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<?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\DecodeHintType;
use Zxing\FormatException;
use Zxing\Common\BitSource;
use Zxing\Common\CharacterSetECI;
use Zxing\Common\DecoderResult;
use Zxing\Common\StringUtils;
/**
* <p>QR Codes can encode text as bits in one of several modes, and can use multiple modes
* in one QR Code. This class decodes the bits back into text.</p>
*
* <p>See ISO 18004:2006, 6.4.3 - 6.4.7</p>
*
* @author Sean Owen
*/
final class DecodedBitStreamParser
{
/**
* See ISO 18004:2006, 6.4.4 Table 5
*/
private static $ALPHANUMERIC_CHARS = [
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
' ', '$', '%', '*', '+', '-', '.', '/', ':',
];
private static $GB2312_SUBSET = 1;
public static function decode($bytes,
$version,
$ecLevel,
$hints)
{
$bits = new BitSource($bytes);
$result = '';//new StringBuilder(50);
$byteSegments = [];
$symbolSequence = -1;
$parityData = -1;
try {
$currentCharacterSetECI = null;
$fc1InEffect = false;
$mode = '';
do {
// While still another segment to read...
if ($bits->available() < 4) {
// OK, assume we're done. Really, a TERMINATOR mode should have been recorded here
$mode = Mode::$TERMINATOR;
} else {
$mode = Mode::forBits($bits->readBits(4)); // mode is encoded by 4 bits
}
if ($mode != Mode::$TERMINATOR) {
if ($mode == Mode::$FNC1_FIRST_POSITION || $mode == Mode::$FNC1_SECOND_POSITION) {
// We do little with FNC1 except alter the parsed result a bit according to the spec
$fc1InEffect = true;
} else if ($mode == Mode::$STRUCTURED_APPEND) {
if ($bits->available() < 16) {
throw FormatException::getFormatInstance();
}
// 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 = $bits->readBits(8);
$parityData = $bits->readBits(8);
} else if ($mode == Mode::$ECI) {
// Count doesn't apply to ECI
$value = self::parseECIValue($bits);
$currentCharacterSetECI = CharacterSetECI::getCharacterSetECIByValue($value);
if ($currentCharacterSetECI == null) {
throw FormatException::getFormatInstance();
}
} else {
// First handle Hanzi mode which does not start with character count
if ($mode == Mode::$HANZI) {
//chinese mode contains a sub set indicator right after mode indicator
$subset = $bits->readBits(4);
$countHanzi = $bits->readBits($mode->getCharacterCountBits($version));
if ($subset == self::$GB2312_SUBSET) {
self::decodeHanziSegment($bits, $result, $countHanzi);
}
} else {
// "Normal" QR code modes:
// How many characters will follow, encoded in this mode?
$count = $bits->readBits($mode->getCharacterCountBits($version));
if ($mode == Mode::$NUMERIC) {
self::decodeNumericSegment($bits, $result, $count);
} else if ($mode == Mode::$ALPHANUMERIC) {
self::decodeAlphanumericSegment($bits, $result, $count, $fc1InEffect);
} else if ($mode == Mode::$BYTE) {
self::decodeByteSegment($bits, $result, $count, $currentCharacterSetECI, $byteSegments, $hints);
} else if ($mode == Mode::$KANJI) {
self::decodeKanjiSegment($bits, $result, $count);
} else {
throw FormatException::getFormatInstance();
}
}
}
}
} while ($mode != Mode::$TERMINATOR);
} catch (\InvalidArgumentException $iae) {
// from readBits() calls
throw FormatException::getFormatInstance();
}
return new DecoderResult($bytes,
$result,
empty($byteSegments) ? null : $byteSegments,
$ecLevel == null ? null : 'L',//ErrorCorrectionLevel::toString($ecLevel),
$symbolSequence,
$parityData);
}
private static function parseECIValue($bits)
{
$firstByte = $bits->readBits(8);
if (($firstByte & 0x80) == 0) {
// just one byte
return $firstByte & 0x7F;
}
if (($firstByte & 0xC0) == 0x80) {
// two bytes
$secondByte = $bits->readBits(8);
return (($firstByte & 0x3F) << 8) | $secondByte;
}
if (($firstByte & 0xE0) == 0xC0) {
// three bytes
$secondThirdBytes = $bits->readBits(16);
return (($firstByte & 0x1F) << 16) | $secondThirdBytes;
}
throw FormatException::getFormatInstance();
}
/**
* See specification GBT 18284-2000
*/
private static function decodeHanziSegment($bits,
&$result,
$count)
{
// Don't crash trying to read more bits than we have available.
