Index: common/common.c
===================================================================
--- common/common.c	(revision 661)
+++ common/common.c	(working copy)
@@ -463,6 +463,8 @@
         p->analyse.i_luma_deadzone[1] = atoi(value);
     OPT("nr")
         p->analyse.i_noise_reduction = atoi(value);
+    OPT("lowpass")
+        p->analyse.b_dct_lowpass = atobool(value);
     OPT("bitrate")
     {
         p->rc.i_bitrate = atoi(value);
@@ -889,6 +891,7 @@
     s += sprintf( s, " chroma_qp_offset=%d", p->analyse.i_chroma_qp_offset );
     s += sprintf( s, " threads=%d", p->i_threads );
     s += sprintf( s, " nr=%d", p->analyse.i_noise_reduction );
+    s += sprintf( s, " lowpass=%d", p->analyse.b_dct_lowpass );
     s += sprintf( s, " decimate=%d", p->analyse.b_dct_decimate );
     s += sprintf( s, " mbaff=%d", p->b_interlaced );
 
Index: common/common.h
===================================================================
--- common/common.h	(revision 661)
+++ common/common.h	(working copy)
@@ -428,6 +428,7 @@
         int     b_chroma_me;
         int     b_trellis;
         int     b_noise_reduction;
+        int     b_dct_lowpass;
 
         int     b_interlaced;
 
Index: encoder/analyse.c
===================================================================
--- encoder/analyse.c	(revision 661)
+++ encoder/analyse.c	(working copy)
@@ -210,6 +210,7 @@
     h->mb.b_trellis = h->param.analyse.i_trellis > 1 && a->b_mbrd;
     h->mb.b_transform_8x8 = 0;
     h->mb.b_noise_reduction = 0;
+    h->mb.b_dct_lowpass = 0;
 
     /* I: Intra part */
     a->i_satd_i16x16 =
@@ -2562,6 +2563,7 @@
 
     h->mb.b_trellis = h->param.analyse.i_trellis;
     h->mb.b_noise_reduction = h->param.analyse.i_noise_reduction;
+    h->mb.b_dct_lowpass = h->param.analyse.b_dct_lowpass;
 }
 
 /*-------------------- Update MB from the analysis ----------------------*/
Index: encoder/encoder.c
===================================================================
--- encoder/encoder.c	(revision 661)
+++ encoder/encoder.c	(working copy)
@@ -407,6 +407,7 @@
         h->param.analyse.i_trellis = 0;
         h->param.analyse.b_fast_pskip = 0;
         h->param.analyse.i_noise_reduction = 0;
+        h->param.analyse.b_dct_lowpass = 0;
         h->param.analyse.i_subpel_refine = x264_clip3( h->param.analyse.i_subpel_refine, 1, 6 );
     }
     if( h->param.rc.i_rc_method == X264_RC_CQP )
@@ -749,6 +750,7 @@
     COPY( analyse.i_me_method );
     COPY( analyse.i_me_range );
     COPY( analyse.i_noise_reduction );
+    COPY( analyse.b_dct_lowpass );
     COPY( analyse.i_subpel_refine );
     COPY( analyse.i_trellis );
     COPY( analyse.b_bidir_me );
Index: encoder/macroblock.c
===================================================================
--- encoder/macroblock.c	(revision 661)
+++ encoder/macroblock.c	(working copy)
@@ -98,6 +98,9 @@
 
     h->dctf.sub4x4_dct( dct4x4, p_src, p_dst );
 
+    if( h->mb.b_dct_lowpass )
+        x264_lowpass_dct( h, (int16_t*)dct4x4 );
+
     if( h->mb.b_trellis )
         x264_quant_4x4_trellis( h, dct4x4, CQM_4IY, i_qscale, DCT_LUMA_4x4, 1 );
     else
@@ -120,6 +123,8 @@
 
     h->dctf.sub8x8_dct8( dct8x8, p_src, p_dst );
 
