Mercurial > touhou

comparison pytouhou/utils/bitstream.pyx @ 490:1b532e7dd521

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Decrease PBG3 loading time by improving lzss and bitstream integration.
author Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
date Fri, 04 Oct 2013 14:28:49 +0200
parents feecdb4a8928
children 3c2f96f1d715
comparison
equal deleted inserted replaced
489:59bd29568753 490:1b532e7dd521
11 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 ## GNU General Public License for more details. 12 ## GNU General Public License for more details.
13 ## 13 ##
14 14
15 cdef class BitStream: 15 cdef class BitStream:
16 cdef public object io
17 cdef unsigned int bits
18 cdef unsigned char byte
19 cdef bytes bytes
20
21
22 def __init__(self, io): 16 def __init__(self, io):
23 self.io = io 17 self.io = io
24 self.bits = 0 18 self.bits = 0
25 self.byte = 0 19 self.byte = 0
26 20
37 self.io.seek(offset, whence) 31 self.io.seek(offset, whence)
38 self.byte = 0 32 self.byte = 0
39 self.bits = 0 33 self.bits = 0
40 34
41 35
42 def tell(self): 36 cdef bint read_bit(self):
43 return self.io.tell() 37 cdef bytes byte
44
45
46 def tell2(self):
47 return self.io.tell(), self.bits
48
49
50 cpdef unsigned char read_bit(self) except? -1:
51 if not self.bits: 38 if not self.bits:
52 self.bytes = self.io.read(1) 39 byte = self.io.read(1)
53 self.byte = (<unsigned char*> self.bytes)[0] 40 self.byte = (<unsigned char*>byte)[0]
54 self.bits = 8 41 self.bits = 8
55 self.bits -= 1 42 self.bits -= 1
56 return (self.byte >> self.bits) & 0x01 43 return (self.byte >> self.bits) & 0x01
57 44
58 45
59 cpdef unsigned int read(self, unsigned int nb_bits) except? -1: 46 cpdef unsigned int read(self, unsigned int nb_bits):
60 cdef unsigned int value = 0, read = 0 47 cdef unsigned int value = 0, read = 0
61 cdef unsigned int nb_bits2 = nb_bits 48 cdef unsigned int nb_bits2 = nb_bits
49 cdef bytes byte
62 50
63 while nb_bits2: 51 while nb_bits2:
64 if not self.bits: 52 if not self.bits:
65 self.bytes = self.io.read(1) 53 byte = self.io.read(1)
66 self.byte = (<unsigned char*> self.bytes)[0] 54 self.byte = (<unsigned char*>byte)[0]
67 self.bits = 8 55 self.bits = 8
68 read = self.bits if nb_bits2 > self.bits else nb_bits2 56 read = self.bits if nb_bits2 > self.bits else nb_bits2
69 nb_bits2 -= read 57 nb_bits2 -= read
70 self.bits -= read 58 self.bits -= read
71 value |= (self.byte >> self.bits) << nb_bits2 59 value |= (self.byte >> self.bits) << nb_bits2
72 return value & ((1 << nb_bits) - 1) 60 return value & ((1 << nb_bits) - 1)
73 61
74 62
75 cpdef write_bit(self, bit): 63 cpdef write_bit(self, bint bit):
76 if self.bits == 8: 64 if self.bits == 8:
77 self.io.write(chr(self.byte)) 65 self.io.write(chr(self.byte))
78 self.bits = 0 66 self.bits = 0
79 self.byte = 0 67 self.byte = 0
80 self.byte &= ~(1 << (7 - self.bits)) 68 self.byte &= ~(1 << (7 - self.bits))
81 self.byte |= bit << (7 - self.bits) 69 self.byte |= bit << (7 - self.bits)
82 self.bits += 1 70 self.bits += 1
83 71
84 72
85 def write(self, bits, nb_bits): 73 cpdef write(self, unsigned int bits, unsigned int nb_bits):
86 for i in range(nb_bits): 74 for i in range(nb_bits):
87 self.write_bit(bits >> (nb_bits - 1 - i) & 0x01) 75 self.write_bit(bits >> (nb_bits - 1 - i) & 0x01)
88 76
89 77
90 def flush(self): 78 cpdef flush(self):
91 self.io.write(chr(self.byte)) 79 self.io.write(chr(self.byte))
92 self.bits = 0 80 self.bits = 0
93 self.byte = 0 81 self.byte = 0
94 self.io.flush() 82 self.io.flush()
95 83