diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index e6eb11f955..678ae5f7ae 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -841,6 +841,7 @@ typedef struct AVCodecContext {
 #define FF_BUG_XVID_ILACE       4
 #define FF_BUG_UMP4             8
 #define FF_BUG_NO_PADDING       16
+#define FF_BUG_AMV              32
 #define FF_BUG_AC_VLC           0  ///< will be removed, libavcodec can now handle these non compliant files by default
 #define FF_BUG_QPEL_CHROMA      64
 #define FF_BUG_STD_QPEL         128
diff --git a/libavcodec/h263.c b/libavcodec/h263.c
index 21185dc586..c1113f5bd2 100644
--- a/libavcodec/h263.c
+++ b/libavcodec/h263.c
@@ -3221,6 +3221,9 @@ static inline int get_amv(MpegEncContext *s, int n){
     int x, y, mb_v, sum, dx, dy, shift;
     int len = 1 << (s->f_code + 4);
     const int a= s->sprite_warping_accuracy;
+    
+    if(s->workaround_bugs & FF_BUG_AMV)
+        len >>= s->quarter_sample;
 
     if(s->real_sprite_warping_points==1){
         if(s->divx_version==500 && s->divx_build==413)