ID3v2.4 tag for .mp3 files: Python parsing library

File extension

mp3

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of ID3v2.4 tag for .mp3 files using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime 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 kaitaistruct

Code

Parse a local file and get structure in memory:

data = Id3v24.from_file("path/to/local/file.mp3")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = Id3v24(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.tag # => get tag

Python source code to parse ID3v2.4 tag for .mp3 files

id3v2_4.py

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

from pkg_resources import parse_version
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO


if parse_version(kaitaistruct.__version__) < parse_version('0.9'):
    raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))

class Id3v24(KaitaiStruct):
    """
    .. seealso::
       Source - http://id3.org/id3v2.4.0-structure
    
    
    .. seealso::
       Source - http://id3.org/id3v2.4.0-frames
    """
    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.tag = Id3v24.Tag(self._io, self, self._root)

    class U1beSynchsafe(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.padding = self._io.read_bits_int_be(1) != 0
            self.value = self._io.read_bits_int_be(7)


    class U2beSynchsafe(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.byte0 = Id3v24.U1beSynchsafe(self._io, self, self._root)
            self.byte1 = Id3v24.U1beSynchsafe(self._io, self, self._root)

        @property
        def value(self):
            if hasattr(self, '_m_value'):
                return self._m_value if hasattr(self, '_m_value') else None

            self._m_value = ((self.byte0.value << 7) | self.byte1.value)
            return self._m_value if hasattr(self, '_m_value') else None


    class Tag(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.header = Id3v24.Header(self._io, self, self._root)
            if self.header.flags.flag_headerex:
                self.header_ex = Id3v24.HeaderEx(self._io, self, self._root)

            self.frames = []
            i = 0
            while True:
                _ = Id3v24.Frame(self._io, self, self._root)
                self.frames.append(_)
                if  (((self._io.pos() + _.size.value) > self.header.size.value) or (_.is_invalid)) :
                    break
                i += 1
            if not (self.header.flags.flag_footer):
                self.padding = Id3v24.Padding(self._io, self, self._root)

            if self.header.flags.flag_footer:
                self.footer = Id3v24.Footer(self._io, self, self._root)



    class U4beSynchsafe(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.short0 = Id3v24.U2beSynchsafe(self._io, self, self._root)
            self.short1 = Id3v24.U2beSynchsafe(self._io, self, self._root)

        @property
        def value(self):
            if hasattr(self, '_m_value'):
                return self._m_value if hasattr(self, '_m_value') else None

            self._m_value = ((self.short0.value << 14) | self.short1.value)
            return self._m_value if hasattr(self, '_m_value') else None


    class Frame(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_bytes(4)).decode(u"ASCII")
            self.size = Id3v24.U4beSynchsafe(self._io, self, self._root)
            self.flags_status = Id3v24.Frame.FlagsStatus(self._io, self, self._root)
            self.flags_format = Id3v24.Frame.FlagsFormat(self._io, self, self._root)
            self.data = self._io.read_bytes(self.size.value)

        class FlagsStatus(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.reserved1 = self._io.read_bits_int_be(1) != 0
                self.flag_discard_alter_tag = self._io.read_bits_int_be(1) != 0
                self.flag_discard_alter_file = self._io.read_bits_int_be(1) != 0
                self.flag_read_only = self._io.read_bits_int_be(1) != 0
                self.reserved2 = self._io.read_bits_int_be(4)


        class FlagsFormat(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.reserved1 = self._io.read_bits_int_be(1) != 0
                self.flag_grouping = self._io.read_bits_int_be(1) != 0
                self.reserved2 = self._io.read_bits_int_be(2)
                self.flag_compressed = self._io.read_bits_int_be(1) != 0
                self.flag_encrypted = self._io.read_bits_int_be(1) != 0
                self.flag_unsynchronisated = self._io.read_bits_int_be(1) != 0
                self.flag_indicator = self._io.read_bits_int_be(1) != 0


        @property
        def is_invalid(self):
            if hasattr(self, '_m_is_invalid'):
                return self._m_is_invalid if hasattr(self, '_m_is_invalid') else None

            self._m_is_invalid = self.id == u"\000\000\000\000"
            return self._m_is_invalid if hasattr(self, '_m_is_invalid') else None


    class HeaderEx(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.size = Id3v24.U4beSynchsafe(self._io, self, self._root)
            self.flags_ex = Id3v24.HeaderEx.FlagsEx(self._io, self, self._root)
            self.data = self._io.read_bytes((self.size.value - 5))

        class FlagsEx(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.reserved1 = self._io.read_bits_int_be(1) != 0
                self.flag_update = self._io.read_bits_int_be(1) != 0
                self.flag_crc = self._io.read_bits_int_be(1) != 0
                self.flag_restrictions = self._io.read_bits_int_be(1) != 0
                self.reserved2 = self._io.read_bits_int_be(4)



    class Header(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.magic = self._io.read_bytes(3)
            if not self.magic == b"\x49\x44\x33":
                raise kaitaistruct.ValidationNotEqualError(b"\x49\x44\x33", self.magic, self._io, u"/types/header/seq/0")
            self.version_major = self._io.read_u1()
            self.version_revision = self._io.read_u1()
            self.flags = Id3v24.Header.Flags(self._io, self, self._root)
            self.size = Id3v24.U4beSynchsafe(self._io, self, self._root)

        class Flags(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.flag_unsynchronization = self._io.read_bits_int_be(1) != 0
                self.flag_headerex = self._io.read_bits_int_be(1) != 0
                self.flag_experimental = self._io.read_bits_int_be(1) != 0
                self.flag_footer = self._io.read_bits_int_be(1) != 0
                self.reserved = self._io.read_bits_int_be(4)



    class Padding(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.padding = self._io.read_bytes((self._root.tag.header.size.value - self._io.pos()))


    class Footer(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.magic = self._io.read_bytes(3)
            if not self.magic == b"\x33\x44\x49":
                raise kaitaistruct.ValidationNotEqualError(b"\x33\x44\x49", self.magic, self._io, u"/types/footer/seq/0")
            self.version_major = self._io.read_u1()
            self.version_revision = self._io.read_u1()
            self.flags = Id3v24.Footer.Flags(self._io, self, self._root)
            self.size = Id3v24.U4beSynchsafe(self._io, self, self._root)

        class Flags(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.flag_unsynchronization = self._io.read_bits_int_be(1) != 0
                self.flag_headerex = self._io.read_bits_int_be(1) != 0
                self.flag_experimental = self._io.read_bits_int_be(1) != 0
                self.flag_footer = self._io.read_bits_int_be(1) != 0
                self.reserved = self._io.read_bits_int_be(4)