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Taking LM into account for anti-collapse

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This commit is contained in:
Jean-Marc Valin 2011-01-24 17:21:12 -05:00
parent 68b8d72e6a
commit 01fa338985
1 changed files with 10 additions and 3 deletions
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13
libcelt/bands.c
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@ -227,10 +227,11 @@ void anti_collapse(const CELTMode *m, celt_norm *_X, unsigned char *collapse_mas
#endif #endif
N0 = m->eBands[i+1]-m->eBands[i]; 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 #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; celt_word32 t;
t = N0<<LM; t = N0<<LM;
@ -239,7 +240,7 @@ void anti_collapse(const CELTMode *m, celt_norm *_X, unsigned char *collapse_mas
sqrt_1 = celt_rsqrt_norm(t); sqrt_1 = celt_rsqrt_norm(t);
} }
#else #else
thresh = .3f*celt_exp2(-depth); thresh = .3f*celt_exp2(-.125f*depth);
sqrt_1 = celt_rsqrt(N0<<LM); sqrt_1 = celt_rsqrt(N0<<LM);
#endif #endif
@ -256,10 +257,16 @@ void anti_collapse(const CELTMode *m, celt_norm *_X, unsigned char *collapse_mas
r = 2*MIN16(16383,SHR32(celt_exp2(-SHL16(Ediff, 11-DB_SHIFT)),1)); r = 2*MIN16(16383,SHR32(celt_exp2(-SHL16(Ediff, 11-DB_SHIFT)),1));
else else
r = 0; r = 0;
if (LM==3)
r = MULT16_16_Q15(QCONST16(.70710678f,15), r);
r = SHR16(MIN16(thresh, r),1); r = SHR16(MIN16(thresh, r),1);
r = SHR32(MULT16_16_Q15(sqrt_1, r),shift); r = SHR32(MULT16_16_Q15(sqrt_1, r),shift);
#else #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); r = 2.f*celt_exp2(-Ediff);
if (LM==3)
r *= .70710678f;
r = MIN16(thresh, r); r = MIN16(thresh, r);
r = r*sqrt_1; r = r*sqrt_1;
#endif #endif