]> git.sesse.net Git - x264/blobdiff - encoder/ratecontrol.c
Slightly faster predictor_difference_mmxext
[x264] / encoder / ratecontrol.c
index ef23f2323d22a3d71a4e80a510f01d673b085658..0e3e99ab080a36d7572faad50cd7658faa185dd9 100644 (file)
@@ -36,6 +36,7 @@
 typedef struct
 {
     int pict_type;
+    int frame_type;
     int kept_as_ref;
     double qscale;
     int mv_bits;
@@ -128,7 +129,9 @@ struct x264_ratecontrol_t
     double lmin[5];             /* min qscale by frame type */
     double lmax[5];
     double lstep;               /* max change (multiply) in qscale per frame */
-    uint16_t *qp_buffer;        /* Global buffer for converting MB-tree quantizer data. */
+    uint16_t *qp_buffer[2];     /* Global buffers for converting MB-tree quantizer data. */
+    int qpbuf_pos;              /* In order to handle pyramid reordering, QP buffer acts as a stack.
+                                 * This value is the current position (0 or 1). */
 
     /* MBRC stuff */
     double frame_size_estimated;
@@ -154,6 +157,15 @@ static void update_vbv_plan( x264_t *h, int overhead );
 static double predict_size( predictor_t *p, double q, double var );
 static void update_predictor( predictor_t *p, double q, double var, double bits );
 
+#define CMP_OPT_FIRST_PASS( opt, param_val )\
+{\
+    if( ( p = strstr( opts, opt "=" ) ) && sscanf( p, opt "=%d" , &i ) && param_val != i )\
+    {\
+        x264_log( h, X264_LOG_ERROR, "different " opt " setting than first pass (%d vs %d)\n", param_val, i );\
+        return -1;\
+    }\
+}
+
 /* Terminology:
  * qp = h.264's quantizer
  * qscale = linearized quantizer = Lagrange multiplier
@@ -278,8 +290,8 @@ void x264_adaptive_quant_frame( x264_t *h, x264_frame_t *frame )
 void x264_adaptive_quant( x264_t *h )
 {
     x264_emms();
-    /* MB-tree currently doesn't adjust quantizers in B-frames. */
-    float qp_offset = h->sh.i_type == SLICE_TYPE_B ? h->fenc->f_qp_offset_aq[h->mb.i_mb_xy] : h->fenc->f_qp_offset[h->mb.i_mb_xy];
+    /* MB-tree currently doesn't adjust quantizers in unreferenced frames. */
+    float qp_offset = h->fdec->b_kept_as_ref ? h->fenc->f_qp_offset[h->mb.i_mb_xy] : h->fenc->f_qp_offset_aq[h->mb.i_mb_xy];
     h->mb.i_qp = x264_clip3( h->rc->f_qpm + qp_offset + .5, h->param.rc.i_qp_min, h->param.rc.i_qp_max );
 }
 
@@ -289,28 +301,35 @@ int x264_macroblock_tree_read( x264_t *h, x264_frame_t *frame )
     uint8_t i_type_actual = rc->entry[frame->i_frame].pict_type;
     int i;
 
-    if( i_type_actual != SLICE_TYPE_B )
+    if( rc->entry[frame->i_frame].kept_as_ref )
     {
         uint8_t i_type;
+        if( rc->qpbuf_pos < 0 )
+        {
+            do
+            {
+                rc->qpbuf_pos++;
 
-        if( !fread( &i_type, 1, 1, rc->p_mbtree_stat_file_in ) )
-            goto fail;
+                if( !fread( &i_type, 1, 1, rc->p_mbtree_stat_file_in ) )
+                    goto fail;
+                if( fread( rc->qp_buffer[rc->qpbuf_pos], sizeof(uint16_t), h->mb.i_mb_count, rc->p_mbtree_stat_file_in ) != h->mb.i_mb_count )
+                    goto fail;
 
-        if( i_type != i_type_actual )
-        {
-            x264_log(h, X264_LOG_ERROR, "MB-tree frametype %d doesn't match actual frametype %d.\n", i_type,i_type_actual);
-            return -1;
+                if( i_type != i_type_actual && rc->qpbuf_pos == 1 )
+                {
+                    x264_log(h, X264_LOG_ERROR, "MB-tree frametype %d doesn't match actual frametype %d.\n", i_type, i_type_actual);
+                    return -1;
+                }
+            } while( i_type != i_type_actual );
         }
 
