X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=encoder%2Fratecontrol.c;h=4a7cc5c5edb5104a18bc01731d01915c2b0af849;hb=87e5994706c76bd628c7e23f0dca95f05e922a7c;hp=e73c9e3521d7e764b7d44c0db77f5e95c7704584;hpb=53295729673187df0ab1143c08fae578b5447376;p=x264

diff --git a/encoder/ratecontrol.c b/encoder/ratecontrol.c
index e73c9e35..4a7cc5c5 100644
--- a/encoder/ratecontrol.c
+++ b/encoder/ratecontrol.c
@@ -1,12 +1,12 @@
 /***************************************************-*- coding: iso-8859-1 -*-
  * ratecontrol.c: h264 encoder library (Rate Control)
  *****************************************************************************
- * Copyright (C) 2003 Laurent Aimar
+ * Copyright (C) 2005 x264 project
  * $Id: ratecontrol.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
  *
- * Authors: Måns Rullgård <mru@mru.ath.cx>
- * 2 pass code: Michael Niedermayer <michaelni@gmx.at>
- *              Loren Merritt <lorenm@u.washington.edu>
+ * Authors: Loren Merritt <lorenm@u.washington.edu>
+ *          Michael Niedermayer <michaelni@gmx.at>
+ *          Måns Rullgård <mru@mru.ath.cx>
  *
  * 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
@@ -34,27 +34,29 @@
 
 #include "common/common.h"
 #include "common/cpu.h"
-#include "common/macroblock.h"
 #include "ratecontrol.h"
 
-#ifdef SYS_MACOSX
-#define exp2f(x) ( (float) exp2( (x) ) )
-#endif
-#ifdef SYS_FREEBSD
+#if defined(SYS_FREEBSD) || defined(SYS_BEOS) || defined(SYS_NETBSD)
 #define exp2f(x) powf( 2, (x) )
 #endif
-
+#if defined(_MSC_VER) || defined(SYS_SunOS)
+#define exp2f(x) pow( 2, (x) )
+#define sqrtf sqrt
+#endif
+#ifdef WIN32 // POSIX says that rename() removes the destination, but win32 doesn't.
+#define rename(src,dst) (unlink(dst), rename(src,dst))
+#endif
 
 typedef struct
 {
     int pict_type;
+    int kept_as_ref;
     float qscale;
     int mv_bits;
     int i_tex_bits;
     int p_tex_bits;
     int misc_bits;
     uint64_t expected_bits;
-    int new_pict_type;
     float new_qscale;
     int new_qp;
     int i_count;
@@ -63,47 +65,60 @@ typedef struct
     float blurred_complexity;
 } ratecontrol_entry_t;
 
+typedef struct
+{
+    double coeff;
+    double count;
+    double decay;
+} predictor_t;
+
 struct x264_ratecontrol_t
 {
     /* constants */
+    int b_abr;
+    int b_2pass;
     double fps;
-    int gop_size;
-    int bitrate;
+    double bitrate;
+    double rate_tolerance;
     int nmb;                    /* number of macroblocks in a frame */
-    int buffer_size;
-    int rcbufrate;
-    int init_qp;
     int qp_constant[5];
 
-    /* 1st pass stuff */
-    int gop_qp;
-    int buffer_fullness;
-    int frames;                 /* frames in current gop */
-    int pframes;
-    int slice_type;
-    int mb;                     /* MBs processed in current frame */
-    int bits_gop;               /* allocated bits current gop */
-    int bits_last_gop;          /* bits consumed in gop */
+    /* current frame */
+    ratecontrol_entry_t *rce;
     int qp;                     /* qp for current frame */
-    int qpm;                    /* qp for next MB */
-    float qpa;                  /* average qp for last frame */
-    int qps;
-    float qp_avg_p;             /* average QP for P frames */
-    float qp_last_p;
-    int fbits;                  /* bits allocated for current frame */
-    int ufbits;                 /* bits used for current frame */
-    int nzcoeffs;               /* # of 0-quantized coefficients */
-    int ncoeffs;                /* total # of coefficients */
-    int overhead;
+    float qpa;                  /* average of macroblocks' qp (same as qp if no adaptive quant) */
+    int slice_type;
+    int qp_force;
+
+    /* VBV stuff */
+    double buffer_size;
+    double buffer_fill;
+    double buffer_rate;         /* # of bits added to buffer_fill after each frame */
+    predictor_t pred[5];        /* predict frame size from satd */
+
+    /* ABR stuff */
+    int    last_satd;
+    double last_rceq;
+    double cplxr_sum;           /* sum of bits*qscale/rceq */
+    double expected_bits_sum;   /* sum of qscale2bits after rceq, ratefactor, and overflow */
+    double wanted_bits_window;  /* target bitrate * window */
+    double cbr_decay;
+    double short_term_cplxsum;
+    double short_term_cplxcount;
+    double rate_factor_constant;
 
     /* 2pass stuff */
     FILE *p_stat_file_out;
+    char *psz_stat_file_tmpname;
 
     int num_entries;            /* number of ratecontrol_entry_ts */
     ratecontrol_entry_t *entry; /* FIXME: copy needed data and free this once init is done */
     double last_qscale;
     double last_qscale_for[5];  /* last qscale for a specific pict type, used for max_diff & ipb factor stuff  */
     int last_non_b_pict_type;
+    double accum_p_qp;          /* for determining I-frame quant */
+    double accum_p_norm;
+    double last_accum_p_norm;
     double lmin[5];             /* min qscale by frame type */
     double lmax[5];
     double lstep;               /* max change (multiply) in qscale per frame */
@@ -111,11 +126,17 @@ struct x264_ratecontrol_t
     double p_cplx_sum[5];
     double mv_bits_sum[5];
     int frame_count[5];         /* number of frames of each type */
+
+    int i_zones;
+    x264_zone_t *zones;
 };
 
 
+static int parse_zones( x264_t *h );
 static int init_pass2(x264_t *);
 static float rate_estimate_qscale( x264_t *h, int pict_type );
+static void update_vbv( x264_t *h, int bits );
+int  x264_rc_analyse_slice( x264_t *h );
 
 /* Terminology:
  * qp = h.264's quantizer
@@ -130,147 +151,158 @@ static inline double qscale2qp(double qscale)
     return 12.0 + 6.0 * log(qscale/0.85) / log(2.0);
 }
 
+/* Texture bitrate is not quite inversely proportional to qscale,
+ * probably due the the changing number of SKIP blocks.
+ * MV bits level off at about qp<=12, because the lambda used
+ * for motion estimation is constant there. */
 static inline double qscale2bits(ratecontrol_entry_t *rce, double qscale)
 {
     if(qscale<0.1)
-    {
-        fprintf(stderr, "qscale<0.1\n");
         qscale = 0.1;
-    }
-    return (double)(rce->i_tex_bits + rce->p_tex_bits + .1) * rce->qscale / qscale;
-}
-
-static inline double bits2qscale(ratecontrol_entry_t *rce, double bits)
-{
-    if(bits<0.9)
-    {
-//      fprintf(stderr, "bits<0.9\n");
-        bits = 1.0;
-    }
-    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + .1) / bits;
+    return (rce->i_tex_bits + rce->p_tex_bits + .1) * pow( rce->qscale / qscale, 1.1 )
+           + rce->mv_bits * pow( X264_MAX(rce->qscale, 12) / X264_MAX(qscale, 12), 0.5 );
 }
 
 
 int x264_ratecontrol_new( x264_t *h )
 {
     x264_ratecontrol_t *rc;
-    float bpp;
     int i;
 
-    /* Needed(?) for 2 pass */
     x264_cpu_restore( h->param.cpu );
 
     h->rc = rc = x264_malloc( sizeof( x264_ratecontrol_t ) );
     memset(rc, 0, sizeof(*rc));
 
+    rc->b_abr = ( h->param.rc.b_cbr || h->param.rc.i_rf_constant ) && !h->param.rc.b_stat_read;
+    rc->b_2pass = h->param.rc.b_cbr && h->param.rc.b_stat_read;
+    h->mb.b_variable_qp = 0;
+    
     /* FIXME: use integers */
     if(h->param.i_fps_num > 0 && h->param.i_fps_den > 0)
         rc->fps = (float) h->param.i_fps_num / h->param.i_fps_den;
     else
         rc->fps = 25.0;
 
