inject.py

f = open('feria.lsr', 'rb')
x = f.read()
f.close()
f = open('feria.txt', 'rb')
y = f.read()
f.close()

s = x.split(b'\0')
t = y.split(b'\r\n|\r\n')

r = []
c = 0
offset = 0
for l in s:
  try:
    # Decoding successful and result != '':
    # Encode new string instead
    decoded = l.decode('shift-jis')
    if len(decoded) < 1:
      raise None
    try:
      encoded = t[c].decode('utf-8').encode('shift-jis')
      offset += len(encoded)-len(l)
      r.append(encoded)
    except:
      print("Could not encode item %d (%s) as shift-jis" % (c, t[c]))
    c += 1
  except:
    r.append(l)

print('Offset: %d' % offset)

# Add the offset to known data pointers that point to data after strings
# 0x30 up to (and excluding) 0x64 are 32-bit integers pointing to
# locations after the strings.
# 0x271 is a 32-bit integer containing the length of the strings.
b = list(b'\0'.join(r))
for i in list(range(0x30, 0x64, 4)) + [0x271]:
  v = b[i] | b[i+1]<<8 | b[i+2]<<16 | b[i+3]<<24
  v += offset
  b[i] = v & 0xff
  b[i+1] = (v & 0xff00) >> 8
  b[i+2] = (v & 0xff0000) >> 16
  b[i+3] = (v & 0xff000000) >> 24

r = bytes(b)

f = open('feria_injected.lsr', 'wb')
f.write(r)
f.close()