diff options
| author | Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> | 2011-01-13 21:22:02 +0300 |
|---|---|---|
| committer | Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> | 2011-01-13 21:22:02 +0300 |
| commit | a387ebfc13788b3639baa9d175cd879b06b051e7 (patch) | |
| tree | 1732d6d6ce117a0eaa8d05c9720c39512f28b7c1 /libcelt/bands.c | |
| parent | 173774bbf974d208942ea2aa9d7b2e24d0880804 (diff) | |
Proper scaling for the mid folding
Nor scaling the mid only after we've been able to store it
for folding.
Diffstat (limited to 'libcelt/bands.c')
| -rw-r--r-- | libcelt/bands.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/libcelt/bands.c b/libcelt/bands.c index 830925f..b96477b 100644 --- a/libcelt/bands.c +++ b/libcelt/bands.c @@ -249,6 +249,7 @@ static void stereo_merge(celt_norm *X, celt_norm *Y, celt_word16 mid, int N) int j; celt_word32 xp=0, side=0; celt_word32 El, Er; + celt_word16 mid2; #ifdef FIXED_POINT int kl, kr; #endif @@ -260,11 +261,12 @@ static void stereo_merge(celt_norm *X, celt_norm *Y, celt_word16 mid, int N) xp = MAC16_16(xp, X[j], Y[j]); side = MAC16_16(side, Y[j], Y[j]); } + /* Compensating for the mid normalization */ + xp = MULT16_32_Q15(mid, xp); /* mid and side are in Q15, not Q14 like X and Y */ - mid = SHR32(mid, 1); - //side = SHR32(side, 1); - El = MULT16_16(mid, mid) + side - 2*xp; - Er = MULT16_16(mid, mid) + side + 2*xp; + mid2 = SHR32(mid, 1); + El = MULT16_16(mid2, mid2) + side - 2*xp; + Er = MULT16_16(mid2, mid2) + side + 2*xp; if (Er < EPSILON) Er = EPSILON; if (El < EPSILON) @@ -289,7 +291,8 @@ static void stereo_merge(celt_norm *X, celt_norm *Y, celt_word16 mid, int N) for (j=0;j<N;j++) { celt_norm r, l; - l = X[j]; + /* Apply mid scaling (side is already scaled) */ + l = MULT16_16_Q15(mid, X[j]); r = Y[j]; X[j] = EXTRACT16(PSHR32(MULT16_16(lgain, SUB16(l,r)), kl+1)); Y[j] = EXTRACT16(PSHR32(MULT16_16(rgain, ADD16(l,r)), kr+1)); @@ -865,9 +868,11 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_ else next_level = level+1; + /* In stereo mode, we to not apply a scaling to the mid because we need the mormalized + mid for folding later */ quant_band(encode, m, i, X, NULL, N, mbits, spread, B, intensity, tf_change, lowband, resynth, ec, remaining_bits, LM, next_lowband_out1, - NULL, next_level, seed, MULT16_16_P15(gain,mid), lowband_scratch, fill); + NULL, next_level, seed, stereo ? Q15ONE : MULT16_16_P15(gain,mid), lowband_scratch, fill); quant_band(encode, m, i, Y, NULL, N, sbits, spread, B, intensity, tf_change, next_lowband2, resynth, ec, remaining_bits, LM, NULL, NULL, next_level, seed, MULT16_16_P15(gain,side), NULL, fill && !stereo); |