The Resource Interchange File Format (RIFF) is a generic file container format for storing data in tagged chunks. It is primarily used to store multimedia such as sound and video, though it may also be used to store any arbitrary data.
The Microsoft implementation is mostly known through container formats like AVI, ANI and WAV, which use RIFF as their basis.
This page hosts a formal specification of Resource Interchange File Format (RIFF) using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = Riff.from_file("path/to/local/file.bin")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = Riff(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.chunk # => get chunk
# 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 Riff(KaitaiStruct):
"""The Resource Interchange File Format (RIFF) is a generic file container format
for storing data in tagged chunks. It is primarily used to store multimedia
such as sound and video, though it may also be used to store any arbitrary data.
The Microsoft implementation is mostly known through container formats
like AVI, ANI and WAV, which use RIFF as their basis.
.. seealso::
Source - https://www.johnloomis.org/cpe102/asgn/asgn1/riff.html
"""
class Fourcc(Enum):
riff = 1179011410
info = 1330007625
list = 1414744396
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.chunk = Riff.Chunk(self._io, self, self._root)
class ListChunkData(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):
if self.parent_chunk_data_ofs < 0:
self.save_parent_chunk_data_ofs = self._io.read_bytes(0)
self.parent_chunk_data = Riff.ParentChunkData(self._io, self, self._root)
@property
def parent_chunk_data_ofs(self):
if hasattr(self, '_m_parent_chunk_data_ofs'):
return self._m_parent_chunk_data_ofs
self._m_parent_chunk_data_ofs = self._io.pos()
return getattr(self, '_m_parent_chunk_data_ofs', None)
@property
def form_type(self):
if hasattr(self, '_m_form_type'):
return self._m_form_type
self._m_form_type = KaitaiStream.resolve_enum(Riff.Fourcc, self.parent_chunk_data.form_type)
return getattr(self, '_m_form_type', None)
@property
def form_type_readable(self):
if hasattr(self, '_m_form_type_readable'):
return self._m_form_type_readable
_pos = self._io.pos()
self._io.seek(self.parent_chunk_data_ofs)
self._m_form_type_readable = (self._io.read_bytes(4)).decode(u"ASCII")
self._io.seek(_pos)
return getattr(self, '_m_form_type_readable', None)
@property
def subchunks(self):
if hasattr(self, '_m_subchunks'):
return self._m_subchunks
io = self.parent_chunk_data.subchunks_slot._io
_pos = io.pos()
io.seek(0)
self._m_subchunks = []
i = 0
while not io.is_eof():
_on = self.form_type
if _on == Riff.Fourcc.info:
self._m_subchunks.append(Riff.InfoSubchunk(io, self, self._root))
else:
self._m_subchunks.append(Riff.ChunkType(io, self, self._root))
i += 1
io.seek(_pos)
return getattr(self, '_m_subchunks', None)
class Chunk(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.id = self._io.read_u4le()
self.len = self._io.read_u4le()
self._raw_data_slot = self._io.read_bytes(self.len)
_io__raw_data_slot = KaitaiStream(BytesIO(self._raw_data_slot))
self.data_slot = Riff.Chunk.Slot(_io__raw_data_slot, self, self._root)
self.pad_byte = self._io.read_bytes((self.len % 2))
class Slot(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):
pass
class ParentChunkData(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.form_type = self._io.read_u4le()
self._raw_subchunks_slot = self._io.read_bytes_full()
_io__raw_subchunks_slot = KaitaiStream(BytesIO(self._raw_subchunks_slot))
self.subchunks_slot = Riff.ParentChunkData.Slot(_io__raw_subchunks_slot, self, self._root)
class Slot(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):
pass
class InfoSubchunk(KaitaiStruct):
"""All registered subchunks in the INFO chunk are NULL-terminated strings,
but the unregistered might not be. By convention, the registered
chunk IDs are in uppercase and the unregistered IDs are in lowercase.
If the chunk ID of an INFO subchunk contains a lowercase
letter, this chunk is considered as unregistered and thus we can make
no assumptions about the type of data.
"""
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):
if self.chunk_ofs < 0:
self.save_chunk_ofs = self._io.read_bytes(0)
self.chunk = Riff.Chunk(self._io, self, self._root)
@property
def chunk_data(self):
if hasattr(self, '_m_chunk_data'):
return self._m_chunk_data
io = self.chunk.data_slot._io
_pos = io.pos()
io.seek(0)
_on = self.is_unregistered_tag
if _on == False:
self._m_chunk_data = (io.read_bytes_term(0, False, True, True)).decode(u"UTF-8")
io.seek(_pos)
return getattr(self, '_m_chunk_data', None)
@property
def is_unregistered_tag(self):
"""Check if chunk_id contains lowercase characters ([a-z], ASCII 97 = a, ASCII 122 = z).