-    rc->gop_size = h->param.i_iframe;
     rc->bitrate = h->param.rc.i_bitrate * 1000;
+    rc->rate_tolerance = h->param.rc.f_rate_tolerance;
     rc->nmb = h->mb.i_mb_count;
-
-    rc->qp = h->param.rc.i_qp_constant;
-    rc->qpa = rc->qp;
-    rc->qpm = rc->qp;
-
-    rc->qp_constant[SLICE_TYPE_P] = h->param.rc.i_qp_constant;
-    rc->qp_constant[SLICE_TYPE_I] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) / fabs( h->param.rc.f_ip_factor )) + 0.5 ), 0, 51 );
-    rc->qp_constant[SLICE_TYPE_B] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) * fabs( h->param.rc.f_pb_factor )) + 0.5 ), 0, 51 );
-
-    /* Init 1pass CBR algo */
-    if( h->param.rc.b_cbr ){
-        rc->buffer_size = h->param.rc.i_rc_buffer_size * 1000;
-        rc->buffer_fullness = h->param.rc.i_rc_init_buffer;
-        rc->rcbufrate = rc->bitrate / rc->fps;
-
-        if(rc->buffer_size < rc->rcbufrate){
-            x264_log(h, X264_LOG_WARNING, "rc buffer size %i too small\n",
-                     rc->buffer_size);
-            rc->buffer_size = 0;
-        }
-
-        if(rc->buffer_size <= 0)
-            rc->buffer_size = rc->bitrate / 2;
-
-        if(rc->buffer_fullness > rc->buffer_size || rc->buffer_fullness < 0){
-            x264_log(h, X264_LOG_WARNING, "invalid initial buffer fullness %i\n",
-                     rc->buffer_fullness);
-            rc->buffer_fullness = 0;
+    rc->last_non_b_pict_type = -1;
+    rc->cbr_decay = 1.0;
+
+    if( rc->b_2pass && h->param.rc.i_rf_constant )
+        x264_log(h, X264_LOG_ERROR, "constant rate-factor is incompatible with 2pass.\n");
+    if( h->param.rc.i_vbv_max_bitrate && !h->param.rc.b_cbr && !h->param.rc.i_rf_constant )
+        x264_log(h, X264_LOG_ERROR, "VBV is incompatible with constant QP.\n");
+    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_ERROR, "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 < 10 * h->param.rc.i_vbv_max_bitrate / rc->fps ) {
+            h->param.rc.i_vbv_buffer_size = 10 * h->param.rc.i_vbv_max_bitrate / rc->fps;
+            x264_log( h, X264_LOG_ERROR, "VBV buffer size too small, using %d kbit\n",
+                      h->param.rc.i_vbv_buffer_size );
         }
+        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->buffer_fill = 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);
+    }
+    else if( h->param.rc.i_vbv_max_bitrate || h->param.rc.i_vbv_buffer_size )
+        x264_log(h, X264_LOG_ERROR, "VBV maxrate or buffer size specified, but not both.\n");
+    if(rc->rate_tolerance < 0.01) {
+        x264_log(h, X264_LOG_ERROR, "bitrate tolerance too small, using .01\n");
+        rc->rate_tolerance = 0.01;
+    }
 
-        bpp = rc->bitrate / (rc->fps * h->param.i_width * h->param.i_height);
-        if(bpp <= 0.6)
-            rc->init_qp = 31;
-        else if(bpp <= 1.4)
-            rc->init_qp = 25;
-        else if(bpp <= 2.4)
-            rc->init_qp = 20;
-        else
-            rc->init_qp = 10;
-        rc->gop_qp = rc->init_qp;
-
-        rc->bits_last_gop = 0;
+    if( rc->b_abr )
+    {
+        /* FIXME shouldn't need to arbitrarily specify a QP,
+         * but this is more robust than BPP measures */
+#define ABR_INIT_QP ( h->param.rc.i_rf_constant > 0 ? h->param.rc.i_rf_constant : 24 )
+        rc->accum_p_norm = .01;
+        rc->accum_p_qp = ABR_INIT_QP * rc->accum_p_norm;
+        rc->cplxr_sum = .01;
+        rc->wanted_bits_window = .01;
+    }
 
-        x264_log(h, X264_LOG_DEBUG, "%f fps, %i bps, bufsize %i\n",
-                 rc->fps, rc->bitrate, rc->buffer_size);
+    if( h->param.rc.i_rf_constant )
+    {
+        /* arbitrary rescaling to make CRF somewhat similar to QP */
+        double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
+        rc->rate_factor_constant = pow( base_cplx, 1 - h->param.rc.f_qcompress )
+                                 / qp2qscale( h->param.rc.i_rf_constant );
     }
 
+    rc->qp_constant[SLICE_TYPE_P] = h->param.rc.i_qp_constant;
+    rc->qp_constant[SLICE_TYPE_I] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) / fabs( h->param.rc.f_ip_factor )) + 0.5 ), 0, 51 );
+    rc->qp_constant[SLICE_TYPE_B] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) * fabs( h->param.rc.f_pb_factor )) + 0.5 ), 0, 51 );
 
     rc->lstep = exp2f(h->param.rc.i_qp_step / 6.0);
+    rc->last_qscale = qp2qscale(26);
     for( i = 0; i < 5; i++ )
     {
         rc->last_qscale_for[i] = qp2qscale(26);
         rc->lmin[i] = qp2qscale( h->param.rc.i_qp_min );
         rc->lmax[i] = qp2qscale( h->param.rc.i_qp_max );
+        rc->pred[i].coeff= 2.0;
+        rc->pred[i].count= 1.0;
+        rc->pred[i].decay= 0.5;
     }
-#if 0 // FIXME: do we want to assign lmin/lmax based on ip_factor, or leave them all the same?
-    rc->lmin[SLICE_TYPE_I] /= fabs(h->param.f_ip_factor);
-    rc->lmax[SLICE_TYPE_I] /= fabs(h->param.f_ip_factor);
-    rc->lmin[SLICE_TYPE_B] *= fabs(h->param.f_pb_factor);
-    rc->lmax[SLICE_TYPE_B] *= fabs(h->param.f_pb_factor);
-#endif
+
+    if( parse_zones( h ) < 0 )
+        return -1;
 
     /* Load stat file and init 2pass algo */
     if( h->param.rc.b_stat_read )
     {
-        int stats_size;
         char *p, *stats_in;
-        FILE *stats_file;
 
         /* read 1st pass stats */
         assert( h->param.rc.psz_stat_in );
-        stats_file = fopen( h->param.rc.psz_stat_in, "rb");
-        if(!stats_file)
+        stats_in = x264_slurp_file( h->param.rc.psz_stat_in );
+        if( !stats_in )
         {
             x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
             return -1;
         }
-        // FIXME: error checking
-        fseek(stats_file, 0, SEEK_END);
-        stats_size = ftell(stats_file);
-        fseek(stats_file, 0, SEEK_SET);
-        stats_in = x264_malloc(stats_size+10);
-        fread(stats_in, 1, stats_size, stats_file);
-        fclose(stats_file);
 
         /* find number of pics */
         p = stats_in;
-        for(i=-1; p; i++){
+        for(i=-1; p; i++)
             p = strchr(p+1, ';');
+        if(i==0)
+        {
+            x264_log(h, X264_LOG_ERROR, "empty stats file\n");
+            return -1;
+        }
+        rc->num_entries = i;
+
+        if( h->param.i_frame_total < rc->num_entries && h->param.i_frame_total > 0 )
+        {
+            x264_log( h, X264_LOG_WARNING, "2nd pass has fewer frames than 1st pass (%d vs %d)\n",
+                      h->param.i_frame_total, rc->num_entries );
+        }
+        if( h->param.i_frame_total > rc->num_entries + h->param.i_bframe )
+        {
+            x264_log( h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d vs %d)\n",
+                      h->param.i_frame_total, rc->num_entries );
+            return -1;
         }
-        i += h->param.i_bframe;
-        rc->entry = (ratecontrol_entry_t*) x264_malloc(i*sizeof(ratecontrol_entry_t));
-        memset(rc->entry, 0, i*sizeof(ratecontrol_entry_t));
-        rc->num_entries= i;
+
+        /* FIXME: ugly padding because VfW drops delayed B-frames */
+        rc->num_entries += h->param.i_bframe;
+
+        rc->entry = (ratecontrol_entry_t*) x264_malloc(rc->num_entries * sizeof(ratecontrol_entry_t));
+        memset(rc->entry, 0, rc->num_entries * sizeof(ratecontrol_entry_t));
 
