# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild import kaitaistruct from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO from enum import Enum if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9): raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__)) class Gif(KaitaiStruct): """GIF (Graphics Interchange Format) is an image file format, developed in 1987. It became popular in 1990s as one of the main image formats used in World Wide Web. GIF format allows encoding of palette-based images up to 256 colors (each of the colors can be chosen from a 24-bit RGB colorspace). Image data stream uses LZW (Lempel-Ziv-Welch) lossless compression. Over the years, several version of the format were published and several extensions to it were made, namely, a popular Netscape extension that allows to store several images in one file, switching between them, which produces crude form of animation. Structurally, format consists of several mandatory headers and then a stream of blocks follows. Blocks can carry additional metainformation or image data. """ class BlockType(Enum): extension = 33 local_image_descriptor = 44 end_of_file = 59 class ExtensionLabel(Enum): graphic_control = 249 comment = 254 application = 255 def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.hdr = Gif.Header(self._io, self, self._root) self.logical_screen_descriptor = Gif.LogicalScreenDescriptorStruct(self._io, self, self._root) if self.logical_screen_descriptor.has_color_table: self._raw_global_color_table = self._io.read_bytes((self.logical_screen_descriptor.color_table_size * 3)) _io__raw_global_color_table = KaitaiStream(BytesIO(self._raw_global_color_table)) self.global_color_table = Gif.ColorTable(_io__raw_global_color_table, self, self._root) self.blocks = [] i = 0 while True: _ = Gif.Block(self._io, self, self._root) self.blocks.append(_) if ((self._io.is_eof()) or (_.block_type == Gif.BlockType.end_of_file)) : break i += 1 class ImageData(KaitaiStruct): """ .. seealso:: - section 22 - https://www.w3.org/Graphics/GIF/spec-gif89a.txt """ def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.lzw_min_code_size = self._io.read_u1() self.subblocks = Gif.Subblocks(self._io, self, self._root) class ColorTableEntry(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.red = self._io.read_u1() self.green = self._io.read_u1() self.blue = self._io.read_u1() class LogicalScreenDescriptorStruct(KaitaiStruct): """ .. seealso:: - section 18 - https://www.w3.org/Graphics/GIF/spec-gif89a.txt """ def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.screen_width = self._io.read_u2le() self.screen_height = self._io.read_u2le() self.flags = self._io.read_u1() self.bg_color_index = self._io.read_u1() self.pixel_aspect_ratio = self._io.read_u1() @property def has_color_table(self): if hasattr(self, '_m_has_color_table'): return self._m_has_color_table self._m_has_color_table = (self.flags & 128) != 0 return getattr(self, '_m_has_color_table', None) @property def color_table_size(self): if hasattr(self, '_m_color_table_size'): return self._m_color_table_size self._m_color_table_size = (2 << (self.flags & 7)) return getattr(self, '_m_color_table_size', None) class LocalImageDescriptor(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.left = self._io.read_u2le() self.top = self._io.read_u2le() self.width = self._io.read_u2le() self.height = self._io.read_u2le() self.flags = self._io.read_u1() if self.has_color_table: self._raw_local_color_table = self._io.read_bytes((self.color_table_size * 3)) _io__raw_local_color_table = KaitaiStream(BytesIO(self._raw_local_color_table)) self.local_color_table = Gif.ColorTable(_io__raw_local_color_table, self, self._root) self.image_data = Gif.ImageData(self._io, self, self._root) @property def has_color_table(self): if hasattr(self, '_m_has_color_table'): return self._m_has_color_table self._m_has_color_table = (self.flags & 128) != 0 return getattr(self, '_m_has_color_table', None) @property def has_interlace(self): if hasattr(self, '_m_has_interlace'): return self._m_has_interlace self._m_has_interlace = (self.flags & 64) != 0 return getattr(self, '_m_has_interlace', None) @property def has_sorted_color_table(self): if