"""
if hasattr(self, '_m_is_unregistered_tag'):
return self._m_is_unregistered_tag
self._m_is_unregistered_tag = (( ((KaitaiStream.byte_array_index(self.id_chars, 0) >= 97) and (KaitaiStream.byte_array_index(self.id_chars, 0) <= 122)) ) or ( ((KaitaiStream.byte_array_index(self.id_chars, 1) >= 97) and (KaitaiStream.byte_array_index(self.id_chars, 1) <= 122)) ) or ( ((KaitaiStream.byte_array_index(self.id_chars, 2) >= 97) and (KaitaiStream.byte_array_index(self.id_chars, 2) <= 122)) ) or ( ((KaitaiStream.byte_array_index(self.id_chars, 3) >= 97) and (KaitaiStream.byte_array_index(self.id_chars, 3) <= 122)) ))
return getattr(self, '_m_is_unregistered_tag', None)
@property
def id_chars(self):
if hasattr(self, '_m_id_chars'):
return self._m_id_chars
_pos = self._io.pos()
self._io.seek(self.chunk_ofs)
self._m_id_chars = self._io.read_bytes(4)
self._io.seek(_pos)
return getattr(self, '_m_id_chars', None)
@property
def chunk_id_readable(self):
if hasattr(self, '_m_chunk_id_readable'):
return self._m_chunk_id_readable
self._m_chunk_id_readable = (self.id_chars).decode(u"ASCII")
return getattr(self, '_m_chunk_id_readable', None)
@property
def chunk_ofs(self):
if hasattr(self, '_m_chunk_ofs'):
return self._m_chunk_ofs
self._m_chunk_ofs = self._io.pos()
return getattr(self, '_m_chunk_ofs', None)
class ChunkType(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):
if self.chunk_ofs < 0:
self.save_chunk_ofs = self._io.read_bytes(0)
self.chunk = Riff.Chunk(self._io, self, self._root)
@property
def chunk_ofs(self):
if hasattr(self, '_m_chunk_ofs'):
return self._m_chunk_ofs
self._m_chunk_ofs = self._io.pos()
return getattr(self, '_m_chunk_ofs', None)
@property
def chunk_id(self):
if hasattr(self, '_m_chunk_id'):
return self._m_chunk_id
self._m_chunk_id = KaitaiStream.resolve_enum(Riff.Fourcc, self.chunk.id)
return getattr(self, '_m_chunk_id', None)
@property
def chunk_id_readable(self):
if hasattr(self, '_m_chunk_id_readable'):
return self._m_chunk_id_readable
_pos = self._io.pos()
self._io.seek(self.chunk_ofs)
self._m_chunk_id_readable = (self._io.read_bytes(4)).decode(u"ASCII")
self._io.seek(_pos)
return getattr(self, '_m_chunk_id_readable', None)
@property
def chunk_data(self):
if hasattr(self, '_m_chunk_data'):
return self._m_chunk_data
io = self.chunk.data_slot._io
_pos = io.pos()
io.seek(0)
_on = self.chunk_id
if _on == Riff.Fourcc.list:
self._m_chunk_data = Riff.ListChunkData(io, self, self._root)
io.seek(_pos)
return getattr(self, '_m_chunk_data', None)
@property
def chunk_id(self):
if hasattr(self, '_m_chunk_id'):
return self._m_chunk_id
self._m_chunk_id = KaitaiStream.resolve_enum(Riff.Fourcc, self.chunk.id)
return getattr(self, '_m_chunk_id', None)
@property
def is_riff_chunk(self):
if hasattr(self, '_m_is_riff_chunk'):
return self._m_is_riff_chunk
self._m_is_riff_chunk = self.chunk_id == Riff.Fourcc.riff
return getattr(self, '_m_is_riff_chunk', None)
@property
def parent_chunk_data(self):
if hasattr(self, '_m_parent_chunk_data'):
return self._m_parent_chunk_data
if self.is_riff_chunk:
io = self.chunk.data_slot._io
_pos = io.pos()
io.seek(0)
self._m_parent_chunk_data = Riff.ParentChunkData(io, self, self._root)
io.seek(_pos)
return getattr(self, '_m_parent_chunk_data', None)
@property
def subchunks(self):
if hasattr(self, '_m_subchunks'):
return self._m_subchunks
if self.is_riff_chunk:
io = self.parent_chunk_data.subchunks_slot._io
_pos = io.pos()
io.seek(0)
self._m_subchunks = []
i = 0
while not io.is_eof():
self._m_subchunks.append(Riff.ChunkType(io, self, self._root))
i += 1
io.seek(_pos)
return getattr(self, '_m_subchunks', None)