diff options
Diffstat (limited to 'vendor/chillerlan/php-qrcode/src/Decoder/Decoder.php')
| -rw-r--r-- | vendor/chillerlan/php-qrcode/src/Decoder/Decoder.php | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/vendor/chillerlan/php-qrcode/src/Decoder/Decoder.php b/vendor/chillerlan/php-qrcode/src/Decoder/Decoder.php new file mode 100644 index 000000000..6f369a6df --- /dev/null +++ b/vendor/chillerlan/php-qrcode/src/Decoder/Decoder.php @@ -0,0 +1,173 @@ +<?php +/** + * Class Decoder + * + * @created 17.01.2021 + * @author ZXing Authors + * @author Smiley <smiley@chillerlan.net> + * @copyright 2021 Smiley + * @license Apache-2.0 + */ + +namespace chillerlan\QRCode\Decoder; + +use chillerlan\QRCode\Common\{BitBuffer, EccLevel, LuminanceSourceInterface, MaskPattern, Mode, Version}; +use chillerlan\QRCode\Data\{AlphaNum, Byte, ECI, Hanzi, Kanji, Number}; +use chillerlan\QRCode\Detector\Detector; +use Throwable; +use function chr, str_replace; + +/** + * The main class which implements QR Code decoding -- as opposed to locating and extracting + * the QR Code from an image. + * + * @author Sean Owen + */ +final class Decoder{ + + private ?Version $version = null; + private ?EccLevel $eccLevel = null; + private ?MaskPattern $maskPattern = null; + private BitBuffer $bitBuffer; + + /** + * Decodes a QR Code represented as a BitMatrix. + * A 1 or "true" is taken to mean a black module. + * + * @throws \Throwable|\chillerlan\QRCode\Decoder\QRCodeDecoderException + */ + public function decode(LuminanceSourceInterface $source):DecoderResult{ + $matrix = (new Detector($source))->detect(); + + try{ + // clone the BitMatrix to avoid errors in case we run into mirroring + return $this->decodeMatrix(clone $matrix); + } + catch(Throwable $e){ + + try{ + /* + * Prepare for a mirrored reading. + * + * 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. + */ + return $this->decodeMatrix($matrix->resetVersionInfo()->mirrorDiagonal()); + } + catch(Throwable $f){ + // Throw the exception from the original reading + throw $e; + } + + } + + } + + /** + * @throws \chillerlan\QRCode\Decoder\QRCodeDecoderException + */ + private function decodeMatrix(BitMatrix $matrix):DecoderResult{ + // Read raw codewords + $rawCodewords = $matrix->readCodewords(); + $this->version = $matrix->getVersion(); + $this->eccLevel = $matrix->getEccLevel(); + $this->maskPattern = $matrix->getMaskPattern(); + + if($this->version === null || $this->eccLevel === null || $this->maskPattern === null){ + throw new QRCodeDecoderException('unable to read version or format info'); // @codeCoverageIgnore + } + + $resultBytes = (new ReedSolomonDecoder($this->version, $this->eccLevel))->decode($rawCodewords); + + return $this->decodeBitStream($resultBytes); + } + + /** + * Decode the contents of that stream of bytes + * + * @throws \chillerlan\QRCode\Decoder\QRCodeDecoderException + */ + private function decodeBitStream(BitBuffer $bitBuffer):DecoderResult{ + $this->bitBuffer = $bitBuffer; + $versionNumber = $this->version->getVersionNumber(); + $symbolSequence = -1; + $parityData = -1; + $fc1InEffect = false; + $result = ''; + + // While still another segment to read... + while($this->bitBuffer->available() >= 4){ + $datamode = $this->bitBuffer->read(4); // mode is encoded by 4 bits + + // OK, assume we're done + if($datamode === Mode::TERMINATOR){ + break; + } + elseif($datamode === Mode::NUMBER){ + $result .= Number::decodeSegment($this->bitBuffer, $versionNumber); + } + elseif($datamode === Mode::ALPHANUM){ + $result .= $this->decodeAlphanumSegment($versionNumber, $fc1InEffect); + } + elseif($datamode === Mode::BYTE){ + $result .= Byte::decodeSegment($this->bitBuffer, $versionNumber); + } + elseif($datamode === Mode::KANJI){ + $result .= Kanji::decodeSegment($this->bitBuffer, $versionNumber); + } + elseif($datamode === Mode::STRCTURED_APPEND){ + + if($this->bitBuffer->available() < 16){ + throw new QRCodeDecoderException('structured append: not enough bits left'); + } + // sequence number and parity is added later to the result metadata + // Read next 8 bits (symbol sequence #) and 8 bits (parity data), then continue + $symbolSequence = $this->bitBuffer->read(8); + $parityData = $this->bitBuffer->read(8); + } + elseif($datamode === Mode::FNC1_FIRST || $datamode === Mode::FNC1_SECOND){ + // We do little with FNC1 except alter the parsed result a bit according to the spec + $fc1InEffect = true; + } + elseif($datamode === Mode::ECI){ + $result .= ECI::decodeSegment($this->bitBuffer, $versionNumber); + } + elseif($datamode === Mode::HANZI){ + $result .= Hanzi::decodeSegment($this->bitBuffer, $versionNumber); + } + else{ + throw new QRCodeDecoderException('invalid data mode'); + } + + } + + return new DecoderResult([ + 'rawBytes' => $this->bitBuffer, + 'data' => $result, + 'version' => $this->version, + 'eccLevel' => $this->eccLevel, + 'maskPattern' => $this->maskPattern, + 'structuredAppendParity' => $parityData, + 'structuredAppendSequence' => $symbolSequence, + ]); + } + + /** + * + */ + private function decodeAlphanumSegment(int $versionNumber, bool $fc1InEffect):string{ + $str = AlphaNum::decodeSegment($this->bitBuffer, $versionNumber); + + // See section 6.4.8.1, 6.4.8.2 + if($fc1InEffect){ // ??? + // We need to massage the result a bit if in an FNC1 mode: + $str = str_replace(chr(0x1d), '%', $str); + $str = str_replace('%%', '%', $str); + } + + return $str; + } + +} |