         /* init all to skipped p frames */
         for(i=0; i<rc->num_entries; i++){
             ratecontrol_entry_t *rce = &rc->entry[i];
-            rce->pict_type = rce->new_pict_type = SLICE_TYPE_P;
+            rce->pict_type = SLICE_TYPE_P;
             rce->qscale = rce->new_qscale = qp2qscale(20);
             rce->misc_bits = rc->nmb + 10;
             rce->new_qp = 0;
@@ -280,7 +312,8 @@ int x264_ratecontrol_new( x264_t *h )
         p = stats_in;
         for(i=0; i < rc->num_entries - h->param.i_bframe; i++){
             ratecontrol_entry_t *rce;
-            int picture_number;
+            int frame_number;
+            char pict_type;
             int e;
             char *next;
             float qp;
@@ -290,15 +323,27 @@ int x264_ratecontrol_new( x264_t *h )
                 (*next)=0; //sscanf is unbelievably slow on looong strings
                 next++;
             }
-            e = sscanf(p, " in:%d ", &picture_number);
+            e = sscanf(p, " in:%d ", &frame_number);
 
-            assert(picture_number >= 0);
-            assert(picture_number < rc->num_entries);
-            rce = &rc->entry[picture_number];
+            if(frame_number < 0 || frame_number >= rc->num_entries)
+            {
+                x264_log(h, X264_LOG_ERROR, "bad frame number (%d) at stats line %d\n", frame_number, i);
+                return -1;
+            }
+            rce = &rc->entry[frame_number];
 
-            e += sscanf(p, " in:%*d out:%*d type:%d q:%f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d",
-                   &rce->pict_type, &qp, &rce->i_tex_bits, &rce->p_tex_bits,
+            e += sscanf(p, " in:%*d out:%*d type:%c q:%f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d",
+                   &pict_type, &qp, &rce->i_tex_bits, &rce->p_tex_bits,
                    &rce->mv_bits, &rce->misc_bits, &rce->i_count, &rce->p_count, &rce->s_count);
+
+            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;
+                default:  e = -1; break;
+            }
             if(e != 10){
                 x264_log(h, X264_LOG_ERROR, "statistics are damaged at line %d, parser out=%d\n", i, e);
                 return -1;
@@ -309,13 +354,22 @@ int x264_ratecontrol_new( x264_t *h )
 
         x264_free(stats_in);
 
-        if(init_pass2(h) < 0) return -1;
+        if(h->param.rc.b_cbr)
+        {
+            if(init_pass2(h) < 0) return -1;
+        } /* else we're using constant quant, so no need to run the bitrate allocation */
     }
 
     /* Open output file */
+    /* If input and output files are the same, output to a temp file
+     * and move it to the real name only when it's complete */
     if( h->param.rc.b_stat_write )
     {
-        rc->p_stat_file_out = fopen( h->param.rc.psz_stat_out, "wb" );
+        rc->psz_stat_file_tmpname = x264_malloc( strlen(h->param.rc.psz_stat_out) + 6 );
+        strcpy( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
+        strcat( rc->psz_stat_file_tmpname, ".temp" );
+
+        rc->p_stat_file_out = fopen( rc->psz_stat_file_tmpname, "wb" );
         if( rc->p_stat_file_out == NULL )
         {
             x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
@@ -326,223 +380,173 @@ int x264_ratecontrol_new( x264_t *h )
     return 0;
 }
 
+static int parse_zones( x264_t *h )
+{
+    x264_ratecontrol_t *rc = h->rc;
+    int i;
+    if( h->param.rc.psz_zones && !h->param.rc.i_zones )
+    {
+        char *p;
+        h->param.rc.i_zones = 1;
+        for( p = h->param.rc.psz_zones; *p; p++ )
+            h->param.rc.i_zones += (*p == '/');
+        h->param.rc.zones = x264_malloc( h->param.rc.i_zones * sizeof(x264_zone_t) );
+        p = h->param.rc.psz_zones;
+        for( i = 0; i < h->param.rc.i_zones; i++)
+        {
+            x264_zone_t *z = &h->param.rc.zones[i];
+            if( 3 == sscanf(p, "%u,%u,q=%u", &z->i_start, &z->i_end, &z->i_qp) )
+                z->b_force_qp = 1;
+            else if( 3 == sscanf(p, "%u,%u,b=%f", &z->i_start, &z->i_end, &z->f_bitrate_factor) )
+                z->b_force_qp = 0;
+            else
+            {
+                char *slash = strchr(p, '/');
+                if(slash) *slash = '\0';
+                x264_log( h, X264_LOG_ERROR, "invalid zone: \"%s\"\n", p );
+                return -1;
+            }
+            p = strchr(p, '/') + 1;
+        }
+    }
+
+    if( h->param.rc.i_zones > 0 )
+    {
+        for( i = 0; i < h->param.rc.i_zones; i++ )
+        {
+            x264_zone_t z = h->param.rc.zones[i];
+            if( z.i_start < 0 || z.i_start > z.i_end )
+            {
+                x264_log( h, X264_LOG_ERROR, "invalid zone: start=%d end=%d\n",
+                          z.i_start, z.i_end );
+                return -1;
+            }
+            else if( !z.b_force_qp && z.f_bitrate_factor <= 0 )
+            {
+                x264_log( h, X264_LOG_ERROR, "invalid zone: bitrate_factor=%f\n",
+                          z.f_bitrate_factor );
+                return -1;
+            }
+        }
+
+        rc->i_zones = h->param.rc.i_zones;
+        rc->zones = x264_malloc( rc->i_zones * sizeof(x264_zone_t) );
+        memcpy( rc->zones, h->param.rc.zones, rc->i_zones * sizeof(x264_zone_t) );
+    }
+
+    return 0;
+}
+
 void x264_ratecontrol_delete( x264_t *h )
 {
     x264_ratecontrol_t *rc = h->rc;
 
     if( rc->p_stat_file_out )
+    {
         fclose( rc->p_stat_file_out );
-    if( rc->entry )
-        x264_free(rc->entry);
+        if( h->i_frame >= rc->num_entries - h->param.i_bframe )
+            if( rename( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out ) != 0 )
+            {
+                x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
+                          rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
+            }
+        x264_free( rc->psz_stat_file_tmpname );
+    }
+    x264_free( rc->entry );
+    x264_free( rc->zones );
     x264_free( rc );
 }
 
-void x264_ratecontrol_start( x264_t *h, int i_slice_type )
+/* Before encoding a frame, choose a QP for it */
+void x264_ratecontrol_start( x264_t *h, int i_slice_type, int i_force_qp )
 {
     x264_ratecontrol_t *rc = h->rc;
-    int gframes, iframes, pframes, bframes;
-    int minbits, maxbits;
-    int gbits, fbits;
-    int zn = 0;
-    float kp;
-    int gbuf;
-
-    rc->slice_type = i_slice_type;
 
     x264_cpu_restore( h->param.cpu );
 
