class Color(bin.Structure):
red = bin.Integer(size=1)
green = bin.Integer(size=1)
blue = bin.Integer(size=1)
def __str__(self):
return '#%x%x%x' % (self.red, self.green, self.blue)
class InternationalText(bin.Structure, encoding='utf8'):
keyword = bin.String()
is_compressed = bin.Integer(size=1)
compression = bin.Integer(size=1, choices=COMPRESSION_CHOICES)
language = bin.String()
translated_keyword = bin.String()
content = bin.Bytes(size=bin.Remainder) # TODO: decompress
class BMP(bin.Structure, endianness=bin.LittleEndian):
signature = bin.FixedString('BM')
filesize = bin.Integer('Total file size', size=4)
reserved = bin.Reserved(size=4)
data_offset = bin.Integer('Offset of the actual image data', size=4)
header_size = bin.Integer(size=4, default_value=40)
width = bin.Integer(size=4)
height = bin.Integer(size=4)
class ImageDescriptor(bin.Structure):
separator = bin.FixedString(b',')
left = bin.Integer(size=2)
top = bin.Integer(size=2)
width = bin.Integer(size=2)
height = bin.Integer(size=2)
info = bin.SubStructure(ImageInfoBits)
with info.has_color_map == True:
color_map = bin.List(bin.SubStructure(Color),
size=2**info.bits_per_pixel)
class TGA(bin.Structure, endianness=bin.LittleEndian):
id_size = bin.Integer(size=1)
color_map_type = bin.Integer(size=1, choices=COLOR_MAP_TYPES)
image_type = bin.Integer(size=1, choices=IMAGE_TYPES)
color_map_info = bin.SubStructure(ColorMap)
x_origin = bin.Integer(size=2)
y_origin = bin.Integer(size=2)
width = bin.Integer(size=2)
height = bin.Integer(size=2)
bit_depth = bin.Integer(size=1)
image_origin, alpha_depth = bin.SubStructure(AlphaOrigin)
image_id = bin.Bytes(size=id_size)
color_map_data = bin.List(bin.Integer(size=color_map_info.entry_size) / 8,
size=color_map_info.length)
image_data = bin.List(bin.Integer(size=1), size=width * height * bit_depth)
class ScreenDescriptor(bin.Structure, endianness=bin.LittleEndian):
width = bin.Integer(size=2)
height = bin.Integer(size=2)
info = bin.SubStructure(ScreenInfoBits)
background_color = bin.Integer(size=1)
pixel_ratio = bin.Integer(size=1)
with info.has_color_map == True:
color_map = bin.List(bin.SubStructure(Color),
size=2**info.bits_per_pixel)
@property
def aspect_ratio(self):
if self.pixel_ratio == 0:
return None
return (self.pixel_ratio + 15) / 64
class Header(bin.Structure):
width = bin.Integer(size=4)
height = bin.Integer(size=4)
bit_depth = bin.Integer(size=1, choices=(1, 2, 4, 8, 16))
color_type = bin.Integer(size=1, choices=(0, 2, 3, 4, 6))
compression_method = bin.Integer(size=1, choices=COMPRESSION_CHOICES)
filter_method = bin.Integer(size=1, choices=FILTER_CHOICES)
interlace_method = bin.Integer(size=1, choices=INTERLACE_CHOICES)
class Timestamp(bin.Structure):
year = bin.Integer(size=2)
month = bin.Integer(size=1)
day = bin.Integer(size=1)
hour = bin.Integer(size=1)
minute = bin.Integer(size=1)
second = bin.Integer(size=1)
def read(self, size=None):
bit_buffer = self._bit_buffer
if size > self._bits_left:
# Read more bytes from the file
read_size = int(((size - self._bits_left) + 7) / 8)
field = bin.Integer(size=read_size)
bytes = self._file.read(read_size)
value = field.decode(bytes)
bit_buffer = (bit_buffer << size) | value
self._bits_left += read_size * 8
self._bits_left -= size % 8
bits = bit_buffer >> self._bits_left
self._bit_buffer = bit_buffer & (1 << self._bits_left) - 1
return bits
class Header(bin.Structure):
marker = bin.FixedString(b'JFIF\x00')
major_version = bin.Integer(size=1)
minor_version = bin.Integer(size=1)
density_units = bin.Integer(size=1, choicse=DENSITY_UNITS)
x_density = bin.Integer(size=2)
y_density = bin.Integer(size=2)
thumb_width = bin.Integer(size=1)
thumb_height = bin.Integer(size=1)
thumb_data = bin.Bytes(size=3 * thumb_width * thumb_height)
@property
def version(self):
return '%i.%02i' % (self.major_version, self.minor_version)
class Chunk(bin.Chunk, encoding='ascii'):
"""
A special chunk for PNG, which puts the size before the type
and includes a CRC field for verifying data integrity.
