%PDF-
%PDF-
Mini Shell
Mini Shell
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2011, Anthon van der Neut <A.van.der.Neut@ruamel.eu>'
# this code is based on:
# Lizardtech DjVu Reference
# DjVu v3
# November 2005
import sys
import struct
from calibre.ebooks.djvu.djvubzzdec import BZZDecoder
class DjvuChunk:
def __init__(self, buf, start, end, align=True, bigendian=True,
inclheader=False, verbose=0):
from calibre_extensions import bzzdec
self.speedup = bzzdec
self.subtype = None
self._subchunks = []
self.buf = buf
pos = start + 4
self.type = buf[start:pos]
self.align = align # whether to align to word (2-byte) boundaries
self.headersize = 0 if inclheader else 8
if bigendian:
self.strflag = b'>'
else:
self.strflag = b'<'
oldpos, pos = pos, pos+4
self.size = struct.unpack(self.strflag+b'L', buf[oldpos:pos])[0]
self.dataend = pos + self.size - (8 if inclheader else 0)
if self.type == b'FORM':
oldpos, pos = pos, pos+4
# print oldpos, pos
self.subtype = buf[oldpos:pos]
# self.headersize += 4
self.datastart = pos
if verbose > 0:
print('found', self.type, self.subtype, pos, self.size)
if self.type in b'FORM'.split():
if verbose > 0:
print('processing substuff %d %d (%x)' % (pos, self.dataend,
self.dataend))
numchunks = 0
while pos < self.dataend:
x = DjvuChunk(buf, pos, start+self.size, verbose=verbose)
numchunks += 1
self._subchunks.append(x)
newpos = pos + x.size + x.headersize + (1 if (x.size % 2) else 0)
if verbose > 0:
print('newpos %d %d (%x, %x) %d' % (newpos, self.dataend,
newpos, self.dataend, x.headersize))
pos = newpos
if verbose > 0:
print(' end of chunk %d (%x)' % (pos, pos))
def dump(self, verbose=0, indent=1, out=None, txtout=None, maxlevel=100):
if out:
out.write(b' ' * indent)
out.write(b'%s%s [%d]\n' % (self.type,
b':' + self.subtype if self.subtype else b'', self.size))
if txtout and self.type == b'TXTz':
if True:
# Use the C BZZ decode implementation
txtout.write(self.speedup.decompress(self.buf[self.datastart:self.dataend]))
else:
inbuf = bytearray(self.buf[self.datastart: self.dataend])
outbuf = bytearray()
decoder = BZZDecoder(inbuf, outbuf)
while True:
xxres = decoder.convert(1024 * 1024)
if not xxres:
break
res = bytes(outbuf)
if not res.strip(b'\0'):
raise ValueError('TXTz block is completely null')
l = 0
for x in bytearray(res[:3]):
l <<= 8
l += x
if verbose > 0 and out:
print(l, file=out)
txtout.write(res[3:3+l])
txtout.write(b'\037')
if txtout and self.type == b'TXTa':
res = self.buf[self.datastart: self.dataend]
l = 0
for x in bytearray(res[:3]):
l <<= 8
l += x
if verbose > 0 and out:
print(l, file=out)
txtout.write(res[3:3+l])
txtout.write(b'\037')
if indent >= maxlevel:
return
for schunk in self._subchunks:
schunk.dump(verbose=verbose, indent=indent+1, out=out, txtout=txtout)
class DJVUFile:
def __init__(self, instream, verbose=0):
self.instream = instream
buf = self.instream.read(4)
assert(buf == b'AT&T')
buf = self.instream.read()
self.dc = DjvuChunk(buf, 0, len(buf), verbose=verbose)
def get_text(self, outfile=None):
self.dc.dump(txtout=outfile)
def dump(self, outfile=None, maxlevel=0):
self.dc.dump(out=outfile, maxlevel=maxlevel)
def main():
f = DJVUFile(open(sys.argv[-1], 'rb'))
print(f.get_text(sys.stdout))
if __name__ == '__main__':
main()
Zerion Mini Shell 1.0