--- branches/dev-api-4/xvidcore/src/utils/mbtransquant.c	2003/05/06 23:41:29	1010
+++ branches/dev-api-4/xvidcore/src/utils/mbtransquant.c	2003/05/09 22:03:13	1011
@@ -21,7 +21,7 @@
  *  along with this program ; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  *
- * $Id: mbtransquant.c,v 1.21.2.9 2003-04-27 19:47:48 chl Exp $
+ * $Id: mbtransquant.c,v 1.21.2.10 2003-05-09 22:03:13 chl Exp $
  *
  ****************************************************************************/
 
@@ -35,6 +35,7 @@
 #include "mem_transfer.h"
 #include "timer.h"
 #include "../bitstream/mbcoding.h"
+#include "../bitstream/zigzag.h"
 #include "../dct/fdct.h"
 #include "../dct/idct.h"
 #include "../quant/quant_mpeg4.h"
@@ -158,6 +159,14 @@
 	}
 }
 
+
+static int 
+dct_quantize_trellis_h263_c(int16_t *const Out, const int16_t *const In, int Q, const uint16_t * const Zigzag, int Non_Zero);
+
+static int 
+dct_quantize_trellis_mpeg_c(int16_t *const Out, const int16_t *const In, int Q, const uint16_t * const Zigzag, int Non_Zero);
+
+
 /* Quantize all blocks -- Inter mode */
 static __inline uint8_t
 MBQuantInter(const MBParam * pParam,
@@ -181,13 +190,13 @@
 		if (!(pParam->vol_flags & XVID_VOL_MPEGQUANT)) {
 			sum = quant_inter(&qcoeff[i*64], &data[i*64], pMB->quant);
 			if ( (sum) && (frame->vop_flags & XVID_VOP_TRELLISQUANT) ) {
-				sum = dct_quantize_trellis_inter_h263_c (&qcoeff[i*64], &data[i*64], pMB->quant)+1;
+				sum = dct_quantize_trellis_h263_c(&qcoeff[i*64], &data[i*64], pMB->quant, &scan_tables[0][0], 63)+1;
 				limit = 1;
 			}
 		} else {
 			sum = quant4_inter(&qcoeff[i * 64], &data[i * 64], pMB->quant);
 //			if ( (sum) && (frame->vop_flags & XVID_VOP_TRELLISQUANT) )
-//				sum = dct_quantize_trellis_inter_mpeg_c (&qcoeff[i*64], &data[i*64], pMB->quant)+1;	
+//				sum = dct_quantize_trellis_mpeg_c (&qcoeff[i*64], &data[i*64], pMB->quant)+1;	
 		}
 		stop_quant_timer();
 
@@ -590,3 +599,441 @@
 	MOVLINE(LINE(3, 5), LINE(3, 3));
 	MOVLINE(LINE(3, 3), tmp);
 }
+
+
+
+
+
+/************************************************************************
+ *               Trellis based R-D optimal quantization                 *        
+ *                                                                      *
+ *   Trellis Quant code (C) 2003 Pascal Massimino skal(at)planet-d.net  *
+ *                                                                      *
+ ************************************************************************/
+
+
+static int
+dct_quantize_trellis_inter_mpeg_c (int16_t *qcoeff, const int16_t *data, int quant)
+{ return 63; }
+
+
+//////////////////////////////////////////////////////////
+//
+//        Trellis-Based quantization
+//
+// So far I understand this paper:
+//
+//  "Trellis-Based R-D Optimal Quantization in H.263+"
+//    J.Wen, M.Luttrell, J.Villasenor
+//    IEEE Transactions on Image Processing, Vol.9, No.8, Aug. 2000.
+//
+// we are at stake with a simplified Bellmand-Ford / Dijkstra Single
+// Source Shorted Path algo. But due to the underlying graph structure
+// ("Trellis"), it can be turned into a dynamic programming algo,
+// partially saving the explicit graph's nodes representation. And 
+// without using a heap, since the open frontier of the DAG is always
+// known, and of fixed sized.
+//
+//////////////////////////////////////////////////////////
+
+
+//////////////////////////////////////////////////////////
+// Codes lengths for relevant levels.
