diff --git a/libavcodec/vorbis.c b/libavcodec/vorbis.c
index 28176f3..b0cfc1c 100644
--- a/libavcodec/vorbis.c
+++ b/libavcodec/vorbis.c
@@ -210,10 +210,16 @@ void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
                                   uint16_t *y_list, int *flag,
                                   int multiplier, float *out, int samples)
 {
-    int lx, i;
+    int lx, i, j;
     uint8_t ly;
     lx = 0;
     ly = y_list[0] * multiplier;
+       for (i = 1; i<values; i++)
+        for (j = i+1; j<values-1; j++)
+            if (list[i].x == list[j].x) {
+                  av_log(0, AV_LOG_ERROR, "Same value of x = %d detected in floor1 list.", list[i].x);
+                  return AVERROR_INVALIDDATA;
+            }
     for (i = 1; i < values; i++) {
         int pos = list[i].sort;
         if (flag[pos]) {