]> git.sesse.net Git - x264/blobdiff - encoder/slicetype.c
Lookaheadless MB-tree support
[x264] / encoder / slicetype.c
index 58e666be804404247a43b617a7fed4fcbd7f7a69..810779af1f1dd482a5b44da6ae84c86db800e498 100644 (file)
@@ -1,9 +1,11 @@
 /*****************************************************************************
  * slicetype.c: h264 encoder library
  *****************************************************************************
- * Copyright (C) 2005 Loren Merritt
+ * Copyright (C) 2005-2008 x264 project
  *
- * Authors: Loren Merritt <lorenm@u.washington.edu>
+ * Authors: Fiona Glaser <fiona@x264.com>
+ *          Loren Merritt <lorenm@u.washington.edu>
+ *          Dylan Yudaken <dyudaken@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
  *****************************************************************************/
 
 #include <math.h>
-#include <limits.h>
 
 #include "common/common.h"
-#include "common/cpu.h"
 #include "macroblock.h"
 #include "me.h"
 
+// Indexed by pic_struct values
+static const uint8_t delta_tfi_divisor[10] = { 0, 2, 1, 1, 2, 2, 3, 3, 4, 6 };
+
+static int x264_slicetype_frame_cost( x264_t *h, x264_mb_analysis_t *a,
+                                      x264_frame_t **frames, int p0, int p1, int b,
+                                      int b_intra_penalty );
 
 static void x264_lowres_context_init( x264_t *h, x264_mb_analysis_t *a )
 {
-    a->i_qp = 12; // arbitrary, but low because SATD scores are 1/4 normal
-    a->i_lambda = i_qp0_cost_table[ a->i_qp ];
+    a->i_qp = X264_LOOKAHEAD_QP;
+    a->i_lambda = x264_lambda_tab[ a->i_qp ];
     x264_mb_analyse_load_costs( h, a );
-    h->mb.i_me_method = X264_MIN( X264_ME_HEX, h->param.analyse.i_me_method ); // maybe dia?
-    h->mb.i_subpel_refine = 4; // 3 should be enough, but not tweaking for speed now
+    if( h->param.analyse.i_subpel_refine > 1 )
+    {
+        h->mb.i_me_method = X264_MIN( X264_ME_HEX, h->param.analyse.i_me_method );
+        h->mb.i_subpel_refine = 4;
+    }
+    else
+    {
+        h->mb.i_me_method = X264_ME_DIA;
+        h->mb.i_subpel_refine = 2;
+    }
     h->mb.b_chroma_me = 0;
 }
 
-int x264_slicetype_mb_cost( x264_t *h, x264_mb_analysis_t *a,
-                            x264_frame_t **frames, int p0, int p1, int b,
-                            int dist_scale_factor )
+/* makes a non-h264 weight (i.e. fix7), into an h264 weight */
+static void x264_weight_get_h264( unsigned int weight_nonh264, int offset, x264_weight_t *w )
+{
+    w->i_offset = offset;
+    w->i_denom = 7;
+    w->i_scale = weight_nonh264;
+    while( w->i_denom > 0 && (w->i_scale > 127 || !(w->i_scale & 1)) )
+    {
+        w->i_denom--;
+        w->i_scale >>= 1;
+    }
+    w->i_scale = X264_MIN( w->i_scale, 127 );
+}
+
+static NOINLINE pixel *x264_weight_cost_init_luma( x264_t *h, x264_frame_t *fenc, x264_frame_t *ref, pixel *dest )
+{
+    int ref0_distance = fenc->i_frame - ref->i_frame - 1;
+    /* Note: this will never run during lookahead as weights_analyse is only called if no
+     * motion search has been done. */
+    if( fenc->lowres_mvs[0][ref0_distance][0][0] != 0x7FFF )
+    {
+        int i_stride = fenc->i_stride_lowres;
+        int i_lines = fenc->i_lines_lowres;
+        int i_width = fenc->i_width_lowres;
+        int i_mb_xy = 0;
+        pixel *p = dest;
+
+        for( int y = 0; y < i_lines; y += 8, p += i_stride*8 )
+            for( int x = 0; x < i_width; x += 8, i_mb_xy++ )
+            {
+                int mvx = fenc->lowres_mvs[0][ref0_distance][i_mb_xy][0];
+                int mvy = fenc->lowres_mvs[0][ref0_distance][i_mb_xy][1];
+                h->mc.mc_luma( p+x, i_stride, ref->lowres, i_stride,
+                               mvx+(x<<2), mvy+(y<<2), 8, 8, weight_none );
+            }
+        x264_emms();
+        return dest;
+    }
+    x264_emms();
+    return ref->lowres[0];
+}
+
+static NOINLINE unsigned int x264_weight_cost( x264_t *h, x264_frame_t *fenc, pixel *src, x264_weight_t *w )
+{
+    unsigned int cost = 0;
+    int i_stride = fenc->i_stride_lowres;
+    int i_lines = fenc->i_lines_lowres;
+    int i_width = fenc->i_width_lowres;
+    pixel *fenc_plane = fenc->lowres[0];
+    ALIGNED_ARRAY_8( pixel, buf,[8*8] );
+    int pixoff = 0;
+    int i_mb = 0;
+
+    if( w )
+    {
+        for( int y = 0; y < i_lines; y += 8, pixoff = y*i_stride )
+            for( int x = 0; x < i_width; x += 8, i_mb++, pixoff += 8)
+            {
+                w->weightfn[8>>2]( buf, 8, &src[pixoff], i_stride, w, 8 );
+                cost += X264_MIN( h->pixf.mbcmp[PIXEL_8x8]( buf, 8, &fenc_plane[pixoff], i_stride ), fenc->i_intra_cost[i_mb] );
+            }
+        /* Add cost of weights in the slice header. */
+        int numslices;
+        if( h->param.i_slice_count )
+            numslices = h->param.i_slice_count;
+        else if( h->param.i_slice_max_mbs )
+            numslices = (h->mb.i_mb_width * h->mb.i_mb_height + h->param.i_slice_max_mbs-1) / h->param.i_slice_max_mbs;
+        else
+            numslices = 1;
+        /* FIXME: find a way to account for --slice-max-size?
+         * Multiply by 2 as there will be a duplicate. 10 bits added as if there is a weighted frame, then an additional duplicate is used.
+         * Since using lowres frames, assume lambda = 1. */
+        cost += numslices * ( 10 + 2 * ( bs_size_ue( w[0].i_denom ) + bs_size_se( w[0].i_scale ) + bs_size_se( w[0].i_offset ) ) );
+    }
+    else
+        for( int y = 0; y < i_lines; y += 8, pixoff = y*i_stride )
+            for( int x = 0; x < i_width; x += 8, i_mb++, pixoff += 8 )
+                cost += X264_MIN( h->pixf.mbcmp[PIXEL_8x8]( &src[pixoff], i_stride, &fenc_plane[pixoff], i_stride ), fenc->i_intra_cost[i_mb] );
+    x264_emms();
+    return cost;
+}
+
+void x264_weights_analyse( x264_t *h, x264_frame_t *fenc, x264_frame_t *ref, int b_lookahead )
+{
+    float fenc_mean, ref_mean, fenc_var, ref_var;
+    int offset_search;
+    int minoff, minscale, mindenom;
+    unsigned int minscore, origscore;
+    int i_delta_index = fenc->i_frame - ref->i_frame - 1;
+    /* epsilon is chosen to require at least a numerator of 127 (with denominator = 128) */
+    const float epsilon = 1.0/128.0;
+    float guess_scale;
+    int found;
+    x264_weight_t *weights = fenc->weight[0];
+
+    fenc_var = round( sqrt( fenc->i_pixel_ssd[0] ) );
+    ref_var  = round( sqrt(  ref->i_pixel_ssd[0] ) );
+    fenc_mean = (float)fenc->i_pixel_sum[0] / (fenc->i_lines[0] * fenc->i_width[0]);
+    ref_mean  = (float) ref->i_pixel_sum[0] / (fenc->i_lines[0] * fenc->i_width[0]);
+
+    //early termination
+    if( fabs( ref_mean - fenc_mean ) < 0.5 && fabs( 1 - fenc_var / ref_var ) < epsilon )
+    {
+        SET_WEIGHT( weights[0], 0, 1, 0, 0 );
+        return;
+    }
+
+    guess_scale = ref_var ? fenc_var/ref_var : 0;
+    x264_weight_get_h264( round( guess_scale * 128 ), 0, &weights[0] );
+
+    found = 0;
+    mindenom = weights[0].i_denom;
+    minscale = weights[0].i_scale;
+    minoff = 0;
+    offset_search = x264_clip3( floor( fenc_mean - ref_mean * minscale / (1 << mindenom) + 0.5f*b_lookahead ), -128, 126 );
+
+    if( !fenc->b_intra_calculated )
+    {
+        x264_mb_analysis_t a;
+        x264_lowres_context_init( h, &a );
+        x264_slicetype_frame_cost( h, &a, &fenc, 0, 0, 0, 0 );
+    }
+    pixel *mcbuf = x264_weight_cost_init_luma( h, fenc, ref, h->mb.p_weight_buf[0] );
+    origscore = minscore = x264_weight_cost( h, fenc, mcbuf, 0 );
+
+    if( !minscore )
+    {
+        SET_WEIGHT( weights[0], 0, 1, 0, 0 );
+        return;
+    }
+
+    // This gives a slight improvement due to rounding errors but only tests
+    // one offset on lookahead.
+    // TODO: currently searches only offset +1. try other offsets/multipliers/combinations thereof?
+    for( int i_off = offset_search; i_off <= offset_search+!b_lookahead; i_off++ )
+    {
+        SET_WEIGHT( weights[0], 1, minscale, mindenom, i_off );
+        unsigned int s = x264_weight_cost( h, fenc, mcbuf, &weights[0] );
+        COPY3_IF_LT( minscore, s, minoff, i_off, found, 1 );
+    }
+    x264_emms();
+
+    /* FIXME: More analysis can be done here on SAD vs. SATD termination. */
+    /* 0.2% termination derived experimentally to avoid weird weights in frames that are mostly intra. */
+    if( !found || (minscale == 1<<mindenom && minoff == 0) || (float)minscore / origscore > 0.998 )
+    {
+        SET_WEIGHT( weights[0], 0, 1, 0, 0 );
+        return;
+    }
+    else
+        SET_WEIGHT( weights[0], 1, minscale, mindenom, minoff );
+
+    if( h->param.analyse.i_weighted_pred == X264_WEIGHTP_FAKE && weights[0].weightfn )
+        fenc->f_weighted_cost_delta[i_delta_index] = (float)minscore / origscore;
+
+    if( weights[0].weightfn && b_lookahead )
+    {
+        //scale lowres in lookahead for slicetype_frame_cost
+        pixel *src = ref->buffer_lowres[0];
+        pixel *dst = h->mb.p_weight_buf[0];
+        int width = ref->i_width_lowres + PADH*2;
+        int height = ref->i_lines_lowres + PADV*2;
+        x264_weight_scale_plane( h, dst, ref->i_stride_lowres, src, ref->i_stride_lowres,
+                                 width, height, &weights[0] );
+        fenc->weighted[0] = h->mb.p_weight_buf[0] + PADH + ref->i_stride_lowres * PADV;
+    }
+}
+
+static void x264_slicetype_mb_cost( x264_t *h, x264_mb_analysis_t *a,
+                                    x264_frame_t **frames, int p0, int p1, int b,
+                                    int dist_scale_factor, int do_search[2], const x264_weight_t *w )
 {
     x264_frame_t *fref0 = frames[p0];
     x264_frame_t *fref1 = frames[p1];
@@ -49,33 +231,38 @@ int x264_slicetype_mb_cost( x264_t *h, x264_mb_analysis_t *a,
     const int b_bidir = (b < p1);
     const int i_mb_x = h->mb.i_mb_x;
     const int i_mb_y = h->mb.i_mb_y;
-    const int i_mb_stride = h->sps->i_mb_width;
+    const int i_mb_stride = h->mb.i_mb_width;
     const int i_mb_xy = i_mb_x + i_mb_y * i_mb_stride;
     const int i_stride = fenc->i_stride_lowres;
-    const int i_pel_offset = 8 * ( i_mb_x + i_mb_y * i_stride );
+    const int i_pel_offset = 8 * (i_mb_x + i_mb_y * i_stride);
+    const int i_bipred_weight = h->param.analyse.b_weighted_bipred ? 64 - (dist_scale_factor>>2) : 32;
+    int16_t (*fenc_mvs[2])[2] = { &frames[b]->lowres_mvs[0][b-p0-1][i_mb_xy], &frames[b]->lowres_mvs[1][p1-b-1][i_mb_xy] };
+    int (*fenc_costs[2]) = { &frames[b]->lowres_mv_costs[0][b-p0-1][i_mb_xy], &frames[b]->lowres_mv_costs[1][p1-b-1][i_mb_xy] };
+    int b_frame_score_mb = (i_mb_x > 0 && i_mb_x < h->mb.i_mb_width - 1 &&
+                            i_mb_y > 0 && i_mb_y < h->mb.i_mb_height - 1) ||
+                            h->mb.i_mb_width <= 2 || h->mb.i_mb_height <= 2;
 
