diff --git a/libavcodec/error_resilience.c b/libavcodec/error_resilience.c
index efd1dd56a6..b0d22ddf97 100644
--- a/libavcodec/error_resilience.c
+++ b/libavcodec/error_resilience.c
@@ -677,8 +677,8 @@ void ff_er_frame_end(MpegEncContext *s){
             
         for(i=0; i<2; i++){
             pic->ref_index[i]= av_mallocz(size * sizeof(uint8_t));
-            pic->motion_val_base[i]= av_mallocz((size+2) * 2 * sizeof(uint16_t));
-            pic->motion_val[i]= pic->motion_val_base[i]+2;
+            pic->motion_val_base[i]= av_mallocz((size+4) * 2 * sizeof(uint16_t));
+            pic->motion_val[i]= pic->motion_val_base[i]+4;
         }
         pic->motion_subsample_log2= 3;
         s->current_picture= *s->current_picture_ptr;
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 3e3e6c6000..50d44c972f 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -385,15 +385,15 @@ static int alloc_picture(MpegEncContext *s, Picture *pic, int shared){
         pic->mb_type= pic->mb_type_base + s->mb_stride+1;
         if(s->out_format == FMT_H264){
             for(i=0; i<2; i++){
-                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b4_array_size+2)  * sizeof(int16_t))
-                pic->motion_val[i]= pic->motion_val_base[i]+2;
+                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b4_array_size+4)  * sizeof(int16_t))
+                pic->motion_val[i]= pic->motion_val_base[i]+4;
                 CHECKED_ALLOCZ(pic->ref_index[i], b8_array_size * sizeof(uint8_t))
             }
             pic->motion_subsample_log2= 2;
         }else if(s->out_format == FMT_H263 || s->encoding || (s->avctx->debug&FF_DEBUG_MV) || (s->avctx->debug_mv)){
             for(i=0; i<2; i++){
-                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b8_array_size+2) * sizeof(int16_t))
-                pic->motion_val[i]= pic->motion_val_base[i]+2;
+                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b8_array_size+4) * sizeof(int16_t))
+                pic->motion_val[i]= pic->motion_val_base[i]+4;
                 CHECKED_ALLOCZ(pic->ref_index[i], b8_array_size * sizeof(uint8_t))
             }
             pic->motion_subsample_log2= 3;