hasattr(self, '_m_has_sorted_color_table'): return self._m_has_sorted_color_table self._m_has_sorted_color_table = (self.flags & 32) != 0 return getattr(self, '_m_has_sorted_color_table', None) @property def color_table_size(self): if hasattr(self, '_m_color_table_size'): return self._m_color_table_size self._m_color_table_size = (2 << (self.flags & 7)) return getattr(self, '_m_color_table_size', None) class Block(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.block_type = KaitaiStream.resolve_enum(Gif.BlockType, self._io.read_u1()) _on = self.block_type if _on == Gif.BlockType.extension: self.body = Gif.Extension(self._io, self, self._root) elif _on == Gif.BlockType.local_image_descriptor: self.body = Gif.LocalImageDescriptor(self._io, self, self._root) class ColorTable(KaitaiStruct): """ .. seealso:: - section 19 - https://www.w3.org/Graphics/GIF/spec-gif89a.txt """ def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.entries = [] i = 0 while not self._io.is_eof(): self.entries.append(Gif.ColorTableEntry(self._io, self, self._root)) i += 1 class Header(KaitaiStruct): """ .. seealso:: - section 17 - https://www.w3.org/Graphics/GIF/spec-gif89a.txt """ def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.magic = self._io.read_bytes(3) if not self.magic == b"\x47\x49\x46": raise kaitaistruct.ValidationNotEqualError(b"\x47\x49\x46", self.magic, self._io, u"/types/header/seq/0") self.version = (self._io.read_bytes(3)).decode(u"ASCII") class ExtGraphicControl(KaitaiStruct): """ .. seealso:: - section 23 - https://www.w3.org/Graphics/GIF/spec-gif89a.txt """ def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.block_size = self._io.read_bytes(1) if not self.block_size == b"\x04": raise kaitaistruct.ValidationNotEqualError(b"\x04", self.block_size, self._io, u"/types/ext_graphic_control/seq/0") self.flags = self._io.read_u1() self.delay_time = self._io.read_u2le() self.transparent_idx = self._io.read_u1() self.terminator = self._io.read_bytes(1) if not self.terminator == b"\x00": raise kaitaistruct.ValidationNotEqualError(b"\x00", self.terminator, self._io, u"/types/ext_graphic_control/seq/4") @property def transparent_color_flag(self): if hasattr(self, '_m_transparent_color_flag'): return self._m_transparent_color_flag self._m_transparent_color_flag = (self.flags & 1) != 0 return getattr(self, '_m_transparent_color_flag', None) @property def user_input_flag(self): if hasattr(self, '_m_user_input_flag'): return self._m_user_input_flag self._m_user_input_flag = (self.flags & 2) != 0 return getattr(self, '_m_user_input_flag', None) class Subblock(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.len_bytes = self._io.read_u1() self.bytes = self._io.read_bytes(self.len_bytes) class ApplicationId(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.len_bytes = self._io.read_u1() if not self.len_bytes == 11: raise kaitaistruct.ValidationNotEqualError(11, self.len_bytes, self._io, u"/types/application_id/seq/0") self.application_identifier = (self._io.read_bytes(8)).decode(u"ASCII") self.application_auth_code = self._io.read_bytes(3) class ExtApplication(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.application_id = Gif.ApplicationId(self._io, self, self._root) self.subblocks = [] i = 0 while True: _ = Gif.Subblock(self._io, self, self._root) self.subblocks.append(_) if _.len_bytes == 0: break i += 1 class Subblocks(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.entries = [] i = 0 while True: _ = Gif.Subblock(self._io, self, self._root) self.entries.append(_) if _.len_bytes == 0: break i += 1 class Extension(KaitaiStruct): def __init__(self, _io, _parent=None, _root=None): self._io = _io self._parent = _parent self._root = _root if _root else self self._read() def _read(self): self.label = KaitaiStream.resolve_enum(Gif.ExtensionLabel, self._io.read_u1()) _on = self.label if _on == Gif.ExtensionLabel.application: self.body = Gif.ExtApplication(self._io, self, self._root) elif _on == Gif.ExtensionLabel.comment: self.body = Gif.Subblocks(self._io, self, self._root) elif _on == Gif.ExtensionLabel.graphic_control: self.body = Gif.ExtGraphicControl(self._io, self, self._root) else: self.body = Gif.Subblocks(self._io, self, self._root)