def test_prim_fcr_long(self):
nn = 48
kk = 34
tt = nn - kk
rs = RSCodec(tt, fcr=120, prim=0x187)
hexencmsg = '08faa123555555c000000354064432c0280e1b4d090cfc04887400' \
'000003500000000e1985ff9c6b33066ca9f43d12e8'
strf = str if sys.version_info[0] >= 3 else unicode
encmsg = bytearray.fromhex(strf(hexencmsg))
decmsg = encmsg[:kk]
tem = rs.encode(decmsg)
self.assertEqual(encmsg, tem, msg="encoded does not match expected")
tdm, _, _ = rs.decode(tem)
self.assertEqual(tdm, decmsg,
msg="decoded does not match original")
tem1 = bytearray(tem)
numerrs = tt >> 1
for i in sample(range(nn), numerrs):
tem1[i] ^= 0xff
tdm, _, _ = rs.decode(tem1)
self.assertEqual(tdm, decmsg,
msg="decoded with errors does not match original")
tem1 = bytearray(tem)
numerrs += 1
for i in sample(range(nn), numerrs):
tem1[i] ^= 0xff
self.assertRaises(ReedSolomonError, rs.decode, tem1)
def test_prim_fcr_basic(self):
nn = 30
kk = 18
tt = nn - kk
rs = RSCodec(tt, fcr=120, prim=0x187)
hexencmsg = '00faa123555555c000000354064432c02800fe97c434e1ff5365' \
'cf8fafe4'
strf = str if sys.version_info[0] >= 3 else unicode
encmsg = bytearray.fromhex(strf(hexencmsg))
decmsg = encmsg[:kk]
tem = rs.encode(decmsg)
self.assertEqual(encmsg, tem, msg="encoded does not match expected")
tdm = rs.decode(tem)
self.assertEqual(tdm, decmsg, msg="decoded does not match original")
tem1 = bytearray(tem) # clone a copy
# encoding and decoding intact message seem OK, so test errors
numerrs = tt >> 1 # inject tt/2 errors (expected to recover fully)
for i in sample(range(nn), numerrs): # inject errors in random places
tem1[i] ^= 0xff # flip all 8 bits
tdm = rs.decode(tem1)
self.assertEqual(tdm, decmsg,
msg="decoded with errors does not match original")
tem1 = bytearray(tem) # clone another copy
numerrs += 1 # inject tt/2 + 1 errors (expected to fail and detect it)
for i in sample(range(nn), numerrs): # inject errors in random places
tem1[i] ^= 0xff # flip all 8 bits
# if this fails, it means excessive errors not detected
self.assertRaises(ReedSolomonError, rs.decode, tem1)
def test_prim_fcr_basic(self):
nn = 30
kk = 18
tt = nn - kk
rs = RSCodec(tt, fcr=120, prim=0x187)
hexencmsg = '00faa123555555c000000354064432c02800fe97c434e1ff5365' \
'cf8fafe4'
strf = str if sys.version_info[0] >= 3 else unicode
encmsg = bytearray.fromhex(strf(hexencmsg))
decmsg = encmsg[:kk]
tem = rs.encode(decmsg)
self.assertEqual(encmsg, tem, msg="encoded does not match expected")
tdm, _, _ = rs.decode(tem)
self.assertEqual(tdm, decmsg, msg="decoded does not match original")
tem1 = bytearray(tem) # clone a copy
# encoding and decoding intact message seem OK, so test errors
numerrs = tt >> 1 # inject tt/2 errors (expected to recover fully)
for i in sample(range(nn), numerrs): # inject errors in random places
tem1[i] ^= 0xff # flip all 8 bits
tdm, _, _ = rs.decode(tem1)
self.assertEqual(tdm, decmsg,
msg="decoded with errors does not match original")
tem1 = bytearray(tem) # clone another copy
numerrs += 1 # inject tt/2 + 1 errors (expected to fail and detect it)
for i in sample(range(nn), numerrs): # inject errors in random places
tem1[i] ^= 0xff # flip all 8 bits
# if this fails, it means excessive errors not detected
self.assertRaises(ReedSolomonError, rs.decode, tem1)
def test_prim_fcr_long(self):
