diff --git a/libavcodec/a64multienc.c b/libavcodec/a64multienc.c
index 55616c8524..91c89c87eb 100644
--- a/libavcodec/a64multienc.c
+++ b/libavcodec/a64multienc.c
@@ -107,13 +107,16 @@ static void render_charset(AVCodecContext *avctx, uint8_t *charset,
     uint8_t pix;
     int lowdiff, highdiff;
     int *best_cb = c->mc_best_cb;
-    static uint8_t index1[256];
-    static uint8_t index2[256];
-    static uint8_t dither[256];
+    uint8_t index1[256];
+    uint8_t index2[256];
+    uint8_t dither[256];
     int i;
     int distance;
 
-    /* generate lookup-tables for dither and index before looping */
+    /* Generate lookup-tables for dither and index before looping.
+     * This code relies on c->mc_luma_vals[c->mc_pal_size - 1] being
+     * the maximum of all the mc_luma_vals values and on the minimum
+     * being zero; this ensures that dither is properly initialized. */
     i = 0;
     for (a=0; a < 256; a++) {
         if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {