diff --git a/common/common.c b/common/common.c
old mode 100644
new mode 100755
index 2d00384..c1b45d9
--- a/common/common.c
+++ b/common/common.c
@@ -140,6 +140,7 @@ void    x264_param_default( x264_param_t *param )
 
     param->b_repeat_headers = 1;
     param->b_aud = 0;
+    param->b_filler = 0;
 }
 
 static int parse_enum( const char *arg, const char * const *names, int *dst )
@@ -527,6 +528,8 @@ int x264_param_parse( x264_param_t *p, const char *name, const char *value )
         p->analyse.b_ssim = atobool(value);
     OPT("aud")
         p->b_aud = atobool(value);
+    OPT("filler")
+        p->b_filler = atobool(value);
     OPT("sps-id")
         p->i_sps_id = atoi(value);
     OPT("global-header")
diff --git a/common/common.h b/common/common.h
old mode 100644
new mode 100755
index b9f4869..329e609
--- a/common/common.h
+++ b/common/common.h
@@ -249,6 +249,7 @@ struct x264_t
         uint8_t     *p_bitstream;   /* will hold data for all nal */
         bs_t        bs;
         int         i_frame_size;
+        int         i_filler_size;
     } out;
 
     /* frame number/poc */
@@ -555,6 +556,8 @@ struct x264_t
         int     i_direct_score[2];
         int     i_direct_frames[2];
 
+        int64_t i_filler_size;
+
     } stat;
 
     /* CPU functions dependents */
diff --git a/encoder/encoder.c b/encoder/encoder.c
old mode 100644
new mode 100755
index 7637dc2..3934462
--- a/encoder/encoder.c
+++ b/encoder/encoder.c
@@ -778,8 +778,8 @@ int x264_encoder_reconfig( x264_t *h, x264_param_t *param )
     return x264_validate_parameters( h );
 }
 
-/* internal usage */
-static void x264_nal_start( x264_t *h, int i_type, int i_ref_idc )
+
+void x264_nal_start( x264_t *h, int i_type, int i_ref_idc )
 {
     x264_nal_t *nal = &h->out.nal[h->out.i_nal];
 
@@ -789,7 +789,8 @@ static void x264_nal_start( x264_t *h, int i_type, int i_ref_idc )
     nal->i_payload= 0;
     nal->p_payload= &h->out.p_bitstream[bs_pos( &h->out.bs ) / 8];
 }
-static void x264_nal_end( x264_t *h )
+
+void x264_nal_end( x264_t *h )
 {
     x264_nal_t *nal = &h->out.nal[h->out.i_nal];
     nal->i_payload = &h->out.p_bitstream[bs_pos( &h->out.bs ) / 8] - nal->p_payload;
@@ -1611,6 +1612,13 @@ static void x264_encoder_frame_end( x264_t *h, x264_t *thread_current,
         return;
     }
 
+    /* ---------------------- Update encoder state ------------------------- */
+
+    /* update rc */
+    x264_cpu_restore( h->param.cpu );
+    x264_ratecontrol_end( h, h->out.i_frame_size * 8 );
+
+
     x264_frame_push_unused( thread_current, h->fenc );
 
     /* End bitstream, set output  */
@@ -1635,10 +1643,6 @@ static void x264_encoder_frame_end( x264_t *h, x264_t *thread_current,
 
     /* ---------------------- Update encoder state ------------------------- */
 
-    /* update rc */
-    x264_cpu_restore( h->param.cpu );
-    x264_ratecontrol_end( h, h->out.i_frame_size * 8 );
-
     /* restore CPU state (before using float again) */
     x264_cpu_restore( h->param.cpu );
 
@@ -1653,6 +1657,7 @@ static void x264_encoder_frame_end( x264_t *h, x264_t *thread_current,
     h->stat.i_slice_count[h->sh.i_type]++;
     h->stat.i_slice_size[h->sh.i_type] += h->out.i_frame_size + NALU_OVERHEAD;
     h->stat.f_slice_qp[h->sh.i_type] += h->fdec->f_qp_avg_aq;
+    h->stat.i_filler_size += h->out.i_filler_size;
 
     for( i = 0; i < X264_MBTYPE_MAX; i++ )
         h->stat.i_mb_count[h->sh.i_type][i] += h->stat.frame.i_mb_count[i];
@@ -1878,7 +1883,7 @@ void    x264_encoder_close  ( x264_t *h )
         float fps = (float) h->param.i_fps_num / h->param.i_fps_den;
 #define SUM3(p) (p[SLICE_TYPE_I] + p[SLICE_TYPE_P] + p[SLICE_TYPE_B])
 #define SUM3b(p,o) (p[SLICE_TYPE_I][o] + p[SLICE_TYPE_P][o] + p[SLICE_TYPE_B][o])
-        float f_bitrate = fps * SUM3(h->stat.i_slice_size) / i_count / 125;
+        float f_bitrate = fps * (SUM3(h->stat.i_slice_size) + h->stat.i_filler_size) / i_count / 125;
 
         if( h->pps->b_transform_8x8_mode )
         {
diff --git a/encoder/ratecontrol.c b/encoder/ratecontrol.c
old mode 100644
new mode 100755
index bb10f5c..f844c0f
--- a/encoder/ratecontrol.c
+++ b/encoder/ratecontrol.c
@@ -1240,6 +1240,8 @@ static void update_predictor( predictor_t *p, double q, double var, double bits
     p->coeff += bits*q / var;
 }
 
