def decode_file(self, file_in, file_out, make_table, is_fix_err: bool = True):
"""
Have inner dependence from method encode_file
Doesn't recomended to call it without calling the encode_file method.
You can get back more bits what in really msg.
Example
You have n = 15, k=9
and lenght of msg in bits is 136.
To decode msg u need extend bitarry to 144 bit (144⋮ 9 144⋮ 8). And it also divide by 8 without remain.
144 = 8 * 9 * 2
And after decoding, u need delete byte at the end of msg
And in other case u have msg with 144 bits lenght
:param file_in:
:param file_out:
:param make_table: function is returned the special dict. See CyclicCode.make_table()
:param is_fix_err:
:return:
"""
bit_a = ba.bitarray()
bit_a.fromfile(file_in)
print(f"endcode {len(bit_a)}, {bit_a}")
bit_a = BaseCode.add_to_multiplicity_n(bit_a, self.n, is_to_less=True)
print(f"endcode {len(bit_a)}, {bit_a}")
decode = self.decode_sys(bit_a, make_table, is_fix_err=is_fix_err)
key = len(decode)
true_len = self.bone.setdefault(key, None)
if true_len:
decode = decode[:true_len]
# clear the memory
del self.bone[key]
print(f"decode {len(decode)}, {decode}")
# decode = BaseCode.add_to_multiplicity_n(decode, 8, is_to_less=True)
decode.tofile(file_out)
def decode_sys(self, bit_arr: ba.bitarray, make_table, is_fix_err: bool = True):
"""
With correct.
:param bit_arr:
:param is_reshaped:
:return:
"""
bit_arr = BaseCode.add_to_multiplicity_n(bit_arr, self.n)
decoded = ba.bitarray()
remain_d = None
syndromes = None
if is_fix_err:
remain_d = self.remain_dev(bit_arr)
syndromes = make_table()
# print("len synd", len(syndromes))
for i in range(len(bit_arr) // self.n):
i_beg = i * self.n
if is_fix_err:
# print(self.n_k)
key = self.ba_to_str_bits(remain_d[i_beg:i_beg + self.n_k])
index_err_bit = syndromes[key]
if len(index_err_bit):
print(bit_arr)
for index_err in index_err_bit:
bit_arr[i_beg + index_err] = not bit_arr[i_beg + index_err]
else:
print(" " * (10 + i_beg + index_err_bit[0]) + "|" * (2))
print(bit_arr)
print(index_err_bit)
print(key)
print(f"{index_err_bit[0]} from {self.n}", )
print(f"error fount. It index is {i_beg + index_err_bit[0]}", "\n")
decoded.extend(bit_arr[i_beg + self.n_k:i_beg + self.n])
return decoded
def encode_file(self, file_in, file_out):
"""
:param file_in:
:param file_out:
:return:
"""
bit_a = ba.bitarray()
bit_a.fromfile(file_in)
len_bit_a = len(bit_a)
print(f"our msg {len(bit_a)}, {bit_a}")
bit_a = BaseCode.add_to_multiplicity_n(bit_a, self.k)
print(f"our msg {len(bit_a)}, {bit_a}")
if len(bit_a) - len_bit_a >= 8:
self.bone[len(bit_a)] = len_bit_a
encode = self.encody_sys(bit_a)
print(f"endcode {len(encode)}, {encode}")
encode.tofile(file_out)