move ff_init_scantable() into dsputil

Originally committed as revision 12311 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/dsputil.h

@@ -153,6 +153,21 @@ typedef int (*me_cmp_func)(void /*MpegEncContext*/ *s, uint8_t *blk1/*align widt
 // for snow slices
 typedef struct slice_buffer_s slice_buffer;
 
+/**
+ * Scantable.
+ */
+typedef struct ScanTable{
+    const uint8_t *scantable;
+    uint8_t permutated[64];
+    uint8_t raster_end[64];
+#ifdef ARCH_POWERPC
+                /** Used by dct_quantize_altivec to find last-non-zero */
+    DECLARE_ALIGNED_8(uint8_t, inverse[64]);
+#endif
+} ScanTable;
+
+void ff_init_scantable(uint8_t *, ScanTable *st, const uint8_t *src_scantable);
+
 /**
  * DSPContext.
  */