-    DECLARE_ALIGNED_8( uint8_t pix1[9*FDEC_STRIDE] );
-    uint8_t *pix2 = pix1+8;
+    ALIGNED_ARRAY_8( pixel, pix1,[9*FDEC_STRIDE] );
+    pixel *pix2 = pix1+8;
     x264_me_t m[2];
     int i_bcost = COST_MAX;
-    int i_cost_bak;
-    int l, i;
+    int list_used = 0;
 
     h->mb.pic.p_fenc[0] = h->mb.pic.fenc_buf;
     h->mc.copy[PIXEL_8x8]( h->mb.pic.p_fenc[0], FENC_STRIDE, &fenc->lowres[0][i_pel_offset], i_stride, 8 );
 
-    if( !p0 && !p1 && !b )
+    if( p0 == p1 )
         goto lowres_intra_mb;
 
     // no need for h->mb.mv_min[]
     h->mb.mv_min_fpel[0] = -8*h->mb.i_mb_x - 4;
-    h->mb.mv_max_fpel[0] = 8*( h->sps->i_mb_width - h->mb.i_mb_x - 1 ) + 4;
+    h->mb.mv_max_fpel[0] = 8*( h->mb.i_mb_width - h->mb.i_mb_x - 1 ) + 4;
     h->mb.mv_min_spel[0] = 4*( h->mb.mv_min_fpel[0] - 8 );
     h->mb.mv_max_spel[0] = 4*( h->mb.mv_max_fpel[0] + 8 );
-    if( h->mb.i_mb_x <= 1 )
+    if( h->mb.i_mb_x >= h->mb.i_mb_width - 2 )
     {
         h->mb.mv_min_fpel[1] = -8*h->mb.i_mb_y - 4;
-        h->mb.mv_max_fpel[1] = 8*( h->sps->i_mb_height - h->mb.i_mb_y - 1 ) + 4;
+        h->mb.mv_max_fpel[1] = 8*( h->mb.i_mb_height - h->mb.i_mb_y - 1 ) + 4;
         h->mb.mv_min_spel[1] = 4*( h->mb.mv_min_fpel[1] - 8 );
         h->mb.mv_max_spel[1] = 4*( h->mb.mv_max_fpel[1] + 8 );
     }
@@ -87,16 +274,9 @@ int x264_slicetype_mb_cost( x264_t *h, x264_mb_analysis_t *a,
         (dst)[2] = &(src)[2][i_pel_offset]; \
         (dst)[3] = &(src)[3][i_pel_offset]; \
     }
-#define SAVE_MVS( mv0, mv1 ) \
-    { \
-        fenc->mv[0][i_mb_xy][0] = mv0[0]; \
-        fenc->mv[0][i_mb_xy][1] = mv0[1]; \
-        if( b_bidir ) \
-        { \
-            fenc->mv[1][i_mb_xy][0] = mv1[0]; \
-            fenc->mv[1][i_mb_xy][1] = mv1[1]; \
-        } \
-    }
+#define LOAD_WPELS_LUMA(dst,src) \
+    (dst) = &(src)[i_pel_offset];
+
 #define CLIP_MV( mv ) \
     { \
         mv[0] = x264_clip3( mv[0], h->mb.mv_min_spel[0], h->mb.mv_max_spel[0] ); \
@@ -104,37 +284,54 @@ int x264_slicetype_mb_cost( x264_t *h, x264_mb_analysis_t *a,
     }
 #define TRY_BIDIR( mv0, mv1, penalty ) \
     { \
-        int stride2 = 16; \
-        uint8_t *src2; \
         int i_cost; \
-        h->mc.mc_luma( pix1, 16, m[0].p_fref, m[0].i_stride[0], \
-                       (mv0)[0], (mv0)[1], 8, 8 ); \
-        src2 = h->mc.get_ref( pix2, &stride2, m[1].p_fref, m[1].i_stride[0], \
-                       (mv1)[0], (mv1)[1], 8, 8 ); \
-        h->mc.avg[PIXEL_8x8]( pix1, 16, src2, stride2 ); \
-        i_cost = penalty + h->pixf.mbcmp[PIXEL_8x8]( \
-                           m[0].p_fenc[0], FENC_STRIDE, pix1, 16 ); \
-        if( i_bcost > i_cost ) \
+        if( h->param.analyse.i_subpel_refine <= 1 ) \
+        { \
+            int hpel_idx1 = (((mv0)[0]&2)>>1) + ((mv0)[1]&2); \
+            int hpel_idx2 = (((mv1)[0]&2)>>1) + ((mv1)[1]&2); \
+            pixel *src1 = m[0].p_fref[hpel_idx1] + ((mv0)[0]>>2) + ((mv0)[1]>>2) * m[0].i_stride[0]; \
+            pixel *src2 = m[1].p_fref[hpel_idx2] + ((mv1)[0]>>2) + ((mv1)[1]>>2) * m[1].i_stride[0]; \
+            h->mc.avg[PIXEL_8x8]( pix1, 16, src1, m[0].i_stride[0], src2, m[1].i_stride[0], i_bipred_weight ); \
+        } \
+        else \
         { \
-            i_bcost = i_cost; \
-            SAVE_MVS( mv0, mv1 ); \
+            int stride1 = 16, stride2 = 16; \
+            pixel *src1, *src2; \
+            src1 = h->mc.get_ref( pix1, &stride1, m[0].p_fref, m[0].i_stride[0], \
+                                  (mv0)[0], (mv0)[1], 8, 8, w ); \
+            src2 = h->mc.get_ref( pix2, &stride2, m[1].p_fref, m[1].i_stride[0], \
+                                  (mv1)[0], (mv1)[1], 8, 8, w ); \
+            h->mc.avg[PIXEL_8x8]( pix1, 16, src1, stride1, src2, stride2, i_bipred_weight ); \
         } \
+        i_cost = penalty + h->pixf.mbcmp[PIXEL_8x8]( \
+                           m[0].p_fenc[0], FENC_STRIDE, pix1, 16 ); \
+        COPY2_IF_LT( i_bcost, i_cost, list_used, 3 ); \
     }
 
     m[0].i_pixel = PIXEL_8x8;
     m[0].p_cost_mv = a->p_cost_mv;
     m[0].i_stride[0] = i_stride;
     m[0].p_fenc[0] = h->mb.pic.p_fenc[0];
+    m[0].weight = w;
+    m[0].i_ref = 0;
     LOAD_HPELS_LUMA( m[0].p_fref, fref0->lowres );
+    m[0].p_fref_w = m[0].p_fref[0];
+    if( w[0].weightfn )
+        LOAD_WPELS_LUMA( m[0].p_fref_w, fenc->weighted[0] );
 
     if( b_bidir )
     {
-        int16_t *mvr = fref1->mv[0][i_mb_xy];
-        int dmv[2][2];
-        int mv0[2] = {0,0};
+        int16_t *mvr = fref1->lowres_mvs[0][p1-p0-1][i_mb_xy];
+        ALIGNED_ARRAY_8( int16_t, dmv,[2],[2] );
 
-        m[1] = m[0];
+        m[1].i_pixel = PIXEL_8x8;
+        m[1].p_cost_mv = a->p_cost_mv;
+        m[1].i_stride[0] = i_stride;
+        m[1].p_fenc[0] = h->mb.pic.p_fenc[0];
+        m[1].i_ref = 0;
+        m[1].weight = weight_none;
         LOAD_HPELS_LUMA( m[1].p_fref, fref1->lowres );
+        m[1].p_fref_w = m[1].p_fref[0];
 
         dmv[0][0] = ( mvr[0] * dist_scale_factor + 128 ) >> 8;
         dmv[0][1] = ( mvr[1] * dist_scale_factor + 128 ) >> 8;
@@ -142,87 +339,113 @@ int x264_slicetype_mb_cost( x264_t *h, x264_mb_analysis_t *a,
         dmv[1][1] = dmv[0][1] - mvr[1];
         CLIP_MV( dmv[0] );
         CLIP_MV( dmv[1] );
+        if( h->param.analyse.i_subpel_refine <= 1 )
+            M64( dmv ) &= ~0x0001000100010001ULL; /* mv & ~1 */
 
         TRY_BIDIR( dmv[0], dmv[1], 0 );
-        if( dmv[0][0] || dmv[0][1] || dmv[1][0] || dmv[1][1] )
-           TRY_BIDIR( mv0, mv0, 0 );
-//      if( i_bcost < 60 ) // arbitrary threshold
-//          return i_bcost;
+        if( M64( dmv ) )
+        {
+            int i_cost;
+            h->mc.avg[PIXEL_8x8]( pix1, 16, m[0].p_fref[0], m[0].i_stride[0], m[1].p_fref[0], m[1].i_stride[0], i_bipred_weight );
+            i_cost = h->pixf.mbcmp[PIXEL_8x8]( m[0].p_fenc[0], FENC_STRIDE, pix1, 16 );
+            COPY2_IF_LT( i_bcost, i_cost, list_used, 3 );
+        }
     }
 