-    if( h->param.rc.b_stat_read )
+    rc->qp_force = i_force_qp;
+    rc->slice_type = i_slice_type;
+
+    if( i_force_qp )
+    {
+        rc->qpa = rc->qp = i_force_qp - 1;
+    }
+    else if( rc->b_abr )
+    {
+        rc->qpa = rc->qp =
+            x264_clip3( (int)(qscale2qp( rate_estimate_qscale( h, i_slice_type ) ) + .5), 0, 51 );
+    }
+    else if( rc->b_2pass )
     {
         int frame = h->fenc->i_frame;
-        ratecontrol_entry_t *rce = &h->rc->entry[frame];
-
+        ratecontrol_entry_t *rce;
         assert( frame >= 0 && frame < rc->num_entries );
+        rce = h->rc->rce = &h->rc->entry[frame];
 
         rce->new_qscale = rate_estimate_qscale( h, i_slice_type );
-        rc->qpm = rc->qpa = rc->qp = rce->new_qp =
-            (int)(qscale2qp(rce->new_qscale) + 0.5);
-        return;
+        rc->qpa = rc->qp = rce->new_qp =
+            x264_clip3( (int)(qscale2qp(rce->new_qscale) + 0.5), 0, 51 );
     }
-    else if( !h->param.rc.b_cbr )
+    else /* CQP */
     {
-        rc->qpm = rc->qpa = rc->qp =
-            rc->qp_constant[ i_slice_type ];
-        return;
-    }
-
-    switch(i_slice_type){
-    case SLICE_TYPE_I:
-        gbuf = rc->buffer_fullness + (rc->gop_size-1) * rc->rcbufrate;
-        rc->bits_gop = gbuf - rc->buffer_size / 2;
-
-        if(!rc->mb && rc->pframes){
-            int qp = rc->qp_avg_p / rc->pframes + 0.5;
-#if 0 /* JM does this without explaining why */
-            int gdq = (float) rc->gop_size / 15 + 0.5;
-            if(gdq > 2)
-                gdq = 2;
-            qp -= gdq;
-            if(qp > rc->qp_last_p - 2)
-                qp--;
-#endif
-            qp = x264_clip3(qp, rc->gop_qp - 4, rc->gop_qp + 4);
-            qp = x264_clip3(qp, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
-            rc->gop_qp = qp;
-        } else if(rc->frames > 4){
-            rc->gop_qp = rc->init_qp;
-        }
-
-        kp = h->param.rc.f_ip_factor * h->param.rc.f_pb_factor;
-
-        x264_log(h, X264_LOG_DEBUG,"gbuf=%i bits_gop=%i frames=%i gop_qp=%i\n",
-                 gbuf, rc->bits_gop, rc->frames, rc->gop_qp);
-
-        rc->bits_last_gop = 0;
-        rc->frames = 0;
-        rc->pframes = 0;
-        rc->qp_avg_p = 0;
-        break;
-
-    case SLICE_TYPE_P:
-        kp = h->param.rc.f_pb_factor;
-        break;
-
-    case SLICE_TYPE_B:
-        kp = 1.0;
-        break;
-
-    default:
-        x264_log(h, X264_LOG_WARNING, "ratecontrol: unknown slice type %i\n",
-                 i_slice_type);
-        kp = 1.0;
-        break;
-    }
-
-    gframes = rc->gop_size - rc->frames;
-    iframes = gframes / rc->gop_size;
-    pframes = gframes / (h->param.i_bframe + 1) - iframes;
-    bframes = gframes - pframes - iframes;
-
-    gbits = rc->bits_gop - rc->bits_last_gop;
-    fbits = kp * gbits /
-        (h->param.rc.f_ip_factor * h->param.rc.f_pb_factor * iframes +
-         h->param.rc.f_pb_factor * pframes + bframes);
-
-    minbits = rc->buffer_fullness + rc->rcbufrate - rc->buffer_size;
-    if(minbits < 0)
-        minbits = 0;
-    maxbits = rc->buffer_fullness;
-    rc->fbits = x264_clip3(fbits, minbits, maxbits);
-
-    if(i_slice_type == SLICE_TYPE_I){
-        rc->qp = rc->gop_qp;
-    } else if(rc->ncoeffs && rc->ufbits){
-        int dqp, nonzc;
-
-        nonzc = (rc->ncoeffs - rc->nzcoeffs);
-        if(nonzc == 0)
-            zn = rc->ncoeffs;
-        else if(rc->fbits < INT_MAX / nonzc)
-            zn = rc->ncoeffs - rc->fbits * nonzc / rc->ufbits;
+        int q;
+        if( i_slice_type == SLICE_TYPE_B && h->fdec->b_kept_as_ref )
+            q = ( rc->qp_constant[ SLICE_TYPE_B ] + rc->qp_constant[ SLICE_TYPE_P ] ) / 2;
         else
-            zn = 0;
-        zn = x264_clip3(zn, 0, rc->ncoeffs);
-        dqp = h->param.rc.i_rc_sens * exp2f(rc->qpa / 6) *
-            (zn - rc->nzcoeffs) / rc->nzcoeffs;
-        dqp = x264_clip3(dqp, -h->param.rc.i_qp_step, h->param.rc.i_qp_step);
-        rc->qp = (int)(rc->qpa + dqp + .5);
-    }
-
-    if(rc->fbits > 0.9 * maxbits)
-        rc->qp += 2;
-    else if(rc->fbits > 0.8 * maxbits)
-        rc->qp += 1;
-    else if(rc->fbits < 1.1 * minbits)
-        rc->qp -= 2;
-    else if(rc->fbits < 1.2 * minbits)
-        rc->qp -= 1;
-
-    rc->qp = x264_clip3(rc->qp, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
-    rc->qpm = rc->qp;
-
-    x264_log(h, X264_LOG_DEBUG, "fbits=%i, qp=%i, z=%i, min=%i, max=%i\n",
-             rc->fbits, rc->qpm, zn, minbits, maxbits);
-
-    rc->fbits -= rc->overhead;
-    rc->ufbits = 0;
-    rc->ncoeffs = 0;
-    rc->nzcoeffs = 0;
-    rc->mb = 0;
-    rc->qps = 0;
+            q = rc->qp_constant[ i_slice_type ];
+        rc->qpa = rc->qp = q;
+    }
 }
 
 void x264_ratecontrol_mb( x264_t *h, int bits )
 {
-    x264_ratecontrol_t *rc = h->rc;
-    int rbits;
-    int zn, enz, nonz;
-    int rcoeffs;
-    int dqp;
-    int i;
-
-    if( !h->param.rc.b_cbr || h->param.rc.b_stat_read )
-        return;
-
-    x264_cpu_restore( h->param.cpu );
-
-    rc->qps += rc->qpm;
-    rc->ufbits += bits;
-    rc->mb++;
-
-    for(i = 0; i < 16 + 8; i++)
-        rc->nzcoeffs += 16 - h->mb.cache.non_zero_count[x264_scan8[i]];
-    rc->ncoeffs += 16 * (16 + 8);
-
-    if(rc->mb < rc->nmb / 16)
-        return;
-    else if(rc->mb == rc->nmb)
-        return;
-
-    rcoeffs = (rc->nmb - rc->mb) * 16 * 24;
-    rbits = rc->fbits - rc->ufbits;
-/*     if(rbits < 0) */
-/*      rbits = 0; */
-
-/*     zn = (rc->nmb - rc->mb) * 16 * 24; */
-    nonz = (rc->ncoeffs - rc->nzcoeffs);
-    if(nonz == 0)
-        zn = rcoeffs;
-    else if(rc->ufbits && rbits < INT_MAX / nonz)
-        zn = rcoeffs - rbits * nonz / rc->ufbits;
-    else
-        zn = 0;
-    zn = x264_clip3(zn, 0, rcoeffs);
-    enz = rc->nzcoeffs * (rc->nmb - rc->mb) / rc->mb;
-    dqp = (float) 2*h->param.rc.i_rc_sens * exp2f((float) rc->qps / rc->mb / 6) *
-        (zn - enz) / enz;
-    rc->qpm = x264_clip3(rc->qpm + dqp, rc->qp - 3, rc->qp + 3);
-    if(rbits <= 0)
-        rc->qpm++;
-    rc->qpm = x264_clip3(rc->qpm, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
+    /* currently no adaptive quant */
 }
 
-int  x264_ratecontrol_qp( x264_t *h )
+int x264_ratecontrol_qp( x264_t *h )
 {
-    return h->rc->qpm;
+    return h->rc->qp;
 }
 
