diff --git a/src/blitter/32bpp_anim.hpp b/src/blitter/32bpp_anim.hpp
--- a/src/blitter/32bpp_anim.hpp
+++ b/src/blitter/32bpp_anim.hpp
@@ -18,14 +18,16 @@
 class Blitter_32bppAnim : public Blitter_32bppOptimized {
 protected:
 	uint16 *anim_buf;    ///< In this buffer we keep track of the 8bpp indexes so we can do palette animation
+	void *anim_alloc;    ///< The raw allocated buffer, not necessarily aligned correctly
 	int anim_buf_width;  ///< The width of the animation buffer.
 	int anim_buf_height; ///< The height of the animation buffer.
-	int anim_buf_pitch;  ///< The pitch of the animation buffer.
+	int anim_buf_pitch;  ///< The pitch of the animation buffer (width rounded up to 16 byte boundary).
 	Palette palette;     ///< The current palette.
 
 public:
 	Blitter_32bppAnim() :
 		anim_buf(NULL),
+		anim_alloc(NULL),
 		anim_buf_width(0),
 		anim_buf_height(0),
 		anim_buf_pitch(0)
@@ -58,6 +60,15 @@ public:
 		return this->palette.palette[index];
 	}
 
+	inline int ScreenToAnimOffset(const uint32 *video)
+	{
+		int raw_offset = video - (const uint32 *)_screen.dst_ptr;
+		if (_screen.pitch == this->anim_buf_pitch) return raw_offset;
+		int lines = raw_offset / _screen.pitch;
+		int across = raw_offset % _screen.pitch;
+		return across + (lines * this->anim_buf_pitch);
+	}
+
 	template <BlitterMode mode> void Draw(const Blitter::BlitterParams *bp, ZoomLevel zoom);
 };