From aead79b133ba976a0f6101748c0cc39c6e12040e Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
Date: Tue, 11 May 2010 07:34:24 -0400
Subject: [PATCH] Proper use of logN and logM for the offsets

---
 libcelt/bands.c | 4 ++--
 libcelt/modes.c | 2 +-
 libcelt/rate.c  | 5 ++++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/libcelt/bands.c b/libcelt/bands.c
index 6733380c..8de5bb72 100644
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -639,7 +639,7 @@ void quant_bands_stereo(const CELTMode *m, int start, celt_norm *_X, const celt_
       if (b<0)
          b = 0;
 
-      qb = (b-2*(N-1)*(QTHETA_OFFSET-log2_frac(N,BITRES)))/(32*(N-1));
+      qb = (b-2*(N-1)*(QTHETA_OFFSET-m->logN[i]-(LM<<BITRES)))/(32*(N-1));
       if (qb > (b>>BITRES)-1)
          qb = (b>>BITRES)-1;
       if (qb<0)
@@ -835,7 +835,7 @@ void unquant_bands_stereo(const CELTMode *m, int start, celt_norm *_X, const cel
       if (b<0)
          b = 0;
 
-      qb = (b-2*(N-1)*(QTHETA_OFFSET-log2_frac(N,BITRES)))/(32*(N-1));
+      qb = (b-2*(N-1)*(QTHETA_OFFSET-m->logN[i]-(LM<<BITRES)))/(32*(N-1));
       if (qb > (b>>BITRES)-1)
          qb = (b>>BITRES)-1;
       if (qb>14)
diff --git a/libcelt/modes.c b/libcelt/modes.c
index 69165a17..147dcc10 100644
--- a/libcelt/modes.c
+++ b/libcelt/modes.c
@@ -379,7 +379,7 @@ CELTMode *celt_mode_create(celt_int32 Fs, int frame_size, int *error)
       goto failure;
 
    for (i=0;i<mode->nbEBands;i++)
-      logN[i] = log2_frac(mode->nbShortMdcts*(mode->eBands[i+1]-mode->eBands[i]), BITRES);
+      logN[i] = log2_frac(mode->eBands[i+1]-mode->eBands[i], BITRES);
    mode->logN = logN;
 #endif /* !STATIC_MODES */
 
diff --git a/libcelt/rate.c b/libcelt/rate.c
index b6845eef..2c0af229 100644
--- a/libcelt/rate.c
+++ b/libcelt/rate.c
@@ -107,8 +107,11 @@ static inline void interp_bits2pulses(const CELTMode *m, int start, int *bits1,
    int psum;
    int lo, hi;
    int j;
+   int logM;
    const int C = CHANNELS(_C);
    SAVE_STACK;
+
+   logM = log2_frac(M, BITRES);
    lo = 0;
    hi = 1<<BITRES;
    while (hi-lo != 1)
@@ -148,7 +151,7 @@ static inline void interp_bits2pulses(const CELTMode *m, int start, int *bits1,
       N=M*(m->eBands[j+1]-m->eBands[j]);
       /* Compensate for the extra DoF in stereo */
       d=(C*N+ ((C==2 && N>2) ? 1 : 0))<<BITRES; 
-      offset = FINE_OFFSET - m->logN[j];
+      offset = FINE_OFFSET - m->logN[j] - logM;
       /* Offset for the number of fine bits compared to their "fair share" of total/N */
       offset = bits[j]-offset*N*C;
       /* Compensate for the prediction gain in stereo */