2 * Copyright 2008 ZXing authors
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing.qrcode.encoder;
19 import com.google.zxing.common.ByteMatrix;
20 import com.google.zxing.common.ByteArray;
21 import com.google.zxing.common.reedsolomon.GF256;
22 import com.google.zxing.common.reedsolomon.ReedSolomonEncoder;
24 import java.util.Vector;
27 * @author satorux@google.com (Satoru Takabayashi) - creator
28 * @author dswitkin@google.com (Daniel Switkin) - ported from C++
30 public final class Encoder {
32 // The original table is defined in the table 5 of JISX0510:2004 (p.19).
33 private static final int kAlphanumericTable[] = {
34 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x00-0x0f
35 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x10-0x1f
36 36, -1, -1, -1, 37, 38, -1, -1, -1, -1, 39, 40, -1, 41, 42, 43, // 0x20-0x2f
37 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 44, -1, -1, -1, -1, -1, // 0x30-0x3f
38 -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, // 0x40-0x4f
39 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1, // 0x50-0x5f
42 private static final class RSBlockInfo {
47 public RSBlockInfo(int num_bytes, int[][] block_info) {
48 this.num_bytes = num_bytes;
49 this.block_info = block_info;
54 // The table is from table 12 of JISX0510:2004 (p. 30). The "block_info" parts are ordered by
55 // L, M, Q, H. Within each block_info, the 0th element is num_ec_bytes, and the 1st element is
56 // num_rs_blocks. The table was doublechecked by komatsu.
57 private static final RSBlockInfo kRSBlockTable[] = {
58 new RSBlockInfo( 26, new int[][]{ { 7, 1}, { 10, 1}, { 13, 1}, { 17, 1}}), // Version 1
59 new RSBlockInfo( 44, new int[][]{ { 10, 1}, { 16, 1}, { 22, 1}, { 28, 1}}), // Version 2
60 new RSBlockInfo( 70, new int[][]{ { 15, 1}, { 26, 1}, { 36, 2}, { 44, 2}}), // Version 3
61 new RSBlockInfo( 100, new int[][]{ { 20, 1}, { 36, 2}, { 52, 2}, { 64, 4}}), // Version 4
62 new RSBlockInfo( 134, new int[][]{ { 26, 1}, { 48, 2}, { 72, 4}, { 88, 4}}), // Version 5
63 new RSBlockInfo( 172, new int[][]{ { 36, 2}, { 64, 4}, { 96, 4}, { 112, 4}}), // Version 6
64 new RSBlockInfo( 196, new int[][]{ { 40, 2}, { 72, 4}, { 108, 6}, { 130, 5}}), // Version 7
65 new RSBlockInfo( 242, new int[][]{ { 48, 2}, { 88, 4}, { 132, 6}, { 156, 6}}), // Version 8
66 new RSBlockInfo( 292, new int[][]{ { 60, 2}, { 110, 5}, { 160, 8}, { 192, 8}}), // Version 9
67 new RSBlockInfo( 346, new int[][]{ { 72, 4}, { 130, 5}, { 192, 8}, { 224, 8}}), // Version 10
68 new RSBlockInfo( 404, new int[][]{ { 80, 4}, { 150, 5}, { 224, 8}, { 264, 11}}), // Version 11
69 new RSBlockInfo( 466, new int[][]{ { 96, 4}, { 176, 8}, { 260, 10}, { 308, 11}}), // Version 12
70 new RSBlockInfo( 532, new int[][]{ {104, 4}, { 198, 9}, { 288, 12}, { 352, 16}}), // Version 13
71 new RSBlockInfo( 581, new int[][]{ {120, 4}, { 216, 9}, { 320, 16}, { 384, 16}}), // Version 14
72 new RSBlockInfo( 655, new int[][]{ {132, 6}, { 240, 10}, { 360, 12}, { 432, 18}}), // Version 15
73 new RSBlockInfo( 733, new int[][]{ {144, 6}, { 280, 10}, { 408, 17}, { 480, 16}}), // Version 16
74 new RSBlockInfo( 815, new int[][]{ {168, 6}, { 308, 11}, { 448, 16}, { 532, 19}}), // Version 17
75 new RSBlockInfo( 901, new int[][]{ {180, 6}, { 338, 13}, { 504, 18}, { 588, 21}}), // Version 18