nn = 48
kk = 34
tt = nn - kk
rs = RSCodec(tt, fcr=120, prim=0x187)
hexencmsg = '08faa123555555c000000354064432c0280e1b4d090cfc04887400' \
'000003500000000e1985ff9c6b33066ca9f43d12e8'
strf = str if sys.version_info[0] >= 3 else unicode
encmsg = bytearray.fromhex(strf(hexencmsg))
decmsg = encmsg[:kk]
tem = rs.encode(decmsg)
self.assertEqual(encmsg, tem, msg="encoded does not match expected")
tdm = rs.decode(tem)
self.assertEqual(tdm, decmsg,
msg="decoded does not match original")
tem1 = bytearray(tem)
numerrs = tt >> 1
for i in sample(range(nn), numerrs):
tem1[i] ^= 0xff
tdm = rs.decode(tem1)
self.assertEqual(tdm, decmsg,
msg="decoded with errors does not match original")
tem1 = bytearray(tem)
numerrs += 1
for i in sample(range(nn), numerrs):
tem1[i] ^= 0xff
self.assertRaises(ReedSolomonError, rs.decode, tem1)
def test_long(self):
rs = RSCodec(10)
msg = bytearray("a" * 10000, "latin1")
enc = rs.encode(msg)
dec, _, _ = rs.decode(enc)
self.assertEqual(dec, msg)
enc[177] = 99
enc[2212] = 88
dec2, _, _ = rs.decode(enc)
self.assertEqual(dec2, msg)
def test_long(self):
rs = RSCodec(10)
msg = bytearray("a" * 10000, "latin1")
enc = rs.encode(msg)
dec = rs.decode(enc)
self.assertEqual(dec, msg)
enc[177] = 99
enc[2212] = 88
dec2 = rs.decode(enc)
self.assertEqual(dec2, msg)
def test_correction(self):
rs = RSCodec(10)
msg = bytearray("hello world " * 10, "latin1")
enc = rs.encode(msg)
self.assertEqual(rs.decode(enc), msg)
for i in [27, -3, -9, 7, 0]:
enc[i] = 99
self.assertEqual(rs.decode(enc), msg)
enc[82] = 99
self.assertRaises(ReedSolomonError, rs.decode, enc)
def test_simple(self):
rs = RSCodec(10)
msg = bytearray("hello world " * 10, "latin1")
enc = rs.encode(msg)
dec, dec_enc, errata_pos = rs.decode(enc)
self.assertEqual(dec, msg)
def test_main(self):
def cartesian_product_dict_items(dicts):
return (dict(izip(dicts, x)) for x in itertools.product(*dicts.values()))
debugg = False # if one or more tests don't pass, you can enable this flag to True to get verbose output to debug
orig_mes = bytearray("hello world", "latin1")
n = len(orig_mes)*2
k = len(orig_mes)
nsym = n-k
istart = 0
params = {"count": 5,
"fcr": [120, 0, 1, 1, 1],
"prim": [0x187, 0x11d, 0x11b, 0xfd, 0xfd],
"generator": [2, 2, 3, 3, 2],
"c_exponent": [8, 8, 8, 7, 7],
}
cases = {
"errmode": [1, 2, 3, 4],
"erratasnb_errorsnb_onlyeras": [[8, 3, False], [6, 5, False], [5, 5, False], [11, 0, True], [11, 0, False], [0,0, False]], # errata number (errors+erasures), erasures number and only_erasures: the last item is the value for only_erasures (True/False)
}
############################$
results_br = []
results_rs = []
it = 0
for p in xrange(params["count"]):
fcr = params["fcr"][p]
prim = params["prim"][p]
generator = params["generator"][p]
c_exponent = params["c_exponent"][p]
for case in cartesian_product_dict_items(cases):
errmode = case["errmode"]
erratanb = case["erratasnb_errorsnb_onlyeras"][0]
errnb = case["erratasnb_errorsnb_onlyeras"][1]
only_erasures = case["erratasnb_errorsnb_onlyeras"][2]
it += 1
if debugg:
print("it ", it)
print("param", p)
print(case)
# REEDSOLO
# Init the RS codec
init_tables(generator=generator, prim=prim, c_exp=c_exponent)
g = rs_generator_poly_all(n, fcr=fcr, generator=generator)
# Encode the message
rmesecc = rs_encode_msg(orig_mes, n-k, gen=g[n-k])