+#define FILLER_OVERHEAD (5 + 1)
+
 // update VBV after encoding a frame
 static void update_vbv( x264_t *h, int bits )
 {
@@ -1253,6 +1255,17 @@ static void update_vbv( x264_t *h, int bits )
         return;
 
     rct->buffer_fill_final += rct->buffer_rate - bits;
+
+    if (rct->buffer_fill_final >= rct->buffer_size &&
+        h->param.b_filler &&
+        h->thread[0]->param.rc.i_vbv_max_bitrate == h->param.rc.i_bitrate)
+    {
+        int padding = (rct->buffer_fill_final - rct->buffer_size) / 8;
+        x264_filler_write(h, padding);
+        h->out.i_filler_size = padding+FILLER_OVERHEAD;
+        rct->buffer_fill_final -= h->out.i_filler_size * 8;
+    }
+
     if( rct->buffer_fill_final < 0 && !rct->b_2pass )
         x264_log( h, X264_LOG_WARNING, "VBV underflow (%.0f bits)\n", rct->buffer_fill_final );
     rct->buffer_fill_final = x264_clip3f( rct->buffer_fill_final, 0, rct->buffer_size );
diff --git a/encoder/set.c b/encoder/set.c
old mode 100644
new mode 100755
index 6cf8773..23c0724
--- a/encoder/set.c
+++ b/encoder/set.c
@@ -28,6 +28,8 @@
 #include "config.h"
 #endif
 
+#include "set.h"
+
 static void transpose( uint8_t *buf, int w )
 {
     int i, j;
@@ -503,6 +505,20 @@ void x264_sei_version_write( x264_t *h, bs_t *s )
     x264_free( version );
 }
 
+
+void x264_filler_write( x264_t *h, int filler_bytes )
+{
+    int i;
+
+    x264_nal_start( h, NAL_FILLER, NAL_PRIORITY_DISPOSABLE );
+    for (i=0; i< filler_bytes; i++)
+    {
+        bs_write( &h->out.bs, 8, 0xFF );
+    }
+    bs_rbsp_trailing(&h->out.bs);
+    x264_nal_end( h );
+}
+
 const x264_level_t x264_levels[] =
 {
     { 10,   1485,    99,   152064,     64,    175,  64, 64,  0, 0, 0, 1 },
diff --git a/encoder/set.h b/encoder/set.h
old mode 100644
new mode 100755
index dac2d2f..0cf4e82
--- a/encoder/set.h
+++ b/encoder/set.h
@@ -24,11 +24,15 @@
 #ifndef _ENCODER_SET_H
 #define _ENCODER_SET_H 1
 
+void x264_nal_start( x264_t *h, int i_type, int i_ref_idc );
+void x264_nal_end( x264_t *h );
+
 void x264_sps_init( x264_sps_t *sps, int i_id, x264_param_t *param );
 void x264_sps_write( bs_t *s, x264_sps_t *sps );
 void x264_pps_init( x264_pps_t *pps, int i_id, x264_param_t *param, x264_sps_t *sps );
 void x264_pps_write( bs_t *s, x264_pps_t *pps );
 void x264_sei_version_write( x264_t *h, bs_t *s );
+void x264_filler_write(  x264_t *h, int filler_bytes );
 void x264_validate_levels( x264_t *h );
 
 #endif
diff --git a/x264.c b/x264.c
old mode 100644
new mode 100755
index 51bd0cd..f1622ca
--- a/x264.c
+++ b/x264.c
@@ -320,6 +320,7 @@ static void Help( x264_param_t *defaults, int b_longhelp )
     H1( "      --visualize             Show MB types overlayed on the encoded video\n" );
     H1( "      --sps-id <integer>      Set SPS and PPS id numbers [%d]\n", defaults->i_sps_id );
     H1( "      --aud                   Use access unit delimiters\n" );
+    H1( "      --filler                Use filler data access units\n" );
     H0( "\n" );
 }
 
@@ -447,6 +448,7 @@ static int  Parse( int argc, char **argv,
             { "visualize",no_argument,      NULL, OPT_VISUALIZE },
             { "sps-id",  required_argument, NULL, 0 },
             { "aud",     no_argument,       NULL, 0 },
+            { "filler",  no_argument,       NULL, 0 },
             { "nr",      required_argument, NULL, 0 },
             { "cqm",     required_argument, NULL, 0 },
             { "cqmfile", required_argument, NULL, 0 },
diff --git a/x264.h b/x264.h
old mode 100644
new mode 100755
index e49f1a4..9d0ca18
--- a/x264.h
+++ b/x264.h
@@ -283,6 +283,7 @@ typedef struct x264_param_t
     } rc;
 
     /* Muxing parameters */
+    int b_filler;               /* use filler data */
     int b_aud;                  /* generate access unit delimiters */
     int b_repeat_headers;       /* put SPS/PPS before each keyframe */
     int i_sps_id;               /* SPS and PPS id number */
@@ -372,6 +373,7 @@ enum nal_unit_type_e
     NAL_SPS         = 7,
     NAL_PPS         = 8,
     NAL_AUD         = 9,
+    NAL_FILLER      = 12,
     /* ref_idc == 0 for 6,9,10,11,12 */
 };
 enum nal_priority_e