ref: 210ccafaff81c6759301613ed493a5e4d5e68444
parent: e45ccb1693c6e230043eda49cb271b824e6fcf11
author: Jean-Marc Valin <[email protected]>
date: Thu Mar 11 17:20:19 EST 2010
Improves fixed-point precision for quant_coarse_energy
--- a/libcelt/quant_bands.c
+++ b/libcelt/quant_bands.c
@@ -103,7 +103,7 @@
prob += 2*m->nbEBands;
}
/* The .8 is a heuristic */
- beta = MULT16_16_Q15(QCONST16(.8f,15),coef);
+ beta = MULT16_16_P15(QCONST16(.8f,15),coef);
/* Encode at a fixed coarse resolution */
for (i=start;i<m->nbEBands;i++)
@@ -114,10 +114,10 @@
celt_word16 q; /* dB */
celt_word16 x; /* dB */
celt_word16 f; /* Q8 */
- celt_word16 mean = (i < E_MEANS_SIZE) ? MULT16_16_Q15(Q15ONE-coef,eMeans[i]) : 0;
+ celt_word16 mean = (i < E_MEANS_SIZE) ? MULT16_16_P15(Q15ONE-coef,eMeans[i]) : 0;
x = eBands[i+c*m->nbEBands];
#ifdef FIXED_POINT
- f = x-mean -MULT16_16_Q15(coef,oldEBands[i+c*m->nbEBands])-prev[c];
+ f = x-mean -MULT16_16_P15(coef,oldEBands[i+c*m->nbEBands])-prev[c];
/* Rounding to nearest integer here is really important! */
qi = (f+128)>>8;
#else
@@ -138,8 +138,8 @@
}
q = SHL16(qi,DB_SHIFT);
- oldEBands[i+c*m->nbEBands] = MULT16_16_Q15(coef,oldEBands[i+c*m->nbEBands])+(mean+prev[c]+q);
- prev[c] = mean+prev[c]+MULT16_16_Q15(Q15ONE-beta,q);
+ oldEBands[i+c*m->nbEBands] = MULT16_16_P15(coef,oldEBands[i+c*m->nbEBands])+(mean+prev[c]+q);
+ prev[c] = mean+prev[c]+MULT16_16_P15(Q15ONE-beta,q);
} while (++c < C);
}
return bits_used;
@@ -234,7 +234,7 @@
prob += 2*m->nbEBands;
}
/* The .8 is a heuristic */
- beta = MULT16_16_Q15(QCONST16(.8f,15),coef);
+ beta = MULT16_16_P15(QCONST16(.8f,15),coef);
/* Decode at a fixed coarse resolution */
for (i=start;i<m->nbEBands;i++)
@@ -243,7 +243,7 @@
do {int qi;
celt_word16 q;
- celt_word16 mean = (i < E_MEANS_SIZE) ? MULT16_16_Q15(Q15ONE-coef,eMeans[i]) : 0;
+ celt_word16 mean = (i < E_MEANS_SIZE) ? MULT16_16_P15(Q15ONE-coef,eMeans[i]) : 0;
/* 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) > budget)
@@ -252,7 +252,7 @@
qi = ec_laplace_decode_start(dec, prob[2*i], prob[2*i+1]);
q = SHL16(qi,DB_SHIFT);
- oldEBands[i+c*m->nbEBands] = MULT16_16_Q15(coef,oldEBands[i+c*m->nbEBands])+(mean+prev[c]+q);
+ oldEBands[i+c*m->nbEBands] = MULT16_16_P15(coef,oldEBands[i+c*m->nbEBands])+(mean+prev[c]+q);
prev[c] = mean+prev[c]+MULT16_16_Q15(Q15ONE-beta,q);
} while (++c < C);
}