rmesecc_orig = rmesecc[:] # make a copy of the original message to check later if fully corrected (because the syndrome may be wrong sometimes)
# Tamper the message
if erratanb > 0:
if errmode == 1:
sl = slice(istart, istart+erratanb)
elif errmode == 2:
sl = slice(-istart-erratanb-(n-k), -(n-k))
elif errmode == 3:
sl = slice(-istart-erratanb-1, -1)
elif errmode == 4:
sl = slice(-istart-erratanb, None)
if debugg:
print("Removed slice:", list(rmesecc[sl]), rmesecc[sl])
rmesecc[sl] = [0] * erratanb
# Generate the erasures positions (if any)
erase_pos = [x for x in xrange(len(rmesecc)) if rmesecc[x] == 0]
if errnb > 0: erase_pos = erase_pos[:-errnb] # remove the errors positions (must not be known by definition)
if debugg:
print("erase_pos", erase_pos)
print("coef_pos", [len(rmesecc) - 1 - pos for pos in erase_pos])
print("Errata total: ", erratanb-errnb + errnb*2, " -- Correctable? ", (erratanb-errnb + errnb*2 <= nsym))
# Decoding the corrupted codeword
# -- Forney syndrome method
try:
rmes, recc, errata_pos = rs_correct_msg(rmesecc, n-k, fcr=fcr, generator=generator, erase_pos=erase_pos, only_erasures=only_erasures)
results_br.append( rs_check(rmes + recc, n-k, fcr=fcr, generator=generator) ) # check if correct by syndrome analysis (can be wrong)
results_br.append( rmesecc_orig == (rmes+recc) ) # check if correct by comparing to the original message (always correct)
if debugg and not rs_check(rmes + recc, n-k, fcr=fcr, generator=generator) or not (rmesecc_orig == (rmes+recc)): raise ReedSolomonError("False!!!!!")
except ReedSolomonError as exc:
results_br.append(False)
results_br.append(False)
if debugg:
print("====")
print("ERROR! Details:")
print("param", p)
print(case)
print(erase_pos)
print("original_msg", rmesecc_orig)
print("tampered_msg", rmesecc)
print("decoded_msg", rmes+recc)
print("checks: ", rs_check(rmes + recc, n-k, fcr=fcr, generator=generator), rmesecc_orig == (rmes+recc))
print("====")
raise exc
# -- Without Forney syndrome method
try:
mes, ecc, errata_pos = rs_correct_msg_nofsynd(rmesecc, n-k, fcr=fcr, generator=generator, erase_pos=erase_pos, only_erasures=only_erasures)
results_br.append( rs_check(rmes + recc, n-k, fcr=fcr, generator=generator) )
results_br.append( rmesecc_orig == (rmes+recc) )
except ReedSolomonError as exc:
results_br.append(False)
results_br.append(False)
if debugg: print("-----")
self.assertTrue(results_br.count(True) == len(results_br))
def test_simple(self):
rs = RSCodec(10)
msg = bytearray("hello world " * 10, "latin1")
enc = rs.encode(msg)
dec = rs.decode(enc)
self.assertEqual(dec, msg)
def test_main(self):
def cartesian_product_dict_items(dicts):
return (dict(izip(dicts, x)) for x in itertools.product(*dicts.values()))
debugg = False # if one or more tests don't pass, you can enable this flag to True to get verbose output to debug
orig_mes = bytearray("hello world", "latin1")
n = len(orig_mes)*2
k = len(orig_mes)
nsym = n-k
istart = 0
params = {"count": 5,
"fcr": [120, 0, 1, 1, 1],
"prim": [0x187, 0x11d, 0x11b, 0xfd, 0xfd],
"generator": [2, 2, 3, 3, 2],
"c_exponent": [8, 8, 8, 7, 7],
}
cases = {
"errmode": [1, 2, 3, 4],
