From 116babc38e2e4023eb0b45eabc02050ed433e240 Mon Sep 17 00:00:00 2001
From: Keir Fraser <keir.xen@gmail.com>
Date: Thu, 4 Jun 2020 10:28:48 +0100
Subject: [PATCH] scripts: Include a helpful MOD analyser script

---
 scripts/mod_info.py | 48 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 scripts/mod_info.py

diff --git a/scripts/mod_info.py b/scripts/mod_info.py
new file mode 100644
index 0000000..ed8ddb6
--- /dev/null
+++ b/scripts/mod_info.py
@@ -0,0 +1,48 @@
+# mod_info.py
+# 
+# Display information about a Protracker module.
+# 
+# Written & released by Keir Fraser <keir.xen@gmail.com>
+# 
+# This is free and unencumbered software released into the public domain.
+# See the file COPYING for more details, or visit <http://unlicense.org>.
+
+import struct, sys
+
+with open(sys.argv[1], "rb") as f:
+    dat = f.read()
+dlen = len(dat)
+
+tname, = struct.unpack("20s", dat[:20])
+print("Name: '%s'" % tname.decode('utf-8'))
+dat = dat[20:]
+samples_len = 0
+for i in range(31):
+    name, wordlen, finetune, volume, repstart, replen = struct.unpack(
+        ">22sH2B2H", dat[:30])
+    dat = dat[30:]
+    if wordlen == 0:
+        continue
+    samples_len += wordlen*2
+print("Sample Data: %u" % samples_len)
+
+songlen, pad = struct.unpack("2B", dat[:2])
+dat = dat[2:]
+#assert pad == 127
+assert songlen <= 128
+print("Song Length: %u" % songlen)
+
+patterns = list(struct.unpack("128B", dat[:128]))
+dat = dat[128:]
+patterns = patterns[:songlen]
+nr_patterns = max(patterns)+1
+print("Nr Patterns: %u (%u bytes)" % (nr_patterns, nr_patterns*1024))
+
+mksig, = struct.unpack("4s", dat[:4])
+dat = dat[4:]
+assert mksig == b'M.K.'
+
+totlen = 1084 + nr_patterns*1024 + samples_len
+print("Total Bytes: %u (0x%x)" % (totlen, totlen))
+assert totlen <= dlen
+