`class ErrorCorrectionBlock`

Definitions

`TABLE`

http://www.thonky.com/qr-code-tutorial/error-correction-table/ Table of [block_count, total_codewords, data_codewords] for each version and error level

Implementation

TABLE = [
	# The order within each group is:
	# 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, 7, 37, 13],
	
	# 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]
].freeze

`def self.for(version, level)`

Create error correction blocks for given version and level

Signature

parameter　version　Integer: QR code version (1-40)
parameter　level　Integer: Error correction level

Implementation

def self.for(version, level)
	entry = table_entry_for(version, level)
	
	if entry.nil?
		raise RuntimeError, "Invalid error correction configuration: version=#{version}, level=#{level}"
	end
	
	blocks = []
	groups = entry.size / 3
	
	(0...groups).each do |i|
		count = entry[i * 3 + 0]
		total_count = entry[i * 3 + 1]
		data_count = entry[i * 3 + 2]
		
		count.times do
			blocks << ErrorCorrectionBlock.new(total_count, data_count)
		end
	end
	
	blocks
end

`def self.table_entry_for(version, level)`

Get table entry for specific version and error correction level

Signature

parameter　version　Integer: QR code version (1-40)
parameter　level　Integer: Error correction level

Implementation

def self.table_entry_for(version, level)
	return nil unless version.between?(1, 40)
	
	case level
	when ERROR_CORRECTION_LEVEL[:l]
		TABLE[(version - 1) * 4 + 0]
	when ERROR_CORRECTION_LEVEL[:m]
		TABLE[(version - 1) * 4 + 1]
	when ERROR_CORRECTION_LEVEL[:q]
		TABLE[(version - 1) * 4 + 2]
	when ERROR_CORRECTION_LEVEL[:h]
		TABLE[(version - 1) * 4 + 3]
	end
end