ref: 01fa3389857b2d809d008fc6b55ff191368b6905
parent: 68b8d72e6a252e8df691b8ef7d458e256f7b7268
author: Jean-Marc Valin <[email protected]>
date: Mon Jan 24 12:21:12 EST 2011
Taking LM into account for anti-collapse
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -227,10 +227,11 @@
#endif
N0 = m->eBands[i+1]-m->eBands[i];
- depth = (1+(pulses[i]>>BITRES))/(m->eBands[i+1]-m->eBands[i]<<LM);
+ /* depth in 1/8 bits */
+ depth = (1+pulses[i])/(m->eBands[i+1]-m->eBands[i]<<LM);
#ifdef FIXED_POINT
- thresh = MULT16_32_Q15(QCONST16(0.3f, 15), MIN32(32767,SHR32(celt_exp2(-SHL16(depth, 11)),1) ));
+ thresh = MULT16_32_Q15(QCONST16(0.3f, 15), MIN32(32767,SHR32(celt_exp2(-SHL16(depth, 11-BITRES)),1) ));
{celt_word32 t;
t = N0<<LM;
@@ -239,7 +240,7 @@
sqrt_1 = celt_rsqrt_norm(t);
}
#else
- thresh = .3f*celt_exp2(-depth);
+ thresh = .3f*celt_exp2(-.125f*depth);
sqrt_1 = celt_rsqrt(N0<<LM);
#endif
@@ -256,10 +257,16 @@
r = 2*MIN16(16383,SHR32(celt_exp2(-SHL16(Ediff, 11-DB_SHIFT)),1));
else
r = 0;
+ if (LM==3)
+ r = MULT16_16_Q15(QCONST16(.70710678f,15), r);
r = SHR16(MIN16(thresh, r),1);
r = SHR32(MULT16_16_Q15(sqrt_1, r),shift);
#else
+ /* r needs to be multiplied by 2 or 2*sqrt(2) depending on LM because
+ short blocks don't have the same energy as long */
r = 2.f*celt_exp2(-Ediff);
+ if (LM==3)
+ r *= .70710678f;
r = MIN16(thresh, r);
r = r*sqrt_1;
#endif