def generate_metadata_stream(self):
ms = StringIO()
ms.write(self.encode_vwi(len(self.md_header['tag'])).encode('iso-8859-1'))
ms.write(self.md_header['tag'])
ms.write(int_to_byte(self.md_header['flags']))
ms.write(int_to_byte(len(self.metadata)))
# Add the metadata fields.
# for tag in self.metadata:
for tag in self.md_seq:
ms.write(self.encode_vwi(len(tag)).encode('iso-8859-1'))
ms.write(tag)
ms.write(self.encode_vwi(len(self.metadata[tag])).encode('iso-8859-1'))
ms.write(self.metadata[tag])
return ms.getvalue()
def write_t2b(t2bfile, coverdata=None):
'''
t2bfile is a file handle ready to write binary data to disk.
coverdata is a string representation of a JPEG file.
'''
from PIL import Image
if coverdata is not None:
coverdata = io.BytesIO(coverdata)
cover = Image.open(coverdata).convert("L")
cover.thumbnail((96, 144), Image.ANTIALIAS)
t2bcover = Image.new('L', (96, 144), 'white')
x, y = cover.size
t2bcover.paste(cover, ((96-x)//2, (144-y)//2))
px = []
pxs = t2bcover.getdata()
for i in range(len(pxs)):
px.append(pxs[i])
if len(px) >= 4:
binstr = i2b(reduce_color(px[0])) + i2b(reduce_color(px[1])) + i2b(reduce_color(px[2])) + i2b(reduce_color(px[3]))
t2bfile.write(int_to_byte(int(binstr, 2)))
px = []
else:
t2bfile.write(DEFAULT_T2B_DATA)
def compress(self, txt):
self._reset()
self.codes = list(set(re.findall(b'(?ms).', txt)))
# Replace the text with their corresponding code
# FIXME: python3 is native bytearray, but all we want are bytes
for c in bytearray(txt):
self.coded_txt += int_to_byte(self.codes.index(int_to_byte(c)))
# Zero the unused codes and record which are unused.
for i in range(len(self.codes), 256):
self.codes.append(b'')
self.unused_codes.add(i)
self._combine_codes()
possible_codes = self._new_codes()
while possible_codes and self.unused_codes:
while possible_codes and self.unused_codes:
unused_code = self.unused_codes.pop()
# Take the last possible codes and split it into individual
# codes. The last possible code is the most often occurring.
code = possible_codes.pop()
self.codes[unused_code] = b'%s%s' % (self.codes[ord(
code[0:1])], self.codes[ord(code[1:2])])
self.coded_txt = self.coded_txt.replace(
code, int_to_byte(unused_code))
self._combine_codes()
self._free_unused_codes()
possible_codes = self._new_codes()
self._free_unused_codes()
# Generate the code dictionary.
code_dict = []
for i in range(0, 256):
if i in self.unused_codes:
code_dict.append(b'\0')
else:
code_dict.append(
int_to_byte(len(self.codes[i])) + self.codes[i])
# Join the identifier with the dictionary and coded text.
return b'!!8-Bit!!' + b''.join(code_dict) + self.coded_txt
def _free_unused_codes(self):
'''
Look for codes that do no not appear in the coded text and add them to
the list of free codes.
'''
for i in range(256):
if i not in self.unused_codes:
if int_to_byte(i) not in self.coded_txt:
self.unused_codes.add(i)
def codepage(match):
try:
return int_to_byte(int(match.group(1), 16)).decode(codec)
except ValueError:
return '?'
def codepage(match):
try:
return int_to_byte(int(match.group(1), 16)).decode(codec)
except ValueError:
return '?'