76 new RSBlockInfo( 991, new int[][]{ {196, 7}, { 364, 14}, { 546, 21}, { 650, 25}}), // Version 19
77 new RSBlockInfo(1085, new int[][]{ {224, 8}, { 416, 16}, { 600, 20}, { 700, 25}}), // Version 20
78 new RSBlockInfo(1156, new int[][]{ {224, 8}, { 442, 17}, { 644, 23}, { 750, 25}}), // Version 21
79 new RSBlockInfo(1258, new int[][]{ {252, 9}, { 476, 17}, { 690, 23}, { 816, 34}}), // Version 22
80 new RSBlockInfo(1364, new int[][]{ {270, 9}, { 504, 18}, { 750, 25}, { 900, 30}}), // Version 23
81 new RSBlockInfo(1474, new int[][]{ {300, 10}, { 560, 20}, { 810, 27}, { 960, 32}}), // Version 24
82 new RSBlockInfo(1588, new int[][]{ {312, 12}, { 588, 21}, { 870, 29}, {1050, 35}}), // Version 25
83 new RSBlockInfo(1706, new int[][]{ {336, 12}, { 644, 23}, { 952, 34}, {1110, 37}}), // Version 26
84 new RSBlockInfo(1828, new int[][]{ {360, 12}, { 700, 25}, {1020, 34}, {1200, 40}}), // Version 27
85 new RSBlockInfo(1921, new int[][]{ {390, 13}, { 728, 26}, {1050, 35}, {1260, 42}}), // Version 28
86 new RSBlockInfo(2051, new int[][]{ {420, 14}, { 784, 28}, {1140, 38}, {1350, 45}}), // Version 29
87 new RSBlockInfo(2185, new int[][]{ {450, 15}, { 812, 29}, {1200, 40}, {1440, 48}}), // Version 30
88 new RSBlockInfo(2323, new int[][]{ {480, 16}, { 868, 31}, {1290, 43}, {1530, 51}}), // Version 31
89 new RSBlockInfo(2465, new int[][]{ {510, 17}, { 924, 33}, {1350, 45}, {1620, 54}}), // Version 32
90 new RSBlockInfo(2611, new int[][]{ {540, 18}, { 980, 35}, {1440, 48}, {1710, 57}}), // Version 33
91 new RSBlockInfo(2761, new int[][]{ {570, 19}, {1036, 37}, {1530, 51}, {1800, 60}}), // Version 34
92 new RSBlockInfo(2876, new int[][]{ {570, 19}, {1064, 38}, {1590, 53}, {1890, 63}}), // Version 35
93 new RSBlockInfo(3034, new int[][]{ {600, 20}, {1120, 40}, {1680, 56}, {1980, 66}}), // Version 36
94 new RSBlockInfo(3196, new int[][]{ {630, 21}, {1204, 43}, {1770, 59}, {2100, 70}}), // Version 37
95 new RSBlockInfo(3362, new int[][]{ {660, 22}, {1260, 45}, {1860, 62}, {2220, 74}}), // Version 38
96 new RSBlockInfo(3532, new int[][]{ {720, 24}, {1316, 47}, {1950, 65}, {2310, 77}}), // Version 39
97 new RSBlockInfo(3706, new int[][]{ {750, 25}, {1372, 49}, {2040, 68}, {2430, 81}}), // Version 40
100 private static final class BlockPair {
102 private ByteArray dataBytes;
103 private ByteArray errorCorrectionBytes;
105 public BlockPair(ByteArray data, ByteArray errorCorrection) {
107 errorCorrectionBytes = errorCorrection;
110 public ByteArray getDataBytes() {
114 public ByteArray getErrorCorrectionBytes() {
115 return errorCorrectionBytes;
120 // Encode "bytes" with the error correction level "ec_level". The encoding mode will be chosen
121 // internally by ChooseMode(). On success, store the result in "qr_code" and return true. On
122 // error, return false. We recommend you to use QRCode.EC_LEVEL_L (the lowest level) for
123 // "ec_level" since our primary use is to show QR code on desktop screens. We don't need very
124 // strong error correction for this purpose.
126 // Note that there is no way to encode bytes in MODE_KANJI. We might want to add EncodeWithMode()
127 // with which clients can specify the encoding mode. For now, we don't need the functionality.
