Current mingw32 doesn't provide <sysinfoapi.h>, so use older API.
--- jasper-3.0.6/src/libjasper/base/jas_malloc.c.orig	2023-03-13 13:16:49.488682893 +0100
+++ jasper-3.0.6/src/libjasper/base/jas_malloc.c	2023-03-13 18:13:28.802255734 +0100
@@ -94,7 +94,6 @@
 #	include <unistd.h>
 #elif defined(_WIN32)
 #	include <windows.h>
-#	include <sysinfoapi.h>
 #endif
 
 /******************************************************************************\
@@ -649,15 +648,14 @@ size_t jas_get_total_mem_size()
 	long page_size = sysconf(_SC_PAGE_SIZE);
 	return pages * page_size;
 #elif defined(_WIN32)
-	/*
-	Reference:
-	https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getphysicallyinstalledsystemmemory
-	*/
-	ULONGLONG size;
-	if (!GetPhysicallyInstalledSystemMemory(&size)) {
+	MEMORYSTATUSEX memStatusEx = {0};
+	memStatusEx.dwLength = sizeof(MEMORYSTATUSEX);
+	BOOL bRet = GlobalMemoryStatusEx(&memStatusEx);
+	return memStatusEx.ullTotalPhys;
+	if (!GlobalMemoryStatusEx(&memStatusEx)) {
 		return 0;
 	}
-	return 1024 * size;
+	return memStatusEx.ullTotalPhys;
 #else
 	return 0;
 #endif