-        if( fread( rc->qp_buffer, sizeof(uint16_t), h->mb.i_mb_count, rc->p_mbtree_stat_file_in ) != h->mb.i_mb_count )
-            goto fail;
-
         for( i = 0; i < h->mb.i_mb_count; i++ )
         {
-            frame->f_qp_offset[i] = ((float)(int16_t)endian_fix16( rc->qp_buffer[i] )) * (1/256.0);
+            frame->f_qp_offset[i] = ((float)(int16_t)endian_fix16( rc->qp_buffer[rc->qpbuf_pos][i] )) * (1/256.0);
             if( h->frames.b_have_lowres )
                 frame->i_inv_qscale_factor[i] = x264_exp2fix8(frame->f_qp_offset[i]);
         }
+        rc->qpbuf_pos--;
     }
     else
         x264_adaptive_quant_frame( h, frame );
@@ -369,6 +388,53 @@ static char *x264_strcat_filename( char *input, char *suffix )
     return output;
 }
 
+void x264_ratecontrol_init_reconfigurable( x264_t *h, int b_init )
+{
+    x264_ratecontrol_t *rc = h->rc;
+    if( !b_init && rc->b_2pass )
+        return;
+
+    if( h->param.rc.i_vbv_max_bitrate > 0 && h->param.rc.i_vbv_buffer_size > 0 )
+    {
+        if( h->param.rc.i_vbv_buffer_size < (int)(h->param.rc.i_vbv_max_bitrate / rc->fps) )
+        {
+            h->param.rc.i_vbv_buffer_size = h->param.rc.i_vbv_max_bitrate / rc->fps;
+            x264_log( h, X264_LOG_WARNING, "VBV buffer size cannot be smaller than one frame, using %d kbit\n",
+                      h->param.rc.i_vbv_buffer_size );
+        }
+
+        /* We don't support changing the ABR bitrate right now,
+           so if the stream starts as CBR, keep it CBR. */
+        if( rc->b_vbv_min_rate )
+            h->param.rc.i_vbv_max_bitrate = h->param.rc.i_bitrate;
+        rc->buffer_rate = h->param.rc.i_vbv_max_bitrate * 1000. / rc->fps;
+        rc->buffer_size = h->param.rc.i_vbv_buffer_size * 1000.;
+        rc->single_frame_vbv = rc->buffer_rate * 1.1 > rc->buffer_size;
+        rc->cbr_decay = 1.0 - rc->buffer_rate / rc->buffer_size
+                      * 0.5 * X264_MAX(0, 1.5 - rc->buffer_rate * rc->fps / rc->bitrate);
+        if( b_init )
+        {
+            if( h->param.rc.f_vbv_buffer_init > 1. )
+                h->param.rc.f_vbv_buffer_init = x264_clip3f( h->param.rc.f_vbv_buffer_init / h->param.rc.i_vbv_buffer_size, 0, 1 );
+            h->param.rc.f_vbv_buffer_init = X264_MAX( h->param.rc.f_vbv_buffer_init, rc->buffer_rate / rc->buffer_size );
+            rc->buffer_fill_final = rc->buffer_size * h->param.rc.f_vbv_buffer_init;
+            rc->b_vbv = 1;
+            rc->b_vbv_min_rate = !rc->b_2pass
+                          && h->param.rc.i_rc_method == X264_RC_ABR
+                          && h->param.rc.i_vbv_max_bitrate <= h->param.rc.i_bitrate;
+        }
+    }
+    if( h->param.rc.i_rc_method == X264_RC_CRF )
+    {
+        /* Arbitrary rescaling to make CRF somewhat similar to QP.
+         * Try to compensate for MB-tree's effects as well. */
+        double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
+        double mbtree_offset = h->param.rc.b_mb_tree ? (1.0-h->param.rc.f_qcompress)*13.5 : 0;
+        rc->rate_factor_constant = pow( base_cplx, 1 - rc->qcompress )
