PoC decoder working \o/

.gitmodules

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+[submodule "splimport/apetag"]
+	path = splimport/apetag
+	url = https://github.com/robertmuth/apetag.git

splimport/apetag

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+Subproject commit 55f3d7a51946787df401573fc92698ed88a2cdee

splimport/apev2.ksy

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+meta:
+  id: apev2
+  file-extension: apetag
+  endian: le
+  
+seq:
+  - id: tag
+    type: tag
+
+types:
+  tag:
+    seq:
+      - id: header
+        type: header
+        size: 32
+      - id: frames
+        type: frame
+        repeat: expr
+        repeat-expr: header.item_count
+      - id: footer
+        type: footer
+        size: 32
+  header:
+    seq:
+      - id: preamble
+        contents: 'APETAGEX'
+      - id: version_number
+        type: u4
+      - id: tag_size
+        type: u4
+      - id: item_count
+        type: u4
+      - id: tag_flags
+        type: b32
+      - id: reserved
+        contents: [0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0]
+        size: 8
+      
+  frame:
+    seq:
+      - id: item_size
+        type: u4
+      - id: item_flags
+        type: b32
+      - id: item_key
+        type: str
+        terminator: 0
+        encoding: UTF-8
+      - id: item_value
+        size: item_size
+        
+  footer:
+    seq:
+      - id: preamble
+        contents: 'APETAGEX'
+      - id: version_number
+        type: u4
+      - id: tag_size
+        type: u4
+      - id: item_count
+        type: u4
+      - id: tag_flags
+        type: b32
+      - id: reserved
+        contents: [0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0]
+        size: 8
+        

splimport/apev2.py

@@ -0,0 +1,86 @@
+# This is a generated section! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
+
+from pkg_resources import parse_version
+from kaitaistruct import __version__ as ks_version, KaitaiStruct, KaitaiStream, BytesIO
+
+
+if parse_version(ks_version) < parse_version('0.7'):
+    raise Exception("Incompatible Kaitai Struct Python API: 0.7 or later is required, but you have %s" % (ks_version))
+
+class Apev2(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.tag = self._root.Tag(self._io, self, self._root)
+
+    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._raw_header = self._io.read_bytes(32)
+            io = KaitaiStream(BytesIO(self._raw_header))
+            self.header = self._root.Header(io, self, self._root)
+            self.frames = [None] * (self.header.item_count)
+            for i in range(self.header.item_count):
+                self.frames[i] = self._root.Frame(self._io, self, self._root)
+
+            self._raw_footer = self._io.read_bytes(32)
+            io = KaitaiStream(BytesIO(self._raw_footer))
+            self.footer = self._root.Footer(io, self, self._root)
+
+
+    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.preamble = self._io.ensure_fixed_contents(b"\x41\x50\x45\x54\x41\x47\x45\x58")
+            self.version_number = self._io.read_u4le()
+            self.tag_size = self._io.read_u4le()
+            self.item_count = self._io.read_u4le()
+            self.tag_flags = self._io.read_bits_int(32)
+            self._io.align_to_byte()
+            self.reserved = self._io.ensure_fixed_contents(b"\x00\x00\x00\x00\x00\x00\x00\x00")
+
+
+    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.item_size = self._io.read_u4le()
+            self.item_flags = self._io.read_bits_int(32)
+            self._io.align_to_byte()
+            self.item_key = (self._io.read_bytes_term(0, False, True, True)).decode(u"UTF-8")
+            self.item_value = self._io.read_bytes(self.item_size)
+
+
+    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.preamble = self._io.ensure_fixed_contents(b"\x41\x50\x45\x54\x41\x47\x45\x58")
+            self.version_number = self._io.read_u4le()
+            self.tag_size = self._io.read_u4le()
+            self.item_count = self._io.read_u4le()
+            self.tag_flags = self._io.read_bits_int(32)
+            self._io.align_to_byte()
+            self.reserved = self._io.ensure_fixed_contents(b"\x00\x00\x00\x00\x00\x00\x00\x00")

splimport/decode.py

@@ -1,10 +1,32 @@
 import struct
+from apev2 import Apev2
 
+# apev2 spec: https://wiki.hydrogenaud.io/index.php?title=APEv2_specification
+
+# parse dates from XLastPlayed and XLastScheduled from SPL. by brainsmoke:
+# d=swap32(0x14a63351)
+# Y,M,D,h,m,s = 1980+(d>>25), (d>>21)&0xf, (d>>16)&0x1f, (d>>11)&0x1f, (d>>5)&0x3f, (d<<1)&0x3f
+# print(Y,M,D,h,m,s)
+
+
+# for swapping endianness of a binary package
 def swap32(i):
     return struct.unpack("<I", struct.pack(">I", i))[0]
 
 
-d=swap32(0x14a63351)
+ape = Apev2.from_file('OMYG.apetag')
-Y,M,D,h,m,s = 1980+(d>>25), (d>>21)&0xf, (d>>16)&0x1f, (d>>11)&0x1f, (d>>5)&0x3f, (d<<1)&0x3f
 
+for item in ape.tag.frames:
+    key = item.item_key
+    value = item.item_value
+    # print(key, value)
+
+    if key == 'XLastPlayed':
+        hex = value.hex()
+
+        for i in range(0, len(hex), 8):
+            hex_chunk = "0x{}".format(hex[i: i+8])
+
+            d=swap32(int(hex_chunk, 16))
+            Y,M,D,h,m,s = 1980+(d>>25), (d>>21)&0xf, (d>>16)&0x1f, (d>>11)&0x1f, (d>>5)&0x3f, (d<<1)&0x3f
             print(Y,M,D,h,m,s)