+    if( h->mb.b_dct_lowpass )
+        x264_lowpass_dct( h, (int16_t*)dct8x8 );
     if( h->mb.b_trellis )
         x264_quant_8x8_trellis( h, dct8x8, CQM_8IY, i_qscale, 1 );
     else 
@@ -159,6 +164,9 @@
         /* copy dc coeff */
         dct4x4[0][block_idx_y[i]][block_idx_x[i]] = dct4x4[1+i][0][0];
 
+        if( h->mb.b_dct_lowpass )
+            x264_lowpass_dct( h, (int16_t*)dct4x4[1+i] );
+
         /* quant/scan/dequant */
         if( h->mb.b_trellis )
             x264_quant_4x4_trellis( h, dct4x4[1+i], CQM_4IY, i_qscale, DCT_LUMA_AC, 1 );
@@ -427,6 +435,8 @@
             {
                 if( h->mb.b_noise_reduction )
                     x264_denoise_dct( h, (int16_t*)dct8x8[idx] );
+                if( h->mb.b_dct_lowpass )
+                    x264_lowpass_dct( h, (int16_t*)dct8x8[idx] );
                 if( h->mb.b_trellis )
                     x264_quant_8x8_trellis( h, dct8x8[idx], CQM_8PY, i_qp, 0 );
                 else
@@ -479,6 +489,8 @@
 
                     if( h->mb.b_noise_reduction )
                         x264_denoise_dct( h, (int16_t*)dct4x4[idx] );
+                    if( h->mb.b_dct_lowpass )
+                        x264_lowpass_dct( h, (int16_t*)dct4x4[idx] );
                     if( h->mb.b_trellis )
                         x264_quant_4x4_trellis( h, dct4x4[idx], CQM_4PY, i_qp, DCT_LUMA_4x4, 0 );
                     else
@@ -725,6 +737,141 @@
     }
 }
 
+#define DCT_SUBBANDS 4
+
+const static DECLARE_ALIGNED( int16_t, subbands_4x4[4][4], 16) = 
+{
+    {0,  1,  2,  3},
+    {1,  1,  2,  3},
+    {2,  2,  2,  3},
+    {3,  3,  3,  3}
+};
+
+const static DECLARE_ALIGNED( int16_t, subbands_8x8[8][8], 16) = 
+{
+    {0,  0,  1,  1,  2,  2,  3,  3},
+    {0,  0,  1,  1,  2,  2,  3,  3},
+    {1,  1,  1,  1,  2,  2,  3,  3},
+    {1,  1,  1,  1,  2,  2,  3,  3},
+    {2,  2,  2,  2,  2,  2,  3,  3},
+    {2,  2,  2,  2,  2,  2,  3,  3},
+    {3,  3,  3,  3,  3,  3,  3,  3},
+    {3,  3,  3,  3,  3,  3,  3,  3},
+};
+
+#define FLT_COEF(a) ((int)(a*128.))
+
+const static int dct_lowpass_coeffs[52][DCT_SUBBANDS] = 
+{
+    //0
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    //5
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    //10
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    //15
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    //20
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    //25
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), },
+    //30
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(.9), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(.8), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(.7), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(.6), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(1), FLT_COEF(.5), },
+    //35
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.9), FLT_COEF(.4), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.9), FLT_COEF(.3), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.9), FLT_COEF(.2), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.8), FLT_COEF(.1), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.8), FLT_COEF(0), },
+    //40
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.7), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.6), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.5), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(1), FLT_COEF(.4), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(.9), FLT_COEF(.2), FLT_COEF(0), },
+    //45
+    {FLT_COEF(1), FLT_COEF(.9), FLT_COEF(.1), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(.8), FLT_COEF(0), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(.6), FLT_COEF(0), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(.4), FLT_COEF(0), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(.3), FLT_COEF(0), FLT_COEF(0), },
+    //50
+    {FLT_COEF(1), FLT_COEF(.2), FLT_COEF(0), FLT_COEF(0), },
+    {FLT_COEF(1), FLT_COEF(.2), FLT_COEF(0), FLT_COEF(0), }
+};
+
+#undef FLT_COEF
+
+void x264_lowpass_dct( x264_t *h, int16_t *dct )
+{
+    DECLARE_ALIGNED(int, subbands_zigzag[8*8], 16);
+    const int cat = h->mb.b_transform_8x8;
+    int i=0;
+    int iQp = h->mb.i_qp;
+
+    if (h->mb.i_type == I_16x16 || h->mb.i_type == I_8x8 || h->mb.i_type == I_4x4)
+        iQp -= 6;
+    if (iQp < 0)
+        iQp = 0;
+
+
+    if (cat)
+    {
+        h->zigzagf.scan_8x8( subbands_zigzag, subbands_8x8 );
+    }
+    else
+    {
+        h->zigzagf.scan_4x4( subbands_zigzag, subbands_4x4 );
+    }
+
+    for( i = (cat ? 63 : 15); i >= 1; i-- )
+    {
+        int level = dct[i];
+        int subband = subbands_zigzag[i];
+        if (level > 0)
+        {
+            level = (level * dct_lowpass_coeffs[iQp][subband] + 64) / 128;
+        }
+        else
+        {
+            level = -(-level * dct_lowpass_coeffs[iQp][subband] + 64) / 128;
+        }
+        dct[i] = level;
+    }
+
+    
+
+}
+
+
 void x264_denoise_dct( x264_t *h, int16_t *dct )
 {
     const int cat = h->mb.b_transform_8x8;
Index: encoder/macroblock.h
===================================================================
--- encoder/macroblock.h	(revision 661)
+++ encoder/macroblock.h	(working copy)
@@ -53,6 +53,7 @@
 
