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- /*
- * Copyright 2008 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.
- */
-
- using System;
- using System.Collections.Generic;
- using System.Text;
-
- using ZXing.Common;
- using ZXing.Common.ReedSolomon;
-
- namespace ZXing.QrCode.Internal
- {
- /// <summary>
- /// </summary>
- /// <author>satorux@google.com (Satoru Takabayashi) - creator</author>
- /// <author>dswitkin@google.com (Daniel Switkin) - ported from C++</author>
- public static class Encoder
- {
-
-
- internal static String DEFAULT_BYTE_MODE_ENCODING = "ISO-8859-1";
-
- // The mask penalty calculation is complicated. See Table 21 of JISX0510:2004 (p.45) for details.
- // Basically it applies four rules and summate all penalties.
- private static int calculateMaskPenalty(ByteMatrix matrix)
- {
- return MaskUtil.applyMaskPenaltyRule1(matrix)
- + MaskUtil.applyMaskPenaltyRule2(matrix)
- + MaskUtil.applyMaskPenaltyRule3(matrix)
- + MaskUtil.applyMaskPenaltyRule4(matrix);
- }
-
- /// <summary>
- /// Encode "bytes" with the error correction level "ecLevel". The encoding mode will be chosen
- /// internally by chooseMode(). On success, store the result in "qrCode".
- /// We recommend you to use QRCode.EC_LEVEL_L (the lowest level) for
- /// "getECLevel" since our primary use is to show QR code on desktop screens. We don't need very
- /// strong error correction for this purpose.
- /// Note that there is no way to encode bytes in MODE_KANJI. We might want to add EncodeWithMode()
- /// with which clients can specify the encoding mode. For now, we don't need the functionality.
- /// </summary>
- /// <param name="content">text to encode</param>
- /// <param name="ecLevel">error correction level to use</param>
- /// <returns><see cref="QRCode"/> representing the encoded QR code</returns>
- public static QRCode encode(String content, ErrorCorrectionLevel ecLevel)
- {
- // Determine what character encoding has been specified by the caller, if any
- #if !SILVERLIGHT || WINDOWS_PHONE
- String encoding = DEFAULT_BYTE_MODE_ENCODING;
- //bool generateECI = !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding);
- #else
- // Silverlight supports only UTF-8 and UTF-16 out-of-the-box
- const string encoding = "UTF-8";
- // caller of the method can only control if the ECI segment should be written
- // character set is fixed to UTF-8; but some scanners doesn't like the ECI segment
- bool generateECI = (hints != null && hints.ContainsKey(EncodeHintType.CHARACTER_SET));
- #endif
-
- // Pick an encoding mode appropriate for the content. Note that this will not attempt to use
- // multiple modes / segments even if that were more efficient. Twould be nice.
- Mode mode = Mode.BYTE;
-
- // This will store the header information, like mode and
- // length, as well as "header" segments like an ECI segment.
- BitArray headerBits = new BitArray();
-
- /*
- // Append ECI segment if applicable
- if (mode == Mode.BYTE && generateECI)
- {
- CharacterSetECI eci = CharacterSetECI.getCharacterSetECIByName(encoding);
- if (eci != null)
- {
- var eciIsExplicitDisabled = (hints != null && hints.ContainsKey(EncodeHintType.DISABLE_ECI) ? (bool)hints[EncodeHintType.DISABLE_ECI] : false);
- if (!eciIsExplicitDisabled)
- {
- appendECI(eci, headerBits);
- }
- }
- }
- * */
-
- // (With ECI in place,) Write the mode marker
- appendModeInfo(mode, headerBits);
-
- // Collect data within the main segment, separately, to count its size if needed. Don't add it to
- // main payload yet.
