lerc2.3: new bitstuffer
  1772. if (fileVersion > 1 && headerInfo.imageType <= 1 && Math.abs(headerInfo.maxZError - 0.5) < 0.00001) {
  1773. //this is 2.x plus 8 bit (unsigned and signed) data, possiblity of Huffman
  1774. var flagHuffman = view.getUint8(1);
  1775. data.ptr++;
  1776. data.encodeMode = flagHuffman;
  1777. if (flagHuffman > 2 || (fileVersion < 4 && flagHuffman > 1)) {
  1778. throw "Invalid Huffman flag " + flagHuffman;
  1779. }
  1780. if (flagHuffman) {//1 - delta Huffman, 2 - Huffman
  1781. //console.log("Huffman");
  1782. Lerc2Helpers.readHuffman(input, data, OutPixelTypeArray);
  1783. }
  1784. else {
  1785. //console.log("Tiles");
  1786. Lerc2Helpers.readTiles(input, data, OutPixelTypeArray);
  1787. }
  1788. }
  1789. else { //lerc2.x non-8 bit data
  1790. //console.log("Tiles");
  1791. Lerc2Helpers.readTiles(input, data, OutPixelTypeArray);
  1792. }
  1793. }
  1794. }
  1795. }
  1796. data.eofOffset = data.ptr;
  1797. var diff;
  1798. if (options.inputOffset) {
  1799. diff = data.headerInfo.blobSize + options.inputOffset - data.ptr;
  1800. if (Math.abs(diff) >= 1) {
  1801. //console.debug("incorrect eof: dataptr " + data.ptr + " offset " + options.inputOffset + " blobsize " + data.headerInfo.blobSize + " diff: " + diff);
  1802. data.eofOffset = options.inputOffset + data.headerInfo.blobSize;
  1803. }
  1804. }
  1805. else {
  1806. diff = data.headerInfo.blobSize - data.ptr;
  1807. if (Math.abs(diff) >= 1) {
  1808. //console.debug("incorrect first band eof: dataptr " + data.ptr + " blobsize " + data.headerInfo.blobSize + " diff: " + diff);
  1809. data.eofOffset = data.headerInfo.blobSize;
  1810. }
  1811. }
  1812. var result = {
  1813. width: headerInfo.width,
  1814. height: headerInfo.height,
  1815. pixelData: data.pixels.resultPixels,
  1816. minValue: headerInfo.zMin,
  1817. maxValue: headerInfo.zMax,
  1818. validPixelCount: headerInfo.numValidPixel,
  1819. dimCount: headerInfo.numDims,
  1820. dimStats: {
  1821. minValues: headerInfo.minValues,
  1822. maxValues: headerInfo.maxValues
  1823. },
  1824. maskData: data.pixels.resultMask
  1825. //noDataValue: noDataValue
  1826. };
  1827. //we should remove this if there's no existing client
  1828. //optional noDataValue processing, it's user's responsiblity
  1829. if (data.pixels.resultMask && Lerc2Helpers.isValidPixelValue(headerInfo.imageType, noDataValue)) {
  1830. var mask = data.pixels.resultMask;
  1831. for (i = 0; i < numPixels; i++) {
  1832. if (!mask[i]) {
  1833. result.pixelData[i] = noDataValue;
  1834. }
  1835. }
  1836. result.noDataValue = noDataValue;
  1837. }
  1838. data.noDataValue = noDataValue;
  1839. if (options.returnFileInfo) {
  1840. result.fileInfo = Lerc2Helpers.formatFileInfo(data);
  1841. }
  1842. return result;
  1843. },
  1844. getBandCount: function(/*byte array*/ input) {
  1845. var count = 0;
  1846. var i = 0;
  1847. var temp = {};
  1848. temp.ptr = 0;
  1849. temp.pixels = {};
  1850. while (i < input.byteLength - 58) {
  1851. Lerc2Helpers.readHeaderInfo(input, temp);
  1852. i += temp.headerInfo.blobSize;
  1853. count++;
  1854. temp.ptr = i;
  1855. }
  1856. return count;
  1857. }
  1858. };
  1859. return Lerc2Decode;
  1860. })();
  1861. var isPlatformLittleEndian = (function() {
  1862. var a = new ArrayBuffer(4);
  1863. var b = new Uint8Array(a);
  1864. var c = new Uint32Array(a);
  1865. c[0] = 1;
  1866. return b[0] === 1;
  1867. })();
  1868. var Lerc = {
  1869. /************wrapper**********************************************/
  1870. /**
  1871. * A wrapper for decoding both LERC1 and LERC2 byte streams capable of handling multiband pixel blocks for various pixel types.
  1872. *
  1873. * @alias module:Lerc
  1874. * @param {ArrayBuffer} input The LERC input byte stream
  1875. * @param {object} [options] The decoding options below are optional.
  1876. * @param {number} [options.inputOffset] The number of bytes to skip in the input byte stream. A valid Lerc file is expected at that position.
  1877. * @param {string} [options.pixelType] (LERC1 only) Default value is F32. Valid pixel types for input are U8/S8/S16/U16/S32/U32/F32.