+/* In 2pass, force the same frame types as in the 1st pass */
 int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
 {
+    x264_ratecontrol_t *rc = h->rc;
     if( h->param.rc.b_stat_read )
     {
-        assert(frame_num < h->rc->num_entries);
-        switch( h->rc->entry[frame_num].new_pict_type )
+        if( frame_num >= rc->num_entries )
+        {
+            /* We could try to initialize everything required for ABR and
+             * adaptive B-frames, but that would be complicated.
+             * So just calculate the average QP used so far. */
+
+            h->param.rc.i_qp_constant = (h->stat.i_slice_count[SLICE_TYPE_P] == 0) ? 24
+                                      : 1 + h->stat.i_slice_qp[SLICE_TYPE_P] / h->stat.i_slice_count[SLICE_TYPE_P];
+            rc->qp_constant[SLICE_TYPE_P] = x264_clip3( h->param.rc.i_qp_constant, 0, 51 );
+            rc->qp_constant[SLICE_TYPE_I] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) / fabs( h->param.rc.f_ip_factor )) + 0.5 ), 0, 51 );
+            rc->qp_constant[SLICE_TYPE_B] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) * fabs( h->param.rc.f_pb_factor )) + 0.5 ), 0, 51 );
+
+            x264_log(h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d)\n", rc->num_entries);
+            x264_log(h, X264_LOG_ERROR, "continuing anyway, at constant QP=%d\n", h->param.rc.i_qp_constant);
+            if( h->param.b_bframe_adaptive )
+                x264_log(h, X264_LOG_ERROR, "disabling adaptive B-frames\n");
+
+            rc->b_abr = 0;
+            rc->b_2pass = 0;
+            h->param.rc.b_cbr = 0;
+            h->param.rc.b_stat_read = 0;
+            h->param.b_bframe_adaptive = 0;
+            if( h->param.i_bframe > 1 )
+                h->param.i_bframe = 1;
+            return X264_TYPE_P;
+        }
+        switch( rc->entry[frame_num].pict_type )
         {
             case SLICE_TYPE_I:
-                return X264_TYPE_I;
+                return rc->entry[frame_num].kept_as_ref ? X264_TYPE_IDR : X264_TYPE_I;
 
             case SLICE_TYPE_B:
-                return X264_TYPE_B;
+                return rc->entry[frame_num].kept_as_ref ? X264_TYPE_BREF : X264_TYPE_B;
 
             case SLICE_TYPE_P:
             default:
@@ -555,87 +559,95 @@ int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
     }
 }
 
+/* After encoding one frame, save stats and update ratecontrol state */
 void x264_ratecontrol_end( x264_t *h, int bits )
 {
     x264_ratecontrol_t *rc = h->rc;
+    const int *mbs = h->stat.frame.i_mb_count;
     int i;
 
     x264_cpu_restore( h->param.cpu );
 
-    h->stat.frame.i_mb_count_skip = h->stat.frame.i_mb_count[P_SKIP] + h->stat.frame.i_mb_count[B_SKIP];
-    h->stat.frame.i_mb_count_p = h->stat.frame.i_mb_count[P_L0] + h->stat.frame.i_mb_count[P_8x8];
+    h->stat.frame.i_mb_count_skip = mbs[P_SKIP] + mbs[B_SKIP];
+    h->stat.frame.i_mb_count_i = mbs[I_16x16] + mbs[I_8x8] + mbs[I_4x4];
+    h->stat.frame.i_mb_count_p = mbs[P_L0] + mbs[P_8x8];
     for( i = B_DIRECT; i < B_8x8; i++ )
-        h->stat.frame.i_mb_count_p += h->stat.frame.i_mb_count[i];
+        h->stat.frame.i_mb_count_p += mbs[i];
 
     if( h->param.rc.b_stat_write )
     {
+        char c_type = rc->slice_type==SLICE_TYPE_I ? (h->fenc->i_poc==0 ? 'I' : 'i')
+                    : rc->slice_type==SLICE_TYPE_P ? 'P'
+                    : h->fenc->b_kept_as_ref ? 'B' : 'b';
         fprintf( rc->p_stat_file_out,
-                 "in:%d out:%d type:%d q:%.3f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d;\n",
+                 "in:%d out:%d type:%c q:%.2f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d;\n",
                  h->fenc->i_frame, h->i_frame-1,
-                 rc->slice_type, rc->qpa,
+                 c_type, rc->qpa,
                  h->stat.frame.i_itex_bits, h->stat.frame.i_ptex_bits,
                  h->stat.frame.i_hdr_bits, h->stat.frame.i_misc_bits,
-                 h->stat.frame.i_mb_count[I_4x4] + h->stat.frame.i_mb_count[I_16x16],
+                 h->stat.frame.i_mb_count_i,
                  h->stat.frame.i_mb_count_p,
                  h->stat.frame.i_mb_count_skip);
     }
 
-    if( !h->param.rc.b_cbr || h->param.rc.b_stat_read )
-        return;
-
-    rc->buffer_fullness += rc->rcbufrate - bits;
-    if(rc->buffer_fullness < 0){
-        x264_log(h, X264_LOG_WARNING, "buffer underflow %i\n",
-                 rc->buffer_fullness);
-        rc->buffer_fullness = 0;
+    if( rc->b_abr )
+    {
+        if( rc->slice_type != SLICE_TYPE_B )
+            rc->cplxr_sum += bits * qp2qscale(rc->qpa) / rc->last_rceq;
+        else
+        {
+            /* Depends on the fact that B-frame's QP is an offset from the following P-frame's.
+             * Not perfectly accurate with B-refs, but good enough. */
+            rc->cplxr_sum += bits * qp2qscale(rc->qpa) / (rc->last_rceq * fabs(h->param.rc.f_pb_factor));
+        }
+        rc->cplxr_sum *= rc->cbr_decay;
+        rc->wanted_bits_window += rc->bitrate / rc->fps;
+        rc->wanted_bits_window *= rc->cbr_decay;
+
+        rc->accum_p_qp   *= .95;
+        rc->accum_p_norm *= .95;
+        rc->accum_p_norm += 1;
+        if( rc->slice_type == SLICE_TYPE_I )
+            rc->accum_p_qp += rc->qpa * fabs(h->param.rc.f_ip_factor);
+        else
+            rc->accum_p_qp += rc->qpa;
     }
 
-    rc->qpa = (float)rc->qps / rc->mb;
-    if(rc->slice_type == SLICE_TYPE_P){
-        rc->qp_avg_p += rc->qpa;
-        rc->qp_last_p = rc->qpa;
-        rc->pframes++;
-    } else if(rc->slice_type == SLICE_TYPE_I){
-        float err = (float) rc->ufbits / rc->fbits;
-        if(err > 1.1)
-            rc->gop_qp++;
-        else if(err < 0.9)
-            rc->gop_qp--;
+    if( rc->b_2pass )
+    {
+        rc->expected_bits_sum += qscale2bits( rc->rce, qp2qscale(rc->rce->new_qp) );
     }
 
-    rc->overhead = bits - rc->ufbits;
-
-    x264_log(h, X264_LOG_DEBUG, "bits=%i, qp=%.1f, z=%i, zr=%6.3f, buf=%i\n",
-             bits, rc->qpa, rc->nzcoeffs, (float) rc->nzcoeffs / rc->ncoeffs,
-             rc->buffer_fullness);
+    update_vbv( h, bits );
 
-    rc->bits_last_gop += bits;
-    rc->frames++;
-    rc->mb = 0;
+    if( rc->slice_type != SLICE_TYPE_B )
+        rc->last_non_b_pict_type = rc->slice_type;
 }
 
 /****************************************************************************
  * 2 pass functions
  ***************************************************************************/
+
 double x264_eval( char *s, double *const_value, const char **const_name,
                   double (**func1)(void *, double), const char **func1_name,
                   double (**func2)(void *, double, double), char **func2_name,
                   void *opaque );
 
 /**
- * modifies the bitrate curve from pass1 for one frame
+ * modify the bitrate curve from pass1 for one frame
  */
-static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor)
+static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor, int frame_num)
 {
     x264_ratecontrol_t *rcc= h->rc;
-    double bits;
-    const int pict_type = rce->new_pict_type;
+    const int pict_type = rce->pict_type;
+    double q;
+    int i;
 
     double const_values[]={
         rce->i_tex_bits * rce->qscale,
         rce->p_tex_bits * rce->qscale,
         (rce->i_tex_bits + rce->p_tex_bits) * rce->qscale,
-        rce->mv_bits / rcc->nmb,
+        rce->mv_bits * rce->qscale,
         (double)rce->i_count / rcc->nmb,
         (double)rce->p_count / rcc->nmb,
         (double)rce->s_count / rcc->nmb,
@@ -668,57 +680,87 @@ static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor
         "avgPPTex",
         "avgBPTex",
         "avgTex",
-        "blurTex",
+        "blurCplx",
         NULL
     };
     static double (*func1[])(void *, double)={
-        (void *)bits2qscale,
+//      (void *)bits2qscale,
         (void *)qscale2bits,
         NULL
     };
     static const char *func1_names[]={
-        "bits2qp",
+//      "bits2qp",
         "qp2bits",
         NULL
     };
 