- BitArray dataBits = new BitArray();
- appendBytes(content, mode, dataBits, encoding);
-
- // Hard part: need to know version to know how many bits length takes. But need to know how many
- // bits it takes to know version. First we take a guess at version by assuming version will be
- // the minimum, 1:
-
- int provisionalBitsNeeded = headerBits.Size
- + mode.getCharacterCountBits(Version.getVersionForNumber(1))
- + dataBits.Size;
- Version provisionalVersion = chooseVersion(provisionalBitsNeeded, ecLevel);
-
- // Use that guess to calculate the right version. I am still not sure this works in 100% of cases.
- int bitsNeeded = headerBits.Size
- + mode.getCharacterCountBits(provisionalVersion)
- + dataBits.Size;
- Version version = chooseVersion(bitsNeeded, ecLevel);
-
- BitArray headerAndDataBits = new BitArray();
- headerAndDataBits.appendBitArray(headerBits);
- // Find "length" of main segment and write it
- int numLetters = mode == Mode.BYTE ? dataBits.SizeInBytes : content.Length;
- appendLengthInfo(numLetters, version, mode, headerAndDataBits);
- // Put data together into the overall payload
- headerAndDataBits.appendBitArray(dataBits);
-
- Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel);
- int numDataBytes = version.TotalCodewords - ecBlocks.TotalECCodewords;
-
- // Terminate the bits properly.
- terminateBits(numDataBytes, headerAndDataBits);
-
- // Interleave data bits with error correction code.
- BitArray finalBits = interleaveWithECBytes(headerAndDataBits,
- version.TotalCodewords,
- numDataBytes,
- ecBlocks.NumBlocks);
-
- QRCode qrCode = new QRCode
- {
- ECLevel = ecLevel,
- Mode = mode,
- Version = version
- };
-
- // Choose the mask pattern and set to "qrCode".
- int dimension = version.DimensionForVersion;
- ByteMatrix matrix = new ByteMatrix(dimension, dimension);
- int maskPattern = chooseMaskPattern(finalBits, ecLevel, version, matrix);
- qrCode.MaskPattern = maskPattern;
-
- // Build the matrix and set it to "qrCode".
- MatrixUtil.buildMatrix(finalBits, ecLevel, version, maskPattern, matrix);
- qrCode.Matrix = matrix;
-
- return qrCode;
- }
-
-
- private static int chooseMaskPattern(BitArray bits,
- ErrorCorrectionLevel ecLevel,
- Version version,
- ByteMatrix matrix)
- {
- int minPenalty = Int32.MaxValue; // Lower penalty is better.
- int bestMaskPattern = -1;
- // We try all mask patterns to choose the best one.
- for (int maskPattern = 0; maskPattern < QRCode.NUM_MASK_PATTERNS; maskPattern++)
- {
-
- MatrixUtil.buildMatrix(bits, ecLevel, version, maskPattern, matrix);
- int penalty = calculateMaskPenalty(matrix);
- if (penalty < minPenalty)
- {
-
- minPenalty = penalty;
- bestMaskPattern = maskPattern;
- }
- }
- return bestMaskPattern;
- }
-
- private static Version chooseVersion(int numInputBits, ErrorCorrectionLevel ecLevel)
- {
- // In the following comments, we use numbers of Version 7-H.
- for (int versionNum = 1; versionNum <= 40; versionNum++)
- {
- Version version = Version.getVersionForNumber(versionNum);
- // numBytes = 196
- int numBytes = version.TotalCodewords;
- // getNumECBytes = 130
- Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel);
- int numEcBytes = ecBlocks.TotalECCodewords;
- // getNumDataBytes = 196 - 130 = 66
- int numDataBytes = numBytes - numEcBytes;
- int totalInputBytes = (numInputBits + 7) / 8;
- if (numDataBytes >= totalInputBytes)
- {
- return version;
- }
- }
- throw new Exception("Data too big");
- }
-
- /// <summary>
- /// Terminate bits as described in 8.4.8 and 8.4.9 of JISX0510:2004 (p.24).