+                                 / qp2qscale( h->param.rc.f_rf_constant + mbtree_offset );
+    }
+}
+
 int x264_ratecontrol_new( x264_t *h )
 {
     x264_ratecontrol_t *rc;
@@ -407,52 +473,10 @@ int x264_ratecontrol_new( x264_t *h )
         x264_log(h, X264_LOG_ERROR, "constant rate-factor is incompatible with 2pass.\n");
         return -1;
     }
-    if( h->param.rc.i_vbv_buffer_size )
-    {
-        if( h->param.rc.i_rc_method == X264_RC_CQP )
-        {
-            x264_log(h, X264_LOG_WARNING, "VBV is incompatible with constant QP, ignored.\n");
-            h->param.rc.i_vbv_max_bitrate = 0;
-            h->param.rc.i_vbv_buffer_size = 0;
-        }
-        else if( h->param.rc.i_vbv_max_bitrate == 0 )
-        {
-            x264_log( h, X264_LOG_DEBUG, "VBV maxrate unspecified, assuming CBR\n" );
-            h->param.rc.i_vbv_max_bitrate = h->param.rc.i_bitrate;
-        }
-    }
-    if( h->param.rc.i_vbv_max_bitrate < h->param.rc.i_bitrate &&
-        h->param.rc.i_vbv_max_bitrate > 0)
-        x264_log(h, X264_LOG_WARNING, "max bitrate less than average bitrate, ignored.\n");
-    else if( h->param.rc.i_vbv_max_bitrate > 0 &&
-             h->param.rc.i_vbv_buffer_size > 0 )
-    {
-        if( h->param.rc.i_vbv_buffer_size < (int)(h->param.rc.i_vbv_max_bitrate / rc->fps) )
-        {
-            h->param.rc.i_vbv_buffer_size = h->param.rc.i_vbv_max_bitrate / rc->fps;
-            x264_log( h, X264_LOG_WARNING, "VBV buffer size cannot be smaller than one frame, using %d kbit\n",
-                      h->param.rc.i_vbv_buffer_size );
-        }
-        if( h->param.rc.f_vbv_buffer_init > 1. )
-            h->param.rc.f_vbv_buffer_init = x264_clip3f( h->param.rc.f_vbv_buffer_init / h->param.rc.i_vbv_buffer_size, 0, 1 );
-        rc->buffer_rate = h->param.rc.i_vbv_max_bitrate * 1000. / rc->fps;
-        rc->buffer_size = h->param.rc.i_vbv_buffer_size * 1000.;
-        rc->single_frame_vbv = rc->buffer_rate * 1.1 > rc->buffer_size;
-        h->param.rc.f_vbv_buffer_init = X264_MAX( h->param.rc.f_vbv_buffer_init, rc->buffer_rate / rc->buffer_size );
-        rc->buffer_fill_final = rc->buffer_size * h->param.rc.f_vbv_buffer_init;
-        rc->cbr_decay = 1.0 - rc->buffer_rate / rc->buffer_size
-                      * 0.5 * X264_MAX(0, 1.5 - rc->buffer_rate * rc->fps / rc->bitrate);
-        rc->b_vbv = 1;
-        rc->b_vbv_min_rate = !rc->b_2pass
-                          && h->param.rc.i_rc_method == X264_RC_ABR
-                          && h->param.rc.i_vbv_max_bitrate <= h->param.rc.i_bitrate;
-    }
-    else if( h->param.rc.i_vbv_max_bitrate )
-    {
-        x264_log(h, X264_LOG_WARNING, "VBV maxrate specified, but no bufsize.\n");
-        h->param.rc.i_vbv_max_bitrate = 0;
-    }
-    if(rc->rate_tolerance < 0.01)
+
+    x264_ratecontrol_init_reconfigurable( h, 1 );
+
+    if( rc->rate_tolerance < 0.01 )
     {
         x264_log(h, X264_LOG_WARNING, "bitrate tolerance too small, using .01\n");
         rc->rate_tolerance = 0.01;
@@ -472,21 +496,12 @@ int x264_ratecontrol_new( x264_t *h )
         rc->last_non_b_pict_type = SLICE_TYPE_I;
     }
 
