mirror of
https://github.com/SickGear/SickGear.git
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294 lines
9.1 KiB
Python
294 lines
9.1 KiB
Python
"""
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PNG picture file parser.
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Documents:
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- RFC 2083
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http://www.faqs.org/rfcs/rfc2083.html
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Author: Victor Stinner
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"""
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from hachoir.parser import Parser
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from hachoir.field import (FieldSet, Fragment,
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ParserError, MissingField,
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UInt8, UInt16, UInt32,
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String, CString,
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Bytes, RawBytes,
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Bit, NullBits,
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Enum, CompressedField)
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from hachoir.parser.image.common import RGB
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from hachoir.core.text_handler import textHandler, hexadecimal
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from hachoir.core.endian import NETWORK_ENDIAN
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from hachoir.core.tools import humanFilesize
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from datetime import datetime
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MAX_FILESIZE = 500 * 1024 * 1024 # 500 MB
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try:
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from zlib import decompressobj
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class Gunzip:
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def __init__(self, stream):
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self.gzip = decompressobj()
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def __call__(self, size, data=None):
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if data is None:
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data = self.gzip.unconsumed_tail
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return self.gzip.decompress(data, size)
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has_deflate = True
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except ImportError:
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has_deflate = False
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UNIT_NAME = {1: "Meter"}
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COMPRESSION_NAME = {
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0: "deflate" # with 32K sliding window
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}
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MAX_CHUNK_SIZE = 64 * 1024 * 1024 # Maximum chunk size heuristic (64 MB)
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def headerParse(parent):
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yield UInt32(parent, "width", "Width (pixels)")
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yield UInt32(parent, "height", "Height (pixels)")
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yield UInt8(parent, "bit_depth", "Bit depth")
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yield NullBits(parent, "reserved", 5)
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yield Bit(parent, "has_alpha", "Has alpha channel?")
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yield Bit(parent, "color", "Color used?")
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yield Bit(parent, "has_palette", "Has a color palette?")
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yield Enum(UInt8(parent, "compression", "Compression method"), COMPRESSION_NAME)
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yield UInt8(parent, "filter", "Filter method")
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yield UInt8(parent, "interlace", "Interlace method")
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def headerDescription(parent):
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return "Header: %ux%u pixels and %u bits/pixel" % \
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(parent["width"].value, parent[
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"height"].value, getBitsPerPixel(parent))
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def paletteParse(parent):
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size = parent["size"].value
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if (size % 3) != 0:
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raise ParserError(
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"Palette have invalid size (%s), should be 3*n!" % size)
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nb_colors = size // 3
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for index in range(nb_colors):
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yield RGB(parent, "color[]")
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def paletteDescription(parent):
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return "Palette: %u colors" % (parent["size"].value // 3)
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def gammaParse(parent):
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yield UInt32(parent, "gamma", "Gamma (x100,000)")
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def gammaValue(parent):
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return float(parent["gamma"].value) / 100000
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def gammaDescription(parent):
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return "Gamma: %.3f" % parent.value
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def textParse(parent):
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yield CString(parent, "keyword", "Keyword", charset="ISO-8859-1")
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length = parent["size"].value - parent["keyword"].size // 8
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if length:
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yield String(parent, "text", length, "Text", charset="ISO-8859-1")
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def textDescription(parent):
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if "text" in parent:
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return 'Text: %s' % parent["text"].display
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else:
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return 'Text'
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def timestampParse(parent):
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yield UInt16(parent, "year", "Year")
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yield UInt8(parent, "month", "Month")
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yield UInt8(parent, "day", "Day")
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yield UInt8(parent, "hour", "Hour")
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yield UInt8(parent, "minute", "Minute")
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yield UInt8(parent, "second", "Second")
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def timestampValue(parent):
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value = datetime(
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parent["year"].value, parent["month"].value, parent["day"].value,
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parent["hour"].value, parent["minute"].value, parent["second"].value)
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return value
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def physicalParse(parent):
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yield UInt32(parent, "pixel_per_unit_x", "Pixel per unit, X axis")
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yield UInt32(parent, "pixel_per_unit_y", "Pixel per unit, Y axis")
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yield Enum(UInt8(parent, "unit", "Unit type"), UNIT_NAME)
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def physicalDescription(parent):
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x = parent["pixel_per_unit_x"].value
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y = parent["pixel_per_unit_y"].value
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desc = "Physical: %ux%u pixels" % (x, y)
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if parent["unit"].value == 1:
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desc += " per meter"
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return desc
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def parseBackgroundColor(parent):
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yield UInt16(parent, "red")
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yield UInt16(parent, "green")
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yield UInt16(parent, "blue")
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def backgroundColorDesc(parent):
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rgb = parent["red"].value, parent["green"].value, parent["blue"].value
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name = RGB.color_name.get(rgb)
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if not name:
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name = "#%02X%02X%02X" % rgb
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return "Background color: %s" % name
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class ImageData(Fragment):
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def __init__(self, parent, name="compressed_data"):