if ($count * 13 > $bits->available()) {
throw FormatException::getFormatInstance();
}
// Each character will require 2 bytes. Read the characters as 2-byte pairs
// and decode as GB2312 afterwards
$buffer = fill_array(0, 2 * $count, 0);
$offset = 0;
while ($count > 0) {
// Each 13 bits encodes a 2-byte character
$twoBytes = $bits->readBits(13);
$assembledTwoBytes = (($twoBytes / 0x060) << 8) | ($twoBytes % 0x060);
if ($assembledTwoBytes < 0x003BF) {
// In the 0xA1A1 to 0xAAFE range
$assembledTwoBytes += 0x0A1A1;
} else {
// In the 0xB0A1 to 0xFAFE range
$assembledTwoBytes += 0x0A6A1;
}
$buffer[$offset] = (($assembledTwoBytes >> 8) & 0xFF);//(byte)
$buffer[$offset + 1] = ($assembledTwoBytes & 0xFF);//(byte)
$offset += 2;
$count--;
}
$result .= iconv('GB2312', 'UTF-8', implode($buffer));
}
private static function decodeNumericSegment($bits,
&$result,
$count)
{
// Read three digits at a time
while ($count >= 3) {
// Each 10 bits encodes three digits
if ($bits->available() < 10) {
throw FormatException::getFormatInstance();
}
$threeDigitsBits = $bits->readBits(10);
if ($threeDigitsBits >= 1000) {
throw FormatException::getFormatInstance();
}
$result .= (self::toAlphaNumericChar($threeDigitsBits / 100));
$result .= (self::toAlphaNumericChar(($threeDigitsBits / 10) % 10));
$result .= (self::toAlphaNumericChar($threeDigitsBits % 10));
$count -= 3;
}
if ($count == 2) {
// Two digits left over to read, encoded in 7 bits
if ($bits->available() < 7) {
throw FormatException::getFormatInstance();
}
$twoDigitsBits = $bits->readBits(7);
if ($twoDigitsBits >= 100) {
throw FormatException::getFormatInstance();
}
$result .= (self::toAlphaNumericChar($twoDigitsBits / 10));
$result .= (self::toAlphaNumericChar($twoDigitsBits % 10));
} else if ($count == 1) {
// One digit left over to read
if ($bits->available() < 4) {
throw FormatException::getFormatInstance();
}
$digitBits = $bits->readBits(4);
if ($digitBits >= 10) {
throw FormatException::getFormatInstance();
}
$result .= (self::toAlphaNumericChar($digitBits));
}
}
private static function toAlphaNumericChar($value)
{
if ($value >= count(self::$ALPHANUMERIC_CHARS)) {
throw FormatException::getFormatInstance();
}
return self::$ALPHANUMERIC_CHARS[$value];
}
private static function decodeAlphanumericSegment($bits,
&$result,
$count,
$fc1InEffect)
{
// Read two characters at a time
$start = strlen($result);
while ($count > 1) {
if ($bits->available() < 11) {
throw FormatException::getFormatInstance();
}
$nextTwoCharsBits = $bits->readBits(11);
$result .= (self::toAlphaNumericChar($nextTwoCharsBits / 45));
$result .= (self::toAlphaNumericChar($nextTwoCharsBits % 45));
$count -= 2;
}
if ($count == 1) {
// special case: one character left
if ($bits->available() < 6) {
throw FormatException::getFormatInstance();
}
$result .= self::toAlphaNumericChar($bits->readBits(6));
}
// See section 6.4.8.1, 6.4.8.2
if ($fc1InEffect) {
// We need to massage the result a bit if in an FNC1 mode:
for ($i = $start; $i < strlen($result); $i++) {
if ($result{$i} == '%') {
if ($i < strlen($result) - 1 && $result{$i + 1} == '%') {
// %% is rendered as %
$result = substr_replace($result, '', $i + 1, 1);//deleteCharAt(i + 1);
} else {
// In alpha mode, % should be converted to FNC1 separator 0x1D
$result . setCharAt($i, chr(0x1D));
}
}
}
}
}
private static function decodeByteSegment($bits,
&$result,
$count,
$currentCharacterSetECI,
&$byteSegments,
$hints)
{
// Don't crash trying to read more bits than we have available.
if (8 * $count > $bits->available()) {
throw FormatException::getFormatInstance();
}
$readBytes = fill_array(0, $count, 0);
for ($i = 0; $i < $count; $i++) {
$readBytes[$i] = $bits->readBits(8);//(byte)
}
$text = implode(array_map('chr', $readBytes));
$encoding = '';
if ($currentCharacterSetECI == null) {
// The spec isn't clear on this mode; see
// section 6.4.5: t does not say which encoding to assuming
// upon decoding. I have seen ISO-8859-1 used as well as
// Shift_JIS -- without anything like an ECI designator to
// give a hint.
$encoding = mb_detect_encoding($text, $hints);
} else {
$encoding = $currentCharacterSetECI->name();
}
// $result.= mb_convert_encoding($text ,$encoding);//(new String(readBytes, encoding));
$result .= $text;//(new String(readBytes, encoding));
$byteSegments = array_merge($byteSegments, $readBytes);
}
private static function decodeKanjiSegment($bits,
&$result,
$count)
{
// Don't crash trying to read more bits than we have available.
if ($count * 13 > $bits->available()) {
throw FormatException::getFormatInstance();
}
// Each character will require 2 bytes. Read the characters as 2-byte pairs
// and decode as Shift_JIS afterwards
$buffer = [0, 2 * $count, 0];
$offset = 0;
while ($count > 0) {
// Each 13 bits encodes a 2-byte character
$twoBytes = $bits->readBits(13);
$assembledTwoBytes = (($twoBytes / 0x0C0) << 8) | ($twoBytes % 0x0C0);
if ($assembledTwoBytes < 0x01F00) {
// In the 0x8140 to 0x9FFC range
$assembledTwoBytes += 0x08140;
} else {
// In the 0xE040 to 0xEBBF range
$assembledTwoBytes += 0x0C140;
}
$buffer[$offset] = ($assembledTwoBytes >> 8);//(byte)
$buffer[$offset + 1] = $assembledTwoBytes; //(byte)
$offset += 2;
$count--;
}
// Shift_JIS may not be supported in some environments:
$result .= iconv('shift-jis', 'utf-8', implode($buffer));
}
private function DecodedBitStreamParser()
{
}
}