mirror of
https://github.com/SickGear/SickGear.git
synced 2024-11-16 09:55:05 +00:00
362 lines
13 KiB
Python
362 lines
13 KiB
Python
"""
|
|
GIF picture parser.
|
|
|
|
Author: Victor Stinner, Robert Xiao
|
|
|
|
- GIF format
|
|
http://local.wasp.uwa.edu.au/~pbourke/dataformats/gif/
|
|
- LZW compression
|
|
http://en.wikipedia.org/wiki/LZW
|
|
"""
|
|
|
|
from hachoir.parser import Parser
|
|
from hachoir.field import (FieldSet, ParserError,
|
|
Enum, UInt8, UInt16,
|
|
Bit, Bits, NullBytes,
|
|
String, PascalString8, Character,
|
|
NullBits, RawBytes,
|
|
CustomFragment)
|
|
from hachoir.parser.image.common import PaletteRGB
|
|
from hachoir.core.endian import LITTLE_ENDIAN
|
|
from hachoir.core.tools import humanDuration, paddingSize
|
|
from hachoir.core.text_handler import textHandler, displayHandler, hexadecimal
|
|
|
|
# Maximum image dimension (in pixel)
|
|
MAX_WIDTH = 6000
|
|
MAX_HEIGHT = MAX_WIDTH
|
|
MAX_FILE_SIZE = 100 * 1024 * 1024
|
|
|
|
|
|
def rle_repr(chain):
|
|
"""Run-length encode a list into an "eval"-able form
|
|
|
|
Example:
|
|
>>> rle_repr([20, 16, 16, 16, 16, 16, 18, 18, 65])
|
|
'[20] + [16]*5 + [18]*2 + [65]'
|
|
|
|
Adapted from http://twistedmatrix.com/trac/browser/trunk/twisted/python/dxprofile.py
|
|
"""
|
|
def add_rle(previous, runlen, result):
|
|
if isinstance(previous, (list, tuple)):
|
|
previous = rle_repr(previous)
|
|
if runlen > 1:
|
|
result.append('[%s]*%i' % (previous, runlen))
|
|
else:
|
|
if result and '*' not in result[-1]:
|
|
result[-1] = '[%s, %s]' % (result[-1][1:-1], previous)
|
|
else:
|
|
result.append('[%s]' % previous)
|
|
iterable = iter(chain)
|
|
runlen = 1
|
|
result = []
|
|
try:
|
|
previous = next(iterable)
|
|
except StopIteration:
|
|
return "[]"
|
|
for element in iterable:
|
|
if element == previous:
|
|
runlen = runlen + 1
|
|
continue
|
|
else:
|
|
add_rle(previous, runlen, result)
|
|
previous = element
|
|
runlen = 1
|
|
add_rle(previous, runlen, result)
|
|
return ' + '.join(result)
|
|
|
|
|
|
class GifImageBlock(Parser):
|
|
endian = LITTLE_ENDIAN
|
|
|
|
def createFields(self):
|
|
dictionary = {}
|
|
self.nbits = self.startbits
|
|
CLEAR_CODE = 2**self.nbits
|
|
END_CODE = CLEAR_CODE + 1
|
|
compress_code = CLEAR_CODE + 2
|
|
obuf = []
|
|
output = []
|
|
while True:
|
|
if compress_code >= 2**self.nbits:
|
|
self.nbits += 1
|
|
code = Bits(self, "code[]", self.nbits)
|
|
if code.value == CLEAR_CODE:
|
|
if compress_code == 2**(self.nbits - 1):
|
|
# this fixes a bizarre edge case where the reset code could
|
|
# appear just after the bits incremented. Apparently, the
|
|
# correct behaviour is to express the reset code with the
|
|
# old number of bits, not the new...
|
|
code = Bits(self, "code[]", self.nbits - 1)
|
|
self.nbits = self.startbits + 1
|
|
dictionary = {}
|
|
compress_code = CLEAR_CODE + 2
|
|
obuf = []
|
|
code._description = "Reset Code (LZW code %i)" % code.value
|
|
yield code
|
|
continue
|
|
elif code.value == END_CODE:
|
|
code._description = "End of Information Code (LZW code %i)" % code.value
|
|
yield code
|
|
break
|
|
if code.value < CLEAR_CODE: # literal
|
|
if obuf:
|
|
chain = obuf + [code.value]
|
|
dictionary[compress_code] = chain
|
|
compress_code += 1
|
|
obuf = [code.value]
|
|
output.append(code.value)
|
|
code._description = "Literal Code %i" % code.value
|
|
elif code.value >= CLEAR_CODE + 2:
|
|
if code.value in dictionary:
|
|
chain = dictionary[code.value]
|
|
code._description = "Compression Code %i (found in dictionary as %s)" % (
|
|
code.value, rle_repr(chain))
|
|
else:
|
|
chain = obuf + [obuf[0]]
|
|
code._description = "Compression Code %i (not found in dictionary; guessed to be %s)" % (
|
|
code.value, rle_repr(chain))
|
|
dictionary[compress_code] = obuf + [chain[0]]
|
|
compress_code += 1
|
|
obuf = chain
|
|
output += chain
|
|
code._description += "; Current Decoded Length %i" % len(output)
|
|
yield code
|
|
padding = paddingSize(self.current_size, 8)
|
|
if padding:
|
|
yield NullBits(self, "padding[]", padding)
|
|
|
|
|
|
class Image(FieldSet):
|
|
|
|
def createFields(self):
|
|
yield UInt16(self, "left", "Left")
|
|
yield UInt16(self, "top", "Top")
|
|
yield UInt16(self, "width", "Width")
|
|
yield UInt16(self, "height", "Height")
|
|
|
|
yield Bits(self, "size_local_map", 3, "log2(size of local map) minus one")
|
|
yield NullBits(self, "reserved", 2)
|
|
yield Bit(self, "sort_flag", "Is the local map sorted by decreasing importance?")