-    i_cost_bak = i_bcost;
-    for( l = 0; l < 1 + b_bidir; l++ )
+    for( int l = 0; l < 1 + b_bidir; l++ )
     {
-        int16_t mvc[4][2] = {{0}};
-        int i_mvc = 0;
-        int16_t (*fenc_mv)[2] = &fenc->mv[l][i_mb_xy];
-#define MVC(mv) { mvc[i_mvc][0] = mv[0]; mvc[i_mvc][1] = mv[1]; i_mvc++; }
-        if( i_mb_x > 0 )
-            MVC(fenc_mv[-1]);
-        if( i_mb_y > 0 )
+        if( do_search[l] )
         {
-            MVC(fenc_mv[-i_mb_stride]);
-            if( i_mb_x < h->sps->i_mb_width - 1 )
-                MVC(fenc_mv[-i_mb_stride+1]);
-            if( i_mb_x > 0 )
-                MVC(fenc_mv[-i_mb_stride-1]);
-        }
+            int i_mvc = 0;
+            int16_t (*fenc_mv)[2] = fenc_mvs[l];
+            ALIGNED_4( int16_t mvc[4][2] );
+
+            /* Reverse-order MV prediction. */
+            M32( mvc[0] ) = 0;
+            M32( mvc[2] ) = 0;
+#define MVC(mv) { CP32( mvc[i_mvc], mv ); i_mvc++; }
+            if( i_mb_x < h->mb.i_mb_width - 1 )
+                MVC( fenc_mv[1] );
+            if( i_mb_y < h->mb.i_mb_height - 1 )
+            {
+                MVC( fenc_mv[i_mb_stride] );
+                if( i_mb_x > 0 )
+                    MVC( fenc_mv[i_mb_stride-1] );
+                if( i_mb_x < h->mb.i_mb_width - 1 )
+                    MVC( fenc_mv[i_mb_stride+1] );
+            }
 #undef MVC
-        m[l].mvp[0] = x264_median( mvc[0][0], mvc[1][0], mvc[2][0] );
-        m[l].mvp[1] = x264_median( mvc[0][1], mvc[1][1], mvc[2][1] );
+            if( i_mvc <= 1 )
+                CP32( m[l].mvp, mvc[0] );
+            else
+                x264_median_mv( m[l].mvp, mvc[0], mvc[1], mvc[2] );
+
+            /* Fast skip for cases of near-zero residual.  Shortcut: don't bother except in the mv0 case,
+             * since anything else is likely to have enough residual to not trigger the skip. */
+            if( !M32( m[l].mvp ) )
+            {
+                m[l].cost = h->pixf.mbcmp[PIXEL_8x8]( m[l].p_fenc[0], FENC_STRIDE, m[l].p_fref[0], m[l].i_stride[0] );
+                if( m[l].cost < 64 )
+                {
+                    M32( m[l].mv ) = 0;
+                    goto skip_motionest;
+                }
+            }
 
-        x264_me_search( h, &m[l], mvc, i_mvc );
+            x264_me_search( h, &m[l], mvc, i_mvc );
+            m[l].cost -= 2; // remove mvcost from skip mbs
+            if( M32( m[l].mv ) )
+                m[l].cost += 5;
 
-        m[l].cost -= 2; // remove mvcost from skip mbs
-        if( m[l].mv[0] || m[l].mv[1] )
-            m[l].cost += 5;
-        i_bcost = X264_MIN( i_bcost, m[l].cost );
+skip_motionest:
+            CP32( fenc_mvs[l], m[l].mv );
+            *fenc_costs[l] = m[l].cost;
+        }
+        else
+        {
+            CP32( m[l].mv, fenc_mvs[l] );
+            m[l].cost = *fenc_costs[l];
+        }
+        COPY2_IF_LT( i_bcost, m[l].cost, list_used, l+1 );
     }
 
-    if( b_bidir && (m[0].mv[0] || m[0].mv[1] || m[1].mv[0] || m[1].mv[1]) )
+    if( b_bidir && ( M32( m[0].mv ) || M32( m[1].mv ) ) )
         TRY_BIDIR( m[0].mv, m[1].mv, 5 );
 
-    if( i_bcost < i_cost_bak )
-        SAVE_MVS( m[0].mv, m[1].mv );
-
-    //FIXME intra part could be shared across multiple encodings of the frame
 lowres_intra_mb:
-    if( !b_bidir ) // forbid intra-mbs in B-frames, because it's rare and not worth checking
+    if( !fenc->b_intra_calculated )
     {
-        uint8_t *pix = &pix1[8+FDEC_STRIDE - 1];
-        uint8_t *src = &fenc->lowres[0][i_pel_offset - 1];
+        ALIGNED_ARRAY_16( pixel, edge,[33] );
+        pixel *pix = &pix1[8+FDEC_STRIDE - 1];
+        pixel *src = &fenc->lowres[0][i_pel_offset - 1];
         const int intra_penalty = 5;
-        int satds[4], i_icost, b_intra;
+        int satds[3];
 
-        memcpy( pix-FDEC_STRIDE, src-i_stride, 17 );
-        for( i=0; i<8; i++ )
+        memcpy( pix-FDEC_STRIDE, src-i_stride, 17 * sizeof(pixel) );
+        for( int i = 0; i < 8; i++ )
             pix[i*FDEC_STRIDE] = src[i*i_stride];
         pix++;
 
-        if( h->pixf.intra_satd_x3_8x8c && h->pixf.mbcmp[0] == h->pixf.satd[0] )
-        {
-            h->pixf.intra_satd_x3_8x8c( h->mb.pic.p_fenc[0], pix, satds );
-            h->predict_8x8c[I_PRED_CHROMA_P]( pix );
-            satds[I_PRED_CHROMA_P] =
-                h->pixf.satd[PIXEL_8x8]( pix, FDEC_STRIDE, h->mb.pic.p_fenc[0], FENC_STRIDE );
-        }
+        if( h->pixf.intra_mbcmp_x3_8x8c )
+            h->pixf.intra_mbcmp_x3_8x8c( h->mb.pic.p_fenc[0], pix, satds );
         else
         {
-            for( i=0; i<4; i++ )
+            for( int i = 0; i < 3; i++ )
             {
                 h->predict_8x8c[i]( pix );
                 satds[i] = h->pixf.mbcmp[PIXEL_8x8]( pix, FDEC_STRIDE, h->mb.pic.p_fenc[0], FENC_STRIDE );
             }
         }
-        i_icost = X264_MIN4( satds[0], satds[1], satds[2], satds[3] );
+        int i_icost = X264_MIN3( satds[0], satds[1], satds[2] );
 
-        if( i_icost < i_bcost * 2 )
+        if( h->param.analyse.i_subpel_refine > 1 )
         {
-            DECLARE_ALIGNED_16( uint8_t edge[33] );
-            x264_predict_8x8_filter( pix, edge, ALL_NEIGHBORS, ALL_NEIGHBORS );
-            for( i=3; i<9; i++ )
+            h->predict_8x8c[I_PRED_CHROMA_P]( pix );
+            int satd = h->pixf.mbcmp[PIXEL_8x8]( pix, FDEC_STRIDE, h->mb.pic.p_fenc[0], FENC_STRIDE );
+            i_icost = X264_MIN( i_icost, satd );
+            h->predict_8x8_filter( pix, edge, ALL_NEIGHBORS, ALL_NEIGHBORS );
+            for( int i = 3; i < 9; i++ )
             {
-                int satd;
                 h->predict_8x8[i]( pix, edge );
                 satd = h->pixf.mbcmp[PIXEL_8x8]( pix, FDEC_STRIDE, h->mb.pic.p_fenc[0], FENC_STRIDE );
                 i_icost = X264_MIN( i_icost, satd );
@@ -230,104 +453,559 @@ lowres_intra_mb:
         }
 
         i_icost += intra_penalty;
-        b_intra = i_icost < i_bcost;
+        fenc->i_intra_cost[i_mb_xy] = i_icost;
+        if( b_frame_score_mb )
+        {
+            int *row_satd_intra = frames[b]->i_row_satds[0][0];
+            int i_icost_aq = i_icost;
+            if( h->param.rc.i_aq_mode )
+                i_icost_aq = (i_icost_aq * frames[b]->i_inv_qscale_factor[i_mb_xy] + 128) >> 8;
+            fenc->i_cost_est[0][0] += i_icost;
+            fenc->i_cost_est_aq[0][0] += i_icost_aq;
+            row_satd_intra[h->mb.i_mb_y] += i_icost_aq;
+        }
+    }
+
+    /* forbid intra-mbs in B-frames, because it's rare and not worth checking */
+    /* FIXME: Should we still forbid them now that we cache intra scores? */
+    if( !b_bidir )
+    {
+        int i_icost = fenc->i_intra_cost[i_mb_xy];
+        int b_intra = i_icost < i_bcost;
         if( b_intra )
-            i_bcost = i_icost;
-        if(    i_mb_x > 0 && i_mb_x < h->sps->i_mb_width - 1
-            && i_mb_y > 0 && i_mb_y < h->sps->i_mb_height - 1 )
         {
+            i_bcost = i_icost;
+            list_used = 0;
+        }
+        if( b_frame_score_mb )
             fenc->i_intra_mbs[b-p0] += b_intra;
-            fenc->i_cost_est[0][0] += i_icost;
+    }
+
+    /* In an I-frame, we've already added the results above in the intra section. */
+    if( p0 != p1 )
+    {
+        int i_bcost_aq = i_bcost;
+        if( h->param.rc.i_aq_mode )
+            i_bcost_aq = (i_bcost_aq * frames[b]->i_inv_qscale_factor[i_mb_xy] + 128) >> 8;
+        fenc->i_row_satds[b-p0][p1-b][h->mb.i_mb_y] += i_bcost_aq;
+        if( b_frame_score_mb )
+        {
+            /* Don't use AQ-weighted costs for slicetype decision, only for ratecontrol. */
+            frames[b]->i_cost_est[b-p0][p1-b] += i_bcost;
+            frames[b]->i_cost_est_aq[b-p0][p1-b] += i_bcost_aq;
         }
     }
 
-    return i_bcost;
+    fenc->lowres_costs[b-p0][p1-b][i_mb_xy] = i_bcost + (list_used << LOWRES_COST_SHIFT);
 }
 #undef TRY_BIDIR
-#undef SAVE_MVS
 
-int x264_slicetype_frame_cost( x264_t *h, x264_mb_analysis_t *a,
-                               x264_frame_t **frames, int p0, int p1, int b,
-                               int b_intra_penalty )
+#define NUM_MBS\
+   (h->mb.i_mb_width > 2 && h->mb.i_mb_height > 2 ?\
+   (h->mb.i_mb_width - 2) * (h->mb.i_mb_height - 2) :\
+    h->mb.i_mb_width * h->mb.i_mb_height)
+
+static int x264_slicetype_frame_cost( x264_t *h, x264_mb_analysis_t *a,
+                                      x264_frame_t **frames, int p0, int p1, int b,
+                                      int b_intra_penalty )
 {
     int i_score = 0;
-
+    int do_search[2];
+    const x264_weight_t *w = weight_none;
     /* Check whether we already evaluated this frame
      * If we have tried this frame as P, then we have also tried
      * the preceding frames as B. (is this still true?) */
-    if( frames[b]->i_cost_est[b-p0][p1-b] >= 0 )
-    {
+    /* Also check that we already calculated the row SATDs for the current frame. */
+    if( frames[b]->i_cost_est[b-p0][p1-b] >= 0 && (!h->param.rc.i_vbv_buffer_size || frames[b]->i_row_satds[b-p0][p1-b][0] != -1) )
         i_score = frames[b]->i_cost_est[b-p0][p1-b];
-    }
     else
     {
         int dist_scale_factor = 128;
         int *row_satd = frames[b]->i_row_satds[b-p0][p1-b];
+        int *row_satd_intra = frames[b]->i_row_satds[0][0];
 
-        /* Init MVs so that we don't have to check edge conditions when loading predictors. */
-        /* FIXME: not needed every time */
-        memset( frames[b]->mv[0], 0, h->sps->i_mb_height * h->sps->i_mb_width * 2*sizeof(int16_t) );
-        if( b != p1 )
-            memset( frames[b]->mv[1], 0, h->sps->i_mb_height * h->sps->i_mb_width * 2*sizeof(int16_t) );
+        /* For each list, check to see whether we have lowres motion-searched this reference frame before. */
+        do_search[0] = b != p0 && frames[b]->lowres_mvs[0][b-p0-1][0][0] == 0x7FFF;
+        do_search[1] = b != p1 && frames[b]->lowres_mvs[1][p1-b-1][0][0] == 0x7FFF;
+        if( do_search[0] )
+        {
+            if( ( h->param.analyse.i_weighted_pred == X264_WEIGHTP_SMART ||
+                  h->param.analyse.i_weighted_pred == X264_WEIGHTP_FAKE ) && b == p1 )
+            {
+                x264_emms();
+                x264_weights_analyse( h, frames[b], frames[p0], 1 );
+                w = frames[b]->weight[0];
+            }
+            frames[b]->lowres_mvs[0][b-p0-1][0][0] = 0;
+        }
+        if( do_search[1] ) frames[b]->lowres_mvs[1][p1-b-1][0][0] = 0;
 
         if( b == p1 )
-        {
             frames[b]->i_intra_mbs[b-p0] = 0;
+        if( !frames[b]->b_intra_calculated )
+        {
             frames[b]->i_cost_est[0][0] = 0;
+            frames[b]->i_cost_est_aq[0][0] = 0;
         }
         if( p1 != p0 )
             dist_scale_factor = ( ((b-p0) << 8) + ((p1-p0) >> 1) ) / (p1-p0);
 