128 public static boolean Encode(final ByteArray bytes, int ec_level, QRCode qr_code) {
129 // Step 1: Choose the mode (encoding).
130 final int mode = ChooseMode(bytes);
132 // Step 2: Append "bytes" into "data_bits" in appropriate encoding.
133 BitVector data_bits = new BitVector();
134 if (!AppendBytes(bytes, mode, data_bits)) {
137 // Step 3: Initialize QR code that can contain "data_bits".
138 final int num_input_bytes = data_bits.num_bytes();
139 if (!InitQRCode(num_input_bytes, ec_level, mode, qr_code)) {
143 // Step 4: Build another bit vector that contains header and data.
144 BitVector header_and_data_bits = new BitVector();
145 if (!AppendModeInfo(qr_code.mode(), header_and_data_bits)) {
148 if (!AppendLengthInfo(bytes.size(), qr_code.version(), qr_code.mode(), header_and_data_bits)) {
151 header_and_data_bits.AppendBitVector(data_bits);
153 // Step 5: Terminate the bits properly.
154 if (!TerminateBits(qr_code.num_data_bytes(), header_and_data_bits)) {
158 // Step 6: Interleave data bits with error correction code.
159 BitVector final_bits = new BitVector();
160 InterleaveWithECBytes(header_and_data_bits, qr_code.num_total_bytes(), qr_code.num_data_bytes(),
161 qr_code.num_rs_blocks(), final_bits);
163 // Step 7: Choose the mask pattern and set to "qr_code".
164 ByteMatrix matrix = new ByteMatrix(qr_code.matrix_width(), qr_code.matrix_width());
165 qr_code.set_mask_pattern(ChooseMaskPattern(final_bits, qr_code.ec_level(), qr_code.version(),
167 if (qr_code.mask_pattern() == -1) {
168 // There was an error.
172 // Step 8. Build the matrix and set it to "qr_code".
173 MatrixUtil.BuildMatrix(final_bits, qr_code.ec_level(), qr_code.version(),
174 qr_code.mask_pattern(), matrix);
175 qr_code.set_matrix(matrix);
176 // Step 9. Make sure we have a valid QR Code.
177 if (!qr_code.IsValid()) {
178 Debug.LOG_ERROR("Invalid QR code: " + qr_code.toString());
184 // Return the code point of the table used in alphanumeric mode. Return -1 if there is no
185 // corresponding code in the table.
186 static int GetAlphanumericCode(int code) {
187 if (code < kAlphanumericTable.length) {
188 return kAlphanumericTable[code];
193 // Choose the best mode by examining the content of "bytes". The function is guaranteed to return
196 // Note that this function does not return MODE_KANJI, as we cannot distinguish Shift_JIS from
197 // other encodings such as ISO-8859-1, from data bytes alone. For example "\xE0\xE0" can be
198 // interpreted as one character in Shift_JIS, but also two characters in ISO-8859-1.
200 // JAVAPORT: This MODE_KANJI limitation sounds like a problem for us.
201 public static int ChooseMode(final ByteArray bytes) {
202 boolean has_numeric = false;
203 boolean has_alphanumeric = false;
204 boolean has_other = false;
205 for (int i = 0; i < bytes.size(); ++i) {
206 final int oneByte = bytes.at(i);
207 if (oneByte >= '0' && oneByte <= '9') {
209 } else if (GetAlphanumericCode(oneByte) != -1) {
210 has_alphanumeric = true;
216 return QRCode.MODE_8BIT_BYTE;
217 } else if (has_alphanumeric) {
218 return QRCode.MODE_ALPHANUMERIC;
219 } else if (has_numeric) {
220 return QRCode.MODE_NUMERIC;
222 // "bytes" must be empty to reach here.
223 Debug.DCHECK(bytes.empty());
224 return QRCode.MODE_8BIT_BYTE;
227 private static int ChooseMaskPattern(final BitVector bits, int ec_level, int version,
229 if (!QRCode.IsValidMatrixWidth(matrix.width())) {
230 Debug.LOG_ERROR("Invalid matrix width: " + matrix.width());
234 int min_penalty = Integer.MAX_VALUE; // Lower penalty is better.
235 int best_mask_pattern = -1;
236 // We try all mask patterns to choose the best one.