"erratasnb_errorsnb_onlyeras": [[8, 3, False], [6, 5, False], [5, 5, False], [11, 0, True], [11, 0, False], [0,0, False]], # errata number (errors+erasures), erasures number and only_erasures: the last item is the value for only_erasures (True/False)
}
############################$
results_br = []
results_rs = []
it = 0
for p in xrange(params["count"]):
fcr = params["fcr"][p]
prim = params["prim"][p]
generator = params["generator"][p]
c_exponent = params["c_exponent"][p]
for case in cartesian_product_dict_items(cases):
errmode = case["errmode"]
erratanb = case["erratasnb_errorsnb_onlyeras"][0]
errnb = case["erratasnb_errorsnb_onlyeras"][1]
only_erasures = case["erratasnb_errorsnb_onlyeras"][2]
it += 1
if debugg:
print("it ", it)
print("param", p)
print(case)
# REEDSOLO
# Init the RS codec
init_tables(generator=generator, prim=prim, c_exp=c_exponent)
g = rs_generator_poly_all(n, fcr=fcr, generator=generator)
# Encode the message
rmesecc = rs_encode_msg(orig_mes, n-k, gen=g[n-k])
rmesecc_orig = rmesecc[:] # make a copy of the original message to check later if fully corrected (because the syndrome may be wrong sometimes)
# Tamper the message
if erratanb > 0:
if errmode == 1:
sl = slice(istart, istart+erratanb)
elif errmode == 2:
sl = slice(-istart-erratanb-(n-k), -(n-k))
elif errmode == 3:
sl = slice(-istart-erratanb-1, -1)
elif errmode == 4:
sl = slice(-istart-erratanb, None)
if debugg:
print("Removed slice:", list(rmesecc[sl]), rmesecc[sl])
rmesecc[sl] = [0] * erratanb
# Generate the erasures positions (if any)
erase_pos = [x for x in xrange(len(rmesecc)) if rmesecc[x] == 0]
if errnb > 0: erase_pos = erase_pos[:-errnb] # remove the errors positions (must not be known by definition)
if debugg:
print("erase_pos", erase_pos)
print("coef_pos", [len(rmesecc) - 1 - pos for pos in erase_pos])
print("Errata total: ", erratanb-errnb + errnb*2, " -- Correctable? ", (erratanb-errnb + errnb*2 <= nsym))
# Decoding the corrupted codeword
# -- Forney syndrome method
try:
rmes, recc = rs_correct_msg(rmesecc, n-k, fcr=fcr, generator=generator, erase_pos=erase_pos, only_erasures=only_erasures)
results_br.append( rs_check(rmes + recc, n-k, fcr=fcr, generator=generator) ) # check if correct by syndrome analysis (can be wrong)
results_br.append( rmesecc_orig == (rmes+recc) ) # check if correct by comparing to the original message (always correct)
if debugg and not rs_check(rmes + recc, n-k, fcr=fcr, generator=generator) or not (rmesecc_orig == (rmes+recc)): raise ReedSolomonError("False!!!!!")
except ReedSolomonError as exc:
results_br.append(False)
results_br.append(False)
if debugg:
print("====")
print("ERROR! Details:")
print("param", p)
print(case)
print(erase_pos)
print("original_msg", rmesecc_orig)
print("tampered_msg", rmesecc)
print("decoded_msg", rmes+recc)
print("checks: ", rs_check(rmes + recc, n-k, fcr=fcr, generator=generator), rmesecc_orig == (rmes+recc))
print("====")
raise exc
# -- Without Forney syndrome method
try:
mes, ecc = rs_correct_msg_nofsynd(rmesecc, n-k, fcr=fcr, generator=generator, erase_pos=erase_pos, only_erasures=only_erasures)
results_br.append( rs_check(rmes + recc, n-k, fcr=fcr, generator=generator) )
results_br.append( rmesecc_orig == (rmes+recc) )
except ReedSolomonError as exc:
results_br.append(False)
results_br.append(False)
if debugg: print("-----")
self.assertTrue(results_br.count(True) == len(results_br))