- /// </summary>
- /// <param name="numDataBytes">The num data bytes.</param>
- /// <param name="bits">The bits.</param>
- internal static void terminateBits(int numDataBytes, BitArray bits)
- {
- int capacity = numDataBytes << 3;
- if (bits.Size > capacity)
- {
- throw new Exception("data bits cannot fit in the QR Code" + bits.Size + " > " +
- capacity);
- }
- for (int i = 0; i < 4 && bits.Size < capacity; ++i)
- {
- bits.appendBit(false);
- }
- // Append termination bits. See 8.4.8 of JISX0510:2004 (p.24) for details.
- // If the last byte isn't 8-bit aligned, we'll add padding bits.
- int numBitsInLastByte = bits.Size & 0x07;
- if (numBitsInLastByte > 0)
- {
- for (int i = numBitsInLastByte; i < 8; i++)
- {
- bits.appendBit(false);
- }
- }
- // If we have more space, we'll fill the space with padding patterns defined in 8.4.9 (p.24).
- int numPaddingBytes = numDataBytes - bits.SizeInBytes;
- for (int i = 0; i < numPaddingBytes; ++i)
- {
- bits.appendBits((i & 0x01) == 0 ? 0xEC : 0x11, 8);
- }
- if (bits.Size != capacity)
- {
- throw new Exception("Bits size does not equal capacity");
- }
- }
-
- /// <summary>
- /// Get number of data bytes and number of error correction bytes for block id "blockID". Store
- /// the result in "numDataBytesInBlock", and "numECBytesInBlock". See table 12 in 8.5.1 of
- /// JISX0510:2004 (p.30)
- /// </summary>
- /// <param name="numTotalBytes">The num total bytes.</param>
- /// <param name="numDataBytes">The num data bytes.</param>
- /// <param name="numRSBlocks">The num RS blocks.</param>
- /// <param name="blockID">The block ID.</param>
- /// <param name="numDataBytesInBlock">The num data bytes in block.</param>
- /// <param name="numECBytesInBlock">The num EC bytes in block.</param>
- internal static void getNumDataBytesAndNumECBytesForBlockID(int numTotalBytes,
- int numDataBytes,
- int numRSBlocks,
- int blockID,
- int[] numDataBytesInBlock,
- int[] numECBytesInBlock)
- {
- if (blockID >= numRSBlocks)
- {
- throw new Exception("Block ID too large");
- }
- // numRsBlocksInGroup2 = 196 % 5 = 1
- int numRsBlocksInGroup2 = numTotalBytes % numRSBlocks;
- // numRsBlocksInGroup1 = 5 - 1 = 4
- int numRsBlocksInGroup1 = numRSBlocks - numRsBlocksInGroup2;
- // numTotalBytesInGroup1 = 196 / 5 = 39
- int numTotalBytesInGroup1 = numTotalBytes / numRSBlocks;
- // numTotalBytesInGroup2 = 39 + 1 = 40
- int numTotalBytesInGroup2 = numTotalBytesInGroup1 + 1;
- // numDataBytesInGroup1 = 66 / 5 = 13
- int numDataBytesInGroup1 = numDataBytes / numRSBlocks;
- // numDataBytesInGroup2 = 13 + 1 = 14
- int numDataBytesInGroup2 = numDataBytesInGroup1 + 1;
- // numEcBytesInGroup1 = 39 - 13 = 26
- int numEcBytesInGroup1 = numTotalBytesInGroup1 - numDataBytesInGroup1;
- // numEcBytesInGroup2 = 40 - 14 = 26
- int numEcBytesInGroup2 = numTotalBytesInGroup2 - numDataBytesInGroup2;
- // Sanity checks.
- // 26 = 26
- if (numEcBytesInGroup1 != numEcBytesInGroup2)
- {
-
- throw new Exception("EC bytes mismatch");
- }
- // 5 = 4 + 1.