-    if( h->param.rc.i_rc_method == X264_RC_CRF )
-    {
-        /* Arbitrary rescaling to make CRF somewhat similar to QP.
-         * Try to compensate for MB-tree's effects as well. */
-        double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
-        double mbtree_offset = h->param.rc.b_mb_tree ? (1.0-h->param.rc.f_qcompress)*13.5 : 0;
-        rc->rate_factor_constant = pow( base_cplx, 1 - rc->qcompress )
-                                 / qp2qscale( h->param.rc.f_rf_constant + mbtree_offset );
-    }
-
     rc->ip_offset = 6.0 * log(h->param.rc.f_ip_factor) / log(2.0);
     rc->pb_offset = 6.0 * log(h->param.rc.f_pb_factor) / log(2.0);
     rc->qp_constant[SLICE_TYPE_P] = h->param.rc.i_qp_constant;
     rc->qp_constant[SLICE_TYPE_I] = x264_clip3( h->param.rc.i_qp_constant - rc->ip_offset + 0.5, 0, 51 );
     rc->qp_constant[SLICE_TYPE_B] = x264_clip3( h->param.rc.i_qp_constant + rc->pb_offset + 0.5, 0, 51 );
+    h->mb.ip_offset = rc->ip_offset + 0.5;
 
     rc->lstep = pow( 2, h->param.rc.i_qp_step / 6.0 );
     rc->last_qscale = qp2qscale(26);
@@ -566,35 +581,11 @@ int x264_ratecontrol_new( x264_t *h )
                 return -1;
             }
 
-            if( ( p = strstr( opts, "bframes=" ) ) && sscanf( p, "bframes=%d", &i )
-                && h->param.i_bframe != i )
-            {
-                x264_log( h, X264_LOG_ERROR, "different number of B-frames than 1st pass (%d vs %d)\n",
-                          h->param.i_bframe, i );
-                return -1;
-            }
-
-            if( ( p = strstr( opts, "wpredp=" ) ) && sscanf( p, "wpredp=%d", &i ) &&
-                X264_MAX( 0, h->param.analyse.i_weighted_pred ) != i )
-            {
-                x264_log( h, X264_LOG_ERROR, "different weightp option than 1st pass (had weightp=%d)\n", i );
-                return -1;
-            }
-
-            /* since B-adapt doesn't (yet) take into account B-pyramid,
-             * the converse is not a problem */
-            if( h->param.i_bframe )
-            {
-                char buf[12];
-                sprintf( buf, "b_pyramid=%d", h->param.i_bframe_pyramid );
-                if( !strstr( opts, buf ) )
-                    x264_log( h, X264_LOG_WARNING, "different B-pyramid setting than 1st pass\n" );
-            }
-
-            if( ( p = strstr( opts, "keyint=" ) ) && sscanf( p, "keyint=%d", &i )
-                && h->param.i_keyint_max != i )
-                x264_log( h, X264_LOG_WARNING, "different keyint than 1st pass (%d vs %d)\n",
-                          h->param.i_keyint_max, i );
+            CMP_OPT_FIRST_PASS( "wpredp", X264_MAX( 0, h->param.analyse.i_weighted_pred ) );
+            CMP_OPT_FIRST_PASS( "bframes", h->param.i_bframe );
+            CMP_OPT_FIRST_PASS( "b_pyramid", h->param.i_bframe_pyramid );
+            CMP_OPT_FIRST_PASS( "intra_refresh", h->param.b_intra_refresh );
+            CMP_OPT_FIRST_PASS( "keyint", h->param.i_keyint_max );
 
             if( strstr( opts, "qp=0" ) && h->param.rc.i_rc_method == X264_RC_ABR )
                 x264_log( h, X264_LOG_WARNING, "1st pass was lossless, bitrate prediction will be inaccurate\n" );
@@ -706,13 +697,30 @@ int x264_ratecontrol_new( x264_t *h )
                 if( sscanf( w, "w:%hd,%hd,%hd", &rce->i_weight_denom, &rce->weight[0], &rce->weight[1] ) != 3 )
                     rce->i_weight_denom = -1;
 