 void x264_noise_reduction_update( x264_t *h );
 void x264_denoise_dct( x264_t *h, int16_t *dct );
+void x264_lowpass_dct( x264_t *h, int16_t *dct );
 
 #define array_non_zero(a) array_non_zero_int(a, sizeof(a))
 static inline int array_non_zero_int( void *v, int i_count )
Index: x264.c
===================================================================
--- x264.c	(revision 661)
+++ x264.c	(working copy)
@@ -253,6 +253,7 @@
         "                                  - 2: enabled on all mode decisions\n", defaults->analyse.i_trellis );
     H0( "      --no-fast-pskip         Disables early SKIP detection on P-frames\n" );
     H0( "      --no-dct-decimate       Disables coefficient thresholding on P-frames\n" );
+    H0( "      --lowpass               Enables adaptive lowpass filter\n" );
     H0( "      --nr <integer>          Noise reduction [%d]\n", defaults->analyse.i_noise_reduction );
     H1( "\n" );
     H1( "      --deadzone-inter <int>  Set the size of the inter luma quantization deadzone [%d]\n", defaults->analyse.i_luma_deadzone[0] );
@@ -414,6 +415,7 @@
             { "bime",    no_argument,       NULL, 0 },
             { "8x8dct",  no_argument,       NULL, '8' },
             { "trellis", required_argument, NULL, 't' },
+            { "lowpass", no_argument, NULL, 0 },
             { "no-fast-pskip", no_argument, NULL, 0 },
             { "no-dct-decimate", no_argument, NULL, 0 },
             { "deadzone-inter", required_argument, NULL, '0' },
Index: x264.h
===================================================================
--- x264.h	(revision 661)
+++ x264.h	(working copy)
@@ -224,6 +224,7 @@
         int          b_fast_pskip; /* early SKIP detection on P-frames */
         int          b_dct_decimate; /* transform coefficient thresholding on P-frames */
         int          i_noise_reduction; /* adaptive pseudo-deadzone */
+        int          b_dct_lowpass; /* adaptive dct lowpass filter */
 
         /* the deadzone size that will be used in luma quantization */
         int          i_luma_deadzone[2]; /* {inter, intra} */