- if (numRSBlocks != numRsBlocksInGroup1 + numRsBlocksInGroup2)
- {
-
- throw new Exception("RS blocks mismatch");
- }
- // 196 = (13 + 26) * 4 + (14 + 26) * 1
- if (numTotalBytes !=
- ((numDataBytesInGroup1 + numEcBytesInGroup1) *
- numRsBlocksInGroup1) +
- ((numDataBytesInGroup2 + numEcBytesInGroup2) *
- numRsBlocksInGroup2))
- {
- throw new Exception("Total bytes mismatch");
- }
-
- if (blockID < numRsBlocksInGroup1)
- {
-
- numDataBytesInBlock[0] = numDataBytesInGroup1;
- numECBytesInBlock[0] = numEcBytesInGroup1;
- }
- else
- {
-
-
- numDataBytesInBlock[0] = numDataBytesInGroup2;
- numECBytesInBlock[0] = numEcBytesInGroup2;
- }
- }
-
- /// <summary>
- /// Interleave "bits" with corresponding error correction bytes. On success, store the result in
- /// "result". The interleave rule is complicated. See 8.6 of JISX0510:2004 (p.37) for details.
- /// </summary>
- /// <param name="bits">The bits.</param>
- /// <param name="numTotalBytes">The num total bytes.</param>
- /// <param name="numDataBytes">The num data bytes.</param>
- /// <param name="numRSBlocks">The num RS blocks.</param>
- /// <returns></returns>
- internal static BitArray interleaveWithECBytes(BitArray bits,
- int numTotalBytes,
- int numDataBytes,
- int numRSBlocks)
- {
- // "bits" must have "getNumDataBytes" bytes of data.
- if (bits.SizeInBytes != numDataBytes)
- {
-
- throw new Exception("Number of bits and data bytes does not match");
- }
-
- // Step 1. Divide data bytes into blocks and generate error correction bytes for them. We'll
- // store the divided data bytes blocks and error correction bytes blocks into "blocks".
- int dataBytesOffset = 0;
- int maxNumDataBytes = 0;
- int maxNumEcBytes = 0;
-
- // Since, we know the number of reedsolmon blocks, we can initialize the vector with the number.
- var blocks = new List<BlockPair>(numRSBlocks);
-
- for (int i = 0; i < numRSBlocks; ++i)
- {
-
- int[] numDataBytesInBlock = new int[1];
- int[] numEcBytesInBlock = new int[1];
- getNumDataBytesAndNumECBytesForBlockID(
- numTotalBytes, numDataBytes, numRSBlocks, i,
- numDataBytesInBlock, numEcBytesInBlock);
-
- int size = numDataBytesInBlock[0];
- byte[] dataBytes = new byte[size];
- bits.toBytes(8 * dataBytesOffset, dataBytes, 0, size);
- byte[] ecBytes = generateECBytes(dataBytes, numEcBytesInBlock[0]);
- blocks.Add(new BlockPair(dataBytes, ecBytes));
-
- maxNumDataBytes = Math.Max(maxNumDataBytes, size);
- maxNumEcBytes = Math.Max(maxNumEcBytes, ecBytes.Length);
- dataBytesOffset += numDataBytesInBlock[0];
- }
- if (numDataBytes != dataBytesOffset)
- {
-
- throw new Exception("Data bytes does not match offset");
- }
-
- BitArray result = new BitArray();
-
- // First, place data blocks.
- for (int i = 0; i < maxNumDataBytes; ++i)
- {
- foreach (BlockPair block in blocks)
- {
- byte[] dataBytes = block.DataBytes;
- if (i < dataBytes.Length)
- {
- result.appendBits(dataBytes[i], 8);
- }
- }
- }
- // Then, place error correction blocks.
- for (int i = 0; i < maxNumEcBytes; ++i)
- {
- foreach (BlockPair block in blocks)
- {
- byte[] ecBytes = block.ErrorCorrectionBytes;
- if (i < ecBytes.Length)
- {
- result.appendBits(ecBytes[i], 8);
- }
- }
- }
- if (numTotalBytes != result.SizeInBytes)
- { // Should be same.
