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#!/usr/bin/python
import sys
def read(f, n):
r = []
for i in range(0, n):
r.append(ord(f.read(1)))
return r
def read_8(f):
r = read(f, 1)
return r[0]
def read_16(f):
r = read(f, 2)
return r[0] << 8 | r[1]
def read_32(f):
r = read(f, 4)
return r[0] << 24 | r[1] << 16 | r[2] << 8 | r[3];
def require(f, data, what):
r = read(f, len(data))
if r != data:
print r
raise Exception()
print what
f = open(sys.argv[1], 'rb')
require(f, [0xff, 0x4f], 'SOC')
require(f, [0xff, 0x51], 'SIZ')
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
require(f, [0xff, 0x52], 'COD')
size = read_16(f)
print '\tlength', size
coding_style = read_8(f)
print '\tcoding style %2x' % coding_style
print '\tprogression order',
po = read_8(f)
if po == 0:
print 'LRCP'
elif po == 1:
print 'RLCP'
elif po == 2:
print 'RPCL'
elif po == 3:
print 'PCRL'
elif po == 4:
print 'CPRL'
print '\tlayers', read_16(f)
print '\tmulti-component transform', read_8(f)
levels = read_8(f)
print '\ttransform levels', levels
print '\tcode-block sizes %dx%d' % (read_8(f), read_8(f))
print '\tmode switches %2x' % read_8(f)
print '\twavelet transform',
wt = read_8(f)
if wt == 0:
print '9/7 irreversible'
else:
print '5/3 reversible'
if coding_style & 1:
print '\tprecinct sizes ',
for i in range(0, levels + 1):
print read_8(f),
print
require(f, [0xff, 0x5C], 'QCD')
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
tile_part_length = None
while True:
r = read(f, 2)
if r == [0xff, 0x53]:
print 'COC'
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
elif r == [0xff, 0x5c]:
print 'QCD'
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
elif r == [0xff, 0x5d]:
print 'QCC'
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
elif r == [0xff, 0x64]:
print 'COM'
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
elif r == [0xff, 0x55]:
print 'TLM'
size = read_16(f)
print '\tlength', size
f.seek(size - 2, 1)
elif r == [0xff, 0x90]:
print 'SOT'
size = read_16(f)
print '\tlength', size
print '\ttile index', read_16(f)
tile_part_length = read_32(f)
print '\ttile-part length', tile_part_length
print '\ttile-part index', read_8(f)
print '\tnumber of tile-parts', read_8(f)
elif r == [0xff, 0x93]:
print 'SOD'
f.seek(tile_part_length - 14, 1)
elif r == [0xff, 0xd9]:
print 'EOC'
sys.exit(0)
else:
print r
raise Exception()
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