-        /* the edge mbs seem to reduce the predictive quality of the
+        frames[b]->i_cost_est[b-p0][p1-b] = 0;
+        frames[b]->i_cost_est_aq[b-p0][p1-b] = 0;
+
+        /* Lowres lookahead goes backwards because the MVs are used as predictors in the main encode.
+         * This considerably improves MV prediction overall. */
+
+        /* The edge mbs seem to reduce the predictive quality of the
          * whole frame's score, but are needed for a spatial distribution. */
-        if( h->param.rc.i_vbv_buffer_size )
+        if( h->param.rc.b_mb_tree || h->param.rc.i_vbv_buffer_size ||
+            h->mb.i_mb_width <= 2 || h->mb.i_mb_height <= 2 )
         {
-            for( h->mb.i_mb_y = 0; h->mb.i_mb_y < h->sps->i_mb_height; h->mb.i_mb_y++ )
+            for( h->mb.i_mb_y = h->mb.i_mb_height - 1; h->mb.i_mb_y >= 0; h->mb.i_mb_y-- )
             {
-                row_satd[ h->mb.i_mb_y ] = 0;
-                for( h->mb.i_mb_x = 0; h->mb.i_mb_x < h->sps->i_mb_width; h->mb.i_mb_x++ )
-                {
-                    int i_mb_cost = x264_slicetype_mb_cost( h, a, frames, p0, p1, b, dist_scale_factor );
-                    row_satd[ h->mb.i_mb_y ] += i_mb_cost;
-                    if( h->mb.i_mb_y > 0 && h->mb.i_mb_y < h->sps->i_mb_height - 1 &&
-                        h->mb.i_mb_x > 0 && h->mb.i_mb_x < h->sps->i_mb_width - 1 )
-                    {
-                        i_score += i_mb_cost;
-                    }
-                }
+                row_satd[h->mb.i_mb_y] = 0;
+                if( !frames[b]->b_intra_calculated )
+                    row_satd_intra[h->mb.i_mb_y] = 0;
+                for( h->mb.i_mb_x = h->mb.i_mb_width - 1; h->mb.i_mb_x >= 0; h->mb.i_mb_x-- )
+                    x264_slicetype_mb_cost( h, a, frames, p0, p1, b, dist_scale_factor, do_search, w );
             }
         }
         else
         {
-            for( h->mb.i_mb_y = 1; h->mb.i_mb_y < h->sps->i_mb_height - 1; h->mb.i_mb_y++ )
-                for( h->mb.i_mb_x = 1; h->mb.i_mb_x < h->sps->i_mb_width - 1; h->mb.i_mb_x++ )
-                    i_score += x264_slicetype_mb_cost( h, a, frames, p0, p1, b, dist_scale_factor );
+            for( h->mb.i_mb_y = h->mb.i_mb_height - 2; h->mb.i_mb_y >= 1; h->mb.i_mb_y-- )
+                for( h->mb.i_mb_x = h->mb.i_mb_width - 2; h->mb.i_mb_x >= 1; h->mb.i_mb_x-- )
+                    x264_slicetype_mb_cost( h, a, frames, p0, p1, b, dist_scale_factor, do_search, w );
         }
 
+        i_score = frames[b]->i_cost_est[b-p0][p1-b];
         if( b != p1 )
-            i_score = i_score * 100 / (120 + h->param.i_bframe_bias);
+            i_score = (uint64_t)i_score * 100 / (120 + h->param.i_bframe_bias);
+        else
+            frames[b]->b_intra_calculated = 1;
 
         frames[b]->i_cost_est[b-p0][p1-b] = i_score;
-//      fprintf( stderr, "frm %d %c(%d,%d): %6d %6d imb:%d  \n", frames[b]->i_frame,
-//               (p1==0?'I':b<p1?'B':'P'), b-p0, p1-b, i_score, frames[b]->i_cost_est[0][0], frames[b]->i_intra_mbs[b-p0] );
         x264_emms();
     }
 
     if( b_intra_penalty )
     {
         // arbitrary penalty for I-blocks after B-frames
-        int nmb = (h->sps->i_mb_width - 2) * (h->sps->i_mb_height - 2);
+        int nmb = NUM_MBS;
         i_score += i_score * frames[b]->i_intra_mbs[b-p0] / (nmb * 8);
     }
     return i_score;
 }
 