-            switch(pict_type)
+            if( pict_type != 'b' )
+                rce->kept_as_ref = 1;
+            switch( pict_type )
             {
-                case 'I': rce->kept_as_ref = 1;
-                case 'i': rce->pict_type = SLICE_TYPE_I; break;
-                case 'P': rce->pict_type = SLICE_TYPE_P; break;
-                case 'B': rce->kept_as_ref = 1;
-                case 'b': rce->pict_type = SLICE_TYPE_B; break;
+                case 'I':
+                    rce->frame_type = X264_TYPE_IDR;
+                    rce->pict_type  = SLICE_TYPE_I;
+                    break;
+                case 'i':
+                    rce->frame_type = X264_TYPE_I;
+                    rce->pict_type  = SLICE_TYPE_I;
+                    break;
+                case 'P':
+                    rce->frame_type = X264_TYPE_P;
+                    rce->pict_type  = SLICE_TYPE_P;
+                    break;
+                case 'B':
+                    rce->frame_type = X264_TYPE_BREF;
+                    rce->pict_type  = SLICE_TYPE_B;
+                    break;
+                case 'b':
+                    rce->frame_type = X264_TYPE_B;
+                    rce->pict_type  = SLICE_TYPE_B;
+                    break;
                 default:  e = -1; break;
             }
             if(e < 10)
@@ -771,7 +779,12 @@ parse_error:
     }
 
     if( h->param.rc.b_mb_tree && (h->param.rc.b_stat_read || h->param.rc.b_stat_write) )
-        CHECKED_MALLOC( rc->qp_buffer, h->mb.i_mb_count * sizeof(uint16_t) );
+    {
+        CHECKED_MALLOC( rc->qp_buffer[0], h->mb.i_mb_count * sizeof(uint16_t) );
+        if( h->param.i_bframe_pyramid && h->param.rc.b_stat_read )
+            CHECKED_MALLOC( rc->qp_buffer[1], h->mb.i_mb_count * sizeof(uint16_t) );
+        rc->qpbuf_pos = -1;
+    }
 
     for( i=0; i<h->param.i_threads; i++ )
     {
@@ -792,7 +805,7 @@ fail:
 static int parse_zone( x264_t *h, x264_zone_t *z, char *p )
 {
     int len = 0;
-    char *tok, UNUSED *saveptr;
+    char *tok, UNUSED *saveptr=NULL;
     z->param = NULL;
     z->f_bitrate_factor = 1;
     if( 3 <= sscanf(p, "%u,%u,q=%u%n", &z->i_start, &z->i_end, &z->i_qp, &len) )
@@ -838,7 +851,7 @@ static int parse_zones( x264_t *h )
     int i;
     if( h->param.rc.psz_zones && !h->param.rc.i_zones )
     {
-        char *psz_zones, *p, *tok, UNUSED *saveptr;
+        char *psz_zones, *p;
         CHECKED_MALLOC( psz_zones, strlen( h->param.rc.psz_zones )+1 );
         strcpy( psz_zones, h->param.rc.psz_zones );
         h->param.rc.i_zones = 1;
@@ -848,10 +861,11 @@ static int parse_zones( x264_t *h )
         p = psz_zones;
         for( i = 0; i < h->param.rc.i_zones; i++ )
         {
-            tok = strtok_r( p, "/", &saveptr );
-            if( !tok || parse_zone( h, &h->param.rc.zones[i], tok ) )
+            int i_tok = strcspn( p, "/" );
+            p[i_tok] = 0;
+            if( parse_zone( h, &h->param.rc.zones[i], p ) )
                 return -1;
-            p = NULL;
+            p += i_tok + 1;
         }
         x264_free( psz_zones );
     }
@@ -959,7 +973,8 @@ void x264_ratecontrol_delete( x264_t *h )
     x264_free( rc->pred );
     x264_free( rc->pred_b_from_p );
     x264_free( rc->entry );
-    x264_free( rc->qp_buffer );
+    x264_free( rc->qp_buffer[0] );
+    x264_free( rc->qp_buffer[1] );
     if( rc->zones )
     {
         x264_free( rc->zones[0].param );
@@ -1110,9 +1125,7 @@ static double predict_row_size( x264_t *h, int y, int qp )
     /* Our QP is lower than the reference! */
     else
     {
-        double newq = qp2qscale(qp);
-        double oldq = qp2qscale(h->fref0[0]->i_row_qp[y]);
-        double pred_intra = predict_size( rc->row_pred[1], (1 - newq / oldq) * newq, h->fdec->i_row_satds[0][0][y] );
+        double pred_intra = predict_size( rc->row_pred[1], qp2qscale(qp), h->fdec->i_row_satds[0][0][y] );
         /* Sum: better to overestimate than underestimate by using only one of the two predictors. */
         return pred_intra + pred_s;
     }
@@ -1155,11 +1168,7 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
 
