From ac1e03d78ed89eb0bbe03d1f4f35911c8ed2a3dc Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
Date: Tue, 12 Feb 2008 23:00:18 +1100
Subject: [PATCH] minor optimisation+tuning of vq search

---
 libcelt/bands.c | 16 ++++++++++++----
 libcelt/vq.c    | 10 +++++++++-
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/libcelt/bands.c b/libcelt/bands.c
index c7ffc108..0150cbf6 100644
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -237,7 +237,8 @@ void quant_bands(const CELTMode *m, float *X, float *P, float *W, struct alloc_d
    float norm[B*eBands[m->nbEBands+1]];
    int pulses[m->nbEBands];
    int offsets[m->nbEBands];
-   
+   float alpha = .7;
+
    for (i=0;i<m->nbEBands;i++)
       offsets[i] = 0;
    /* Use a single-bit margin to guard against overrunning (make sure it's enough) */
@@ -262,17 +263,20 @@ void quant_bands(const CELTMode *m, float *X, float *P, float *W, struct alloc_d
       if (eBands[i] >= m->pitchEnd || q<=0)
       {
          q -= 1;
+         alpha = 0;
          if (q<0)
             intra_fold(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, norm, P+B*eBands[i], B, eBands[i]);
          else
             intra_prediction(X+B*eBands[i], W+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, norm, P+B*eBands[i], B, eBands[i], enc);
+      } else {
+         alpha = .7;
       }
       
       if (q > 0)
       {
          exp_rotation(P+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, -1, B, 8);
          exp_rotation(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, -1, B, 8);
-         alg_quant(X+B*eBands[i], W+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, P+B*eBands[i], 0.7, enc);
+         alg_quant(X+B*eBands[i], W+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, P+B*eBands[i], alpha, enc);
          exp_rotation(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, 1, B, 8);
       }
       for (j=B*eBands[i];j<B*eBands[i+1];j++)
@@ -294,7 +298,8 @@ void unquant_bands(const CELTMode *m, float *X, float *P, struct alloc_data *all
    float norm[B*eBands[m->nbEBands+1]];
    int pulses[m->nbEBands];
    int offsets[m->nbEBands];
-   
+   float alpha = .7;
+
    for (i=0;i<m->nbEBands;i++)
       offsets[i] = 0;
    /* Use a single-bit margin to guard against overrunning (make sure it's enough) */
@@ -314,16 +319,19 @@ void unquant_bands(const CELTMode *m, float *X, float *P, struct alloc_data *all
       if (eBands[i] >= m->pitchEnd || q<=0)
       {
          q -= 1;
+         alpha = 0;
          if (q<0)
             intra_fold(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, norm, P+B*eBands[i], B, eBands[i]);
          else
             intra_unquant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, norm, P+B*eBands[i], B, eBands[i], dec);
+      } else {
+         alpha = .7;
       }
       
       if (q > 0)
       {
          exp_rotation(P+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, -1, B, 8);
-         alg_unquant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, P+B*eBands[i], 0.7, dec);
+         alg_unquant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, P+B*eBands[i], alpha, dec);
          exp_rotation(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, 1, B, 8);
       }
       for (j=B*eBands[i];j<B*eBands[i+1];j++)
diff --git a/libcelt/vq.c b/libcelt/vq.c
index 1a3a58ef..85270f5c 100644
--- a/libcelt/vq.c
+++ b/libcelt/vq.c
@@ -115,10 +115,11 @@ void alg_quant(float *x, float *W, int N, int K, float *p, float alpha, ec_enc *
          for (j=0;j<N;j++)
          {
             int sign;
+            //if (x[j]>0) sign=1; else sign=-1;
             for (sign=-1;sign<=1;sign+=2)
             {
                /* All pulses at one location must have the same size */
-               if (iy[m][j]*sign < 0)
+               if (iy[m][j]*sign < 0 || (x[j]*sign<0 && pulsesLeft>((K+1)>>1)))
                   continue;
                //fprintf (stderr, "%d/%d %d/%d %d/%d\n", i, K, m, L2, j, N);
                float tmp_xy, tmp_yy, tmp_yp;
@@ -200,6 +201,13 @@ void alg_quant(float *x, float *W, int N, int K, float *p, float alpha, ec_enc *
       pulsesLeft -= pulsesAtOnce;
    }
    
+   if (0) {
+      float err=0;
+      for (i=0;i<N;i++)
+         err += (x[i]-gain[0]*y[0][i])*(x[i]-gain[0]*y[0][i]);
+      //if (N<=10)
+      //printf ("%f %d %d\n", err, K, N);
+   }
    for (i=0;i<N;i++)
       x[i] = p[i]+gain[0]*y[0][i];
    if (0) {