diff --git a/common/common.c b/common/common.c
index 4617387..d24835e 100644
--- a/common/common.c
+++ b/common/common.c
@@ -99,6 +99,7 @@ void    x264_param_default( x264_param_t *param )
     param->rc.f_pb_factor = 1.3;
     param->rc.i_aq_mode = X264_AQ_VARIANCE;
     param->rc.f_aq_strength = 1.0;
+    param->rc.f_aq_offset_strength = 0;
     param->rc.i_lookahead = 40;
 
     param->rc.b_stat_write = 0;
@@ -569,7 +570,20 @@ int x264_param_parse( x264_param_t *p, const char *name, const char *value )
     OPT("aq-mode")
         p->rc.i_aq_mode = atoi(value);
     OPT("aq-strength")
-        p->rc.f_aq_strength = atof(value);
+    {
+        if( 2 == sscanf( value, "%f:%f", &p->rc.f_aq_strength, &p->rc.f_aq_offset_strength ) ||
+            2 == sscanf( value, "%f,%f", &p->rc.f_aq_strength, &p->rc.f_aq_offset_strength ) )
+        { }
+        else if( sscanf( value, "%f", &p->rc.f_aq_strength ) )
+        {
+            p->rc.f_aq_offset_strength = 0;
+        }
+        else
+        {
+            p->rc.f_aq_strength = 0;
+            p->rc.f_aq_offset_strength = 0;
+        }
+    }
     OPT("pass")
     {
         int i = x264_clip3( atoi(value), 0, 3 );
@@ -921,6 +935,8 @@ char *x264_param2string( x264_param_t *p, int b_res )
         s += sprintf( s, " aq=%d", p->rc.i_aq_mode );
         if( p->rc.i_aq_mode )
             s += sprintf( s, ":%.2f", p->rc.f_aq_strength );
+        if( p->rc.i_aq_mode == X264_AQ_AUTOVARIANCE && p->rc.f_aq_offset_strength != 0 )
+            s += sprintf( s, ":%.2f", p->rc.f_aq_offset_strength );
         if( p->rc.psz_zones )
             s += sprintf( s, " zones=%s", p->rc.psz_zones );
         else if( p->rc.i_zones )
diff --git a/encoder/encoder.c b/encoder/encoder.c
index b797a38..541dcbb 100644
--- a/encoder/encoder.c
+++ b/encoder/encoder.c
@@ -595,13 +595,15 @@ static int x264_validate_parameters( x264_t *h )
     h->param.analyse.i_chroma_qp_offset = x264_clip3(h->param.analyse.i_chroma_qp_offset, -12, 12);
     h->param.rc.i_aq_mode = x264_clip3( h->param.rc.i_aq_mode, 0, 2 );
     h->param.rc.f_aq_strength = x264_clip3f( h->param.rc.f_aq_strength, 0, 3 );
-    if( h->param.rc.f_aq_strength == 0 )
+    h->param.rc.f_aq_offset_strength = h->param.rc.i_aq_mode == X264_AQ_AUTOVARIANCE ? x264_clip3f( h->param.rc.f_aq_offset_strength, 0, 3 ) : 0;
+    if( h->param.rc.f_aq_strength == 0 && h->param.rc.f_aq_offset_strength == 0 )
         h->param.rc.i_aq_mode = 0;
     /* MB-tree requires AQ to be on, even if the strength is zero. */
     if( !h->param.rc.i_aq_mode && h->param.rc.b_mb_tree )
     {
         h->param.rc.i_aq_mode = 1;
         h->param.rc.f_aq_strength = 0;
+        h->param.rc.f_aq_offset_strength = 0;
     }
     if( h->param.rc.b_mb_tree && h->param.b_bframe_pyramid )
     {
diff --git a/encoder/ratecontrol.c b/encoder/ratecontrol.c
index 12c6fc5..85ee705 100644
--- a/encoder/ratecontrol.c
+++ b/encoder/ratecontrol.c
@@ -203,8 +203,9 @@ void x264_adaptive_quant_frame( x264_t *h, x264_frame_t *frame )
     int mb_x, mb_y;
     float strength;
     float avg_adj = 0.f;
+    float avg_offset = 0.f;
     /* Need to init it anyways for MB tree. */
-    if( h->param.rc.f_aq_strength == 0 )
+    if( h->param.rc.f_aq_strength == 0 && h->param.rc.f_aq_offset_strength == 0 )
     {
         int mb_xy;
         memset( frame->f_qp_offset, 0, h->mb.i_mb_count * sizeof(float) );
@@ -228,6 +229,7 @@ void x264_adaptive_quant_frame( x264_t *h, x264_frame_t *frame )
             }
         avg_adj /= h->mb.i_mb_count;
         strength = h->param.rc.f_aq_strength * avg_adj * (1.f / 6000.f);
+        avg_offset = h->param.rc.f_aq_offset_strength * (avg_adj * avg_adj - 48000.f) * (1.f / 8000.f);
     }
     else
         strength = h->param.rc.f_aq_strength * 1.0397f;
@@ -239,7 +241,7 @@ void x264_adaptive_quant_frame( x264_t *h, x264_frame_t *frame )
             if( h->param.rc.i_aq_mode == X264_AQ_AUTOVARIANCE )
             {
                 qp_adj = frame->f_qp_offset[mb_x + mb_y*h->mb.i_mb_stride];
-                qp_adj = strength * (qp_adj - avg_adj);
+                qp_adj = strength * (qp_adj - avg_adj) + avg_offset;
             }
             else
             {
diff --git a/x264.h b/x264.h
index 66f4f28..aeacc09 100644
--- a/x264.h
+++ b/x264.h
@@ -277,6 +277,7 @@ typedef struct x264_param_t
 
         int         i_aq_mode;      /* psy adaptive QP. (X264_AQ_*) */
         float       f_aq_strength;
+        float       f_aq_offset_strength;
         int         b_mb_tree;      /* Macroblock-tree ratecontrol. */
         int         i_lookahead;