From 10d7958f2e0c50966636578cbcf1c4895fa449d3 Mon Sep 17 00:00:00 2001
From: Patrick Urban <patrick.urban@web.de>
Date: Tue, 8 Jul 2025 16:29:32 +0200
Subject: [PATCH] Disable crc bytes if set to "unused"

---
 libgm/src/Bitstream.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libgm/src/Bitstream.cpp b/libgm/src/Bitstream.cpp
index aebf2b9..6065313 100644
--- a/libgm/src/Bitstream.cpp
+++ b/libgm/src/Bitstream.cpp
@@ -114,8 +114,10 @@ class BitstreamReadWriter
 
     std::vector<uint8_t> data;
     std::vector<uint8_t>::iterator iter;
+    bool crc_unused = false;
     Crc16 crc16;
 
+
     // Return a single byte and update CRC
     inline uint8_t get_byte()
     {
@@ -240,6 +242,8 @@ class BitstreamReadWriter
     // Insert the calculated CRC16 into the bitstream
     void insert_crc16()
     {
+        if (crc_unused)
+            return;
         uint16_t actual_crc = crc16.get_crc16();
         write_byte(uint8_t((actual_crc) & 0xFF));
         write_byte(uint8_t((actual_crc >> 8) & 0xFF));
@@ -290,6 +294,9 @@ class BitstreamReadWriter
         }
         insert_crc16();
         write_nops(4);
+        if (crcmode == 0x02) {
+            crc_unused = true;
+        }
     }
 
     void write_cmd_spll(uint8_t data)