diff options
| author | Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> | 2010-06-17 08:35:26 +0400 |
|---|---|---|
| committer | Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> | 2010-06-17 08:35:26 +0400 |
| commit | 3a9699ee9496765c9ffd450e3685044d548c58ab (patch) | |
| tree | ca4eaf759579b7f38fe9367dc5b512767f8839f7 /libcelt/plc.c | |
| parent | bd82ca80f7f74595d6e5cd73cdf9e5151725e622 (diff) | |
minor tweaks to frac_div32()
Diffstat (limited to 'libcelt/plc.c')
| -rw-r--r-- | libcelt/plc.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/libcelt/plc.c b/libcelt/plc.c index 763a5b8..334da8f 100644 --- a/libcelt/plc.c +++ b/libcelt/plc.c @@ -6,13 +6,14 @@ #ifdef FIXED_POINT static celt_word32 frac_div32(celt_word32 a, celt_word32 b) { - celt_word32 rcp, result, rem; - while (b<(1<<30)) - { - a = SHL32(a,1); - b = SHL32(b,1); - } - rcp = PSHR32(celt_rcp(ROUND16(b,16)),2); + celt_word16 rcp; + celt_word32 result, rem; + int shift = 30-celt_ilog2(b); + a = SHL32(a,shift); + b = SHL32(b,shift); + + /* 16-bit reciprocal */ + rcp = ROUND16(celt_rcp(ROUND16(b,16)),2); result = SHL32(MULT16_32_Q15(rcp, a),1); rem = a-MULT32_32_Q31(result, b); result += SHL32(MULT16_32_Q15(rcp, rem),1); @@ -48,7 +49,6 @@ int p for (j = 0; j < i; j++) rr += MULT32_32_Q31(lpc[j],ac[i - j]); rr += SHR32(ac[i + 1],3); - //r = -RC_SCALING*1.*SHL32(rr,3)/(error+1e-15); r = -frac_div32(SHL32(rr,3), error); /* Update LPC coefficients and total error */ lpc[i] = SHR32(r,3); |