diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index fae07c5511..ce9efb26b9 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -336,18 +336,18 @@ static int alloc_picture(MpegEncContext *s, Picture *pic, int shared){
 
         CHECKED_ALLOCZ(pic->mbskip_table , mb_array_size * sizeof(uint8_t)+2) //the +2 is for the slice end check
         CHECKED_ALLOCZ(pic->qscale_table , mb_array_size * sizeof(uint8_t))
-        CHECKED_ALLOCZ(pic->mb_type_base , big_mb_num    * sizeof(int))
+        CHECKED_ALLOCZ(pic->mb_type_base , big_mb_num    * sizeof(uint32_t))
         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+1)  * sizeof(uint16_t))
+                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b4_array_size+1)  * sizeof(int16_t))
                 pic->motion_val[i]= pic->motion_val_base[i]+1;
                 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+1) * sizeof(uint16_t)*2) //FIXME
+                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b8_array_size+1) * sizeof(int16_t)*2) //FIXME
                 pic->motion_val[i]= pic->motion_val_base[i]+1;
             }
             pic->motion_subsample_log2= 3;