     update_predictor( rc->row_pred[0], qp2qscale(rc->qpm), h->fdec->i_row_satd[y], h->fdec->i_row_bits[y] );
     if( h->sh.i_type == SLICE_TYPE_P && rc->qpm < h->fref0[0]->i_row_qp[y] )
-    {
-        double newq = qp2qscale(rc->qpm);
-        double oldq = qp2qscale(h->fref0[0]->i_row_qp[y]);
-        update_predictor( rc->row_pred[1], (1 - newq / oldq) * newq, h->fdec->i_row_satds[0][0][y], h->fdec->i_row_bits[y] );
-    }
+        update_predictor( rc->row_pred[1], qp2qscale(rc->qpm), h->fdec->i_row_satds[0][0][y], h->fdec->i_row_bits[y] );
 
     /* tweak quality based on difference from predicted size */
     if( y < h->i_threadslice_end-1 )
@@ -1180,6 +1189,7 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
         float size_of_other_slices = rc->frame_size_planned - slice_size_planned;
         /* More threads means we have to be more cautious in letting ratecontrol use up extra bits. */
         float rc_tol = buffer_left_planned / h->param.i_threads * rc->rate_tolerance;
+        float max_frame_error = X264_MAX( 0.05, 1.0 / h->sps->i_mb_height );
         int b1 = predict_row_size_sum( h, y, rc->qpm );
 
         /* Assume that if this slice has become larger than expected,
@@ -1219,7 +1229,7 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
 
         /* avoid VBV underflow */
         while( (rc->qpm < h->param.rc.i_qp_max)
-               && (rc->buffer_fill - b1 < rc->buffer_rate * 0.05 ) )
+               && (rc->buffer_fill - b1 < rc->buffer_rate * max_frame_error) )
         {
             rc->qpm ++;
             b1 = predict_row_size_sum( h, y, rc->qpm );
@@ -1275,23 +1285,10 @@ int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
             }
             return X264_TYPE_AUTO;
         }
-        switch( rc->entry[frame_num].pict_type )
-        {
-            case SLICE_TYPE_I:
-                return rc->entry[frame_num].kept_as_ref ? X264_TYPE_IDR : X264_TYPE_I;
-
-            case SLICE_TYPE_B:
-                return rc->entry[frame_num].kept_as_ref ? X264_TYPE_BREF : X264_TYPE_B;
-
-            case SLICE_TYPE_P:
-            default:
-                return X264_TYPE_P;
-        }
+        return rc->entry[frame_num].frame_type;
     }
     else
-    {
         return X264_TYPE_AUTO;
-    }
 }
 
 void x264_ratecontrol_set_weights( x264_t *h, x264_frame_t *frm )
@@ -1373,10 +1370,10 @@ int x264_ratecontrol_end( x264_t *h, int bits )
             int i;
             /* Values are stored as big-endian FIX8.8 */
             for( i = 0; i < h->mb.i_mb_count; i++ )
-                rc->qp_buffer[i] = endian_fix16( h->fenc->f_qp_offset[i]*256.0 );
+                rc->qp_buffer[0][i] = endian_fix16( h->fenc->f_qp_offset[i]*256.0 );
             if( fwrite( &i_type, 1, 1, rc->p_mbtree_stat_file_out ) < 1 )
                 goto fail;
-            if( fwrite( rc->qp_buffer, sizeof(uint16_t), h->mb.i_mb_count, rc->p_mbtree_stat_file_out ) < h->mb.i_mb_count )
+            if( fwrite( rc->qp_buffer[0], sizeof(uint16_t), h->mb.i_mb_count, rc->p_mbtree_stat_file_out ) < h->mb.i_mb_count )
                 goto fail;
         }
     }
@@ -1567,22 +1564,22 @@ static void update_vbv( x264_t *h, int bits )
     if( rct->buffer_fill_final < 0 )
         x264_log( h, X264_LOG_WARNING, "VBV underflow (frame %d, %.0f bits)\n", h->i_frame, rct->buffer_fill_final );
     rct->buffer_fill_final = X264_MAX( rct->buffer_fill_final, 0 );
-    rct->buffer_fill_final += rct->buffer_rate;
-    rct->buffer_fill_final = X264_MIN( rct->buffer_fill_final, rct->buffer_size );
+    rct->buffer_fill_final += rcc->buffer_rate;
+    rct->buffer_fill_final = X264_MIN( rct->buffer_fill_final, rcc->buffer_size );
 }
 
