from qrcode import constants EXP_TABLE = list(range(256)) LOG_TABLE = list(range(256)) for i in range(8): EXP_TABLE[i] = 1 << i for i in range(8, 256): EXP_TABLE[i] = (EXP_TABLE[i - 4] ^ EXP_TABLE[i - 5] ^ EXP_TABLE[i - 6] ^ EXP_TABLE[i - 8]) for i in range(255): LOG_TABLE[EXP_TABLE[i]] = i RS_BLOCK_OFFSET = { constants.ERROR_CORRECT_L: 0, constants.ERROR_CORRECT_M: 1, constants.ERROR_CORRECT_Q: 2, constants.ERROR_CORRECT_H: 3, } RS_BLOCK_TABLE = [ # L # M # Q # H # 1 [1, 26, 19], [1, 26, 16], [1, 26, 13], [1, 26, 9], # 2 [1, 44, 34], [1, 44, 28], [1, 44, 22], [1, 44, 16], # 3 [1, 70, 55], [1, 70, 44], [2, 35, 17], [2, 35, 13], # 4 [1, 100, 80], [2, 50, 32], [2, 50, 24], [4, 25, 9], # 5 [1, 134, 108], [2, 67, 43], [2, 33, 15, 2, 34, 16], [2, 33, 11, 2, 34, 12], # 6 [2, 86, 68], [4, 43, 27], [4, 43, 19], [4, 43, 15], # 7 [2, 98, 78], [4, 49, 31], [2, 32, 14, 4, 33, 15], [4, 39, 13, 1, 40, 14], # 8 [2, 121, 97], [2, 60, 38, 2, 61, 39], [4, 40, 18, 2, 41, 19], [4, 40, 14, 2, 41, 15], # 9 [2, 146, 116], [3, 58, 36, 2, 59, 37], [4, 36, 16, 4, 37, 17], [4, 36, 12, 4, 37, 13], # 10 [2, 86, 68, 2, 87, 69], [4, 69, 43, 1, 70, 44], [6, 43, 19, 2, 44, 20], [6, 43, 15, 2, 44, 16], # 11 [4, 101, 81], [1, 80, 50, 4, 81, 51], [4, 50, 22, 4, 51, 23], [3, 36, 12, 8, 37, 13], # 12 [2, 116, 92, 2, 117, 93], [6, 58, 36, 2, 59, 37], [4, 46, 20, 6, 47, 21], [7, 42, 14, 4, 43, 15], # 13 [4, 133, 107], [8, 59, 37, 1, 60, 38], [8, 44, 20, 4, 45, 21], [12, 33, 11, 4, 34, 12], # 14 [3, 145, 115, 1, 146, 116], [4, 64, 40, 5, 65, 41], [11, 36, 16, 5, 37, 17], [11, 36, 12, 5, 37, 13], # 15 [5, 109, 87, 1, 110, 88], [5, 65, 41, 5, 66, 42], [5, 54, 24, 7, 55, 25], [11, 36, 12], # 16 [5, 122, 98, 1, 123, 99], [7, 73, 45, 3, 74, 46], [15, 43, 19, 2, 44, 20], [3, 45, 15, 13, 46, 16], # 17 [1, 135, 107, 5, 136, 108], [10, 74, 46, 1, 75, 47], [1, 50, 22, 15, 51, 23], [2, 42, 14, 17, 43, 15], # 18 [5, 150, 120, 1, 151, 121], [9, 69, 43, 4, 70, 44], [17, 50, 22, 1, 51, 23], [2, 42, 14, 19, 43, 15], # 19 [3, 141, 113, 4, 142, 114], [3, 70, 44, 11, 71, 45], [17, 47, 21, 4, 48, 22], [9, 39, 13, 16, 40, 14], # 20 [3, 135, 107, 5, 136, 108], [3, 67, 41, 13, 68, 42], [15, 54, 24, 5, 55, 25], [15, 43, 15, 10, 44, 16], # 21 [4, 144, 116, 4, 145, 117], [17, 68, 42], [17, 50, 22, 6, 51, 23], [19, 46, 16, 6, 47, 17], # 22 [2, 139, 111, 7, 140, 112], [17, 74, 46], [7, 54, 24, 16, 55, 25], [34, 37, 13], # 23 [4, 151, 121, 5, 152, 122], [4, 75, 47, 14, 76, 48], [11, 54, 24, 14, 55, 25], [16, 45, 15, 14, 46, 16], # 24 [6, 147, 117, 4, 148, 118], [6, 73, 45, 14, 74, 46], [11, 54, 24, 16, 55, 25], [30, 46, 16, 2, 47, 17], # 25 [8, 132, 106, 4, 133, 107], [8, 75, 47, 13, 76, 48], [7, 54, 24, 22, 55, 25], [22, 45, 15, 13, 46, 16], # 26 [10, 142, 114, 2, 143, 115], [19, 74, 46, 4, 75, 47], [28, 50, 22, 6, 51, 23], [33, 46, 16, 4, 47, 17], # 27 [8, 152, 122, 4, 153, 123], [22, 73, 45, 3, 74, 46], [8, 53, 23, 26, 54, 24], [12, 45, 15, 28, 46, 16], # 28 [3, 147, 117, 10, 148, 118], [3, 73, 45, 23, 74, 46], [4, 54, 24, 31, 