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Fragment.__init__(self, parent, name, None, 8 * parent["size"].value)
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data = parent.name.split('[')
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data, next = "../%s[%%u]" % data[0], int(data[1][:-1]) + 1
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first = parent.getField(data % 0)
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if first is parent:
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first = None
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if has_deflate:
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CompressedField(self, Gunzip)
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else:
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first = first[name]
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try:
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_next = parent[data % next]
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def next():
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return _next[name]
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except MissingField:
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next = None
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self.setLinks(first, next)
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def parseTransparency(parent):
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for i in range(parent["size"].value):
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yield UInt8(parent, "alpha_value[]", "Alpha value for palette entry %i" % i)
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def getBitsPerPixel(header):
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nr_component = 1
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if header["has_alpha"].value:
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nr_component += 1
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if header["color"].value and not header["has_palette"].value:
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nr_component += 2
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return nr_component * header["bit_depth"].value
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class Chunk(FieldSet):
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TAG_INFO = {
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"tIME": ("time", timestampParse, "Timestamp", timestampValue),
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"pHYs": ("physical", physicalParse, physicalDescription, None),
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"IHDR": ("header", headerParse, headerDescription, None),
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"PLTE": ("palette", paletteParse, paletteDescription, None),
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"gAMA": ("gamma", gammaParse, gammaDescription, gammaValue),
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"tEXt": ("text[]", textParse, textDescription, None),
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"tRNS": ("transparency", parseTransparency, "Transparency Info", None),
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"bKGD": ("background", parseBackgroundColor, backgroundColorDesc, None),
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"IDAT": ("data[]", lambda parent: (ImageData(parent),), "Image data", None),
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"iTXt": ("utf8_text[]", None, "International text (encoded in UTF-8)", None),
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"zTXt": ("comp_text[]", None, "Compressed text", None),
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"IEND": ("end", None, "End", None)
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}
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def createValueFunc(self):
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return self.value_func(self)
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def __init__(self, parent, name, description=None):
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FieldSet.__init__(self, parent, name, description)
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self._size = (self["size"].value + 3 * 4) * 8
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if MAX_CHUNK_SIZE < (self._size // 8):
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raise ParserError("PNG: Chunk is too big (%s)"
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% humanFilesize(self._size // 8))
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tag = self["tag"].value
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self.desc_func = None
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self.value_func = None
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if tag in self.TAG_INFO:
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self._name, self.parse_func, desc, value_func = self.TAG_INFO[tag]
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if value_func:
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self.value_func = value_func
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self.createValue = self.createValueFunc
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if desc:
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if isinstance(desc, str):
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self._description = desc
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else:
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self.desc_func = desc
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else:
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self._description = ""
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self.parse_func = None
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def createFields(self):
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yield UInt32(self, "size", "Size")
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yield String(self, "tag", 4, "Tag", charset="ASCII")
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size = self["size"].value
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if size != 0:
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if self.parse_func:
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yield from self.parse_func(self)
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else:
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yield RawBytes(self, "content", size, "Data")
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yield textHandler(UInt32(self, "crc32", "CRC32"), hexadecimal)
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def createDescription(self):
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if self.desc_func:
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return self.desc_func(self)
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else:
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return "Chunk: %s" % self["tag"].display
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class PngFile(Parser):
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PARSER_TAGS = {
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"id": "png",
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"category": "image",
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"file_ext": ("png",),
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"mime": ("image/png", "image/x-png"),
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"min_size": 8 * 8, # just the identifier
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"magic": [(b'\x89PNG\r\n\x1A\n', 0)],
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"description": "Portable Network Graphics (PNG) picture"
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}
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endian = NETWORK_ENDIAN
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def validate(self):
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if self["id"].value != b'\x89PNG\r\n\x1A\n':
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return "Invalid signature"
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if self[1].name != "header":
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return "First chunk is not header"
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return True
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def createFields(self):
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yield Bytes(self, "id", 8, r"PNG identifier ('\x89PNG\r\n\x1A\n')")
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while not self.eof:
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yield Chunk(self, "chunk[]")
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def createDescription(self):
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header = self["header"]
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desc = "PNG picture: %ux%ux%u" % (
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header["width"].value, header["height"].value, getBitsPerPixel(header))
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if header["has_alpha"].value:
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desc += " (alpha layer)"
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return desc
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def createContentSize(self):
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field = self["header"]
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start = field.absolute_address + field.size
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end = MAX_FILESIZE * 8
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pos = self.stream.searchBytes(
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b"\0\0\0\0IEND\xae\x42\x60\x82", start, end)
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if pos is not None:
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return pos + 12 * 8
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return None
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