 // provisionally update VBV according to the planned size of all frames currently in progress
 static void update_vbv_plan( x264_t *h, int overhead )
 {
     x264_ratecontrol_t *rcc = h->rc;
-    rcc->buffer_fill = h->thread[0]->rc->buffer_fill_final - overhead;
-    if( h->param.i_threads > 1 && !h->param.b_sliced_threads )
+    rcc->buffer_fill = h->thread[0]->rc->buffer_fill_final;
+    if( h->i_thread_frames > 1 )
     {
         int j = h->rc - h->thread[0]->rc;
         int i;
-        for( i=1; i<h->param.i_threads; i++ )
+        for( i=1; i<h->i_thread_frames; i++ )
         {
-            x264_t *t = h->thread[ (j+i)%h->param.i_threads ];
+            x264_t *t = h->thread[ (j+i)%h->i_thread_frames ];
             double bits = t->rc->frame_size_planned;
             if( !t->b_thread_active )
                 continue;
@@ -1593,6 +1590,8 @@ static void update_vbv_plan( x264_t *h, int overhead )
             rcc->buffer_fill = X264_MIN( rcc->buffer_fill, rcc->buffer_size );
         }
     }
+    rcc->buffer_fill = X264_MIN( rcc->buffer_fill, rcc->buffer_size );
+    rcc->buffer_fill -= overhead;
 }
 
 // apply VBV constraints and clip qscale to between lmin and lmax
@@ -1792,7 +1791,7 @@ static float rate_estimate_qscale( x264_t *h )
     }
     else
     {
-        double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate;
+        double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate * h->i_thread_frames;
 
         if( rcc->b_2pass )
         {
@@ -1802,13 +1801,13 @@ static float rate_estimate_qscale( x264_t *h )
 
             if( rcc->b_vbv )
             {
-                if( h->param.i_threads > 1 && !h->param.b_sliced_threads )
+                if( h->i_thread_frames > 1 )
                 {
                     int j = h->rc - h->thread[0]->rc;
                     int i;
-                    for( i=1; i<h->param.i_threads; i++ )
+                    for( i=1; i<h->i_thread_frames; i++ )
                     {
-                        x264_t *t = h->thread[ (j+i)%h->param.i_threads ];
+                        x264_t *t = h->thread[ (j+i)%h->i_thread_frames ];
                         double bits = t->rc->frame_size_planned;
                         if( !t->b_thread_active )
                             continue;
@@ -1819,16 +1818,16 @@ static float rate_estimate_qscale( x264_t *h )
             }
             else
             {
-                if( h->fenc->i_frame < h->param.i_threads )
+                if( h->fenc->i_frame < h->i_thread_frames )
                     predicted_bits += (int64_t)h->fenc->i_frame * rcc->bitrate / rcc->fps;
                 else
-                    predicted_bits += (int64_t)(h->param.i_threads - 1) * rcc->bitrate / rcc->fps;
+                    predicted_bits += (int64_t)(h->i_thread_frames - 1) * rcc->bitrate / rcc->fps;
             }
 
             diff = predicted_bits - (int64_t)rce.expected_bits;
             q = rce.new_qscale;
             q /= x264_clip3f((double)(abr_buffer - diff) / abr_buffer, .5, 2);
-            if( ((h->fenc->i_frame + 1 - h->param.i_threads) >= rcc->fps) &&
+            if( ((h->fenc->i_frame + 1 - h->i_thread_frames) >= rcc->fps) &&
                 (rcc->expected_bits_sum > 0))
             {
                 /* Adjust quant based on the difference between
@@ -1895,7 +1894,7 @@ static float rate_estimate_qscale( x264_t *h )
             }
             else
             {
-                int i_frame_done = h->fenc->i_frame + 1 - h->param.i_threads;
+                int i_frame_done = h->fenc->i_frame + 1 - h->i_thread_frames;
 
                 q = get_qscale( h, &rce, rcc->wanted_bits_window / rcc->cplxr_sum, h->fenc->i_frame );
 
