--- a/src/xs_support.c	Mon Feb 09 13:23:32 2009 +0200
+++ b/src/xs_support.c	Mon Feb 09 14:56:56 2009 +0200
@@ -243,3 +243,64 @@
         (*pos)++;
 }
 
+
+/* Let's do some preprocessor magic :) */
+#define XS_FVAR(T, P, K) g ## K ## int ## P *sp_ ## T ## P , *dp_ ## T ## P
+
+#define XS_FILTER1(T, P, K, Q)                            \
+    dataSize /= sizeof(g ## K ## int ## P);                 \
+    sp_ ## T ## P = (g ## K ## int ## P *) srcBuf;                \
+    dp_ ## T ## P = (g ## K ## int ## P *) destBuf;                \
+    while (dataSize-- > 0) {                        \
+        for (tmp = 0, i = 0; i < oversampleFactor; i++)            \
+            tmp += (gint32) ((gint ## P) (*(sp_ ## T ## P ++) Q));    \
+        xs_filter_mbn = (tmp + xs_filter_mbn) / (oversampleFactor + 1);    \
+        *(dp_ ## T ## P ++) = ((g ## K ## int ## P) xs_filter_mbn) Q ;    \
+        }
+
+
+static gint32 xs_filter_mbn = 0;
+
+
+gint xs_filter_rateconv(void *destBuf, void *srcBuf, const AFormat audioFormat,
+            const gint oversampleFactor, const gint bufSize)
+{
+    static gint32 tmp;
+    XS_FVAR(s, 8,);
+    XS_FVAR(u, 8, u);
+    XS_FVAR(s, 16,);
+    XS_FVAR(u, 16, u);
+    gint i;
+    gint dataSize = bufSize;
+
+    if (dataSize <= 0)
+        return dataSize;
+
+    switch (audioFormat) {
+    case FMT_U8:
+        XS_FILTER1(u, 8, u, ^0x80)
+            break;
+
+    case FMT_S8:
+        XS_FILTER1(s, 8,,)
+            break;
+
+
+    case FMT_U16_BE:
+    case FMT_U16_LE:
+    case FMT_U16_NE:
+        XS_FILTER1(u, 16, u, ^0x8000)
+            break;
+
+    case FMT_S16_BE:
+    case FMT_S16_LE:
+    case FMT_S16_NE:
+        XS_FILTER1(s, 16,,)
+            break;
+
+    default:
+        return -1;
+    }
+
+    return 0;
+}