237 for (int i = 0; i < QRCode.kNumMaskPatterns; ++i) {
238 final int mask_pattern = i;
239 if (!MatrixUtil.BuildMatrix(bits, ec_level, version,
240 mask_pattern, matrix)) {
243 final int penalty = MaskUtil.CalculateMaskPenalty(matrix);
244 Debug.LOG_INFO("mask_pattern: " + mask_pattern + ", " + "penalty: " + penalty);
245 if (penalty < min_penalty) {
246 min_penalty = penalty;
247 best_mask_pattern = mask_pattern;
250 return best_mask_pattern;
253 // Initialize "qr_code" according to "num_input_bytes", "ec_level", and "mode". On success, modify
254 // "qr_code" and return true. On error, return false.
255 private static boolean InitQRCode(int num_input_bytes, int ec_level, int mode, QRCode qr_code) {
256 qr_code.set_ec_level(ec_level);
257 qr_code.set_mode(mode);
259 if (!QRCode.IsValidECLevel(ec_level)) {
260 Debug.LOG_ERROR("Invalid EC level: " + ec_level);
264 // In the following comments, we use numbers of Version 7-H.
265 for (int i = 0; i < kRSBlockTable.length; ++i) {
266 final RSBlockInfo row = kRSBlockTable[i];
268 final int num_bytes = row.num_bytes;
269 // num_ec_bytes = 130
270 final int num_ec_bytes = row.block_info[ec_level][0];
272 final int num_rs_blocks = row.block_info[ec_level][1];
273 // num_data_bytes = 196 - 130 = 66
274 final int num_data_bytes = num_bytes - num_ec_bytes;
275 // We want to choose the smallest version which can contain data of "num_input_bytes" + some
276 // extra bits for the header (mode info and length info). The header can be three bytes
277 // (precisely 4 + 16 bits) at most. Hence we do +3 here.
278 if (num_data_bytes >= num_input_bytes + 3) {
279 // Yay, we found the proper rs block info!
280 qr_code.set_version(i + 1);
281 qr_code.set_num_total_bytes(num_bytes);
282 qr_code.set_num_data_bytes(num_data_bytes);
283 qr_code.set_num_rs_blocks(num_rs_blocks);
284 // num_ec_bytes = 196 - 66 = 130
285 qr_code.set_num_ec_bytes(num_bytes - num_data_bytes);
286 // num_matrix_width = 21 + 6 * 4 = 45
287 qr_code.set_matrix_width(21 + i * 4);
291 Debug.LOG_ERROR("Cannot find proper rs block info (input data too big?)");
295 // Terminate bits as described in 8.4.8 and 8.4.9 of JISX0510:2004 (p.24).
296 static boolean TerminateBits(int num_data_bytes, BitVector bits) {
297 final int capacity = num_data_bytes * 8;
298 if (bits.size() > capacity) {
299 Debug.LOG_ERROR("data bits cannot fit in the QR Code" + bits.size() + " > " + capacity);
302 // Append termination bits. See 8.4.8 of JISX0510:2004 (p.24) for details.
303 for (int i = 0; i < 4 && bits.size() < capacity; ++i) {
306 final int num_bits_in_last_byte = bits.size() % 8;
307 // If the last byte isn't 8-bit aligned, we'll add padding bits.
308 if (num_bits_in_last_byte > 0) {
309 final int num_padding_bits = 8 - num_bits_in_last_byte;
310 for (int i = 0; i < num_padding_bits; ++i) {
314 // Should be 8-bit aligned here.
315 Debug.DCHECK_EQ(0, bits.size() % 8);
316 // If we have more space, we'll fill the space with padding patterns defined in 8.4.9 (p.24).