-static int scenecut( x264_t *h, x264_frame_t *frame, int pdist )
+/* If MB-tree changes the quantizers, we need to recalculate the frame cost without
+ * re-running lookahead. */
+static int x264_slicetype_frame_cost_recalculate( x264_t *h, x264_frame_t **frames, int p0, int p1, int b )
+{
+    int i_score = 0;
+    int *row_satd = frames[b]->i_row_satds[b-p0][p1-b];
+    float *qp_offset = IS_X264_TYPE_B(frames[b]->i_type) ? frames[b]->f_qp_offset_aq : frames[b]->f_qp_offset;
+    x264_emms();
+    for( h->mb.i_mb_y = h->mb.i_mb_height - 1; h->mb.i_mb_y >= 0; h->mb.i_mb_y-- )
+    {
+        row_satd[ h->mb.i_mb_y ] = 0;
+        for( h->mb.i_mb_x = h->mb.i_mb_width - 1; h->mb.i_mb_x >= 0; h->mb.i_mb_x-- )
+        {
+            int i_mb_xy = h->mb.i_mb_x + h->mb.i_mb_y*h->mb.i_mb_stride;
+            int i_mb_cost = frames[b]->lowres_costs[b-p0][p1-b][i_mb_xy] & LOWRES_COST_MASK;
+            float qp_adj = qp_offset[i_mb_xy];
+            i_mb_cost = (i_mb_cost * x264_exp2fix8(qp_adj) + 128) >> 8;
+            row_satd[ h->mb.i_mb_y ] += i_mb_cost;
+            if( (h->mb.i_mb_y > 0 && h->mb.i_mb_y < h->mb.i_mb_height - 1 &&
+                 h->mb.i_mb_x > 0 && h->mb.i_mb_x < h->mb.i_mb_width - 1) ||
+                 h->mb.i_mb_width <= 2 || h->mb.i_mb_height <= 2 )
+            {
+                i_score += i_mb_cost;
+            }
+        }
+    }
+    return i_score;
+}
+
+static void x264_macroblock_tree_finish( x264_t *h, x264_frame_t *frame, int ref0_distance )
+{
+    x264_emms();
+    float weightdelta = 0.0;
+    if( ref0_distance && frame->f_weighted_cost_delta[ref0_distance-1] > 0 )
+        weightdelta = (1.0 - frame->f_weighted_cost_delta[ref0_distance-1]);
+
+    /* Allow the strength to be adjusted via qcompress, since the two
+     * concepts are very similar. */
+    float strength = 5.0f * (1.0f - h->param.rc.f_qcompress);
+    for( int mb_index = 0; mb_index < h->mb.i_mb_count; mb_index++ )
+    {
+        int intra_cost = (frame->i_intra_cost[mb_index] * frame->i_inv_qscale_factor[mb_index]+128)>>8;
+        if( intra_cost )
+        {
+            int propagate_cost = frame->i_propagate_cost[mb_index];
+            float log2_ratio = x264_log2(intra_cost + propagate_cost) - x264_log2(intra_cost) + weightdelta;
+            frame->f_qp_offset[mb_index] = frame->f_qp_offset_aq[mb_index] - strength * log2_ratio;
+        }
+    }
+}
+
+static void x264_macroblock_tree_propagate( x264_t *h, x264_frame_t **frames, int p0, int p1, int b, int referenced )
+{
+    uint16_t *ref_costs[2] = {frames[p0]->i_propagate_cost,frames[p1]->i_propagate_cost};
+    int dist_scale_factor = ( ((b-p0) << 8) + ((p1-p0) >> 1) ) / (p1-p0);
+    int i_bipred_weight = h->param.analyse.b_weighted_bipred ? 64 - (dist_scale_factor>>2) : 32;
+    int16_t (*mvs[2])[2] = { frames[b]->lowres_mvs[0][b-p0-1], frames[b]->lowres_mvs[1][p1-b-1] };
+    int bipred_weights[2] = {i_bipred_weight, 64 - i_bipred_weight};
+    int *buf = h->scratch_buffer;
+    uint16_t *propagate_cost = frames[b]->i_propagate_cost;
+
+    /* For non-reffed frames the source costs are always zero, so just memset one row and re-use it. */
+    if( !referenced )
+        memset( frames[b]->i_propagate_cost, 0, h->mb.i_mb_width * sizeof(uint16_t) );
+
+    for( h->mb.i_mb_y = 0; h->mb.i_mb_y < h->mb.i_mb_height; h->mb.i_mb_y++ )
+    {
+        int mb_index = h->mb.i_mb_y*h->mb.i_mb_stride;
+        h->mc.mbtree_propagate_cost( buf, propagate_cost,
+            frames[b]->i_intra_cost+mb_index, frames[b]->lowres_costs[b-p0][p1-b]+mb_index,
+            frames[b]->i_inv_qscale_factor+mb_index, h->mb.i_mb_width );
+        if( referenced )
+            propagate_cost += h->mb.i_mb_width;
+        for( h->mb.i_mb_x = 0; h->mb.i_mb_x < h->mb.i_mb_width; h->mb.i_mb_x++, mb_index++ )
+        {
+            int propagate_amount = buf[h->mb.i_mb_x];
+            /* Don't propagate for an intra block. */
+            if( propagate_amount > 0 )
+            {
+                /* Access width-2 bitfield. */
+                int lists_used = frames[b]->lowres_costs[b-p0][p1-b][mb_index] >> LOWRES_COST_SHIFT;
+                /* Follow the MVs to the previous frame(s). */
+                for( int list = 0; list < 2; list++ )
+                    if( (lists_used >> list)&1 )
+                    {
+#define CLIP_ADD(s,x) (s) = X264_MIN((s)+(x),(1<<16)-1)
+                        int listamount = propagate_amount;
+                        /* Apply bipred weighting. */
+                        if( lists_used == 3 )
+                            listamount = (listamount * bipred_weights[list] + 32) >> 6;
+
+                        /* Early termination for simple case of mv0. */
+                        if( !M32( mvs[list][mb_index] ) )
+                        {
+                            CLIP_ADD( ref_costs[list][mb_index], listamount );
+                            continue;
+                        }
+
+                        int x = mvs[list][mb_index][0];
+                        int y = mvs[list][mb_index][1];
+                        int mbx = (x>>5)+h->mb.i_mb_x;
+                        int mby = (y>>5)+h->mb.i_mb_y;
+                        int idx0 = mbx + mby * h->mb.i_mb_stride;
+                        int idx1 = idx0 + 1;
+                        int idx2 = idx0 + h->mb.i_mb_stride;
+                        int idx3 = idx0 + h->mb.i_mb_stride + 1;
+                        x &= 31;
+                        y &= 31;
+                        int idx0weight = (32-y)*(32-x);
+                        int idx1weight = (32-y)*x;
+                        int idx2weight = y*(32-x);
+                        int idx3weight = y*x;
+
+                        /* We could just clip the MVs, but pixels that lie outside the frame probably shouldn't
+                         * be counted. */
+                        if( mbx < h->mb.i_mb_width-1 && mby < h->mb.i_mb_height-1 && mbx >= 0 && mby >= 0 )
+                        {
+                            CLIP_ADD( ref_costs[list][idx0], (listamount*idx0weight+512)>>10 );
+                            CLIP_ADD( ref_costs[list][idx1], (listamount*idx1weight+512)>>10 );
+                            CLIP_ADD( ref_costs[list][idx2], (listamount*idx2weight+512)>>10 );
+                            CLIP_ADD( ref_costs[list][idx3], (listamount*idx3weight+512)>>10 );
+                        }
+                        else /* Check offsets individually */
+                        {
+                            if( mbx < h->mb.i_mb_width && mby < h->mb.i_mb_height && mbx >= 0 && mby >= 0 )
+                                CLIP_ADD( ref_costs[list][idx0], (listamount*idx0weight+512)>>10 );
+                            if( mbx+1 < h->mb.i_mb_width && mby < h->mb.i_mb_height && mbx+1 >= 0 && mby >= 0 )
+                                CLIP_ADD( ref_costs[list][idx1], (listamount*idx1weight+512)>>10 );
+                            if( mbx < h->mb.i_mb_width && mby+1 < h->mb.i_mb_height && mbx >= 0 && mby+1 >= 0 )
+                                CLIP_ADD( ref_costs[list][idx2], (listamount*idx2weight+512)>>10 );
+                            if( mbx+1 < h->mb.i_mb_width && mby+1 < h->mb.i_mb_height && mbx+1 >= 0 && mby+1 >= 0 )
+                                CLIP_ADD( ref_costs[list][idx3], (listamount*idx3weight+512)>>10 );
+                        }
+                    }
+            }
+        }
+    }
+
+    if( h->param.rc.i_vbv_buffer_size && h->param.rc.i_lookahead && referenced )
+        x264_macroblock_tree_finish( h, frames[b], b == p1 ? b - p0 : 0 );
+}
+
+static void x264_macroblock_tree( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, int num_frames, int b_intra )
 {
+    int idx = !b_intra;
+    int last_nonb, cur_nonb = 1;
+    int bframes = 0;
+    int i = num_frames;
+
+    if( b_intra )
+        x264_slicetype_frame_cost( h, a, frames, 0, 0, 0, 0 );
+
+    while( i > 0 && frames[i]->i_type == X264_TYPE_B )
+        i--;
+    last_nonb = i;
+
+    /* Lookaheadless MB-tree is not a theoretically distinct case; the same extrapolation could
+     * be applied to the end of a lookahead buffer of any size.  However, it's most needed when
+     * lookahead=0, so that's what's currently implemented. */
+    if( !h->param.rc.i_lookahead )
+    {
+        if( b_intra )
+        {
+            memset( frames[0]->i_propagate_cost, 0, h->mb.i_mb_count * sizeof(uint16_t) );
+            memcpy( frames[0]->f_qp_offset, frames[0]->f_qp_offset_aq, h->mb.i_mb_count * sizeof(float) );
+            return;
+        }
+        XCHG( uint16_t*, frames[last_nonb]->i_propagate_cost, frames[0]->i_propagate_cost );
+        memset( frames[0]->i_propagate_cost, 0, h->mb.i_mb_count * sizeof(uint16_t) );
+    }
+    else
+    {
+        if( last_nonb < idx )
+            return;
+        memset( frames[last_nonb]->i_propagate_cost, 0, h->mb.i_mb_count * sizeof(uint16_t) );
+    }
+
+    while( i-- > idx )
+    {
+        cur_nonb = i;
+        while( frames[cur_nonb]->i_type == X264_TYPE_B && cur_nonb > 0 )
+            cur_nonb--;
+        if( cur_nonb < idx )
+            break;
+        x264_slicetype_frame_cost( h, a, frames, cur_nonb, last_nonb, last_nonb, 0 );
+        memset( frames[cur_nonb]->i_propagate_cost, 0, h->mb.i_mb_count * sizeof(uint16_t) );
+        bframes = last_nonb - cur_nonb - 1;
+        if( h->param.i_bframe_pyramid && bframes > 1 )
+        {
+            int middle = (bframes + 1)/2 + cur_nonb;
+            x264_slicetype_frame_cost( h, a, frames, cur_nonb, last_nonb, middle, 0 );
+            memset( frames[middle]->i_propagate_cost, 0, h->mb.i_mb_count * sizeof(uint16_t) );
+            while( i > cur_nonb )
+            {
+                int p0 = i > middle ? middle : cur_nonb;
+                int p1 = i < middle ? middle : last_nonb;
+                if( i != middle )
+                {
+                    x264_slicetype_frame_cost( h, a, frames, p0, p1, i, 0 );
+                    x264_macroblock_tree_propagate( h, frames, p0, p1, i, 0 );
+                }
+                i--;
+            }
+            x264_macroblock_tree_propagate( h, frames, cur_nonb, last_nonb, middle, 1 );
+        }
+        else
+        {
+            while( i > cur_nonb )
+            {
+                x264_slicetype_frame_cost( h, a, frames, cur_nonb, last_nonb, i, 0 );
+                x264_macroblock_tree_propagate( h, frames, cur_nonb, last_nonb, i, 0 );
+                i--;
+            }
+        }
+        x264_macroblock_tree_propagate( h, frames, cur_nonb, last_nonb, last_nonb, 1 );
+        last_nonb = cur_nonb;
+    }
+
+    if( !h->param.rc.i_lookahead )
+    {
+        x264_macroblock_tree_propagate( h, frames, 0, last_nonb, last_nonb, 1 );
+        XCHG( uint16_t*, frames[last_nonb]->i_propagate_cost, frames[0]->i_propagate_cost );
+    }
+
+    x264_macroblock_tree_finish( h, frames[last_nonb], last_nonb );
+    if( h->param.i_bframe_pyramid && bframes > 1 && !h->param.rc.i_vbv_buffer_size )
+        x264_macroblock_tree_finish( h, frames[last_nonb+(bframes+1)/2], 0 );
+}
+
+static int x264_vbv_frame_cost( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, int p0, int p1, int b )
+{
+    int cost = x264_slicetype_frame_cost( h, a, frames, p0, p1, b, 0 );
+    if( h->param.rc.i_aq_mode )
+    {
+        if( h->param.rc.b_mb_tree )
+            return x264_slicetype_frame_cost_recalculate( h, frames, p0, p1, b );
+        else
+            return frames[b]->i_cost_est_aq[b-p0][p1-b];
+    }
+    return cost;
+}
+
+static void x264_calculate_durations( x264_t *h, x264_frame_t *cur_frame, x264_frame_t *prev_frame, int *i_cpb_delay, int *i_coded_fields )
+{
+    cur_frame->i_cpb_delay = *i_cpb_delay;
+    cur_frame->i_dpb_output_delay = cur_frame->i_field_cnt - *i_coded_fields;
+
+    // add a correction term for frame reordering
+    cur_frame->i_dpb_output_delay += h->sps->vui.i_num_reorder_frames*2;
+
+    // fix possible negative dpb_output_delay because of pulldown changes and reordering
+    if( cur_frame->i_dpb_output_delay < 0 )
+    {
+        cur_frame->i_cpb_delay += cur_frame->i_dpb_output_delay;
+        cur_frame->i_dpb_output_delay = 0;
+        if( prev_frame )
+            prev_frame->i_cpb_duration += cur_frame->i_dpb_output_delay;
+    }
+
+    if( cur_frame->b_keyframe )
+        *i_cpb_delay = 0;
+
+    *i_cpb_delay += cur_frame->i_duration;
+    *i_coded_fields += cur_frame->i_duration;
+    cur_frame->i_cpb_duration = cur_frame->i_duration;
+}
+
+static void x264_vbv_lookahead( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, int num_frames, int keyframe )
+{
+    int last_nonb = 0, cur_nonb = 1, idx = 0;
+    x264_frame_t *prev_frame = NULL;
+    int prev_frame_idx = 0;
+    while( cur_nonb < num_frames && frames[cur_nonb]->i_type == X264_TYPE_B )
+        cur_nonb++;
+    int next_nonb = keyframe ? last_nonb : cur_nonb;
+
+    if( frames[cur_nonb]->i_coded_fields_lookahead >= 0 )
+    {
+        h->i_coded_fields_lookahead = frames[cur_nonb]->i_coded_fields_lookahead;
+        h->i_cpb_delay_lookahead = frames[cur_nonb]->i_cpb_delay_lookahead;
+    }
+
+    while( cur_nonb < num_frames )
+    {
+        /* P/I cost: This shouldn't include the cost of next_nonb */
+        if( next_nonb != cur_nonb )
+        {
+            int p0 = IS_X264_TYPE_I( frames[cur_nonb]->i_type ) ? cur_nonb : last_nonb;
+            frames[next_nonb]->i_planned_satd[idx] = x264_vbv_frame_cost( h, a, frames, p0, cur_nonb, cur_nonb );
+            frames[next_nonb]->i_planned_type[idx] = frames[cur_nonb]->i_type;
+            frames[cur_nonb]->i_coded_fields_lookahead = h->i_coded_fields_lookahead;
+            frames[cur_nonb]->i_cpb_delay_lookahead = h->i_cpb_delay_lookahead;
+            x264_calculate_durations( h, frames[cur_nonb], prev_frame, &h->i_cpb_delay_lookahead, &h->i_coded_fields_lookahead );
+            if( prev_frame )
+            {
+                frames[next_nonb]->f_planned_cpb_duration[prev_frame_idx] = (double)prev_frame->i_cpb_duration *
+                                                                            h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+            }
+            frames[next_nonb]->f_planned_cpb_duration[idx] = (double)frames[cur_nonb]->i_cpb_duration *
+                                                             h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+            prev_frame = frames[cur_nonb];
+            prev_frame_idx = idx;
+            idx++;
+        }
+        /* Handle the B-frames: coded order */
+        for( int i = last_nonb+1; i < cur_nonb; i++, idx++ )
+        {
+            frames[next_nonb]->i_planned_satd[idx] = x264_vbv_frame_cost( h, a, frames, last_nonb, cur_nonb, i );
+            frames[next_nonb]->i_planned_type[idx] = X264_TYPE_B;
+            frames[i]->i_coded_fields_lookahead = h->i_coded_fields_lookahead;
+            frames[i]->i_cpb_delay_lookahead = h->i_cpb_delay_lookahead;
+            x264_calculate_durations( h, frames[i], prev_frame, &h->i_cpb_delay_lookahead, &h->i_coded_fields_lookahead );
+            if( prev_frame )
+            {
+                frames[next_nonb]->f_planned_cpb_duration[prev_frame_idx] = (double)prev_frame->i_cpb_duration *
+                                                                            h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+            }
+            frames[next_nonb]->f_planned_cpb_duration[idx] = (double)frames[i]->i_cpb_duration *
+                                                             h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+            prev_frame = frames[i];
+            prev_frame_idx = idx;
+        }
+        last_nonb = cur_nonb;
+        cur_nonb++;
+        while( cur_nonb <= num_frames && frames[cur_nonb]->i_type == X264_TYPE_B )
+            cur_nonb++;
+    }
+    frames[next_nonb]->i_planned_type[idx] = X264_TYPE_AUTO;
+}
+
+static int x264_slicetype_path_cost( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, char *path, int threshold )
+{
+    int loc = 1;
+    int cost = 0;
+    int cur_p = 0;
+    path--; /* Since the 1st path element is really the second frame */
+    while( path[loc] )
+    {
+        int next_p = loc;
+        /* Find the location of the next P-frame. */
+        while( path[next_p] != 'P' )
+            next_p++;
+
+        /* Add the cost of the P-frame found above */
+        cost += x264_slicetype_frame_cost( h, a, frames, cur_p, next_p, next_p, 0 );
+        /* Early terminate if the cost we have found is larger than the best path cost so far */
+        if( cost > threshold )
+            break;
+
+        if( h->param.i_bframe_pyramid && next_p - cur_p > 2 )
+        {
+            int middle = cur_p + (next_p - cur_p)/2;
+            cost += x264_slicetype_frame_cost( h, a, frames, cur_p, next_p, middle, 0 );
+            for( int next_b = loc; next_b < middle && cost < threshold; next_b++ )
+                cost += x264_slicetype_frame_cost( h, a, frames, cur_p, middle, next_b, 0 );
+            for( int next_b = middle+1; next_b < next_p && cost < threshold; next_b++ )
+                cost += x264_slicetype_frame_cost( h, a, frames, middle, next_p, next_b, 0 );
+        }
+        else
+            for( int next_b = loc; next_b < next_p && cost < threshold; next_b++ )
+                cost += x264_slicetype_frame_cost( h, a, frames, cur_p, next_p, next_b, 0 );
+
+        loc = next_p + 1;
+        cur_p = next_p;
+    }
+    return cost;
+}
+
+/* Viterbi/trellis slicetype decision algorithm. */
+/* Uses strings due to the fact that the speed of the control functions is
+   negligible compared to the cost of running slicetype_frame_cost, and because
+   it makes debugging easier. */
+static void x264_slicetype_path( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, int length, char (*best_paths)[X264_LOOKAHEAD_MAX] )
+{
+    char paths[2][X264_LOOKAHEAD_MAX];
+    int num_paths = X264_MIN( h->param.i_bframe+1, length );
+    int best_cost = COST_MAX;
+    int idx = 0;
+
+    /* Iterate over all currently possible paths */
+    for( int path = 0; path < num_paths; path++ )
+    {
+        /* Add suffixes to the current path */
+        int len = length - (path + 1);
+        memcpy( paths[idx], best_paths[len % (X264_BFRAME_MAX+1)], len );
+        memset( paths[idx]+len, 'B', path );
+        strcpy( paths[idx]+len+path, "P" );
+
+        /* Calculate the actual cost of the current path */
+        int cost = x264_slicetype_path_cost( h, a, frames, paths[idx], best_cost );
+        if( cost < best_cost )
+        {
+            best_cost = cost;
+            idx ^= 1;
+        }
+    }
+
+    /* Store the best path. */
+    memcpy( best_paths[length % (X264_BFRAME_MAX+1)], paths[idx^1], length );
+}
+
+static int scenecut_internal( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, int p0, int p1, int print )
+{
+    x264_frame_t *frame = frames[p1];
+    x264_slicetype_frame_cost( h, a, frames, p0, p1, p1, 0 );
+
     int icost = frame->i_cost_est[0][0];
-    int pcost = frame->i_cost_est[pdist][0];
+    int pcost = frame->i_cost_est[p1-p0][0];
     float f_bias;
-    int i_gop_size = frame->i_frame - h->frames.i_last_idr;
+    int i_gop_size = frame->i_frame - h->lookahead->i_last_keyframe;
     float f_thresh_max = h->param.i_scenecut_threshold / 100.0;
     /* magic numbers pulled out of thin air */
     float f_thresh_min = f_thresh_max * h->param.i_keyint_min
@@ -336,7 +1014,7 @@ static int scenecut( x264_t *h, x264_frame_t *frame, int pdist )
 
