diff --git a/src/filters/interframe.cpp b/src/filters/interframe.cpp
index 407be592..c7e9d8ed 100644
--- a/src/filters/interframe.cpp
+++ b/src/filters/interframe.cpp
@@ -2,6 +2,8 @@
 #include <stdlib.h>
 #include <memory.h>
 
+#include "interframe.hpp"
+
 #ifdef MMX
 extern "C" bool cpu_mmx;
 #endif
@@ -16,7 +18,6 @@ static uint8_t *frm1 = NULL;
 static uint8_t *frm2 = NULL;
 static uint8_t *frm3 = NULL;
 
-extern int RGB_LOW_BITS_MASK;
 extern uint32_t qRGB_COLOR_MASK[2];
 
 static void Init()
@@ -31,11 +32,12 @@ static void Init()
 
 void InterframeCleanup()
 {
+  //Hack to prevent double freeing *It looks like this is not being called in a thread safe manner)
   if(frm1)
     free(frm1);
-  if(frm2)
+  if(frm2 && (frm1 != frm2))
     free(frm2);
-  if(frm3)
+  if(frm3 && (frm1 != frm3) && (frm2 != frm3))
     free(frm3);
   frm1 = frm2 = frm3 = NULL;
 }
diff --git a/src/filters/interframe.hpp b/src/filters/interframe.hpp
new file mode 100644
index 00000000..66c2d2f4
--- /dev/null
+++ b/src/filters/interframe.hpp
@@ -0,0 +1,31 @@
+/// Interframe blending filters
+
+#ifndef INTERFRAME_HPP
+#define INTERFRAME_HPP
+
+extern int RGB_LOW_BITS_MASK;
+
+static void Init();
+
+// call ifc to ignore previous frame / when starting new
+void InterframeCleanup();
+
+// all 4 are MMX-accelerated if enabled
+void SmartIB(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+void SmartIB32(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+void MotionBlurIB(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+void MotionBlurIB32(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+
+#ifdef MMX
+static void SmartIB_MMX(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+static void SmartIB32_MMX(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+static void MotionBlurIB_MMX(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+static void MotionBlurIB32_MMX(uint8_t *srcPtr, uint32_t srcPitch, int width, int starty, int height);
+#endif
+
+//Options for if start is 0
+void SmartIB(uint8_t *srcPtr, uint32_t srcPitch, int width, int height);
+void SmartIB32(uint8_t *srcPtr, uint32_t srcPitch, int width, int height);
+void MotionBlurIB(uint8_t *srcPtr, uint32_t srcPitch, int width, int height);
+void MotionBlurIB32(uint8_t *srcPtr, uint32_t srcPitch, int width, int height);
+#endif  //INTERFRAME_HPP
diff --git a/src/sdl/filters.cpp b/src/sdl/filters.cpp
index dd858b26..f3d02499 100644
--- a/src/sdl/filters.cpp
+++ b/src/sdl/filters.cpp
@@ -22,6 +22,8 @@
 
 #include "filters.h"
 
+#include "../filters/interframe.hpp"
+
 //
 // Screen filters
 //
@@ -164,15 +166,6 @@ FilterFunc initFilter(const int f, const int colorDepth, const int srcWidth)
     return func;
 }
 
-//
-// Interframe blending filters
-//
-
-extern void SmartIB(uint8_t*, uint32_t, int, int);
-extern void SmartIB32(uint8_t*, uint32_t, int, int);
-extern void MotionBlurIB(uint8_t*, uint32_t, int, int);
-extern void MotionBlurIB32(uint8_t*, uint32_t, int, int);
-
 struct IFBFilterDesc {
     char name[30];
     IFBFilterFunc func16;
diff --git a/src/wx/filters.h b/src/wx/filters.h
index 339412e7..0e313871 100644
--- a/src/wx/filters.h
+++ b/src/wx/filters.h
@@ -6,6 +6,9 @@
 // most 16-bit filters require space in src rounded up to uint32_t
 // those that take delta take 1 src line of pixels, rounded up to uint32_t size
 // initial value appears to be all-0xff
+
+#include "../filters/interframe.hpp"
+
 void Pixelate32(uint8_t* src, uint32_t spitch, uint8_t*, uint8_t* dst, uint32_t dstp, int w, int h);
 void Pixelate(uint8_t* src, uint32_t spitch, uint8_t* delta, uint8_t* dst, uint32_t dstp, int w, int h);
 // next 3*2 use Init_2xSaI(555|565) and do not take into account
@@ -68,16 +71,4 @@ void xbrz4x32(uint8_t* src, uint32_t spitch, uint8_t*, uint8_t* dst, uint32_t ds
 void xbrz5x32(uint8_t* src, uint32_t spitch, uint8_t*, uint8_t* dst, uint32_t dstp, int w, int h);
 void xbrz6x32(uint8_t* src, uint32_t spitch, uint8_t*, uint8_t* dst, uint32_t dstp, int w, int h);
 
-// call ifc to ignore previous frame / when starting new
-void InterframeCleanup();
-// all 4 are MMX-accelerated if enabled
-void SmartIB(uint8_t* src, uint32_t spitch, int width, int height);
-void SmartIB32(uint8_t* src, uint32_t spitch, int width, int height);
-void MotionBlurIB(uint8_t* src, uint32_t spitch, int width, int height);
-void MotionBlurIB32(uint8_t* src, uint32_t spitch, int width, int height);
-void SmartIB(uint8_t* src, uint32_t spitch, int width, int starty, int height);
-void SmartIB32(uint8_t* src, uint32_t spitch, int width, int starty, int height);
-void MotionBlurIB(uint8_t* src, uint32_t spitch, int width, int starty, int height);
-void MotionBlurIB32(uint8_t* src, uint32_t spitch, int width, int starty, int height);
-
 #endif /* FILTERS_H */