SickGear/lib/hachoir/parser/archive/lzx.py

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"""LZX data stream parser.
Also includes a decompression function (slow!!) which can decompress
LZX data stored in a Hachoir stream.
Author: Robert Xiao
Creation date: July 18, 2007
"""
from hachoir.parser import Parser
from hachoir.field import (FieldSet,
UInt32, Bit, Bits, PaddingBits,
RawBytes, ParserError)
from hachoir.core.endian import MIDDLE_ENDIAN, LITTLE_ENDIAN
from hachoir.core.tools import paddingSize
from hachoir.parser.archive.zlib import build_tree, HuffmanCode, extend_data
class LZXPreTreeEncodedTree(FieldSet):
def __init__(self, parent, name, num_elements, *args, **kwargs):
FieldSet.__init__(self, parent, name, *args, **kwargs)
self.num_elements = num_elements
def createFields(self):
for i in range(20):
yield Bits(self, "pretree_lengths[]", 4)
pre_tree = build_tree(
[self['pretree_lengths[%d]' % x].value for x in range(20)])
if not hasattr(self.root, "lzx_tree_lengths_" + self.name):
self.lengths = [0] * self.num_elements
setattr(self.root, "lzx_tree_lengths_" + self.name, self.lengths)
else:
self.lengths = getattr(self.root, "lzx_tree_lengths_" + self.name)
i = 0
while i < self.num_elements:
field = HuffmanCode(self, "tree_code[]", pre_tree)
if field.realvalue <= 16:
self.lengths[i] = (self.lengths[i] - field.realvalue) % 17
field._description = "Literal tree delta length %i (new length value %i for element %i)" % (
field.realvalue, self.lengths[i], i)
i += 1
yield field
elif field.realvalue == 17:
field._description = "Tree Code 17: Zeros for 4-19 elements"
yield field
extra = Bits(self, "extra[]", 4)
zeros = 4 + extra.value
extra._description = "Extra bits: zeros for %i elements (elements %i through %i)" % (
zeros, i, i + zeros - 1)
yield extra
self.lengths[i:i + zeros] = [0] * zeros
i += zeros
elif field.realvalue == 18:
field._description = "Tree Code 18: Zeros for 20-51 elements"
yield field
extra = Bits(self, "extra[]", 5)
zeros = 20 + extra.value
extra._description = "Extra bits: zeros for %i elements (elements %i through %i)" % (
zeros, i, i + zeros - 1)
yield extra
self.lengths[i:i + zeros] = [0] * zeros
i += zeros
elif field.realvalue == 19:
field._description = "Tree Code 19: Same code for 4-5 elements"
yield field
extra = Bits(self, "extra[]", 1)
run = 4 + extra.value
extra._description = "Extra bits: run for %i elements (elements %i through %i)" % (
run, i, i + run - 1)
yield extra
newfield = HuffmanCode(self, "tree_code[]", pre_tree)
assert newfield.realvalue <= 16
newfield._description = "Literal tree delta length %i (new length value %i for elements %i through %i)" % (
newfield.realvalue, self.lengths[i], i, i + run - 1)
self.lengths[
i:i + run] = [(self.lengths[i] - newfield.realvalue) % 17] * run
i += run
yield newfield
class LZXBlock(FieldSet):
WINDOW_SIZE = {15: 30,
16: 32,
17: 34,
18: 36,
19: 38,
20: 42,
21: 50}
POSITION_SLOTS = {0: (0, 0, 0),
1: (1, 1, 0),
2: (2, 2, 0),
3: (3, 3, 0),
4: (4, 5, 1),
5: (6, 7, 1),
6: (8, 11, 2),
7: (12, 15, 2),
8: (16, 23, 3),
9: (24, 31, 3),
10: (32, 47, 4),
11: (48, 63, 4),
12: (64, 95, 5),
13: (96, 127, 5),
14: (128, 191, 6),
15: (192, 255, 6),
16: (256, 383, 7),
17: (384, 511, 7),
18: (512, 767, 8),
19: (768, 1023, 8),
20: (1024, 1535, 9),
21: (1536, 2047, 9),
22: (2048, 3071, 10),
23: (3072, 4095, 10),
24: (4096, 6143, 11),
25: (6144, 8191, 11),
26: (8192, 12287, 12),
27: (12288, 16383, 12),
28: (16384, 24575, 13),
29: (24576, 32767, 13),
30: (32768, 49151, 14),
31: (49152, 65535, 14),
32: (65536, 98303, 15),
33: (98304, 131071, 15),
34: (131072, 196607, 16),
35: (196608, 262143, 16),
36: (262144, 393215, 17),
37: (393216, 524287, 17),
38: (524288, 655359, 17),
39: (655360, 786431, 17),
40: (786432, 917503, 17),
41: (917504, 1048575, 17),
42: (1048576, 1179647, 17),
43: (1179648, 1310719, 17),
44: (1310720, 1441791, 17),
45: (1441792, 1572863, 17),
46: (1572864, 1703935, 17),
47: (1703936, 1835007, 17),
48: (1835008, 1966079, 17),
49: (1966080, 2097151, 17),
}
def createFields(self):
yield Bits(self, "block_type", 3)
yield Bits(self, "block_size", 24)
self.uncompressed_size = self["block_size"].value
self.compression_level = self.root.compr_level
self.window_size = self.WINDOW_SIZE[self.compression_level]
self.block_type = self["block_type"].value
curlen = len(self.parent.uncompressed_data)
if self.block_type in (1, 2): # Verbatim or aligned offset block
if self.block_type == 2:
for i in range(8):
yield Bits(self, "aligned_len[]", 3)
aligned_tree = build_tree(
[self['aligned_len[%d]' % i].value for i in range(8)])
yield LZXPreTreeEncodedTree(self, "main_tree_start", 256)
