+    * Some implementations of aplib do not require a header.

+    * I could not find a tool that could create the aplib header from 

+      compressd data. 

+    * The below code returns the compressed data with the header.

+aplib header example 

+no header example 

+Author:

+    Alexaner Hanel

+

+Note:

+    * Some implementations of aplib do not require a header

+    * I could not find a tool that could create the aplib header from data

+      compressd data. The below code returns the compressed data with the header.

+    * Relies on Ange Albertini aplib.py 

+

+

+aplib header

+Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

+

+00000000  41 50 33 32 18 00 00 00 6A 2D 00 00 C3 5B 3C CC  AP32....j-..Ã[<Ì

+00000010  00 64 00 00 3A F8 81 21 4D 38 5A 90 38 03 66 02  .d..:ø.!M8Z.8.f.

+

+no header 

+Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

+

+00000000  4D 38 5A 90 38 03 66 02 04 09 71 FF 81 B8 C2 91  M8Z.8.f...qÿ.¸Â‘

+00000010  01 40 C2 15 C6 80 09 1C 0E 1F BA F8 00 B4 09 CD  .@Â.Æ€....ºø.´.Í

+

+Aplib header notes 

+ * tag: 4 bytes, 41 50 33 32 or "AP32"

+ * header_size: 4 bytes // offset to the compressed data 

+ * packed_size: 4 bytes // size of the compressed data

+ * packed_crc: 4 bytes  // crc of the compressed data 

+ * original_size: 4 bytes // original size of the uncompressed data 

+ * original_crc: 4 bytes  // crc of the uncompress data

+

+Source: See Aplib's spack.asm 

+

+'''

+

+from zlib import crc32

+from aplib import *

+import struct

+

+

+HEADER_TAG = "AP32"

+HEADER_SIZE = struct.pack("<I", 0x18)

+

+def create_header(data):

+    header = HEADER_TAG + HEADER_SIZE

+    header += struct.pack("<I", len(data))

+    header += struct.pack("<I", crc32(data) & 0xFFFFFFFF)

+    try:

+        decompressed_data = decompress(data).do()[0]

+    except:

+        return None

+    header += struct.pack("<I", len(decompressed_data))

+    header += struct.pack("<I", crc32(decompressed_data) & 0xFFFFFFFF)