"""
size = bin.Integer(size=4)
id = bin.String(size=4)
payload = bin.Payload(size=size)
crc = bin.CRC32(first=id)
@property
def is_critical(self):
# Critical chunks will always have an uppercase letter for the
# first character in the type. Ancillary will always be lower.
return self.type[0].upper() == self.type[0]
@property
def is_public(self):
# Public chunks will always have an uppercase letter for the
# second character in the type. Private will always be lower.
return self.type[1].upper() == self.type[1]
class ScanChunk(bin.Chunk):
id = bin.Integer(size=2)
size = bin.Integer(size=2)
payload = bin.Payload(size=size - 2)
class EmptyChunk(bin.Chunk):
id = bin.Integer(size=2)
size = bin.Bytes(size=0)
payload = bin.Payload(size=0)
class TestStructure(bin.Structure):
integer = bin.Integer('number', size=1)
string = bin.String(encoding='ascii')
class SuggestedPaletteEntry(bin.Structure):
red = bin.Integer(size=2)
green = bin.Integer(size=2)
blue = bin.Integer(size=2)
alpha = bin.Integer(size=2)
frequency = bin.Integer(size=2)
class FineTune(bin.PackedStructure):
Reserved(size=4)
value = bin.Integer(size=4)
class PNG(bin.Structure):
signature = bin.FixedString(b'\x89PNG\x0d\x0a\x1a\x0a')
header_size = bin.Integer(size=4)
header_id = bin.FixedString(b'IHDR')
width = bin.Integer(size=4, min_value=1)
height = bin.Integer(size=4, min_value=1)
class Form(bin.Chunk, encoding='ascii'):
tag = bin.FixedString('FORM')
size = bin.Integer(size=4)
id = bin.String(size=4)
payload = bin.Payload(size=size)
class Histogram(bin.Structure):
frequencies = bin.List(bin.Integer(size=2), size=bin.Remainder)
class CompressedText(bin.Structure, encoding='latin-1'):
keyword = bin.String()
compression = bin.Integer(size=1, choices=COMPRESSION_CHOICES)
content = bin.Bytes(size=bin.Remainder) # TODO: decompress
class SuggestedPalette(bin.Structure):
name = bin.String(encoding='latin-1')
sample_depth = bin.Integer(size=1)
colors = bin.List(bin.SubStructure(SuggestedPaletteEntry), size=bin.Remainder)
class StartFrame(bin.Structure):
precision = bin.Integer(size=1)
width = bin.Integer(size=2)
height = bin.Integer(size=2)
class sRGB(bin.Structure):
rendering_intent = bin.Integer(size=1, choices=RENDERING_INTENT_CHOICES)
class PaletteColor(bin.Structure):
red = bin.Integer(size=1)
green = bin.Integer(size=1)
blue = bin.Integer(size=1)
class GIF(bin.Structure, endianness=bin.LittleEndian, encoding='ascii'):
tag = bin.FixedString('GIF')
version = bin.String(size=3, choices=GIF_VERSIONS)
width = bin.Integer(size=2)
height = bin.Integer(size=2)
class TestStructure(bin.Structure):
length = bin.Integer('number', size=1)
content = bin.String(encoding='ascii', size=length)
class TestStructure(bin.Structure):
forty_two = bin.Integer(size=2, endianness=bin.LittleEndian)
sixty_six = bin.Integer(size=1)
valid = bin.String(encoding='ascii')
test = bin.String(encoding='ascii')
class PhysicalDimentions(bin.Structure):
x = bin.Integer(size=4)
y = bin.Integer(size=4)
unit = bin.Integer(size=1, choices=PHYSICAL_UNIT_CHOICES)
class Chunk(bin.Chunk):
id = bin.String(size=4, encoding='ascii')
size = bin.Integer(size=4)
payload = bin.Payload(size=size)
class ICCProfile(bin.Structure):
name = bin.String(encoding='latin-1')
compression = bin.Integer(size=1, choices=COMPRESSION_CHOICES)
profile = bin.Bytes(size=bin.Remainder) # TODO: decompress