yield LZXPreTreeEncodedTree(self, "main_tree_rest", self.window_size * 8)
main_tree = build_tree(
self["main_tree_start"].lengths + self["main_tree_rest"].lengths)
yield LZXPreTreeEncodedTree(self, "length_tree", 249)
length_tree = build_tree(self["length_tree"].lengths)
current_decoded_size = 0
while current_decoded_size < self.uncompressed_size:
if (curlen + current_decoded_size) % 32768 == 0 and (curlen + current_decoded_size) != 0:
padding = paddingSize(self.address + self.current_size, 16)
if padding:
yield PaddingBits(self, "padding[]", padding)
field = HuffmanCode(self, "main_code[]", main_tree)
if field.realvalue < 256:
field._description = "Literal value %r" % chr(
field.realvalue)
current_decoded_size += 1
self.parent.uncompressed_data += chr(field.realvalue)
yield field
continue
position_header, length_header = divmod(
field.realvalue - 256, 8)
info = self.POSITION_SLOTS[position_header]
if info[2] == 0:
if info[0] == 0:
position = self.parent.r0
field._description = "Position Slot %i, Position [R0] (%i)" % (
position_header, position)
elif info[0] == 1:
position = self.parent.r1
self.parent.r1 = self.parent.r0
self.parent.r0 = position
field._description = "Position Slot %i, Position [R1] (%i)" % (
position_header, position)
elif info[0] == 2:
position = self.parent.r2
self.parent.r2 = self.parent.r0
self.parent.r0 = position
field._description = "Position Slot %i, Position [R2] (%i)" % (
position_header, position)
else:
position = info[0] - 2
self.parent.r2 = self.parent.r1
self.parent.r1 = self.parent.r0
self.parent.r0 = position
field._description = "Position Slot %i, Position %i" % (
position_header, position)
else:
field._description = "Position Slot %i, Positions %i to %i" % (
position_header, info[0] - 2, info[1] - 2)
if length_header == 7:
field._description += ", Length Values 9 and up"
yield field
length_field = HuffmanCode(
self, "length_code[]", length_tree)
length = length_field.realvalue + 9
length_field._description = "Length Code %i, total length %i" % (
length_field.realvalue, length)
yield length_field
else:
field._description += ", Length Value %i (Huffman Code %i)" % (
length_header + 2, field.value)
yield field
length = length_header + 2
if info[2]:
if self.block_type == 1 or info[2] < 3: # verbatim
extrafield = Bits(
self, "position_extra[%s" % field.name.split('[')[1], info[2])
position = extrafield.value + info[0] - 2
extrafield._description = "Position Extra Bits (%i), total position %i" % (
extrafield.value, position)
yield extrafield
else: # aligned offset
position = info[0] - 2
if info[2] > 3:
extrafield = Bits(
self, "position_verbatim[%s" % field.name.split('[')[1], info[2] - 3)
position += extrafield.value * 8
extrafield._description = "Position Verbatim Bits (%i), added position %i" % (
extrafield.value, extrafield.value * 8)
yield extrafield
if info[2] >= 3:
extrafield = HuffmanCode(
self, "position_aligned[%s" % field.name.split('[')[1], aligned_tree)
position += extrafield.realvalue
extrafield._description = "Position Aligned Bits (%i), total position %i" % (
extrafield.realvalue, position)
yield extrafield
self.parent.r2 = self.parent.r1
self.parent.r1 = self.parent.r0
self.parent.r0 = position
self.parent.uncompressed_data = extend_data(
self.parent.uncompressed_data, length, position)
current_decoded_size += length
elif self.block_type == 3: # Uncompressed block
padding = paddingSize(self.address + self.current_size, 16)
if padding:
yield PaddingBits(self, "padding[]", padding)
else:
yield PaddingBits(self, "padding[]", 16)
self.endian = LITTLE_ENDIAN
yield UInt32(self, "r[]", "New value of R0")
yield UInt32(self, "r[]", "New value of R1")
yield UInt32(self, "r[]", "New value of R2")
self.parent.r0 = self["r[0]"].value
self.parent.r1 = self["r[1]"].value
self.parent.r2 = self["r[2]"].value
yield RawBytes(self, "data", self.uncompressed_size)
self.parent.uncompressed_data += self["data"].value
if self["block_size"].value % 2:
yield PaddingBits(self, "padding", 8)
else:
raise ParserError("Unknown block type %d!" % self.block_type)
class LZXStream(Parser):
endian = MIDDLE_ENDIAN
def createFields(self):
self.uncompressed_data = ""
self.r0 = 1
self.r1 = 1
self.r2 = 1
yield Bit(self, "filesize_indicator")
if self["filesize_indicator"].value:
yield UInt32(self, "filesize")
while self.current_size < self.size:
block = LZXBlock(self, "block[]")
yield block
if self.size - self.current_size < 16:
padding = paddingSize(self.address + self.current_size, 16)
if padding:
yield PaddingBits(self, "padding[]", padding)
break
def lzx_decompress(stream, window_bits):
data = LZXStream(stream)
data.compr_level = window_bits
for unused in data:
pass
return data.uncompressed_data