- throw new Exception("Interleaving error: " + numTotalBytes + " and " +
- result.SizeInBytes + " differ.");
- }
-
- return result;
- }
-
- internal static byte[] generateECBytes(byte[] dataBytes, int numEcBytesInBlock)
- {
- int numDataBytes = dataBytes.Length;
- int[] toEncode = new int[numDataBytes + numEcBytesInBlock];
- for (int i = 0; i < numDataBytes; i++)
- {
- toEncode[i] = dataBytes[i] & 0xFF;
-
- }
- new ReedSolomonEncoder(GenericGF.QR_CODE_FIELD_256).encode(toEncode, numEcBytesInBlock);
-
- byte[] ecBytes = new byte[numEcBytesInBlock];
- for (int i = 0; i < numEcBytesInBlock; i++)
- {
- ecBytes[i] = (byte)toEncode[numDataBytes + i];
-
- }
- return ecBytes;
- }
-
- /// <summary>
- /// Append mode info. On success, store the result in "bits".
- /// </summary>
- /// <param name="mode">The mode.</param>
- /// <param name="bits">The bits.</param>
- internal static void appendModeInfo(Mode mode, BitArray bits)
- {
- bits.appendBits(mode.Bits, 4);
- }
-
-
- /// <summary>
- /// Append length info. On success, store the result in "bits".
- /// </summary>
- /// <param name="numLetters">The num letters.</param>
- /// <param name="version">The version.</param>
- /// <param name="mode">The mode.</param>
- /// <param name="bits">The bits.</param>
- internal static void appendLengthInfo(int numLetters, Version version, Mode mode, BitArray bits)
- {
- int numBits = mode.getCharacterCountBits(version);
- if (numLetters >= (1 << numBits))
- {
- throw new Exception(numLetters + " is bigger than " + ((1 << numBits) - 1));
- }
- bits.appendBits(numLetters, numBits);
- }
-
- /// <summary>
- /// Append "bytes" in "mode" mode (encoding) into "bits". On success, store the result in "bits".
- /// </summary>
- /// <param name="content">The content.</param>
- /// <param name="mode">The mode.</param>
- /// <param name="bits">The bits.</param>
- /// <param name="encoding">The encoding.</param>
- internal static void appendBytes(String content,
- Mode mode,
- BitArray bits,
- String encoding)
- {
- if (mode.Equals(Mode.BYTE))
- append8BitBytes(content, bits, encoding);
- else
- throw new Exception("Invalid mode: " + mode);
- }
-
- internal static void append8BitBytes(String content, BitArray bits, String encoding)
- {
- byte[] bytes;
- try
- {
- bytes = Encoding.GetEncoding(encoding).GetBytes(content);
- }
- #if WindowsCE
- catch (PlatformNotSupportedException)
- {
- try
- {
- // WindowsCE doesn't support all encodings. But it is device depended.
- // So we try here the some different ones
- if (encoding == "ISO-8859-1")
- {
- bytes = Encoding.GetEncoding(1252).GetBytes(content);
- }
- else
- {
- bytes = Encoding.GetEncoding("UTF-8").GetBytes(content);
- }
- }
- catch (Exception uee)
- {
- throw new WriterException(uee.Message, uee);
- }
- }
- #endif
- catch (Exception uee)
- {
- throw new Exception(uee.Message, uee);
- }
- foreach (byte b in bytes)
- {
- bits.appendBits(b, 8);
- }
- }
-
-
- /*
- private static void appendECI(CharacterSetECI eci, BitArray bits)
- {
- bits.appendBits(Mode.ECI.Bits, 4);
-
- // This is correct for values up to 127, which is all we need now.
- bits.appendBits(eci.Value, 8);
- }
- * */
- }
- }
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