ref: 5f3ad5f98560d82a828767ede8ed2edb30ccb94e
parent: 79b4533846a26e8ac4095233189a2edcfe6b95c2
author: Jean-Marc Valin <[email protected]>
date: Tue Sep 14 06:30:32 EDT 2010
Fix stereo for N=2
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -703,6 +703,14 @@
delta = (N-1)*(log2_frac(iside,BITRES+2)-log2_frac(imid,BITRES+2))>>2;
}
+#ifdef FIXED_POINT
+ mid = imid;
+ side = iside;
+#else
+ mid = (1.f/32768)*imid;
+ side = (1.f/32768)*iside;
+#endif
+
/* This is a special case for N=2 that only works for stereo and takes
advantage of the fact that mid and side are orthogonal to encode
the side with just one bit. */
@@ -737,6 +745,20 @@
quant_band(encode, m, i, x2, NULL, N, mbits, spread, B, tf_change, lowband, resynth, ec, remaining_bits, LM, lowband_out, NULL, level+1, seed, gain, lowband_scratch);
y2[0] = -sign*x2[1];
y2[1] = sign*x2[0];
+ if (resynth)
+ {+ celt_norm tmp;
+ X[0] = MULT16_16_Q15(mid, X[0]);
+ X[1] = MULT16_16_Q15(mid, X[1]);
+ Y[0] = MULT16_16_Q15(side, Y[0]);
+ Y[1] = MULT16_16_Q15(side, Y[1]);
+ tmp = X[0];
+ X[0] = SUB16(tmp,Y[0]);
+ Y[0] = ADD16(tmp,Y[0]);
+ tmp = X[1];
+ X[1] = SUB16(tmp,Y[1]);
+ Y[1] = ADD16(tmp,Y[1]);
+ }
} else {/* "Normal" split code */
celt_norm *next_lowband2=NULL;
@@ -743,14 +765,6 @@
celt_norm *next_lowband_out1=NULL;
int next_level=0;
-#ifdef FIXED_POINT
- mid = imid;
- side = iside;
-#else
- mid = (1.f/32768)*imid;
- side = (1.f/32768)*iside;
-#endif
-
/* Give more bits to low-energy MDCTs than they would otherwise deserve */
if (B>1 && !stereo)
delta >>= 1;
@@ -808,7 +822,8 @@
{if (stereo)
{- stereo_merge(X, Y, mid, side, N);
+ if (N!=2)
+ stereo_merge(X, Y, mid, side, N);
} else if (level == 0)
{int k;