+
+  // let's factorize:
+static const uint8_t Code_Len0[64] = {
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len1[64] = {
+  20,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len2[64] = {
+  19,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len3[64] = {
+  18,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len4[64] = {
+  17,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len5[64] = {
+  16,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len6[64] = {
+  15,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len7[64] = {
+  13,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len8[64] = {
+  11,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len9[64] = {
+  12,21,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len10[64] = {
+  12,20,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len11[64] = {
+  12,19,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len12[64] = {
+  11,17,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len13[64] = {
+  11,15,21,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len14[64] = {
+  10,12,19,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len15[64] = {
+  10,13,17,19,21,21,21,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len16[64] = {
+   9,12,13,18,18,19,19,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30};
+static const uint8_t Code_Len17[64] = {
+   8,11,13,14,14,14,15,19,19,19,21,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len18[64] = {
+   7, 9,11,11,13,13,13,15,15,15,16,22,22,22,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len19[64] = {
+   5, 7, 9,10,10,11,11,11,11,11,13,14,16,17,17,18,18,18,18,18,18,18,18,20,20,21,21,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30 };
+static const uint8_t Code_Len20[64] = {
+   3, 4, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9,10,10,10,10,10,10,10,10,12,12,13,13,12,13,14,15,15,
+  15,16,16,16,16,17,17,17,18,18,19,19,19,19,19,19,19,19,21,21,22,22,30,30,30,30,30,30,30,30,30,30 };
+
+  // a few more table for LAST table:
+static const uint8_t Code_Len21[64] = {
+  13,20,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30};
+static const uint8_t Code_Len22[64] = {
+  12,15,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,
+  30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30};
+static const uint8_t Code_Len23[64] = {
+  10,12,15,15,15,16,16,16,16,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,18,19,19,19,19,20,20,20,
+  20,21,21,21,21,21,21,21,21,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30};
+static const uint8_t Code_Len24[64] = {
+   5, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9,10,10,10,10,10,10,10,10,11,11,11,11,12,12,12,
+  12,13,13,13,13,13,13,13,13,14,16,16,16,16,17,17,17,17,18,18,18,18,18,18,18,18,19,19,19,19,19,19};
+
+
+static const uint8_t * const B16_17_Code_Len[24] = { // levels [1..24]
+  Code_Len20,Code_Len19,Code_Len18,Code_Len17,
+  Code_Len16,Code_Len15,Code_Len14,Code_Len13,
+  Code_Len12,Code_Len11,Code_Len10,Code_Len9,
+  Code_Len8, Code_Len7 ,Code_Len6 ,Code_Len5,
+  Code_Len4, Code_Len3, Code_Len3 ,Code_Len2,
+  Code_Len2, Code_Len1, Code_Len1, Code_Len1,
+};
+
+static const uint8_t * const B16_17_Code_Len_Last[6] = { // levels [1..6]
+  Code_Len24,Code_Len23,Code_Len22,Code_Len21, Code_Len3, Code_Len1, 
+};
+
+#define TL(q) 0xfe00/(q*q)
+
+static const int Trellis_Lambda_Tabs[31] = {
+         TL( 1),TL( 2),TL( 3),TL( 4),TL( 5),TL( 6), TL( 7),
+  TL( 8),TL( 9),TL(10),TL(11),TL(12),TL(13),TL(14), TL(15),
+  TL(16),TL(17),TL(18),TL(19),TL(20),TL(21),TL(22), TL(23),
+  TL(24),TL(25),TL(26),TL(27),TL(28),TL(29),TL(30), TL(31)
+};
+#undef TL
+
