From ab4dcc5c90140f7a6fefdef2e2acfdf7ecc152c9 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
Date: Wed, 21 Oct 2009 07:08:27 -0400
Subject: [PATCH] Allow coarse energy to take almost all the bits. Also, fixed
 a some issues with the VBR rate controller.

---
 libcelt/celt.c        |  9 +++------
 libcelt/quant_bands.c | 12 ++++--------
 2 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/libcelt/celt.c b/libcelt/celt.c
index 2c9f4ef8..21edb0ca 100644
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -546,7 +546,7 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
    int pitch_index;
    int bits;
    int has_fold=1;
-   unsigned coarse_needed;
+   int coarse_needed;
    ec_byte_buffer buf;
    ec_enc         enc;
    VARDECL(celt_sig, in);
@@ -766,7 +766,7 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
 
    /* Bit allocation */
    ALLOC(error, C*st->mode->nbEBands, celt_word16);
-   coarse_needed = quant_coarse_energy(st->mode, bandLogE, st->oldBandE, nbCompressedBytes*8/3, intra_ener, st->mode->prob, error, &enc, C);
+   coarse_needed = quant_coarse_energy(st->mode, bandLogE, st->oldBandE, nbCompressedBytes*8-16, intra_ener, st->mode->prob, error, &enc, C);
    coarse_needed = ((coarse_needed*3-1)>>3)+1;
 
    /* Variable bitrate */
@@ -791,7 +791,6 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
      /* In VBR mode the frame size must not be reduced so much that it would result in the coarse energy busting its budget */
      target=IMAX(coarse_needed,(target+64)/128);
      nbCompressedBytes=IMIN(nbCompressedBytes,target);
-
      /* Make the adaptation coef (alpha) higher at the beginning */
      if (st->vbr_count < 990)
      {
@@ -820,7 +819,6 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
         int adjust = 1+(st->vbr_reservoir-vbr_bound-1)/(8<<BITRES);
         nbCompressedBytes -= adjust;
         st->vbr_reservoir -= adjust*(8<<BITRES);
-        st->vbr_offset -= 8<<BITRES;
         /*printf ("-%d\n", adjust);*/
      } else if (st->vbr_reservoir < 0)
      {
@@ -828,7 +826,6 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
         int adjust = 1-(st->vbr_reservoir-1)/(8<<BITRES);
         st->vbr_reservoir += adjust*(8<<BITRES);
         nbCompressedBytes += adjust;
-        st->vbr_offset += 8<<BITRES;
         /*printf ("+%d\n", adjust);*/
      }
 
@@ -1376,7 +1373,7 @@ int celt_decode_float(CELTDecoder * restrict st, const unsigned char *data, int
 
    ALLOC(fine_quant, st->mode->nbEBands, int);
    /* Get band energies */
-   unquant_coarse_energy(st->mode, bandE, st->oldBandE, len*8/3, intra_ener, st->mode->prob, &dec, C);
+   unquant_coarse_energy(st->mode, bandE, st->oldBandE, len*8-16, intra_ener, st->mode->prob, &dec, C);
    
    ALLOC(pulses, st->mode->nbEBands, int);
    ALLOC(offsets, st->mode->nbEBands, int);
diff --git a/libcelt/quant_bands.c b/libcelt/quant_bands.c
index 753c01d6..dac64be8 100644
--- a/libcelt/quant_bands.c
+++ b/libcelt/quant_bands.c
@@ -89,7 +89,6 @@ void quant_prob_free(int *freq)
 unsigned quant_coarse_energy(const CELTMode *m, celt_word16 *eBands, celt_word16 *oldEBands, int budget, int intra, int *prob, celt_word16 *error, ec_enc *enc, int _C)
 {
    int i, c;
-   unsigned bits;
    unsigned bits_used = 0;
    celt_word16 prev[2] = {0,0};
    celt_word16 coef = m->ePredCoef;
@@ -103,8 +102,7 @@ unsigned quant_coarse_energy(const CELTMode *m, celt_word16 *eBands, celt_word16
    }
    /* The .8 is a heuristic */
    beta = MULT16_16_Q15(QCONST16(.8f,15),coef);
-   
-   bits = ec_enc_tell(enc, 0);
+
    /* Encode at a fixed coarse resolution */
    for (i=0;i<m->nbEBands;i++)
    {
@@ -127,7 +125,7 @@ unsigned quant_coarse_energy(const CELTMode *m, celt_word16 *eBands, celt_word16
 #endif
          /* If we don't have enough bits to encode all the energy, just assume something safe.
             We allow slightly busting the budget here */
-         bits_used=ec_enc_tell(enc, 0) - bits;
+         bits_used=ec_enc_tell(enc, 0);
          if (bits_used > budget)
          {
             qi = -1;
@@ -223,7 +221,6 @@ void quant_energy_finalise(const CELTMode *m, celt_ener *eBands, celt_word16 *ol
 void unquant_coarse_energy(const CELTMode *m, celt_ener *eBands, celt_word16 *oldEBands, int budget, int intra, int *prob, ec_dec *dec, int _C)
 {
    int i, c;
-   unsigned bits;
    celt_word16 prev[2] = {0, 0};
    celt_word16 coef = m->ePredCoef;
    celt_word16 beta;
@@ -236,8 +233,7 @@ void unquant_coarse_energy(const CELTMode *m, celt_ener *eBands, celt_word16 *ol
    }
    /* The .8 is a heuristic */
    beta = MULT16_16_Q15(QCONST16(.8f,15),coef);
-   
-   bits = ec_dec_tell(dec, 0);
+
    /* Decode at a fixed coarse resolution */
    for (i=0;i<m->nbEBands;i++)
    {
@@ -248,7 +244,7 @@ void unquant_coarse_energy(const CELTMode *m, celt_ener *eBands, celt_word16 *ol
          celt_word16 mean = MULT16_16_Q15(Q15ONE-coef,eMeans[i]);
          /* If we didn't have enough bits to encode all the energy, just assume something safe.
             We allow slightly busting the budget here */
-         if (ec_dec_tell(dec, 0) - bits > budget)
+         if (ec_dec_tell(dec, 0) > budget)
             qi = -1;
          else
             qi = ec_laplace_decode_start(dec, prob[2*i], prob[2*i+1]);