zx/vendor/khanamiryan/qrcode-detector-decoder/lib/Qrcode/Decoder/Decoder.php

209 lines
6.4 KiB
PHP

<?php
/*
* Copyright 2007 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
namespace Zxing\Qrcode\Decoder;
use Zxing\ChecksumException;
use Zxing\Common\BitMatrix;
use Zxing\Common\Reedsolomon\GenericGF;
use Zxing\Common\Reedsolomon\ReedSolomonDecoder;
use Zxing\Common\Reedsolomon\ReedSolomonException;
use Zxing\FormatException;
/**
* <p>The main class which implements QR Code decoding -- as opposed to locating and extracting
* the QR Code from an image.</p>
*
* @author Sean Owen
*/
final class Decoder
{
private readonly \Zxing\Common\Reedsolomon\ReedSolomonDecoder $rsDecoder;
public function __construct()
{
$this->rsDecoder = new ReedSolomonDecoder(GenericGF::$QR_CODE_FIELD_256);
}
public function decode($variable, $hints = null)
{
if (is_array($variable)) {
return $this->decodeImage($variable, $hints);
} elseif ($variable instanceof BitMatrix) {
return $this->decodeBits($variable, $hints);
} elseif ($variable instanceof BitMatrixParser) {
return $this->decodeParser($variable, $hints);
}
die('decode error Decoder.php');
}
/**
* <p>Convenience method that can decode a QR Code represented as a 2D array of booleans.
* "true" is taken to mean a black module.</p>
*
* @param array $image booleans representing white/black QR Code modules
* @param decoding $hints hints that should be used to influence decoding
*
* @return text and bytes encoded within the QR Code
* @throws FormatException if the QR Code cannot be decoded
* @throws ChecksumException if error correction fails
*/
public function decodeImage($image, $hints = null)
{
$dimension = count($image);
$bits = new BitMatrix($dimension);
for ($i = 0; $i < $dimension; $i++) {
for ($j = 0; $j < $dimension; $j++) {
if ($image[$i][$j]) {
$bits->set($j, $i);
}
}
}
return $this->decode($bits, $hints);
}
/**
* <p>Decodes a QR Code represented as a {@link BitMatrix}. A 1 or "true" is taken to mean a black module.</p>
*
* @param BitMatrix $bits booleans representing white/black QR Code modules
* @param decoding $hints hints that should be used to influence decoding
*
* @return text and bytes encoded within the QR Code
* @throws FormatException if the QR Code cannot be decoded
* @throws ChecksumException if error correction fails
*/
public function decodeBits($bits, $hints = null)
{
// Construct a parser and read version, error-correction level
$parser = new BitMatrixParser($bits);
$fe = null;
$ce = null;
try {
return $this->decode($parser, $hints);
} catch (FormatException $e) {
$fe = $e;
} catch (ChecksumException $e) {
$ce = $e;
}
try {
// Revert the bit matrix
$parser->remask();
// Will be attempting a mirrored reading of the version and format info.
$parser->setMirror(true);
// Preemptively read the version.
$parser->readVersion();
// Preemptively read the format information.
$parser->readFormatInformation();
/*
* Since we're here, this means we have successfully detected some kind
* of version and format information when mirrored. This is a good sign,
* that the QR code may be mirrored, and we should try once more with a
* mirrored content.
*/
// Prepare for a mirrored reading.
$parser->mirror();
$result = $this->decode($parser, $hints);
// Success! Notify the caller that the code was mirrored.
$result->setOther(new QRCodeDecoderMetaData(true));
return $result;
} catch (FormatException $e) {// catch (FormatException | ChecksumException e) {
// Throw the exception from the original reading
if ($fe != null) {
throw $fe;
}
if ($ce != null) {
throw $ce;
}
throw $e;
}
}
private function decodeParser($parser, $hints = null)
{
$version = $parser->readVersion();
$ecLevel = $parser->readFormatInformation()->getErrorCorrectionLevel();
// Read codewords
$codewords = $parser->readCodewords();
// Separate into data blocks
$dataBlocks = DataBlock::getDataBlocks($codewords, $version, $ecLevel);
// Count total number of data bytes
$totalBytes = 0;
foreach ($dataBlocks as $dataBlock) {
$totalBytes += $dataBlock->getNumDataCodewords();
}
$resultBytes = fill_array(0, $totalBytes, 0);
$resultOffset = 0;
// Error-correct and copy data blocks together into a stream of bytes
foreach ($dataBlocks as $dataBlock) {
$codewordBytes = $dataBlock->getCodewords();
$numDataCodewords = $dataBlock->getNumDataCodewords();
$this->correctErrors($codewordBytes, $numDataCodewords);
for ($i = 0; $i < $numDataCodewords; $i++) {
$resultBytes[$resultOffset++] = $codewordBytes[$i];
}
}
// Decode the contents of that stream of bytes
return DecodedBitStreamParser::decode($resultBytes, $version, $ecLevel, $hints);
}
/**
* <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 data $codewordBytes and error correction codewords
* @param number $numDataCodewords of codewords that are data bytes
*
* @throws ChecksumException if error correction fails
*/
private function correctErrors(&$codewordBytes, $numDataCodewords)
{
$numCodewords = is_countable($codewordBytes) ? count($codewordBytes) : 0;
// First read into an array of ints
$codewordsInts = fill_array(0, $numCodewords, 0);
for ($i = 0; $i < $numCodewords; $i++) {
$codewordsInts[$i] = $codewordBytes[$i] & 0xFF;
}
$numECCodewords = (is_countable($codewordBytes) ? count($codewordBytes) : 0) - $numDataCodewords;
try {
$this->rsDecoder->decode($codewordsInts, $numECCodewords);
} catch (ReedSolomonException) {
throw ChecksumException::getChecksumInstance();
}
// Copy back into array of bytes -- only need to worry about the bytes that were data
// We don't care about errors in the error-correction codewords
for ($i = 0; $i < $numDataCodewords; $i++) {
$codewordBytes[$i] = $codewordsInts[$i];
}
}
}