317 final int num_padding_bytes = num_data_bytes - bits.num_bytes();
318 for (int i = 0; i < num_padding_bytes; ++i) {
320 bits.AppendBits(0xec, 8);
322 bits.AppendBits(0x11, 8);
325 Debug.DCHECK_EQ(bits.size(), capacity); // Should be same.
326 return bits.size() == capacity;
329 // Get number of data bytes and number of error correction bytes for block id "block_id". Store
330 // the result in "num_data_bytes_in_block", and "num_ec_bytes_in_block". See table 12 in 8.5.1 of
331 // JISX0510:2004 (p.30)
332 static void GetNumDataBytesAndNumECBytesForBlockID(int num_total_bytes, int num_data_bytes,
333 int num_rs_blocks, int block_id, int[] num_data_bytes_in_block,
334 int[] num_ec_bytes_in_block) {
335 Debug.DCHECK_LT(block_id, num_rs_blocks);
336 // num_rs_blocks_in_group2 = 196 % 5 = 1
337 final int num_rs_blocks_in_group2 = num_total_bytes % num_rs_blocks;
338 // num_rs_blocks_in_group1 = 5 - 1 = 4
339 final int num_rs_blocks_in_group1 = num_rs_blocks - num_rs_blocks_in_group2;
340 // num_total_bytes_in_group1 = 196 / 5 = 39
341 final int num_total_bytes_in_group1 = num_total_bytes / num_rs_blocks;
342 // num_total_bytes_in_group2 = 39 + 1 = 40
343 final int num_total_bytes_in_group2 = num_total_bytes_in_group1 + 1;
344 // num_data_bytes_in_group1 = 66 / 5 = 13
345 final int num_data_bytes_in_group1 = num_data_bytes / num_rs_blocks;
346 // num_data_bytes_in_group2 = 13 + 1 = 14
347 final int num_data_bytes_in_group2 = num_data_bytes_in_group1 + 1;
348 // num_ec_bytes_in_group1 = 39 - 13 = 26
349 final int num_ec_bytes_in_group1 = num_total_bytes_in_group1 -
350 num_data_bytes_in_group1;
351 // num_ec_bytes_in_group2 = 40 - 14 = 26
352 final int num_ec_bytes_in_group2 = num_total_bytes_in_group2 -
353 num_data_bytes_in_group2;
356 Debug.DCHECK_EQ(num_ec_bytes_in_group1, num_ec_bytes_in_group2);
358 Debug.DCHECK_EQ(num_rs_blocks, num_rs_blocks_in_group1 + num_rs_blocks_in_group2);
359 // 196 = (13 + 26) * 4 + (14 + 26) * 1
360 Debug.DCHECK_EQ(num_total_bytes,
361 ((num_data_bytes_in_group1 + num_ec_bytes_in_group1) *
362 num_rs_blocks_in_group1) +
363 ((num_data_bytes_in_group2 + num_ec_bytes_in_group2) *
364 num_rs_blocks_in_group2));
366 if (block_id < num_rs_blocks_in_group1) {
367 num_data_bytes_in_block[0] = num_data_bytes_in_group1;
368 num_ec_bytes_in_block[0] = num_ec_bytes_in_group1;
370 num_data_bytes_in_block[0] = num_data_bytes_in_group2;
371 num_ec_bytes_in_block[0] = num_ec_bytes_in_group2;
375 // Interleave "bits" with corresponding error correction bytes. On success, store the result in
376 // "result" and return true. On error, return false. The interleave rule is complicated. See 8.6
377 // of JISX0510:2004 (p.37) for details.
378 static boolean InterleaveWithECBytes(final BitVector bits, int num_total_bytes,
379 int num_data_bytes, int num_rs_blocks, BitVector result) {
381 // "bits" must have "num_data_bytes" bytes of data.
382 Debug.DCHECK(bits.num_bytes() == num_data_bytes);
384 // Step 1. Divide data bytes into blocks and generate error correction bytes for them. We'll
385 // store the divided data bytes blocks and error correction bytes blocks into "blocks".
386 int data_bytes_offset = 0;
387 int max_num_data_bytes = 0;
388 int max_num_ec_bytes = 0;
390 // Since, we know the number of reedsolmon blocks, we can initialize the vector with the number.
391 Vector blocks = new Vector(num_rs_blocks);
393 for (int i = 0; i < num_rs_blocks; ++i) {
394 int[] num_data_bytes_in_block = new int[1];
395 int[] num_ec_bytes_in_block = new int[1];
396 GetNumDataBytesAndNumECBytesForBlockID(
397 num_total_bytes, num_data_bytes, num_rs_blocks, i,
398 num_data_bytes_in_block, num_ec_bytes_in_block);
400 ByteArray data_bytes = new ByteArray();
401 data_bytes.set(bits.getArray(), data_bytes_offset, num_data_bytes_in_block[0]);
402 ByteArray ec_bytes = GenerateECBytes(data_bytes, num_ec_bytes_in_block[0]);
403 blocks.addElement(new BlockPair(data_bytes, ec_bytes));
405 max_num_data_bytes = Math.max(max_num_data_bytes, data_bytes.size());
406 max_num_ec_bytes = Math.max(max_num_ec_bytes, ec_bytes.size());
407 data_bytes_offset += num_data_bytes_in_block[0];
409 Debug.DCHECK_EQ(num_data_bytes, data_bytes_offset);
411 // First, place data blocks.
