Let us start here, from square one. No, from Zero!

util/secplug.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstdint>
+#include <array>
+
+namespace secplug {
+    constexpr std::array<uint8_t, 6> encode_secplug_model(const char model[8]) {
+        // 6-bit character code similar to the one used by avs in its binary xml format.
+        std::array<uint8_t, 6> packed {};
+        packed[0] = ((model[0] - 32))      | ((model[1] - 32) << 6);
+        packed[1] = ((model[1] - 32) >> 2) | ((model[2] - 32) << 4);
+        packed[2] = ((model[2] - 32) >> 4) | ((model[3] - 32) << 2);
+        packed[3] = ((model[4] - 32))      | ((model[5] - 32) << 6);
+        packed[4] = ((model[5] - 32) >> 2) | ((model[6] - 32) << 4);
+        packed[5] = ((model[6] - 32) >> 4) | ((model[7] - 32) << 2);
+
+        return packed;
+    }
+};