My goal is to figure out how to parse MD3 quake model files so that I can write an import/export tool for DeleD. So I found a model here...

http://ioquake3.org/files/models2/q3mdl-imp.zip

And the format definition here...

http://en.wikipedia.org/wiki/MD3_%28file_format%29

I decompressed everything and tried to parse part of the header of the 'head.MD3' file with this python 2 code...

import binascii
import struct

filename = 'head.MD3'
bytes = ''
with open(filename,'rb') as fileptr:
    bytes = fileptr.read()
bytes = binascii.hexlify(bytes)
print bytes
print 'IDENT', bytes[0:8].decode("hex"), 'VERSION', bytes[9:17]

Both IDENT and VERSION are supposed to be 32 bits (so says wikipedia). The IDENT comes in good but VERSION is junk...

IDENT IDP3 VERSION f0000000

f0 is 15 which is consistent with the header info but what about the trailing zeroes?

The rest of the hex dump is attached...it does not seem to be consistent with the format defenition. I don't know if I'm not parsing this correctly, if the wikipedia info is wrong or the model is junk. Full output (hex dump of the file) is attached in a txt. Can anyone offer a starting point? Any thoughts?

Thanks for the suggestions. Figured it out by programmatically walking through the bytes looking for sane values for NUM_FRAMES, NUM_TAGS and NUM_SURFACES. Crude but effective. Code sample in case anyone else needs help figuring this out later on...

import binascii
import struct

filename = 'head.MD3'
bytes = ''
with open(filename,'rb') as fileptr:
    bytes = fileptr.read()
bytes = binascii.hexlify(bytes)

def test2(bytes, start):
    for x in range(0,512):
        hexstart1 = start+x
        hexstart2 = start+x+8
        hexstart3 = start+x+8+8
        hexstart4 = start+x+8+8+8
        hexstart5 = start+x+8+8+8+8
        hexstart6 = start+x+8+8+8+8+8
        hexstart7 = start+x+8+8+8+8+8+8
        hexstart8 = start+x+8+8+8+8+8+8+8
        NUM_FRAMES = struct.unpack('<I', bytes[hexstart1:hexstart1+8].decode("hex"))[0]
        NUM_TAGS = struct.unpack('<I', bytes[hexstart2:hexstart2+8].decode("hex"))[0]
        NUM_SURFACES = struct.unpack('<I', bytes[hexstart3:hexstart3+8].decode("hex"))[0]
        NUM_SKINS = struct.unpack('<I', bytes[hexstart4:hexstart4+8].decode("hex"))[0]
        OFS_FRAMES = struct.unpack('<I', bytes[hexstart5:hexstart5+8].decode("hex"))[0]
        OFS_TAGS = struct.unpack('<I', bytes[hexstart6:hexstart6+8].decode("hex"))[0]
        OFS_SURFACES = struct.unpack('<I', bytes[hexstart7:hexstart7+8].decode("hex"))[0]
        OFS_EOF = struct.unpack('<I', bytes[hexstart8:hexstart8+8].decode("hex"))[0]
        if NUM_FRAMES < 1024 and NUM_FRAMES > 0 and NUM_TAGS < 16 and NUM_TAGS > 0 and NUM_SURFACES < 32 and NUM_SURFACES > 0:
            print hexstart1
            print NUM_FRAMES, NUM_TAGS, NUM_SURFACES, NUM_SKINS, OFS_FRAMES, OFS_TAGS, OFS_SURFACES, OFS_EOF
            print '~~~~~~~~'

test2(bytes,0)
print len(bytes)/2

Output...

152
1 1 1 0 108 164 276 3284
~~~~~~~~
3284