412 for (int i = 0; i < max_num_data_bytes; ++i) {
413 for (int j = 0; j < blocks.size(); ++j) {
414 final ByteArray data_bytes = ((BlockPair) blocks.elementAt(j)).getDataBytes();
415 if (i < data_bytes.size()) {
416 result.AppendBits(data_bytes.at(i), 8);
420 // Then, place error correction blocks.
421 for (int i = 0; i < max_num_ec_bytes; ++i) {
422 for (int j = 0; j < blocks.size(); ++j) {
423 final ByteArray ec_bytes = ((BlockPair) blocks.elementAt(j)).getErrorCorrectionBytes();
424 if (i < ec_bytes.size()) {
425 result.AppendBits(ec_bytes.at(i), 8);
429 if (num_total_bytes == result.num_bytes()) { // Should be same.
432 Debug.LOG_ERROR("Interleaving error: " + num_total_bytes + " and " + result.num_bytes() +
437 static ByteArray GenerateECBytes(ByteArray data_bytes, int num_ec_bytes_in_block) {
438 int numDataBytes = data_bytes.size();
439 int[] toEncode = new int[numDataBytes + num_ec_bytes_in_block];
440 for (int i = 0; i < numDataBytes; i++) {
441 toEncode[i] = data_bytes.at(i);
443 new ReedSolomonEncoder(GF256.QR_CODE_FIELD).encode(toEncode, num_ec_bytes_in_block);
445 ByteArray ec_bytes = new ByteArray(num_ec_bytes_in_block);
446 for (int i = 0; i < num_ec_bytes_in_block; i++) {
447 ec_bytes.set(i, toEncode[numDataBytes + i]);
452 // Append mode info. On success, store the result in "bits" and return true. On error, return
454 static boolean AppendModeInfo(int mode, BitVector bits) {
455 final int code = QRCode.GetModeCode(mode);
457 Debug.LOG_ERROR("Invalid mode: " + mode);
460 bits.AppendBits(code, 4);
465 // Append length info. On success, store the result in "bits" and return true. On error, return
467 static boolean AppendLengthInfo(int num_bytes, int version, int mode, BitVector bits) {
468 int num_letters = num_bytes;
469 // In Kanji mode, a letter is represented in two bytes.
470 if (mode == QRCode.MODE_KANJI) {
471 Debug.DCHECK_EQ(0, num_letters % 2);
475 final int num_bits = QRCode.GetNumBitsForLength(version, mode);
476 if (num_bits == -1) {
477 Debug.LOG_ERROR("num_bits unset");
480 if (num_letters > ((1 << num_bits) - 1)) {
481 Debug.LOG_ERROR(num_letters + "is bigger than" + ((1 << num_bits) - 1));
484 bits.AppendBits(num_letters, num_bits);
488 // Append "bytes" in "mode" mode (encoding) into "bits". On success, store the result in "bits"
489 // and return true. On error, return false.
490 static boolean AppendBytes(final ByteArray bytes, int mode, BitVector bits) {
492 case QRCode.MODE_NUMERIC:
493 return AppendNumericBytes(bytes, bits);
494 case QRCode.MODE_ALPHANUMERIC:
495 return AppendAlphanumericBytes(bytes, bits);
496 case QRCode.MODE_8BIT_BYTE:
497 return Append8BitBytes(bytes, bits);
498 case QRCode.MODE_KANJI:
499 return AppendKanjiBytes(bytes, bits);
503 Debug.LOG_ERROR("Invalid mode: " + mode);
507 // Append "bytes" to "bits" using QRCode.MODE_NUMERIC mode. On success, store the result in "bits"
508 // and return true. On error, return false.
509 static boolean AppendNumericBytes(final ByteArray bytes, BitVector bits) {
510 // Validate all the bytes first.