|
|
yield Bit(self, "interlaced", "Interlaced?")
|
|
yield Bit(self, "has_local_map", "Use local color map?")
|
|
|
|
if self["has_local_map"].value:
|
|
nb_color = 1 << (1 + self["size_local_map"].value)
|
|
yield PaletteRGB(self, "local_map", nb_color, "Local color map")
|
|
|
|
yield UInt8(self, "lzw_min_code_size", "LZW Minimum Code Size")
|
|
group = None
|
|
while True:
|
|
size = UInt8(self, "image_block_size[]")
|
|
if size.value == 0:
|
|
break
|
|
yield size
|
|
block = CustomFragment(
|
|
self, "image_block[]", size.value * 8, GifImageBlock, "GIF Image Block", group)
|
|
if group is None:
|
|
block.group.args["startbits"] = self["lzw_min_code_size"].value
|
|
group = block.group
|
|
yield block
|
|
yield NullBytes(self, "terminator", 1, "Terminator (0)")
|
|
|
|
def createDescription(self):
|
|
return "Image: %ux%u pixels at (%u,%u)" % (
|
|
self["width"].value, self["height"].value,
|
|
self["left"].value, self["top"].value)
|
|
|
|
|
|
DISPOSAL_METHOD = {
|
|
0: "No disposal specified",
|
|
1: "Do not dispose",
|
|
2: "Restore to background color",
|
|
3: "Restore to previous",
|
|
}
|
|
|
|
NETSCAPE_CODE = {
|
|
1: "Loop count",
|
|
}
|
|
|
|
|
|
def parseApplicationExtension(parent):
|
|
yield PascalString8(parent, "app_name", "Application name")
|
|
while True:
|
|
size = UInt8(parent, "size[]")
|
|
if size.value == 0:
|
|
break
|
|
yield size
|
|
if parent["app_name"].value == "NETSCAPE2.0" and size.value == 3:
|
|
yield Enum(UInt8(parent, "netscape_code"), NETSCAPE_CODE)
|
|
if parent["netscape_code"].value == 1:
|
|
yield UInt16(parent, "loop_count")
|
|
else:
|
|
yield RawBytes(parent, "raw[]", 2)
|
|
else:
|
|
yield RawBytes(parent, "raw[]", size.value)
|
|
yield NullBytes(parent, "terminator", 1, "Terminator (0)")
|
|
|
|
|
|
def parseGraphicControl(parent):
|
|
yield UInt8(parent, "size", "Block size (4)")
|
|
|
|
yield Bit(parent, "has_transp", "Has transparency")
|
|
yield Bit(parent, "user_input", "User input")
|
|
yield Enum(Bits(parent, "disposal_method", 3), DISPOSAL_METHOD)
|
|
yield NullBits(parent, "reserved[]", 3)
|
|
|
|
if parent["size"].value != 4:
|
|
raise ParserError("Invalid graphic control size")
|
|
yield displayHandler(UInt16(parent, "delay", "Delay time in millisecond"), humanDuration)
|
|
yield UInt8(parent, "transp", "Transparent color index")
|
|
yield NullBytes(parent, "terminator", 1, "Terminator (0)")
|
|
|
|
|
|
def parseComments(parent):
|
|
while True:
|
|
field = PascalString8(parent, "comment[]", strip=" \0\r\n\t")
|
|
yield field
|
|
if field.length == 0:
|
|
break
|
|
|
|
|
|
def parseTextExtension(parent):
|
|
yield UInt8(parent, "block_size", "Block Size")
|
|
yield UInt16(parent, "left", "Text Grid Left")
|
|
yield UInt16(parent, "top", "Text Grid Top")
|
|
yield UInt16(parent, "width", "Text Grid Width")
|
|
yield UInt16(parent, "height", "Text Grid Height")
|
|
yield UInt8(parent, "cell_width", "Character Cell Width")
|
|
yield UInt8(parent, "cell_height", "Character Cell Height")
|
|
yield UInt8(parent, "fg_color", "Foreground Color Index")
|
|
yield UInt8(parent, "bg_color", "Background Color Index")
|
|
while True:
|
|
field = PascalString8(parent, "comment[]", strip=" \0\r\n\t")
|
|
yield field
|
|
if field.length == 0:
|
|
break
|
|
|
|
|
|
def defaultExtensionParser(parent):
|
|
while True:
|
|
size = UInt8(parent, "size[]", "Size (in bytes)")
|
|
yield size
|
|
if 0 < size.value:
|
|
yield RawBytes(parent, "content[]", size.value)
|
|
else:
|
|
break
|
|
|
|
|
|
class Extension(FieldSet):
|
|
ext_code = {
|
|
0xf9: ("graphic_ctl[]", parseGraphicControl, "Graphic control"),
|
|
0xfe: ("comments[]", parseComments, "Comments"),
|
|
