eden-emu/opus
19
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix stereo for N=2

Browse source
This commit is contained in:
Jean-Marc Valin 2010-09-14 10:30:32 -04:00
parent 79b4533846
commit 5f3ad5f985
1 changed files with 24 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

33
libcelt/bands.c
View file

@ -703,6 +703,14 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
delta = (N-1)*(log2_frac(iside,BITRES+2)-log2_frac(imid,BITRES+2))>>2; 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 /* 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 advantage of the fact that mid and side are orthogonal to encode
the side with just one bit. */ the side with just one bit. */
@ -737,20 +745,26 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
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); 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[0] = -sign*x2[1];
y2[1] = sign*x2[0]; 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 { } else {
/* "Normal" split code */ /* "Normal" split code */
celt_norm *next_lowband2=NULL; celt_norm *next_lowband2=NULL;
celt_norm *next_lowband_out1=NULL; celt_norm *next_lowband_out1=NULL;
int next_level=0; 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 */ /* Give more bits to low-energy MDCTs than they would otherwise deserve */
if (B>1 && !stereo) if (B>1 && !stereo)
delta >>= 1; delta >>= 1;
@ -808,7 +822,8 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
{ {
if (stereo) if (stereo)
{ {
stereo_merge(X, Y, mid, side, N); if (N!=2)
stereo_merge(X, Y, mid, side, N);
} else if (level == 0) } else if (level == 0)
{ {
int k; int k;