+static inline int Find_Last(const int16_t *C, const uint16_t *Zigzag, int i)
+{
+  while(i>=0)
+    if (C[Zigzag[i]])
+      return i;
+    else i--;
+  return -1;
+}
+
+//////////////////////////////////////////////////////////
+
+#define DBG 0
+
+static uint32_t Evaluate_Cost(const int16_t *C, int Mult, int Bias,
+                                const uint16_t * Zigzag, int Max, int Lambda)
+{
+#if (DBG>0)
+  const int16_t * const Ref = C + 6*64;
+  int Last = Max;
+  while(Last>=0 && C[Zigzag[Last]]==0) Last--;
+  int Bits = 0;
+  if (Last>=0) {
+    Bits = 2;   // CBP
+    int j=0, j0=0;
+    int Run, Level;
+    while(j<Last) {
+      while(!C[Zigzag[j]]) j++;
+      if (j==Last) break;
+      Level=C[Zigzag[j]];
+      Run = j - j0;
+      j0 = ++j;
+      if (Level>=-24 && Level<=24) Bits += B16_17_Code_Len[(Level<0) ? -Level-1 : Level-1][Run];
+      else Bits += 30;
+    }
+    Level = C[Zigzag[Last]];
+    Run = j - j0;
+    if (Level>=-6 && Level<=6) Bits += B16_17_Code_Len_Last[(Level<0) ? -Level-1 : Level-1][Run];
+    else Bits += 30;
+  }
+
+  int Dist = 0;
+  int i;
+  for(i=0; i<=Last; ++i) {
+    int V = C[Zigzag[i]]*Mult;
+    if      (V>0) V += Bias;
+    else if (V<0) V -= Bias;
+    V -= Ref[Zigzag[i]];
+    Dist += V*V;
+  }
+  uint32_t Cost = Lambda*Dist + (Bits<<16);
+  if (DBG==1)
+    printf( " Last:%2d/%2d Cost = [(Bits=%5.0d) + Lambda*(Dist=%6.0d) = %d ] >>12= %d ", Last,Max, Bits, Dist, Cost, Cost>>12 );
+  return Cost;
+
+#else
+  return 0;
+#endif
+}
+
+
+static int 
+dct_quantize_trellis_h263_c(int16_t *const Out, const int16_t *const In, int Q, const uint16_t * const Zigzag, int Non_Zero)
+{
+
+    // Note: We should search last non-zero coeffs on *real* DCT input coeffs (In[]), 
+    // not quantized one (Out[]). However, it only improves the result *very* 
+    // slightly (~0.01dB), whereas speed drops to crawling level :)
+    // Well, actually, taking 1 more coeff past Non_Zero into account sometimes helps,
+  
+  typedef struct { int16_t Run, Level; } NODE;
+  
+  NODE Nodes[65], Last;
+  uint32_t Run_Costs0[64+1], * const Run_Costs = Run_Costs0 + 1;
+
+  const int Mult = 2*Q;
+  const int Bias = (Q-1) | 1;
+  const int Lev0 = Mult + Bias;
+  const int Lambda = Trellis_Lambda_Tabs[Q-1];    // it's 1/lambda, actually
+
+  int Run_Start = -1;
+  Run_Costs[-1] = 2<<16;                          // source (w/ CBP penalty)
+  uint32_t Min_Cost = 2<<16;
+
+  int Last_Node = -1;
+  uint32_t Last_Cost = 0;
+
+#if (DBG>0)
+  Last.Level = 0; Last.Run = -1; // just initialize to smthg
+#endif
+
+  int i, j;
+
+  Non_Zero = Find_Last(Out, Zigzag, Non_Zero);
+  if (Non_Zero<0)
+      return -1;  
+
+  for(i=0; i<=Non_Zero; i++)
+  {
+    const int AC = In[Zigzag[i]];
+    const int Level1 = Out[Zigzag[i]];
+    const int Dist0 = Lambda* AC*AC;
+    uint32_t Best_Cost = 0xf0000000;
+    Last_Cost += Dist0;
+
+    if ((uint32_t)(Level1+1)<3)                 // very specialized loop for -1,0,+1
+    {
+      int dQ;
+	  int Run;
+
+      if (AC<0) {
+        Nodes[i].Level = -1;
+        dQ = Lev0 + AC;
+      } else {
+        Nodes[i].Level = 1;
+        dQ = Lev0 - AC;
+      }
+      const uint32_t Cost0 = Lambda*dQ*dQ;
+
+      Nodes[i].Run = 1;
+      Best_Cost = (Code_Len20[0]<<16) + Run_Costs[i-1]+Cost0;
+      for(Run=i-Run_Start; Run>0; --Run)
+      {
+        const uint32_t Cost_Base = Cost0 + Run_Costs[i-Run];
+        const uint32_t Cost = Cost_Base + (Code_Len20[Run-1]<<16);
+          // TODO: what about tie-breaks? Should we favor short runs or
+          // long runs? Although the error is the same, it would not be
+          // spread the same way along high and low frequencies...
