var __values = (this && this.__values) || function(o) {
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var s = typeof Symbol === "function" && Symbol.iterator, m = s && o[s], i = 0;
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if (m) return m.call(o);
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if (o && typeof o.length === "number") return {
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next: function () {
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if (o && i >= o.length) o = void 0;
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return { value: o && o[i++], done: !o };
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}
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};
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throw new TypeError(s ? "Object is not iterable." : "Symbol.iterator is not defined.");
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};
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import ChecksumException from '../../ChecksumException';
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import GenericGF from '../../common/reedsolomon/GenericGF';
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import ReedSolomonDecoder from '../../common/reedsolomon/ReedSolomonDecoder';
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import BitMatrixParser from './BitMatrixParser';
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import DataBlock from './DataBlock';
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import DecodedBitStreamParser from './DecodedBitStreamParser';
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/*
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* Copyright 2007 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/**
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* <p>The main class which implements Data Matrix Code decoding -- as opposed to locating and extracting
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* the Data Matrix Code from an image.</p>
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*
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* @author bbrown@google.com (Brian Brown)
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*/
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var Decoder = /** @class */ (function () {
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function Decoder() {
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this.rsDecoder = new ReedSolomonDecoder(GenericGF.DATA_MATRIX_FIELD_256);
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}
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/**
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* <p>Decodes a Data Matrix Code represented as a {@link BitMatrix}. A 1 or "true" is taken
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* to mean a black module.</p>
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*
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* @param bits booleans representing white/black Data Matrix Code modules
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* @return text and bytes encoded within the Data Matrix Code
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* @throws FormatException if the Data Matrix Code cannot be decoded
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* @throws ChecksumException if error correction fails
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*/
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Decoder.prototype.decode = function (bits) {
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var e_1, _a;
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// Construct a parser and read version, error-correction level
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var parser = new BitMatrixParser(bits);
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var version = parser.getVersion();
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// Read codewords
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var codewords = parser.readCodewords();
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// Separate into data blocks
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var dataBlocks = DataBlock.getDataBlocks(codewords, version);
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// Count total number of data bytes
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var totalBytes = 0;
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try {
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for (var dataBlocks_1 = __values(dataBlocks), dataBlocks_1_1 = dataBlocks_1.next(); !dataBlocks_1_1.done; dataBlocks_1_1 = dataBlocks_1.next()) {
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var db = dataBlocks_1_1.value;
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totalBytes += db.getNumDataCodewords();
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}
|
}
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catch (e_1_1) { e_1 = { error: e_1_1 }; }
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finally {
|
try {
|
if (dataBlocks_1_1 && !dataBlocks_1_1.done && (_a = dataBlocks_1.return)) _a.call(dataBlocks_1);
|
}
|
finally { if (e_1) throw e_1.error; }
|
}
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var resultBytes = new Uint8Array(totalBytes);
|
var dataBlocksCount = dataBlocks.length;
|
// Error-correct and copy data blocks together into a stream of bytes
|
for (var j = 0; j < dataBlocksCount; j++) {
|
var dataBlock = dataBlocks[j];
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var codewordBytes = dataBlock.getCodewords();
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var numDataCodewords = dataBlock.getNumDataCodewords();
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this.correctErrors(codewordBytes, numDataCodewords);
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for (var i = 0; i < numDataCodewords; i++) {
|
// De-interlace data blocks.
|
resultBytes[i * dataBlocksCount + j] = codewordBytes[i];
|
}
|
}
|
// Decode the contents of that stream of bytes
|
return DecodedBitStreamParser.decode(resultBytes);
|
};
|
/**
|
* <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to
|
* correct the errors in-place using Reed-Solomon error correction.</p>
|
*
|
* @param codewordBytes data and error correction codewords
|
* @param numDataCodewords number of codewords that are data bytes
|
* @throws ChecksumException if error correction fails
|
*/
|
Decoder.prototype.correctErrors = function (codewordBytes, numDataCodewords) {
|
// const numCodewords = codewordBytes.length;
|
// First read into an array of ints
|
var codewordsInts = new Int32Array(codewordBytes);
|
// for (let i = 0; i < numCodewords; i++) {
|
// codewordsInts[i] = codewordBytes[i] & 0xFF;
|
// }
|
try {
|
this.rsDecoder.decode(codewordsInts, codewordBytes.length - numDataCodewords);
|
}
|
catch (ignored /* ReedSolomonException */) {
|
throw new ChecksumException();
|
}
|
// Copy back into array of bytes -- only need to worry about the bytes that were data
|
// We don't care about errors in the error-correction codewords
|
for (var i = 0; i < numDataCodewords; i++) {
|
codewordBytes[i] = codewordsInts[i];
|
}
|
};
|
return Decoder;
|
}());
|
export default Decoder;
|