-    bits = x264_eval((char*)h->param.rc.psz_rc_eq, const_values, const_names, func1, func1_names, NULL, NULL, rce);
+    q = x264_eval((char*)h->param.rc.psz_rc_eq, const_values, const_names, func1, func1_names, NULL, NULL, rce);
 
     // avoid NaN's in the rc_eq
-    if(bits != bits || rce->i_tex_bits + rce->p_tex_bits == 0)
-        bits = 0;
-
-    bits *= rate_factor;
-    if(bits<0.0) bits=0.0;
-    bits += 1.0; //avoid 1/0 issues
+    if(q != q || rce->i_tex_bits + rce->p_tex_bits + rce->mv_bits == 0)
+        q = rcc->last_qscale;
+    else {
+        rcc->last_rceq = q;
+        q /= rate_factor;
+        rcc->last_qscale = q;
+    }
 
-    /* I/B difference */
-    if( pict_type==SLICE_TYPE_I && h->param.rc.f_ip_factor > 0 )
-        bits *= h->param.rc.f_ip_factor;
-    else if( pict_type==SLICE_TYPE_B && h->param.rc.f_pb_factor > 0 )
-        bits /= h->param.rc.f_pb_factor;
+    for( i = rcc->i_zones-1; i >= 0; i-- )
+    {
+        x264_zone_t *z = &rcc->zones[i];
+        if( frame_num >= z->i_start && frame_num <= z->i_end )
+        {
+            if( z->b_force_qp )
+                q = qp2qscale(z->i_qp);
+            else
+                q /= z->f_bitrate_factor;
+            break;
+        }
+    }
 
-    return bits2qscale(rce, bits);
+    return q;
 }
 
 static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
 {
     x264_ratecontrol_t *rcc = h->rc;
-    const int pict_type = rce->new_pict_type;
+    const int pict_type = rce->pict_type;
 
     // force I/B quants as a function of P quants
     const double last_p_q    = rcc->last_qscale_for[SLICE_TYPE_P];
     const double last_non_b_q= rcc->last_qscale_for[rcc->last_non_b_pict_type];
-    if( pict_type == SLICE_TYPE_I && h->param.rc.f_ip_factor < 0 )
-        q = last_p_q / fabs( h->param.rc.f_ip_factor );
-    else if( pict_type == SLICE_TYPE_B
-             && ( h->param.rc.f_pb_factor < 0 || rce->i_tex_bits + rce->p_tex_bits == 0 ) )
-        q = last_non_b_q * fabs( h->param.rc.f_pb_factor );
-    else if( pict_type == SLICE_TYPE_P && rce->i_tex_bits + rce->p_tex_bits == 0 )
+    if( pict_type == SLICE_TYPE_I )
+    {
+        double iq = q;
+        double pq = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
+        double ip_factor = fabs( h->param.rc.f_ip_factor );
+        /* don't apply ip_factor if the following frame is also I */
+        if( rcc->accum_p_norm <= 0 )
+            q = iq;
+        else if( h->param.rc.f_ip_factor < 0 )
+            q = iq / ip_factor;
+        else if( rcc->accum_p_norm >= 1 )
+            q = pq / ip_factor;
+        else
+            q = rcc->accum_p_norm * pq / ip_factor + (1 - rcc->accum_p_norm) * iq;
+    }
+    else if( pict_type == SLICE_TYPE_B )
+    {
+        if( h->param.rc.f_pb_factor > 0 )
+            q = last_non_b_q;
+        if( !rce->kept_as_ref )
+            q *= fabs( h->param.rc.f_pb_factor );
+    }
+    else if( pict_type == SLICE_TYPE_P
+             && rcc->last_non_b_pict_type == SLICE_TYPE_P
+             && rce->i_tex_bits + rce->p_tex_bits == 0 )
+    {
         q = last_p_q;
+    }
 
     /* last qscale / qdiff stuff */
-    if(rcc->last_non_b_pict_type==pict_type || pict_type!=SLICE_TYPE_I)
+    if(rcc->last_non_b_pict_type==pict_type
+       && (pict_type!=SLICE_TYPE_I || rcc->last_accum_p_norm < 1))
     {
         double last_q = rcc->last_qscale_for[pict_type];
         double max_qscale = last_q * rcc->lstep;
@@ -731,18 +773,87 @@ static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
     rcc->last_qscale_for[pict_type] = q;
     if(pict_type!=SLICE_TYPE_B)
         rcc->last_non_b_pict_type = pict_type;
+    if(pict_type==SLICE_TYPE_I)
+    {
+        rcc->last_accum_p_norm = rcc->accum_p_norm;
+        rcc->accum_p_norm = 0;
+        rcc->accum_p_qp = 0;
+    }
+    if(pict_type==SLICE_TYPE_P)
+    {
+        float mask = 1 - pow( (float)rce->i_count / rcc->nmb, 2 );
+        rcc->accum_p_qp   = mask * (qscale2qp(q) + rcc->accum_p_qp);
+        rcc->accum_p_norm = mask * (1 + rcc->accum_p_norm);
+    }
     return q;
 }
 
-// clip a qscale to between lmin and lmax
-static double clip_qscale( x264_t *h, ratecontrol_entry_t *rce, double q )
+static double predict_size( predictor_t *p, double q, double var )
+{
+     return p->coeff*var / (q*p->count);
+}
+
+static void update_predictor( predictor_t *p, double q, double var, double bits )
 {
-    double lmin = h->rc->lmin[rce->new_pict_type];
-    double lmax = h->rc->lmax[rce->new_pict_type];
+    p->count *= p->decay;
+    p->coeff *= p->decay;
+    p->count ++;
+    p->coeff += bits*q / var;
+}
 
-    if(lmin==lmax){
+static void update_vbv( x264_t *h, int bits )
+{
+    x264_ratecontrol_t *rcc = h->rc;
+    if( !rcc->buffer_size )
+        return;
+
+    rcc->buffer_fill += rcc->buffer_rate - bits;
+    if( rcc->buffer_fill < 0 && !rcc->b_2pass )
+        x264_log( h, X264_LOG_WARNING, "VBV underflow (%.0f bits)\n", rcc->buffer_fill );
+    rcc->buffer_fill = x264_clip3( rcc->buffer_fill, 0, rcc->buffer_size );
+
+    if(rcc->last_satd > 100)
+        update_predictor( &rcc->pred[rcc->slice_type], qp2qscale(rcc->qpa), rcc->last_satd, bits );
+}
+
+// apply VBV constraints and clip qscale to between lmin and lmax
+static double clip_qscale( x264_t *h, int pict_type, double q )
+{
+    x264_ratecontrol_t *rcc = h->rc;
+    double lmin = rcc->lmin[pict_type];
+    double lmax = rcc->lmax[pict_type];
+    double q0 = q;
+
+    /* B-frames are not directly subject to VBV,
+     * since they are controlled by the P-frames' QPs.
+     * FIXME: in 2pass we could modify previous frames' QP too,
+     *        instead of waiting for the buffer to fill */
+    if( rcc->buffer_size &&
+        ( pict_type == SLICE_TYPE_P ||
+          ( pict_type == SLICE_TYPE_I && rcc->last_non_b_pict_type == SLICE_TYPE_I ) ) )
+    {
+        if( rcc->buffer_fill/rcc->buffer_size < 0.5 )
+            q /= x264_clip3f( 2.0*rcc->buffer_fill/rcc->buffer_size, 0.5, 1.0 );
+    }
+    /* Now a hard threshold to make sure the frame fits in VBV.
+     * This one is mostly for I-frames. */
+    if( rcc->buffer_size && rcc->last_satd > 0 )
+    {
+        double bits = predict_size( &rcc->pred[rcc->slice_type], q, rcc->last_satd );
+        double qf = 1.0;
+        if( bits > rcc->buffer_fill/2 )
+            qf = x264_clip3f( rcc->buffer_fill/(2*bits), 0.2, 1.0 );
+        q /= qf;
+        bits *= qf;
+        if( bits < rcc->buffer_rate/2 )
+            q *= bits*2/rcc->buffer_rate;
+        q = X264_MAX( q0, q );
+    }
+
+    if(lmin==lmax)
         return lmin;
-    }else{
+    else if(rcc->b_2pass)
+    {
         double min2 = log(lmin);
         double max2 = log(lmax);
         q = (log(q) - min2)/(max2-min2) - 0.5;
@@ -750,38 +861,142 @@ static double clip_qscale( x264_t *h, ratecontrol_entry_t *rce, double q )
         q = q*(max2-min2) + min2;
         return exp(q);
     }
+    else
+        return x264_clip3f(q, lmin, lmax);
 }
 
