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| author | Dave Hooper <dave@beermex.com> | 2010-02-18 00:14:13 +0000 |
|---|---|---|
| committer | Dave Hooper <dave@beermex.com> | 2010-02-18 00:14:13 +0000 |
| commit | 3a9852be1c2fa1fc6da47fedef978476c82ec951 (patch) | |
| tree | f0ce1a0e40b60b611900d1f1482cabc48eff57d0 /apps/codecs/lib/mdct.c | |
| parent | 8b4ee2cfddb0828e7985d5af1ff883280c4d2965 (diff) | |
| download | rockbox-3a9852be1c2fa1fc6da47fedef978476c82ec951.zip rockbox-3a9852be1c2fa1fc6da47fedef978476c82ec951.tar.gz rockbox-3a9852be1c2fa1fc6da47fedef978476c82ec951.tar.bz2 rockbox-3a9852be1c2fa1fc6da47fedef978476c82ec951.tar.xz | |
I don't yet fully understand why this is required, but without it the output is signed-inverted (compared to e.g. the output of oggdec). ac3 confirmed to be ok so the problem must be in the imdct not the ifft. but the algo seems correct (in that seems same as original ffmpeg version)..
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24739 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/codecs/lib/mdct.c')
| -rw-r--r-- | apps/codecs/lib/mdct.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/apps/codecs/lib/mdct.c b/apps/codecs/lib/mdct.c index 03baa4d..3c9fe41 100644 --- a/apps/codecs/lib/mdct.c +++ b/apps/codecs/lib/mdct.c @@ -139,10 +139,10 @@ void ff_imdct_half(unsigned int nbits, fixed32 *output, const fixed32 *input) fixed32 r0,i0,r1,i1; XNPROD31_R(z1[1], z1[0], T[0], T[1], r0, i1 ); T+=newstep; XNPROD31_R(z2[1], z2[0], T[1], T[0], r1, i0 ); T+=newstep; - z1[0] = r0; - z1[1] = i0; - z2[0] = r1; - z2[1] = i1; + z1[0] = -r0; + z1[1] = -i0; + z2[0] = -r1; + z2[1] = -i1; z1+=2; z2-=2; } @@ -171,10 +171,10 @@ void ff_imdct_half(unsigned int nbits, fixed32 *output, const fixed32 *input) v0 += (t0 = (T[0]>>1)); v1 += (t1 = (T[1]>>1)); XNPROD31_R(z2[1], z2[0], v1, v0, r1, i0 ); - z1[0] = r0; - z1[1] = i0; - z2[0] = r1; - z2[1] = i1; + z1[0] = -r0; + z1[1] = -i0; + z2[0] = -r1; + z2[1] = -i1; z1+=2; z2-=2; V+=2; @@ -205,10 +205,10 @@ void ff_imdct_half(unsigned int nbits, fixed32 *output, const fixed32 *input) t0 = v0-q0; t1 = v1-q1; XNPROD31_R(z2[1], z2[0], t1, t0, r1, i0 ); - z1[0] = r0; - z1[1] = i0; - z2[0] = r1; - z2[1] = i1; + z1[0] = -r0; + z1[1] = -i0; + z2[0] = -r1; + z2[1] = -i1; z1+=2; z2-=2; T+=2; @@ -220,10 +220,10 @@ void ff_imdct_half(unsigned int nbits, fixed32 *output, const fixed32 *input) v0 = t0-q0; v1 = t1-q1; XNPROD31_R(z2[1], z2[0], v1, v0, r1, i0 ); - z1[0] = r0; - z1[1] = i0; - z2[0] = r1; - z2[1] = i1; + z1[0] = -r0; + z1[1] = -i0; + z2[0] = -r1; + z2[1] = -i1; z1+=2; z2-=2; V+=2; |