511 for (int i = 0; i < bytes.size(); ++i) {
512 int oneByte = bytes.at(i);
513 if (oneByte < '0' || oneByte > '9') {
517 for (int i = 0; i < bytes.size();) {
518 final int num1 = bytes.at(i) - '0';
519 if (i + 2 < bytes.size()) {
520 // Encode three numeric letters in ten bits.
521 final int num2 = bytes.at(i + 1) - '0';
522 final int num3 = bytes.at(i + 2) - '0';
523 bits.AppendBits(num1 * 100 + num2 * 10 + num3, 10);
525 } else if (i + 1 < bytes.size()) {
526 // Encode two numeric letters in seven bits.
527 final int num2 = bytes.at(i + 1) - '0';
528 bits.AppendBits(num1 * 10 + num2, 7);
531 // Encode one numeric letter in four bits.
532 bits.AppendBits(num1, 4);
539 // Append "bytes" to "bits" using QRCode.MODE_ALPHANUMERIC mode. On success, store the result in
540 // "bits" and return true. On error, return false.
541 static boolean AppendAlphanumericBytes(final ByteArray bytes, BitVector bits) {
542 for (int i = 0; i < bytes.size();) {
543 final int code1 = GetAlphanumericCode(bytes.at(i));
547 if (i + 1 < bytes.size()) {
548 final int code2 = GetAlphanumericCode(bytes.at(i + 1));
552 // Encode two alphanumeric letters in 11 bits.
553 bits.AppendBits(code1 * 45 + code2, 11);
556 // Encode one alphanumeric letter in six bits.
557 bits.AppendBits(code1, 6);
564 // Append "bytes" to "bits" using QRCode.MODE_8BIT_BYTE mode. On success, store the result in
565 // "bits" and return true. On error, return false.
566 static boolean Append8BitBytes(final ByteArray bytes, BitVector bits) {
567 for (int i = 0; i < bytes.size(); ++i) {
568 bits.AppendBits(bytes.at(i), 8);
573 // Append "bytes" to "bits" using QRCode.MODE_KANJI mode. On success, store the result in "bits"
574 // and return true. On error, return false. See 8.4.5 of JISX0510:2004 (p.21) for how to encode
576 static boolean AppendKanjiBytes(final ByteArray bytes, BitVector bits) {
577 if (bytes.size() % 2 != 0) {
578 // JAVAPORT: Our log implementation throws, which causes the unit test to fail.
579 //Debug.LOG_ERROR("Invalid byte sequence: " + bytes);
582 for (int i = 0; i < bytes.size(); i += 2) {
583 Debug.DCHECK(IsValidKanji(bytes.at(i), bytes.at(i + 1)));
584 final int code = (bytes.at(i) << 8) | bytes.at(i + 1);
586 if (code >= 0x8140 && code <= 0x9ffc) {
587 subtracted = code - 0x8140;
588 } else if (code >= 0xe040 && code <= 0xebbf) {
589 subtracted = code - 0xc140;
591 if (subtracted == -1) {
592 Debug.LOG_ERROR("Invalid byte sequence: " + bytes);
595 final int encoded = ((subtracted >> 8) * 0xc0) + (subtracted & 0xff);
596 bits.AppendBits(encoded, 13);
601 // Check if "byte1" and "byte2" can compose a valid Kanji letter (2-byte Shift_JIS letter). The
602 // numbers are from http://ja.wikipedia.org/wiki/Shift_JIS.
603 static boolean IsValidKanji(final int byte1, final int byte2) {
604 return (byte2 != 0x7f &&
605 ((byte1 >= 0x81 && byte1 <= 0x9f &&
606 byte2 >= 0x40 && byte2 <= 0xfc) ||
607 ((byte1 >= 0xe0 && byte1 <= 0xfc &&
608 byte2 >= 0x40 && byte2 <= 0xfc))));
611 // Check if "bytes" is a valid Kanji sequence. Used by the unit tests.
612 static boolean IsValidKanjiSequence(final ByteArray bytes) {
613 if (bytes.size() % 2 != 0) {
617 for (; i < bytes.size(); i += 2) {
618 if (!IsValidKanji(bytes.at(i), bytes.at(i + 1))) {
622 return i == bytes.size(); // Consumed all bytes?