 // update qscale for 1 frame based on actual bits used so far
 static float rate_estimate_qscale(x264_t *h, int pict_type)
 {
     float q;
-    float br_compensation;
-    double diff;
-    int picture_number = h->fenc->i_frame;
     x264_ratecontrol_t *rcc = h->rc;
-    ratecontrol_entry_t *rce;
+    ratecontrol_entry_t rce;
     double lmin = rcc->lmin[pict_type];
     double lmax = rcc->lmax[pict_type];
     int64_t total_bits = 8*(h->stat.i_slice_size[SLICE_TYPE_I]
                           + h->stat.i_slice_size[SLICE_TYPE_P]
                           + h->stat.i_slice_size[SLICE_TYPE_B]);
 
-//printf("input_pic_num:%d pic_num:%d frame_rate:%d\n", s->input_picture_number, s->picture_number, s->frame_rate);
+    if( rcc->b_2pass )
+    {
+        rce = *rcc->rce;
+        if(pict_type != rce.pict_type)
+        {
+            x264_log(h, X264_LOG_ERROR, "slice=%c but 2pass stats say %c\n",
+                     slice_type_to_char[pict_type], slice_type_to_char[rce.pict_type]);
+        }
+    }
+
+    if( pict_type == SLICE_TYPE_B )
+    {
+        rcc->last_satd = 0;
+        if(h->fenc->b_kept_as_ref)
+            q = rcc->last_qscale * sqrtf(h->param.rc.f_pb_factor);
+        else
+            q = rcc->last_qscale * h->param.rc.f_pb_factor;
+        return x264_clip3f(q, lmin, lmax);
+    }
+    else
+    {
+        double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate;
+        if( rcc->b_2pass )
+        {
+            //FIXME adjust abr_buffer based on distance to the end of the video
+            int64_t diff = total_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 > 30 )
+            {
+                /* Adjust quant based on the difference between
+                 * achieved and expected bitrate so far */
+                double time = (double)h->fenc->i_frame / rcc->num_entries;
+                double w = x264_clip3f( time*100, 0.0, 1.0 );
+                q *= pow( (double)total_bits / rcc->expected_bits_sum, w );
+            }
+            q = x264_clip3f( q, lmin, lmax );
+        }
+        else /* 1pass ABR */
+        {
+            /* Calculate the quantizer which would have produced the desired
+             * average bitrate if it had been applied to all frames so far.
+             * Then modulate that quant based on the current frame's complexity
+             * relative to the average complexity so far (using the 2pass RCEQ).
+             * Then bias the quant up or down if total size so far was far from
+             * the target.
+             * Result: Depending on the value of rate_tolerance, there is a
+             * tradeoff between quality and bitrate precision. But at large
+             * tolerances, the bit distribution approaches that of 2pass. */
+
+            double wanted_bits, overflow, lmin, lmax;
+
+            rcc->last_satd = x264_rc_analyse_slice( h );
+            rcc->short_term_cplxsum *= 0.5;
+            rcc->short_term_cplxcount *= 0.5;
+            rcc->short_term_cplxsum += rcc->last_satd;
+            rcc->short_term_cplxcount ++;
+
+            rce.p_tex_bits = rcc->last_satd;
+            rce.blurred_complexity = rcc->short_term_cplxsum / rcc->short_term_cplxcount;
+            rce.i_tex_bits = 0;
+            rce.mv_bits = 0;
+            rce.p_count = rcc->nmb;
+            rce.i_count = 0;
+            rce.s_count = 0;
+            rce.qscale = 1;
+            rce.pict_type = pict_type;
+
+            if( h->param.rc.i_rf_constant )
+            {
+                q = get_qscale( h, &rce, rcc->rate_factor_constant, h->fenc->i_frame );
+                overflow = 1;
+            }
+            else
+            {
+                q = get_qscale( h, &rce, rcc->wanted_bits_window / rcc->cplxr_sum, h->fenc->i_frame );
+
+                wanted_bits = h->fenc->i_frame * rcc->bitrate / rcc->fps;
+                abr_buffer *= X264_MAX( 1, sqrt(h->fenc->i_frame/25) );
+                overflow = x264_clip3f( 1.0 + (total_bits - wanted_bits) / abr_buffer, .5, 2 );
+                q *= overflow;
+            }
 
-    rce = &rcc->entry[picture_number];
+            if( pict_type == SLICE_TYPE_I && h->param.i_keyint_max > 1
+                /* should test _next_ pict type, but that isn't decided yet */
+                && rcc->last_non_b_pict_type != SLICE_TYPE_I )
+            {
+                q = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
+                q /= fabs( h->param.rc.f_ip_factor );
+                q = clip_qscale( h, pict_type, q );
+            }
+            else
+            {
+                if( h->stat.i_slice_count[h->param.i_keyint_max > 1 ? SLICE_TYPE_P : SLICE_TYPE_I] < 5 )
+                {
+                    float w = h->stat.i_slice_count[SLICE_TYPE_P] / 5.;
+                    float q2 = qp2qscale(ABR_INIT_QP);
+                    q = q*w + q2*(1-w);
+                }
 
-    if(pict_type!=SLICE_TYPE_I)
-        assert(pict_type == rce->new_pict_type);
+                /* Asymmetric clipping, because symmetric would prevent
+                 * overflow control in areas of rapidly oscillating complexity */
+                lmin = rcc->last_qscale_for[pict_type] / rcc->lstep;
+                lmax = rcc->last_qscale_for[pict_type] * rcc->lstep;
+                if( overflow > 1.1 )
+                    lmax *= rcc->lstep;
+                else if( overflow < 0.9 )
+                    lmin /= rcc->lstep;
+
+                q = x264_clip3f(q, lmin, lmax);
+                q = clip_qscale(h, pict_type, q);
+                //FIXME use get_diff_limited_q() ?
+            }
+        }
 
-    diff = (int64_t)total_bits - (int64_t)rce->expected_bits;
-    br_compensation = (rcc->buffer_size - diff) / rcc->buffer_size;
-    if(br_compensation<=0.0) br_compensation=0.001;
+        rcc->last_qscale_for[pict_type] =
+        rcc->last_qscale = q;
 
-    q = rce->new_qscale / br_compensation;
-    q = x264_clip3f(q, lmin, lmax);
-    rcc->last_qscale = q;
-    return q;
+        return q;
+    }
 }
 
 static int init_pass2( x264_t *h )
@@ -793,7 +1008,6 @@ static int init_pass2( x264_t *h )
     double qblur = h->param.rc.f_qblur;
     double cplxblur = h->param.rc.f_complexity_blur;
     const int filter_size = (int)(qblur*4) | 1;
-    const int cplx_filter_size = (int)(cplxblur*2);
     double expected_bits;
     double *qscale, *blurred_qscale;
     int i;
@@ -801,12 +1015,11 @@ static int init_pass2( x264_t *h )
     /* find total/average complexity & const_bits */
     for(i=0; i<rcc->num_entries; i++){
         ratecontrol_entry_t *rce = &rcc->entry[i];
-        rce->new_pict_type = rce->pict_type;
-        all_const_bits += rce->mv_bits + rce->misc_bits;
-        rcc->i_cplx_sum[rce->new_pict_type] += rce->i_tex_bits * rce->qscale;
-        rcc->p_cplx_sum[rce->new_pict_type] += rce->p_tex_bits * rce->qscale;
-        rcc->mv_bits_sum[rce->new_pict_type] += rce->mv_bits;
-        rcc->frame_count[rce->new_pict_type] ++;
+        all_const_bits += rce->misc_bits;
+        rcc->i_cplx_sum[rce->pict_type] += rce->i_tex_bits * rce->qscale;
+        rcc->p_cplx_sum[rce->pict_type] += rce->p_tex_bits * rce->qscale;
+        rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits * rce->qscale;
+        rcc->frame_count[rce->pict_type] ++;
     }
 
     if( all_available_bits < all_const_bits)
@@ -816,32 +1029,32 @@ static int init_pass2( x264_t *h )
         return -1;
     }
 