0xff: ("app_ext[]", parseApplicationExtension, "Application extension"),
|
|
0x01: ("text_ext[]", parseTextExtension, "Plain text extension")
|
|
}
|
|
|
|
def __init__(self, *args):
|
|
FieldSet.__init__(self, *args)
|
|
code = self["code"].value
|
|
if code in self.ext_code:
|
|
self._name, self.parser, self._description = self.ext_code[code]
|
|
else:
|
|
self.parser = defaultExtensionParser
|
|
|
|
def createFields(self):
|
|
yield textHandler(UInt8(self, "code", "Extension code"), hexadecimal)
|
|
yield from self.parser(self)
|
|
|
|
def createDescription(self):
|
|
return "Extension: function %s" % self["func"].display
|
|
|
|
|
|
class ScreenDescriptor(FieldSet):
|
|
|
|
def createFields(self):
|
|
yield UInt16(self, "width", "Width")
|
|
yield UInt16(self, "height", "Height")
|
|
yield Bits(self, "size_global_map", 3, "log2(size of global map) minus one")
|
|
yield Bit(self, "sort_flag", "Is the global map sorted by decreasing importance?")
|
|
yield Bits(self, "color_res", 3, "Color resolution minus one")
|
|
yield Bit(self, "global_map", "Has global map?")
|
|
yield UInt8(self, "background", "Background color")
|
|
field = UInt8(self, "pixel_aspect_ratio")
|
|
if field.value:
|
|
field._description = "Pixel aspect ratio: %f (stored as %i)" % (
|
|
(field.value + 15) / 64., field.value)
|
|
else:
|
|
field._description = "Pixel aspect ratio: not specified"
|
|
yield field
|
|
|
|
def createDescription(self):
|
|
colors = 1 << (self["size_global_map"].value + 1)
|
|
return "Screen descriptor: %ux%u pixels %u colors" \
|
|
% (self["width"].value, self["height"].value, colors)
|
|
|
|
|
|
class GifFile(Parser):
|
|
endian = LITTLE_ENDIAN
|
|
separator_name = {
|
|
"!": "Extension",
|
|
",": "Image",
|
|
";": "Terminator"
|
|
}
|
|
PARSER_TAGS = {
|
|
"id": "gif",
|
|
"category": "image",
|
|
"file_ext": ("gif",),
|
|
"mime": ("image/gif",),
|
|
# signature + screen + separator + image
|
|
"min_size": (6 + 7 + 1 + 9) * 8,
|
|
"magic": ((b"GIF87a", 0), (b"GIF89a", 0)),
|
|
"description": "GIF picture"
|
|
}
|
|
|
|
def validate(self):
|
|
if self.stream.readBytes(0, 6) not in (b"GIF87a", b"GIF89a"):
|
|
return "Wrong header"
|
|
if self["screen/width"].value == 0 or self["screen/height"].value == 0:
|
|
return "Invalid image size"
|
|
if MAX_WIDTH < self["screen/width"].value:
|
|
return "Image width too big (%u)" % self["screen/width"].value
|
|
if MAX_HEIGHT < self["screen/height"].value:
|
|
return "Image height too big (%u)" % self["screen/height"].value
|
|
return True
|
|
|
|
def createFields(self):
|
|
# Header
|
|
yield String(self, "magic", 3, "File magic code", charset="ASCII")
|
|
yield String(self, "version", 3, "GIF version", charset="ASCII")
|
|
|
|
yield ScreenDescriptor(self, "screen")
|
|
if self["screen/global_map"].value:
|
|
bpp = (self["screen/size_global_map"].value + 1)
|
|
yield PaletteRGB(self, "color_map", 1 << bpp, "Color map")
|
|
self.color_map = self["color_map"]
|
|
else:
|
|
self.color_map = None
|
|
|
|
self.images = []
|
|
while True:
|
|
code = Enum(Character(self, "separator[]",
|
|
"Separator code"), self.separator_name)
|
|
yield code
|
|
code = code.value
|
|
if code == "!":
|
|
yield Extension(self, "extensions[]")
|
|
elif code == ",":
|
|
yield Image(self, "image[]")
|
|
elif code == ";":
|
|
# GIF Terminator
|
|
break
|
|
else:
|
|
raise ParserError(
|
|
"Wrong GIF image separator: 0x%02X" % ord(code))
|
|
|
|
def createContentSize(self):
|
|
field = self["image[0]"]
|
|
start = field.absolute_address + field.size
|
|
end = start + MAX_FILE_SIZE * 8
|
|
pos = self.stream.searchBytes(b"\0;", start, end)
|
|
if pos:
|
|
return pos + 16
|
|
return None
|