     if( h->param.i_keyint_min == h->param.i_keyint_max )
         f_thresh_min= f_thresh_max;
-    if( i_gop_size < h->param.i_keyint_min / 4 )
+    if( i_gop_size < h->param.i_keyint_min / 4 || h->param.b_intra_refresh )
         f_bias = f_thresh_min / 4;
     else if( i_gop_size <= h->param.i_keyint_min )
         f_bias = f_thresh_min * i_gop_size / h->param.i_keyint_min;
@@ -344,15 +1022,15 @@ static int scenecut( x264_t *h, x264_frame_t *frame, int pdist )
     {
         f_bias = f_thresh_min
                  + ( f_thresh_max - f_thresh_min )
-                   * ( i_gop_size - h->param.i_keyint_min )
-                   / ( h->param.i_keyint_max - h->param.i_keyint_min );
+                    * ( i_gop_size - h->param.i_keyint_min )
+                   / ( h->param.i_keyint_max - h->param.i_keyint_min ) ;
     }
 
     res = pcost >= (1.0 - f_bias) * icost;
-    if( res )
+    if( res && print )
     {
-        int imb = frame->i_intra_mbs[pdist];
-        int pmb = (h->sps->i_mb_width - 2) * (h->sps->i_mb_height - 2) - imb;
+        int imb = frame->i_intra_mbs[p1-p0];
+        int pmb = NUM_MBS - imb;
         x264_log( h, X264_LOG_DEBUG, "scene cut at %d Icost:%d Pcost:%d ratio:%.4f bias:%.4f gop:%d (imb:%d pmb:%d)\n",
                   frame->i_frame,
                   icost, pcost, 1. - (double)pcost / icost,
@@ -361,127 +1039,343 @@ static int scenecut( x264_t *h, x264_frame_t *frame, int pdist )
     return res;
 }
 
-void x264_slicetype_analyse( x264_t *h )
+static int scenecut( x264_t *h, x264_mb_analysis_t *a, x264_frame_t **frames, int p0, int p1, int real_scenecut, int num_frames )
+{
+    /* Only do analysis during a normal scenecut check. */
+    if( real_scenecut && h->param.i_bframe )
+    {
+        int maxp1 = p0 + 1;
+        /* Look ahead to avoid coding short flashes as scenecuts. */
+        if( h->param.i_bframe_adaptive == X264_B_ADAPT_TRELLIS )
+            /* Don't analyse any more frames than the trellis would have covered. */
+            maxp1 += h->param.i_bframe;
+        else
+            maxp1++;
+        maxp1 = X264_MIN( maxp1, num_frames );
+
+        /* Where A and B are scenes: AAAAAABBBAAAAAA
+         * If BBB is shorter than (maxp1-p0), it is detected as a flash
+         * and not considered a scenecut. */
+        for( int curp1 = p1; curp1 <= maxp1; curp1++ )
+            if( !scenecut_internal( h, a, frames, p0, curp1, 0 ) )
+                /* Any frame in between p0 and cur_p1 cannot be a real scenecut. */
+                for( int i = curp1; i > p0; i-- )
+                    frames[i]->b_scenecut = 0;
+
+        /* Where A-F are scenes: AAAAABBCCDDEEFFFFFF
+         * If each of BB ... EE are shorter than (maxp1-p0), they are
+         * detected as flashes and not considered scenecuts.
+         * Instead, the first F frame becomes a scenecut. */
+        for( int curp0 = p0; curp0 < maxp1; curp0++ )
+            if( scenecut_internal( h, a, frames, curp0, maxp1, 0 ) )
+                /* If cur_p0 is the p0 of a scenecut, it cannot be the p1 of a scenecut. */
+                    frames[curp0]->b_scenecut = 0;
+    }
+
+    /* Ignore frames that are part of a flash, i.e. cannot be real scenecuts. */
+    if( !frames[p1]->b_scenecut )
+        return 0;
+    return scenecut_internal( h, a, frames, p0, p1, real_scenecut );
+}
+
+void x264_slicetype_analyse( x264_t *h, int keyframe )
 {
     x264_mb_analysis_t a;
-    x264_frame_t *frames[X264_BFRAME_MAX+3] = { NULL, };
-    int num_frames;
-    int keyint_limit;
-    int j;
-    int i_mb_count = (h->sps->i_mb_width - 2) * (h->sps->i_mb_height - 2);
+    x264_frame_t *frames[X264_LOOKAHEAD_MAX+3] = { NULL, };
+    int num_frames, orig_num_frames, keyint_limit, framecnt;
+    int i_mb_count = NUM_MBS;
     int cost1p0, cost2p0, cost1b1, cost2p1;
-    int idr_frame_type;
+    int i_max_search = X264_MIN( h->lookahead->next.i_size, X264_LOOKAHEAD_MAX );
+    int vbv_lookahead = h->param.rc.i_vbv_buffer_size && h->param.rc.i_lookahead;
+    if( h->param.b_deterministic )
+        i_max_search = X264_MIN( i_max_search, h->lookahead->i_slicetype_length + !keyframe );
 
     assert( h->frames.b_have_lowres );
 
-    if( !h->frames.last_nonb )
+    if( !h->lookahead->last_nonb )
         return;
-    frames[0] = h->frames.last_nonb;
-    for( j = 0; h->frames.next[j]; j++ )
-        frames[j+1] = h->frames.next[j];
-    keyint_limit = h->param.i_keyint_max - frames[0]->i_frame + h->frames.i_last_idr - 1;
-    num_frames = X264_MIN( j, keyint_limit );
-    if( num_frames == 0 )
+    frames[0] = h->lookahead->last_nonb;
+    for( framecnt = 0; framecnt < i_max_search && h->lookahead->next.list[framecnt]->i_type == X264_TYPE_AUTO; framecnt++ )
+        frames[framecnt+1] = h->lookahead->next.list[framecnt];
+
+    if( !framecnt )
+    {
+        if( h->param.rc.b_mb_tree )
+            x264_macroblock_tree( h, &a, frames, 0, keyframe );
         return;
+    }
+
+    keyint_limit = h->param.i_keyint_max - frames[0]->i_frame + h->lookahead->i_last_keyframe - 1;
+    orig_num_frames = num_frames = h->param.b_intra_refresh ? framecnt : X264_MIN( framecnt, keyint_limit );
 
     x264_lowres_context_init( h, &a );
-    idr_frame_type = frames[1]->i_frame - h->frames.i_last_idr >= h->param.i_keyint_min ? X264_TYPE_IDR : X264_TYPE_I;
 
-    if( num_frames == 1 )
+    /* This is important psy-wise: if we have a non-scenecut keyframe,
+     * there will be significant visual artifacts if the frames just before
+     * go down in quality due to being referenced less, despite it being
+     * more RD-optimal. */
+    if( (h->param.analyse.b_psy && h->param.rc.b_mb_tree) || vbv_lookahead )
+        num_frames = framecnt;
+    else if( num_frames == 0 )
     {
-no_b_frames:
-        frames[1]->i_type = X264_TYPE_P;
-        if( h->param.b_pre_scenecut )
-        {
-            x264_slicetype_frame_cost( h, &a, frames, 0, 1, 1, 0 );
-            if( scenecut( h, frames[1], 1 ) )
-                frames[1]->i_type = idr_frame_type;
-        }
+        frames[1]->i_type = X264_TYPE_I;
         return;
     }
 
-    cost2p1 = x264_slicetype_frame_cost( h, &a, frames, 0, 2, 2, 1 );
-    if( frames[2]->i_intra_mbs[2] > i_mb_count / 2 )
-        goto no_b_frames;
+    int num_bframes = 0;
+    int num_analysed_frames = num_frames;
+    int reset_start;
+    if( h->param.i_scenecut_threshold && scenecut( h, &a, frames, 0, 1, 1, orig_num_frames ) )
+    {
+        frames[1]->i_type = X264_TYPE_I;
+        return;
+    }
 
-    cost1b1 = x264_slicetype_frame_cost( h, &a, frames, 0, 2, 1, 0 );
-    cost1p0 = x264_slicetype_frame_cost( h, &a, frames, 0, 1, 1, 0 );
-    cost2p0 = x264_slicetype_frame_cost( h, &a, frames, 1, 2, 2, 0 );
-//  fprintf( stderr, "PP: %d + %d <=> BP: %d + %d \n",
-//           cost1p0, cost2p0, cost1b1, cost2p1 );
-    if( cost1p0 + cost2p0 < cost1b1 + cost2p1 )
-        goto no_b_frames;
+    if( h->param.i_bframe )
+    {
+        if( h->param.i_bframe_adaptive == X264_B_ADAPT_TRELLIS )
+        {
+            if( num_frames > 1 )
+            {
+                char best_paths[X264_BFRAME_MAX+1][X264_LOOKAHEAD_MAX] = {"","P"};
+                int best_path_index = (num_frames-1) % (X264_BFRAME_MAX+1);
 