+        if (Cost<Best_Cost)
+        {
+          Best_Cost    = Cost;
+          Nodes[i].Run = Run;
+        }
+        const uint32_t lCost = Cost_Base + (Code_Len24[Run-1]<<16);
+        if (lCost<Last_Cost)
+        {
+          Last_Cost  = lCost;
+          Last.Run   = Run;
+          Last_Node  = i;
+        }
+      }
+      if (Last_Node==i) Last.Level = Nodes[i].Level;
+
+
+      if (DBG==1) {
+        Run_Costs[i] = Best_Cost;
+        printf( "Costs #%2d: ", i);
+        for(j=-1;j<=Non_Zero;++j) {
+          if (j==Run_Start)            printf( " %3.0d|", Run_Costs[j]>>12 );
+          else if (j>Run_Start && j<i) printf( " %3.0d|", Run_Costs[j]>>12 );
+          else if (j==i)               printf( "(%3.0d)", Run_Costs[j]>>12 );
+          else                         printf( "  - |" );
+        }
+        printf( "<%3.0d %2d %d>", Min_Cost>>12, Nodes[i].Level, Nodes[i].Run );
+        printf( "  Last:#%2d {%3.0d %2d %d}", Last_Node, Last_Cost>>12, Last.Level, Last.Run );
+        printf( " AC:%3.0d Dist0:%3d Dist(%d)=%d", AC, Dist0>>12, Nodes[i].Level, Cost0>>12 );
+        printf( "\n" );
+      }
+    }
+    else                      // "big" levels
+    {
+      const uint8_t *Tbl_L1, *Tbl_L2, *Tbl_L1_Last, *Tbl_L2_Last;
+      int Level2;
+      int dQ1, dQ2;
+      int Run;
+	  
+	  if (Level1>1) {
+        dQ1 = Level1*Mult-AC + Bias;
+        dQ2 = dQ1 - Mult;
+        Level2 = Level1-1;
+        Tbl_L1      = (Level1<=24) ? B16_17_Code_Len[Level1-1]     : Code_Len0;
+        Tbl_L2      = (Level2<=24) ? B16_17_Code_Len[Level2-1]     : Code_Len0;
+        Tbl_L1_Last = (Level1<=6) ? B16_17_Code_Len_Last[Level1-1] : Code_Len0;
+        Tbl_L2_Last = (Level2<=6) ? B16_17_Code_Len_Last[Level2-1] : Code_Len0;
+      }
+      else { // Level1<-1
+        dQ1 = Level1*Mult-AC - Bias;
+        dQ2 = dQ1 + Mult;
+        Level2 = Level1 + 1;
+        Tbl_L1      = (Level1>=-24) ? B16_17_Code_Len[Level1^-1]      : Code_Len0;
+        Tbl_L2      = (Level2>=-24) ? B16_17_Code_Len[Level2^-1]      : Code_Len0;
+        Tbl_L1_Last = (Level1>=- 6) ? B16_17_Code_Len_Last[Level1^-1] : Code_Len0;
+        Tbl_L2_Last = (Level2>=- 6) ? B16_17_Code_Len_Last[Level2^-1] : Code_Len0;
+      }
+      const uint32_t Dist1 = Lambda*dQ1*dQ1;
+      const uint32_t Dist2 = Lambda*dQ2*dQ2;
+      const int dDist21 = Dist2-Dist1;
+
+      for(Run=i-Run_Start; Run>0; --Run)
+      {
+        const uint32_t Cost_Base = Dist1 + Run_Costs[i-Run];
+
+// for sub-optimal (but slightly worth it, speed-wise) search, uncomment the following:
+//        if (Cost_Base>=Best_Cost) continue;
+
+        uint32_t Cost1, Cost2;
+        int bLevel;
+
+        Cost1 = Cost_Base + (Tbl_L1[Run-1]<<16);
+        Cost2 = Cost_Base + (Tbl_L2[Run-1]<<16) + dDist21;
+
+        if (Cost2<Cost1) { Cost1 = Cost2; bLevel = Level2; }
+        else bLevel = Level1;