  1878. * @param {number} [options.noDataValue] (LERC1 only). It is recommended to use the returned mask instead of setting this value.
  1879. * @returns {{width, height, pixels, pixelType, mask, statistics}}
  1880. * @property {number} width Width of decoded image.
  1881. * @property {number} height Height of decoded image.
  1882. * @property {array} pixels [band1, band2, …] Each band is a typed array of width*height.
  1883. * @property {string} pixelType The type of pixels represented in the output.
  1884. * @property {mask} mask Typed array with a size of width*height, or null if all pixels are valid.
  1885. * @property {array} statistics [statistics_band1, statistics_band2, …] Each element is a statistics object representing min and max values
  1886. **/
  1887. decode: function(encodedData, options) {
  1888. if (!isPlatformLittleEndian) {
  1889. throw "Big endian system is not supported.";
  1890. }
  1891. options = options || {};
  1892. var inputOffset = options.inputOffset || 0;
  1893. var fileIdView = new Uint8Array(encodedData, inputOffset, 10);
  1894. var fileIdentifierString = String.fromCharCode.apply(null, fileIdView);
  1895. var lerc, majorVersion;
  1896. if (fileIdentifierString.trim() === "CntZImage") {
  1897. lerc = LercDecode;
  1898. majorVersion = 1;
  1899. }
  1900. else if (fileIdentifierString.substring(0, 5) === "Lerc2") {
  1901. lerc = Lerc2Decode;
  1902. majorVersion = 2;
  1903. }
  1904. else {
  1905. throw "Unexpected file identifier string: " + fileIdentifierString;
  1906. }
  1907. var iPlane = 0, eof = encodedData.byteLength - 10, encodedMaskData, bandMasks = [], bandMask, maskData;
  1908. var decodedPixelBlock = {
  1909. width: 0,
  1910. height: 0,
  1911. pixels: [],
  1912. pixelType: options.pixelType,
  1913. mask: null,
  1914. statistics: []
  1915. };
  1916. while (inputOffset < eof) {
  1917. var result = lerc.decode(encodedData, {
  1918. inputOffset: inputOffset,//for both lerc1 and lerc2
  1919. encodedMaskData: encodedMaskData,//lerc1 only
  1920. maskData: maskData,//lerc2 only
  1921. returnMask: iPlane === 0 ? true : false,//lerc1 only
  1922. returnEncodedMask: iPlane === 0 ? true : false,//lerc1 only
  1923. returnFileInfo: true,//for both lerc1 and lerc2
  1924. pixelType: options.pixelType || null,//lerc1 only
  1925. noDataValue: options.noDataValue || null//lerc1 only
  1926. });
  1927. inputOffset = result.fileInfo.eofOffset;
  1928. if (iPlane === 0) {
  1929. encodedMaskData = result.encodedMaskData;//lerc1
  1930. maskData = result.maskData;//lerc2
  1931. decodedPixelBlock.width = result.width;
  1932. decodedPixelBlock.height = result.height;
  1933. decodedPixelBlock.dimCount = result.dimCount || 1;
  1934. //decodedPixelBlock.dimStats = decodedPixelBlock.dimStats;
  1935. decodedPixelBlock.pixelType = result.pixelType || result.fileInfo.pixelType;
  1936. decodedPixelBlock.mask = result.maskData;
  1937. }
  1938. if (majorVersion >1 && result.fileInfo.mask && result.fileInfo.mask.numBytes > 0) {
  1939. bandMasks.push(result.maskData);
  1940. }
  1941. iPlane++;
  1942. decodedPixelBlock.pixels.push(result.pixelData);
  1943. decodedPixelBlock.statistics.push({
  1944. minValue: result.minValue,
  1945. maxValue: result.maxValue,
  1946. noDataValue: result.noDataValue,
  1947. dimStats: result.dimStats
  1948. });
  1949. }
  1950. var i, j, numPixels;
  1951. if (majorVersion > 1 && bandMasks.length > 1) {
  1952. numPixels = decodedPixelBlock.width * decodedPixelBlock.height;
  1953. decodedPixelBlock.bandMasks = bandMasks;
  1954. maskData = new Uint8Array(numPixels);
  1955. maskData.set(bandMasks[0]);
  1956. for (i = 1; i < bandMasks.length; i++) {
  1957. bandMask = bandMasks[i];
  1958. for (j = 0; j < numPixels; j++) {
  1959. maskData[j] = maskData[j] & bandMask[j];
  1960. }
  1961. }
  1962. decodedPixelBlock.maskData = maskData;
  1963. }
  1964. return decodedPixelBlock;
  1965. }
  1966. };
  1967. if (module.exports) {/* jshint ignore:line */
  1968. //commonJS module 1.0/1.1/1.1.1 systems, such as nodeJS
  1969. //http://wiki.commonjs.org/wiki/Modules
  1970. module.exports = Lerc;/* jshint ignore:line */
  1971. }
  1972. else {
  1973. //assign to this, most likely window
  1974. this.Lerc = Lerc;
  1975. }
  1976. })();
  1977. });
  1978. export { LercDecode as default };