-// arbitrary and untuned
-#define INTER_THRESH 300
-#define P_SENS_BIAS (50 - h->param.i_bframe_bias)
-    frames[1]->i_type = X264_TYPE_B;
+                /* Perform the frametype analysis. */
+                for( int j = 2; j < num_frames; j++ )
+                    x264_slicetype_path( h, &a, frames, j, best_paths );
 
-    for( j = 2; j <= X264_MIN( h->param.i_bframe, num_frames-1 ); j++ )
-    {
-        int pthresh = X264_MAX(INTER_THRESH - P_SENS_BIAS * (j-1), INTER_THRESH/10);
-        int pcost = x264_slicetype_frame_cost( h, &a, frames, 0, j+1, j+1, 1 );
-//      fprintf( stderr, "frm%d+%d: %d <=> %d, I:%d/%d \n",
-//               frames[0]->i_frame, j-1, pthresh, pcost/i_mb_count,
-//               frames[j+1]->i_intra_mbs[j+1], i_mb_count );
-        if( pcost > pthresh*i_mb_count || frames[j+1]->i_intra_mbs[j+1] > i_mb_count/3 )
+                num_bframes = strspn( best_paths[best_path_index], "B" );
+                /* Load the results of the analysis into the frame types. */
+                for( int j = 1; j < num_frames; j++ )
+                    frames[j]->i_type = best_paths[best_path_index][j-1] == 'B' ? X264_TYPE_B : X264_TYPE_P;
+            }
+            frames[num_frames]->i_type = X264_TYPE_P;
+        }
+        else if( h->param.i_bframe_adaptive == X264_B_ADAPT_FAST )
         {
-            frames[j]->i_type = X264_TYPE_P;
-            break;
+            for( int i = 0; i <= num_frames-2; )
+            {
+                cost2p1 = x264_slicetype_frame_cost( h, &a, frames, i+0, i+2, i+2, 1 );
+                if( frames[i+2]->i_intra_mbs[2] > i_mb_count / 2 )
+                {
+                    frames[i+1]->i_type = X264_TYPE_P;
+                    frames[i+2]->i_type = X264_TYPE_P;
+                    i += 2;
+                    continue;
+                }
+
+                cost1b1 = x264_slicetype_frame_cost( h, &a, frames, i+0, i+2, i+1, 0 );
+                cost1p0 = x264_slicetype_frame_cost( h, &a, frames, i+0, i+1, i+1, 0 );
+                cost2p0 = x264_slicetype_frame_cost( h, &a, frames, i+1, i+2, i+2, 0 );
+
+                if( cost1p0 + cost2p0 < cost1b1 + cost2p1 )
+                {
+                    frames[i+1]->i_type = X264_TYPE_P;
+                    i += 1;
+                    continue;
+                }
+
+                // arbitrary and untuned
+                #define INTER_THRESH 300
+                #define P_SENS_BIAS (50 - h->param.i_bframe_bias)
+                frames[i+1]->i_type = X264_TYPE_B;
+
+                int j;
+                for( j = i+2; j <= X264_MIN( i+h->param.i_bframe, num_frames-1 ); j++ )
+                {
+                    int pthresh = X264_MAX(INTER_THRESH - P_SENS_BIAS * (j-i-1), INTER_THRESH/10);
+                    int pcost = x264_slicetype_frame_cost( h, &a, frames, i+0, j+1, j+1, 1 );
+                    if( pcost > pthresh*i_mb_count || frames[j+1]->i_intra_mbs[j-i+1] > i_mb_count/3 )
+                        break;
+                    frames[j]->i_type = X264_TYPE_B;
+                }
+                frames[j]->i_type = X264_TYPE_P;
+                i = j;
+            }
+            frames[num_frames]->i_type = X264_TYPE_P;
+            num_bframes = 0;
+            while( num_bframes < num_frames && frames[num_bframes+1]->i_type == X264_TYPE_B )
+                num_bframes++;
         }
         else
-            frames[j]->i_type = X264_TYPE_B;
+        {
+            num_bframes = X264_MIN(num_frames-1, h->param.i_bframe);
+            for( int j = 1; j < num_frames; j++ )
+                frames[j]->i_type = (j%(num_bframes+1)) ? X264_TYPE_B : X264_TYPE_P;
+            frames[num_frames]->i_type = X264_TYPE_P;
+        }
+
+        /* Check scenecut on the first minigop. */
+        for( int j = 1; j < num_bframes+1; j++ )
+            if( h->param.i_scenecut_threshold && scenecut( h, &a, frames, j, j+1, 0, orig_num_frames ) )
+            {
+                frames[j]->i_type = X264_TYPE_P;
+                num_analysed_frames = j;
+                break;
+            }
+
+        reset_start = keyframe ? 1 : X264_MIN( num_bframes+2, num_analysed_frames+1 );
     }
+    else
+    {
+        for( int j = 1; j <= num_frames; j++ )
+            frames[j]->i_type = X264_TYPE_P;
+        reset_start = !keyframe + 1;
+        num_bframes = 0;
+    }
+
+    /* Perform the actual macroblock tree analysis.
+     * Don't go farther than the maximum keyframe interval; this helps in short GOPs. */
+    if( h->param.rc.b_mb_tree )
+        x264_macroblock_tree( h, &a, frames, X264_MIN(num_frames, h->param.i_keyint_max), keyframe );
+
+    /* Enforce keyframe limit. */
+    if( !h->param.b_intra_refresh )
+        for( int i = keyint_limit+1; i <= num_frames; i += h->param.i_keyint_max )
+        {
+            int j = i;
+            if( h->param.i_open_gop == X264_OPEN_GOP_CODED_ORDER )
+            {
+                while( IS_X264_TYPE_B( frames[i]->i_type ) )
+                    i++;
+                while( IS_X264_TYPE_B( frames[j-1]->i_type ) )
+                    j--;
+            }
+            frames[i]->i_type = X264_TYPE_I;
+            reset_start = X264_MIN( reset_start, i+1 );
+            i = j;
+        }
+
+    if( vbv_lookahead )
+        x264_vbv_lookahead( h, &a, frames, num_frames, keyframe );
+
+    /* Restore frametypes for all frames that haven't actually been decided yet. */
+    for( int j = reset_start; j <= num_frames; j++ )
+        frames[j]->i_type = X264_TYPE_AUTO;
 }
 
 void x264_slicetype_decide( x264_t *h )
 {
+    x264_frame_t *frames[X264_BFRAME_MAX+2];
     x264_frame_t *frm;
     int bframes;
-    int i;
+    int brefs;
 
-    if( h->frames.next[0] == NULL )
+    if( !h->lookahead->next.i_size )
         return;
 
+    int lookahead_size = h->lookahead->next.i_size;
+
+    if( h->param.rc.i_rc_method == X264_RC_ABR || h->param.rc.b_stat_write || h->param.rc.i_vbv_buffer_size )
+    {
+        for( int i = 0; i < h->lookahead->next.i_size; i++ )
+        {
+            if( h->param.b_vfr_input )
+            {
+                if( lookahead_size-- > 1 )
+                    h->lookahead->next.list[i]->i_duration = 2 * (h->lookahead->next.list[i+1]->i_pts - h->lookahead->next.list[i]->i_pts);
+                else
+                    h->lookahead->next.list[i]->i_duration = h->i_prev_duration;
+            }
+            else
+                h->lookahead->next.list[i]->i_duration = delta_tfi_divisor[h->lookahead->next.list[i]->i_pic_struct];
+            h->i_prev_duration = h->lookahead->next.list[i]->i_duration;
+
+            if( h->lookahead->next.list[i]->i_frame > h->i_disp_fields_last_frame && lookahead_size > 0 )
+            {
+                h->lookahead->next.list[i]->i_field_cnt = h->i_disp_fields;
+                h->i_disp_fields += h->lookahead->next.list[i]->i_duration;
+                h->i_disp_fields_last_frame = h->lookahead->next.list[i]->i_frame;
+            }
+            else if( lookahead_size == 0 )
+            {
+                h->lookahead->next.list[i]->i_field_cnt = h->i_disp_fields;
+                h->lookahead->next.list[i]->i_duration = h->i_prev_duration;
+            }
+        }
+    }
+
     if( h->param.rc.b_stat_read )
     {
         /* Use the frame types from the first pass */
-        for( i = 0; h->frames.next[i] != NULL; i++ )
-            h->frames.next[i]->i_type =
-                x264_ratecontrol_slice_type( h, h->frames.next[i]->i_frame );
+        for( int i = 0; i < h->lookahead->next.i_size; i++ )
+            h->lookahead->next.list[i]->i_type =
+                x264_ratecontrol_slice_type( h, h->lookahead->next.list[i]->i_frame );
     }
-    else if( (h->param.i_bframe && h->param.b_bframe_adaptive)
-             || h->param.b_pre_scenecut )
-        x264_slicetype_analyse( h );
+    else if( (h->param.i_bframe && h->param.i_bframe_adaptive)
+             || h->param.i_scenecut_threshold
+             || h->param.rc.b_mb_tree
+             || (h->param.rc.i_vbv_buffer_size && h->param.rc.i_lookahead) )
+        x264_slicetype_analyse( h, 0 );
 
-    for( bframes = 0;; bframes++ )
+    for( bframes = 0, brefs = 0;; bframes++ )
     {
-        frm = h->frames.next[bframes];
+        frm = h->lookahead->next.list[bframes];
+        if( frm->i_type == X264_TYPE_BREF && h->param.i_bframe_pyramid < X264_B_PYRAMID_NORMAL &&
+            brefs == h->param.i_bframe_pyramid )
+        {
+            frm->i_type = X264_TYPE_B;
+            x264_log( h, X264_LOG_WARNING, "B-ref at frame %d incompatible with B-pyramid %s \n",
+                      frm->i_frame, x264_b_pyramid_names[h->param.i_bframe_pyramid] );
+        }
+        /* pyramid with multiple B-refs needs a big enough dpb that the preceding P-frame stays available.
+           smaller dpb could be supported by smart enough use of mmco, but it's easier just to forbid it. */
+        else if( frm->i_type == X264_TYPE_BREF && h->param.i_bframe_pyramid == X264_B_PYRAMID_NORMAL &&
+            brefs && h->param.i_frame_reference <= (brefs+3) )
+        {
+            frm->i_type = X264_TYPE_B;
+            x264_log( h, X264_LOG_WARNING, "B-ref at frame %d incompatible with B-pyramid %s and %d reference frames\n",
+                      frm->i_frame, x264_b_pyramid_names[h->param.i_bframe_pyramid], h->param.i_frame_reference );
+        }
+
+        if( frm->i_type == X264_TYPE_KEYFRAME )
+            frm->i_type = h->param.i_open_gop ? X264_TYPE_I : X264_TYPE_IDR;
 