+
+        if (Cost1<Best_Cost)
+        {
+          Best_Cost = Cost1;
+          Nodes[i].Run   = Run;
+          Nodes[i].Level = bLevel;
+        }
+
+        Cost1 = Cost_Base + (Tbl_L1_Last[Run-1]<<16);
+        Cost2 = Cost_Base + (Tbl_L2_Last[Run-1]<<16) + dDist21;
+
+        if (Cost2<Cost1) { Cost1 = Cost2; bLevel = Level2; }
+        else bLevel = Level1;
+        if (Cost1<Last_Cost)
+        {
+          Last_Cost  = Cost1;
+          Last.Run   = Run;
+          Last.Level = bLevel;
+          Last_Node  = i;
+        }
+      }
+
+      if (DBG==1) {
+        Run_Costs[i] = Best_Cost;
+        printf( "Costs #%2d: ", i);
+        for(j=-1;j<=Non_Zero;++j) {
+          if (j==Run_Start)            printf( " %3.0d|", Run_Costs[j]>>12 );
+          else if (j>Run_Start && j<i) printf( " %3.0d|", Run_Costs[j]>>12 );
+          else if (j==i)               printf( "(%3.0d)", Run_Costs[j]>>12 );
+          else                         printf( "  - |" );
+        }
+        printf( "<%3.0d %2d %d>", Min_Cost>>12, Nodes[i].Level, Nodes[i].Run );
+        printf( "  Last:#%2d {%3.0d %2d %d}", Last_Node, Last_Cost>>12, Last.Level, Last.Run );
+        printf( " AC:%3.0d Dist0:%3d Dist(%2d):%3d Dist(%2d):%3d", AC, Dist0>>12, Level1, Dist1>>12, Level2, Dist2>>12 );
+        printf( "\n" );
+      }
+    }
+
+    Run_Costs[i] = Best_Cost;
+
+    if (Best_Cost < Min_Cost + Dist0) {
+      Min_Cost = Best_Cost;
+      Run_Start = i;
+    }
+    else
+    {
+        // as noticed by Michael Niedermayer (michaelni at gmx.at), there's
+        // a code shorter by 1 bit for a larger run (!), same level. We give
+        // it a chance by not moving the left barrier too much.
+      while( Run_Costs[Run_Start]>Min_Cost+(1<<16) )
+        Run_Start++;
+
+        // spread on preceding coeffs the cost incurred by skipping this one
+      for(j=Run_Start; j<i; ++j) Run_Costs[j] += Dist0;
+      Min_Cost += Dist0;
+    }
+  }
+
+  if (DBG) {
+    Last_Cost = Evaluate_Cost(Out,Mult,Bias, Zigzag,Non_Zero, Lambda);
+    if (DBG==1) {
+      printf( "=> " );
+      for(i=0; i<=Non_Zero; ++i) printf( "[%3.0d] ", Out[Zigzag[i]] );
+      printf( "\n" );
+   }
+  }
+
+  if (Last_Node<0)
+    return -1;
+
+       // reconstruct optimal sequence backward with surviving paths
+  bzero(Out, 64*sizeof(*Out));
+  Out[Zigzag[Last_Node]] = Last.Level;
+  i = Last_Node - Last.Run;
+  while(i>=0) {
+    Out[Zigzag[i]] = Nodes[i].Level;
+    i -= Nodes[i].Run;
+  }
+
+  if (DBG) {
+    uint32_t Cost = Evaluate_Cost(Out,Mult,Bias, Zigzag,Non_Zero, Lambda);
+    if (DBG==1) {
+      printf( "<= " ); 
+      for(i=0; i<=Last_Node; ++i) printf( "[%3.0d] ", Out[Zigzag[i]] );
+      printf( "\n--------------------------------\n" );
+    }
+    if (Cost>Last_Cost) printf( "!!! %u > %u\n", Cost, Last_Cost );
+  }
+  return Last_Node;
+}
+
+#undef DBG