avcodec/huffyuvenc : remove code duplication in sub_left_prediction

start of the line (before dsp call), can be merge with width < 32 part

libavcodec/huffyuvenc.c

@@ -52,42 +52,30 @@ static inline int sub_left_prediction(HYuvContext *s, uint8_t *dst,
                                       const uint8_t *src, int w, int left)
 {
     int i;
+    int min_width = FFMIN(w, 32);
+
     if (s->bps <= 8) {
-        if (w < 32) {
-            for (i = 0; i < w; i++) {
-                const int temp = src[i];
-                dst[i] = temp - left;
-                left   = temp;
-            }
-            return left;
-        } else {
-            for (i = 0; i < 32; i++) {
-                const int temp = src[i];
-                dst[i] = temp - left;
-                left   = temp;
-            }
-            s->llvidencdsp.diff_bytes(dst + 32, src + 32, src + 31, w - 32);
-            return src[w-1];
+        for (i = 0; i < min_width; i++) { /* scalar loop before dsp call */
+            const int temp = src[i];
+            dst[i] = temp - left;
+            left   = temp;
         }
+        if (w < 32)
+            return left;
+        s->llvidencdsp.diff_bytes(dst + 32, src + 32, src + 31, w - 32);
+        return src[w-1];
     } else {
         const uint16_t *src16 = (const uint16_t *)src;
         uint16_t       *dst16 = (      uint16_t *)dst;
-        if (w < 32) {
-            for (i = 0; i < w; i++) {
-                const int temp = src16[i];
-                dst16[i] = temp - left;
-                left   = temp;
-            }
-            return left;
-        } else {
-            for (i = 0; i < 32; i++) {
-                const int temp = src16[i];
-                dst16[i] = temp - left;
-                left   = temp;
-            }
-            s->hencdsp.diff_int16(dst16 + 32, src16 + 32, src16 + 31, s->n - 1, w - 32);
-            return src16[w-1];
+        for (i = 0; i < min_width; i++) { /* scalar loop before dsp call */
+            const int temp = src16[i];
+            dst16[i] = temp - left;
+            left   = temp;
         }
+        if (w < 32)
+            return left;
+        s->hencdsp.diff_int16(dst16 + 32, src16 + 32, src16 + 31, s->n - 1, w - 32);
+        return src16[w-1];
     }
 }