-    if(cplxblur<.01)
-        cplxblur = .01;
+    /* Blur complexities, to reduce local fluctuation of QP.
+     * We don't blur the QPs directly, because then one very simple frame
+     * could drag down the QP of a nearby complex frame and give it more
+     * bits than intended. */
     for(i=0; i<rcc->num_entries; i++){
         ratecontrol_entry_t *rce = &rcc->entry[i];
-        double weight, weight_sum = 0;
+        double weight_sum = 0;
         double cplx_sum = 0;
-        double mask = 1.0;
+        double weight = 1.0;
         int j;
         /* weighted average of cplx of future frames */
-        for(j=1; j<cplx_filter_size && j<rcc->num_entries-i; j++){
+        for(j=1; j<cplxblur*2 && j<rcc->num_entries-i; j++){
             ratecontrol_entry_t *rcj = &rcc->entry[i+j];
-            mask *= (double)(rcc->nmb + rcj->i_count) / rcc->nmb;
-            weight = mask * exp(-j*j/(cplxblur*cplxblur));
+            weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
             if(weight < .0001)
                 break;
             weight_sum += weight;
-            cplx_sum += weight * (rcj->i_tex_bits + rcj->p_tex_bits) * rce->qscale;
+            cplx_sum += weight * qscale2bits(rcj, 1);
         }
         /* weighted average of cplx of past frames */
-        mask = 1.0;
-        for(j=0; j<cplx_filter_size && j<=i; j++){
+        weight = 1.0;
+        for(j=0; j<=cplxblur*2 && j<=i; j++){
             ratecontrol_entry_t *rcj = &rcc->entry[i-j];
-            weight = mask * exp(-j*j/(cplxblur*cplxblur));
             weight_sum += weight;
-            cplx_sum += weight * (rcj->i_tex_bits + rcj->p_tex_bits) * rce->qscale;
-            mask *= (double)(rcc->nmb + rcj->i_count) / rcc->nmb;
+            cplx_sum += weight * qscale2bits(rcj, 1);
+            weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
             if(weight < .0001)
                 break;
         }
@@ -854,9 +1067,16 @@ static int init_pass2( x264_t *h )
     else
         blurred_qscale = qscale;
 
+    /* Search for a factor which, when multiplied by the RCEQ values from
+     * each frame, adds up to the desired total size.
+     * There is no exact closed-form solution because of VBV constraints and
+     * because qscale2bits is not invertible, but we can start with the simple
+     * approximation of scaling the 1st pass by the ratio of bitrates.
+     * The search range is probably overkill, but speed doesn't matter here. */
+
     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));
+        expected_bits += qscale2bits(&rcc->entry[i], get_qscale(h, &rcc->entry[i], 1.0, i));
     step_mult = all_available_bits / expected_bits;
 
     rate_factor = 0;
@@ -864,12 +1084,17 @@ static int init_pass2( x264_t *h )
         expected_bits = 0;
         rate_factor += step;
 
+        rcc->last_non_b_pict_type = -1;
+        rcc->last_accum_p_norm = 1;
+        rcc->accum_p_norm = 0;
+        rcc->buffer_fill = rcc->buffer_size * h->param.rc.f_vbv_buffer_init;
+
         /* find qscale */
         for(i=0; i<rcc->num_entries; i++){
-            qscale[i] = get_qscale(h, &rcc->entry[i], rate_factor);
+            qscale[i] = get_qscale(h, &rcc->entry[i], rate_factor, i);
         }
 
-        /* fixed I/B QP relative to P mode */
+        /* fixed I/B qscale relative to P */
         for(i=rcc->num_entries-1; i>=0; i--){
             qscale[i] = get_diff_limited_q(h, &rcc->entry[i], qscale[i]);
             assert(qscale[i] >= 0);
@@ -880,7 +1105,6 @@ static int init_pass2( x264_t *h )
             assert(filter_size%2==1);
             for(i=0; i<rcc->num_entries; i++){
                 ratecontrol_entry_t *rce = &rcc->entry[i];
-                const int pict_type = rce->new_pict_type;
                 int j;
                 double q=0.0, sum=0.0;
 
@@ -889,7 +1113,7 @@ static int init_pass2( x264_t *h )
                     double d = index-i;
                     double coeff = qblur==0 ? 1.0 : exp(-d*d/(qblur*qblur));
                     if(index < 0 || index >= rcc->num_entries) continue;
-                    if(pict_type != rcc->entry[index].new_pict_type) continue;
+                    if(rce->pict_type != rcc->entry[index].pict_type) continue;
                     q += qscale[index] * coeff;
                     sum += coeff;
                 }
@@ -901,12 +1125,13 @@ static int init_pass2( x264_t *h )
         for(i=0; i<rcc->num_entries; i++){
             ratecontrol_entry_t *rce = &rcc->entry[i];
             double bits;
-            rce->new_qscale = clip_qscale(h, rce, blurred_qscale[i]);
+            rce->new_qscale = clip_qscale(h, rce->pict_type, blurred_qscale[i]);
             assert(rce->new_qscale >= 0);
-            bits = qscale2bits(rce, rce->new_qscale) + rce->mv_bits + rce->misc_bits;
+            bits = qscale2bits(rce, rce->new_qscale) + rce->misc_bits;
 
             rce->expected_bits = expected_bits;
             expected_bits += bits;
+            update_vbv(h, bits);
         }
 
 //printf("expected:%llu available:%llu factor:%lf avgQ:%lf\n", (uint64_t)expected_bits, all_available_bits, rate_factor);
@@ -925,12 +1150,26 @@ static int init_pass2( x264_t *h )
         avgq = qscale2qp(avgq / rcc->num_entries);
 
         x264_log(h, X264_LOG_ERROR, "Error: 2pass curve failed to converge\n");
-        x264_log(h, X264_LOG_ERROR, "expected bits: %llu, available: %llu, avg QP: %.4lf\n", (uint64_t)expected_bits, all_available_bits, avgq);
-        if(expected_bits < all_available_bits && avgq < h->param.rc.i_qp_min + 1)
-            x264_log(h, X264_LOG_ERROR, "try reducing bitrate or reducing qp_min\n");
-        if(expected_bits > all_available_bits && avgq > h->param.rc.i_qp_min - 1)
-            x264_log(h, X264_LOG_ERROR, "try increasing bitrate or increasing qp_max\n");
-        return -1;
+        x264_log(h, X264_LOG_ERROR, "target: %.2f kbit/s, expected: %.2f kbit/s, avg QP: %.4f\n",
+                 (float)h->param.rc.i_bitrate,
+                 expected_bits * rcc->fps / (rcc->num_entries * 1000.),
+                 avgq);
+        if(expected_bits < all_available_bits && avgq < h->param.rc.i_qp_min + 2)
+        {
+            if(h->param.rc.i_qp_min > 0)
+                x264_log(h, X264_LOG_ERROR, "try reducing target bitrate or reducing qp_min (currently %d)\n", h->param.rc.i_qp_min);
+            else
+                x264_log(h, X264_LOG_ERROR, "try reducing target bitrate\n");
+        }
+        else if(expected_bits > all_available_bits && avgq > h->param.rc.i_qp_max - 2)
+        {
+            if(h->param.rc.i_qp_max < 51)
+                x264_log(h, X264_LOG_ERROR, "try increasing target bitrate or increasing qp_max (currently %d)\n", h->param.rc.i_qp_max);
+            else
+                x264_log(h, X264_LOG_ERROR, "try increasing target bitrate\n");
+        }
+        else
+            x264_log(h, X264_LOG_ERROR, "internal error\n");
     }
 
     return 0;