@@ -1949,6 +1948,10 @@ static float rate_estimate_qscale( x264_t *h )
             rcc->frame_size_planned = qscale2bits(&rce, q);
         else
             rcc->frame_size_planned = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
+
+        /* Always use up the whole VBV in this case. */
+        if( rcc->single_frame_vbv )
+            rcc->frame_size_planned = rcc->buffer_rate;
         x264_ratecontrol_set_estimated_size(h, rcc->frame_size_planned);
         return q;
     }
@@ -1962,19 +1965,19 @@ void x264_threads_distribute_ratecontrol( x264_t *h )
             totalsize += h->fdec->i_row_satd[row];
     for( i = 0; i < h->param.i_threads; i++ )
     {
-        x264_ratecontrol_t *t = h->thread[i]->rc;
+        x264_t *t = h->thread[i];
         x264_ratecontrol_t *rc = h->rc;
-        memcpy( t, rc, sizeof( x264_ratecontrol_t ) );
+        memcpy( t->rc, rc, sizeof(x264_ratecontrol_t) );
         /* Calculate the planned slice size. */
         if( h->rc->b_vbv && rc->frame_size_planned )
         {
             int size = 0;
-            for( row = h->i_threadslice_start; row < h->i_threadslice_end; row++ )
+            for( row = t->i_threadslice_start; row < t->i_threadslice_end; row++ )
                 size += h->fdec->i_row_satd[row];
-            t->slice_size_planned = size * rc->frame_size_planned / totalsize;
+            t->rc->slice_size_planned = size * rc->frame_size_planned / totalsize;
         }
         else
-            t->slice_size_planned = 0;
+            t->rc->slice_size_planned = 0;
     }
 }
 
@@ -2013,8 +2016,7 @@ void x264_thread_sync_ratecontrol( x264_t *cur, x264_t *prev, x264_t *next )
 #define COPY(var) memcpy(&cur->rc->var, &prev->rc->var, sizeof(cur->rc->var))
         /* these vars are updated in x264_ratecontrol_start()
          * so copy them from the context that most recently started (prev)
-         * to the context that's about to start (cur).
-         */
+         * to the context that's about to start (cur). */
         COPY(accum_p_qp);
         COPY(accum_p_norm);
         COPY(last_satd);
@@ -2025,6 +2027,15 @@ void x264_thread_sync_ratecontrol( x264_t *cur, x264_t *prev, x264_t *next )
         COPY(short_term_cplxcount);
         COPY(bframes);
         COPY(prev_zone);
+        COPY(qpbuf_pos);
+        /* these vars can be updated by x264_ratecontrol_init_reconfigurable */
+        COPY(buffer_rate);
+        COPY(buffer_size);
+        COPY(single_frame_vbv);
+        COPY(cbr_decay);
+        COPY(b_vbv_min_rate);
+        COPY(rate_factor_constant);
+        COPY(bitrate);
 #undef COPY
     }
     if( cur != next )
@@ -2032,8 +2043,7 @@ void x264_thread_sync_ratecontrol( x264_t *cur, x264_t *prev, x264_t *next )
 #define COPY(var) next->rc->var = cur->rc->var
         /* these vars are updated in x264_ratecontrol_end()
          * so copy them from the context that most recently ended (cur)
-         * to the context that's about to end (next)
-         */
+         * to the context that's about to end (next) */
         COPY(cplxr_sum);
         COPY(expected_bits_sum);
         COPY(wanted_bits_window);
@@ -2253,7 +2263,11 @@ static int init_pass2( x264_t *h )
 
     expected_bits = 1;
     for(i=0; i<rcc->num_entries; i++)
-        expected_bits += qscale2bits(&rcc->entry[i], get_qscale(h, &rcc->entry[i], 1.0, i));
+    {
+        double q = get_qscale(h, &rcc->entry[i], 1.0, i);
+        expected_bits += qscale2bits(&rcc->entry[i], q);
+        rcc->last_qscale_for[rcc->entry[i].pict_type] = q;
+    }
     step_mult = all_available_bits / expected_bits;
 
     rate_factor = 0;
@@ -2270,6 +2284,7 @@ static int init_pass2( x264_t *h )
         for(i=0; i<rcc->num_entries; i++)
         {
             qscale[i] = get_qscale(h, &rcc->entry[i], rate_factor, i);
+            rcc->last_qscale_for[rcc->entry[i].pict_type] = qscale[i];
         }
 
         /* fixed I/B qscale relative to P */