55, 25], [11, 45, 15, 31, 46, 16], # 29 [7, 146, 116, 7, 147, 117], [21, 73, 45, 7, 74, 46], [1, 53, 23, 37, 54, 24], [19, 45, 15, 26, 46, 16], # 30 [5, 145, 115, 10, 146, 116], [19, 75, 47, 10, 76, 48], [15, 54, 24, 25, 55, 25], [23, 45, 15, 25, 46, 16], # 31 [13, 145, 115, 3, 146, 116], [2, 74, 46, 29, 75, 47], [42, 54, 24, 1, 55, 25], [23, 45, 15, 28, 46, 16], # 32 [17, 145, 115], [10, 74, 46, 23, 75, 47], [10, 54, 24, 35, 55, 25], [19, 45, 15, 35, 46, 16], # 33 [17, 145, 115, 1, 146, 116], [14, 74, 46, 21, 75, 47], [29, 54, 24, 19, 55, 25], [11, 45, 15, 46, 46, 16], # 34 [13, 145, 115, 6, 146, 116], [14, 74, 46, 23, 75, 47], [44, 54, 24, 7, 55, 25], [59, 46, 16, 1, 47, 17], # 35 [12, 151, 121, 7, 152, 122], [12, 75, 47, 26, 76, 48], [39, 54, 24, 14, 55, 25], [22, 45, 15, 41, 46, 16], # 36 [6, 151, 121, 14, 152, 122], [6, 75, 47, 34, 76, 48], [46, 54, 24, 10, 55, 25], [2, 45, 15, 64, 46, 16], # 37 [17, 152, 122, 4, 153, 123], [29, 74, 46, 14, 75, 47], [49, 54, 24, 10, 55, 25], [24, 45, 15, 46, 46, 16], # 38 [4, 152, 122, 18, 153, 123], [13, 74, 46, 32, 75, 47], [48, 54, 24, 14, 55, 25], [42, 45, 15, 32, 46, 16], # 39 [20, 147, 117, 4, 148, 118], [40, 75, 47, 7, 76, 48], [43, 54, 24, 22, 55, 25], [10, 45, 15, 67, 46, 16], # 40 [19, 148, 118, 6, 149, 119], [18, 75, 47, 31, 76, 48], [34, 54, 24, 34, 55, 25], [20, 45, 15, 61, 46, 16] ] def glog(n): if n < 1: raise ValueError("glog(%s)" % n) return LOG_TABLE[n] def gexp(n): return EXP_TABLE[n % 255] class Polynomial: def __init__(self, num, shift): if not num: raise Exception("%s/%s" % (len(num), shift)) offset = 0 for item in num: if item != 0: break offset += 1 self.num = [0] * (len(num) - offset + shift) for i in range(len(num) - offset): self.num[i] = num[i + offset] def __getitem__(self, index): return self.num[index] def __iter__(self): return iter(self.num) def __len__(self): return len(self.num) def __mul__(self, other): num = [0] * (len(self) + len(other) - 1) for i, item in enumerate(self): for j, other_item in enumerate(other): num[i + j] ^= gexp(glog(item) + glog(other_item)) return Polynomial(num, 0) def __mod__(self, other): difference = len(self) - len(other) if difference < 0: return self ratio = glog(self[0]) - glog(other[0]) num = self[:] num = [ item ^ gexp(glog(other_item) + ratio) for item, other_item in zip(self, other)] if difference: num.extend(self[-difference:]) # recursive call return Polynomial(num, 0) % other class RSBlock: def __init__(self, total_count, data_count): self.total_count = total_count self.data_count = data_count def rs_blocks(version, error_correction): if error_correction not in RS_BLOCK_OFFSET: raise Exception("bad rs block @ version: %s / error_correction: %s" % (version, error_correction)) offset = RS_BLOCK_OFFSET[error_correction] rs_block = RS_BLOCK_TABLE[(version - 1) * 4 + offset] blocks = [] for i in range(0, len(rs_block), 3): count, total_count, data_count = rs_block[i:i + 3] for j in range(count): blocks.append(RSBlock(total_count, data_count)) return blocks