         /* Limit GOP size */
-        if( frm->i_frame - h->frames.i_last_idr >= h->param.i_keyint_max )
+        if( (!h->param.b_intra_refresh || frm->i_frame == 0) && frm->i_frame - h->lookahead->i_last_keyframe >= h->param.i_keyint_max )
+        {
+            if( frm->i_type == X264_TYPE_AUTO || frm->i_type == X264_TYPE_I )
+                frm->i_type = h->param.i_open_gop && h->lookahead->i_last_keyframe >= 0 ? X264_TYPE_I : X264_TYPE_IDR;
+            int warn = frm->i_type != X264_TYPE_IDR;
+            if( warn && h->param.i_open_gop == X264_OPEN_GOP_DISPLAY_ORDER )
+                warn &= frm->i_type != X264_TYPE_I && frm->i_type != X264_TYPE_KEYFRAME;
+            if( warn && h->param.i_open_gop == X264_OPEN_GOP_CODED_ORDER )
+            {
+                /* if this minigop ends with i, it's not a violation */
+                int j = bframes;
+                while( IS_X264_TYPE_B( h->lookahead->next.list[j]->i_type ) )
+                    j++;
+                warn = h->lookahead->next.list[j]->i_type != X264_TYPE_I && h->lookahead->next.list[j]->i_type != X264_TYPE_KEYFRAME;
+            }
+            if( warn )
+                x264_log( h, X264_LOG_WARNING, "specified frame type (%d) at %d is not compatible with keyframe interval\n", frm->i_type, frm->i_frame );
+        }
+        if( frm->i_type == X264_TYPE_I && frm->i_frame - h->lookahead->i_last_keyframe >= h->param.i_keyint_min )
         {
-            if( frm->i_type == X264_TYPE_AUTO )
+            if( h->param.i_open_gop )
+            {
+                h->lookahead->i_last_keyframe = frm->i_frame; // Use display order
+                if( h->param.i_open_gop == X264_OPEN_GOP_CODED_ORDER )
+                    h->lookahead->i_last_keyframe -= bframes; // Use coded order
+                frm->b_keyframe = 1;
+            }
+            else
                 frm->i_type = X264_TYPE_IDR;
-            if( frm->i_type != X264_TYPE_IDR )
-                x264_log( h, X264_LOG_WARNING, "specified frame type (%d) is not compatible with keyframe interval\n", frm->i_type );
         }
         if( frm->i_type == X264_TYPE_IDR )
         {
             /* Close GOP */
+            h->lookahead->i_last_keyframe = frm->i_frame;
+            frm->b_keyframe = 1;
             if( bframes > 0 )
             {
                 bframes--;
-                h->frames.next[bframes]->i_type = X264_TYPE_P;
-            }
-            else
-            {
-                h->i_frame_num = 0;
+                h->lookahead->next.list[bframes]->i_type = X264_TYPE_P;
             }
         }
 
-        if( bframes == h->param.i_bframe
-            || h->frames.next[bframes+1] == NULL )
+        if( bframes == h->param.i_bframe ||
+            !h->lookahead->next.list[bframes+1] )
         {
             if( IS_X264_TYPE_B( frm->i_type ) )
                 x264_log( h, X264_LOG_WARNING, "specified frame type is not compatible with max B-frames\n" );
@@ -490,47 +1384,168 @@ void x264_slicetype_decide( x264_t *h )
                 frm->i_type = X264_TYPE_P;
         }
 
-        if( frm->i_type != X264_TYPE_AUTO && frm->i_type != X264_TYPE_B && frm->i_type != X264_TYPE_BREF )
-            break;
+        if( frm->i_type == X264_TYPE_BREF )
+            brefs++;
 
-        frm->i_type = X264_TYPE_B;
+        if( frm->i_type == X264_TYPE_AUTO )
+            frm->i_type = X264_TYPE_B;
+
+        else if( !IS_X264_TYPE_B( frm->i_type ) ) break;
+    }
+
+    if( bframes )
+        h->lookahead->next.list[bframes-1]->b_last_minigop_bframe = 1;
+    h->lookahead->next.list[bframes]->i_bframes = bframes;
+
+    /* insert a bref into the sequence */
+    if( h->param.i_bframe_pyramid && bframes > 1 && !brefs )
+    {
+        h->lookahead->next.list[bframes/2]->i_type = X264_TYPE_BREF;
+        brefs++;
+    }
+
+    /* calculate the frame costs ahead of time for x264_rc_analyse_slice while we still have lowres */
+    if( h->param.rc.i_rc_method != X264_RC_CQP )
+    {
+        x264_mb_analysis_t a;
+        int p0, p1, b;
+        p1 = b = bframes + 1;
+
+        x264_lowres_context_init( h, &a );
+
+        frames[0] = h->lookahead->last_nonb;
+        memcpy( &frames[1], h->lookahead->next.list, (bframes+1) * sizeof(x264_frame_t*) );
+        if( IS_X264_TYPE_I( h->lookahead->next.list[bframes]->i_type ) )
+            p0 = bframes + 1;
+        else // P
+            p0 = 0;
+
+        x264_slicetype_frame_cost( h, &a, frames, p0, p1, b, 0 );
+
+        if( (p0 != p1 || bframes) && h->param.rc.i_vbv_buffer_size )
+        {
+            /* We need the intra costs for row SATDs. */
+            x264_slicetype_frame_cost( h, &a, frames, b, b, b, 0 );
+
+            /* We need B-frame costs for row SATDs. */
+            p0 = 0;
+            for( b = 1; b <= bframes; b++ )
+            {
+                if( frames[b]->i_type == X264_TYPE_B )
+                    for( p1 = b; frames[p1]->i_type == X264_TYPE_B; )
+                        p1++;
+                else
+                    p1 = bframes + 1;
+                x264_slicetype_frame_cost( h, &a, frames, p0, p1, b, 0 );
+                if( frames[b]->i_type == X264_TYPE_BREF )
+                    p0 = b;
+            }
+        }
+    }
+
+    /* Analyse for weighted P frames */
+    if( !h->param.rc.b_stat_read && h->lookahead->next.list[bframes]->i_type == X264_TYPE_P
+        && h->param.analyse.i_weighted_pred == X264_WEIGHTP_SMART )
+    {
+        x264_emms();
+        x264_weights_analyse( h, h->lookahead->next.list[bframes], h->lookahead->last_nonb, 0 );
+    }
+
+    /* shift sequence to coded order.
+       use a small temporary list to avoid shifting the entire next buffer around */
+    int i_coded = h->lookahead->next.list[0]->i_frame;
+    if( bframes )
+    {
+        int idx_list[] = { brefs+1, 1 };
+        for( int i = 0; i < bframes; i++ )
+        {
+            int idx = idx_list[h->lookahead->next.list[i]->i_type == X264_TYPE_BREF]++;
+            frames[idx] = h->lookahead->next.list[i];
+            frames[idx]->i_reordered_pts = h->lookahead->next.list[idx]->i_pts;
+        }
+        frames[0] = h->lookahead->next.list[bframes];
+        frames[0]->i_reordered_pts = h->lookahead->next.list[0]->i_pts;
+        memcpy( h->lookahead->next.list, frames, (bframes+1) * sizeof(x264_frame_t*) );
+    }
+
+    for( int i = 0; i <= bframes; i++ )
+    {
+        h->lookahead->next.list[i]->i_coded = i_coded++;
+        if( h->param.rc.i_rc_method == X264_RC_ABR || h->param.rc.b_stat_write || h->param.rc.i_vbv_buffer_size )
+        {
+            if( i )
+            {
+                x264_calculate_durations( h, h->lookahead->next.list[i], h->lookahead->next.list[i-1], &h->i_cpb_delay, &h->i_coded_fields );
+                h->lookahead->next.list[0]->f_planned_cpb_duration[i-1] = (double)h->lookahead->next.list[i-1]->i_cpb_duration *
+                                                                          h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+            }
+            else
+                x264_calculate_durations( h, h->lookahead->next.list[i], NULL, &h->i_cpb_delay, &h->i_coded_fields );
+
+            h->lookahead->next.list[0]->f_planned_cpb_duration[i] = (double)h->lookahead->next.list[i]->i_cpb_duration *
+                                                                    h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+        }
     }
 }
 
 int x264_rc_analyse_slice( x264_t *h )
 {
-    x264_mb_analysis_t a;
-    x264_frame_t *frames[X264_BFRAME_MAX+2] = { NULL, };
-    int p0=0, p1, b;
+    int p0 = 0, p1, b;
     int cost;
-
-    x264_lowres_context_init( h, &a );
+    x264_emms();
 
     if( IS_X264_TYPE_I(h->fenc->i_type) )
-    {
         p1 = b = 0;
-    }
-    else if( X264_TYPE_P == h->fenc->i_type )
-    {
-        p1 = 0;
-        while( h->frames.current[p1] && IS_X264_TYPE_B( h->frames.current[p1]->i_type ) )
-            p1++;
-        p1++;
-        b = p1;
-    }
+    else if( h->fenc->i_type == X264_TYPE_P )
+        p1 = b = h->fenc->i_bframes + 1;
     else //B
     {
         p1 = (h->fref1[0]->i_poc - h->fref0[0]->i_poc)/2;
-        b  = (h->fref1[0]->i_poc - h->fenc->i_poc)/2;
-        frames[p1] = h->fref1[0];
+        b  = (h->fenc->i_poc - h->fref0[0]->i_poc)/2;
     }
-    frames[p0] = h->fref0[0];
-    frames[b] = h->fenc;
+    /* We don't need to assign p0/p1 since we are not performing any real analysis here. */
+    x264_frame_t **frames = &h->fenc - b;
+
+    /* cost should have been already calculated by x264_slicetype_decide */
+    cost = frames[b]->i_cost_est[b-p0][p1-b];
+    assert( cost >= 0 );
+
+    if( h->param.rc.b_mb_tree && !h->param.rc.b_stat_read )
+    {
+        cost = x264_slicetype_frame_cost_recalculate( h, frames, p0, p1, b );
+        if( b && h->param.rc.i_vbv_buffer_size )
+            x264_slicetype_frame_cost_recalculate( h, frames, b, b, b );
+    }
+    /* In AQ, use the weighted score instead. */
+    else if( h->param.rc.i_aq_mode )
+        cost = frames[b]->i_cost_est_aq[b-p0][p1-b];
 
-    cost = x264_slicetype_frame_cost( h, &a, frames, p0, p1, b, 0 );
     h->fenc->i_row_satd = h->fenc->i_row_satds[b-p0][p1-b];
     h->fdec->i_row_satd = h->fdec->i_row_satds[b-p0][p1-b];
     h->fdec->i_satd = cost;
-    memcpy( h->fdec->i_row_satd, h->fenc->i_row_satd, h->sps->i_mb_height * sizeof(int) );
+    memcpy( h->fdec->i_row_satd, h->fenc->i_row_satd, h->mb.i_mb_height * sizeof(int) );
+    if( !IS_X264_TYPE_I(h->fenc->i_type) )
+        memcpy( h->fdec->i_row_satds[0][0], h->fenc->i_row_satds[0][0], h->mb.i_mb_height * sizeof(int) );
+
+    if( h->param.b_intra_refresh && h->param.rc.i_vbv_buffer_size && h->fenc->i_type == X264_TYPE_P )
+    {
+        int ip_factor = 256 * h->param.rc.f_ip_factor; /* fix8 */
+        for( int y = 0; y < h->mb.i_mb_height; y++ )
+        {
+            int mb_xy = y * h->mb.i_mb_stride;
+            for( int x = h->fdec->i_pir_start_col; x <= h->fdec->i_pir_end_col; x++, mb_xy++ )
+            {
+                int intra_cost = (h->fenc->i_intra_cost[mb_xy] * ip_factor + 128) >> 8;
+                int inter_cost = h->fenc->lowres_costs[b-p0][p1-b][mb_xy] & LOWRES_COST_MASK;
+                int diff = intra_cost - inter_cost;
+                if( h->param.rc.i_aq_mode )
+                    h->fdec->i_row_satd[y] += (diff * frames[b]->i_inv_qscale_factor[mb_xy] + 128) >> 8;
+                else
+                    h->fdec->i_row_satd[y] += diff;
+                cost += diff;
+            }
+        }
+    }
+
     return cost;
 }