diff options
Diffstat (limited to 'libavcodec/mdct.c')
-rw-r--r-- | libavcodec/mdct.c | 32 |
1 files changed, 14 insertions, 18 deletions
diff --git a/libavcodec/mdct.c b/libavcodec/mdct.c index ca686b4..2232024 100644 --- a/libavcodec/mdct.c +++ b/libavcodec/mdct.c @@ -24,12 +24,19 @@ #include "libavutil/common.h" #include "libavutil/mathematics.h" #include "fft.h" +#include "fft-internal.h" /** * @file * MDCT/IMDCT transforms. */ +#if CONFIG_FFT_FLOAT +# define RSCALE(x) (x) +#else +# define RSCALE(x) ((x) >> 1) +#endif + /** * init MDCT or IMDCT computation. */ @@ -70,8 +77,8 @@ av_cold int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale) scale = sqrt(fabs(scale)); for(i=0;i<n4;i++) { alpha = 2 * M_PI * (i + theta) / n; - s->tcos[i*tstep] = -cos(alpha) * scale; - s->tsin[i*tstep] = -sin(alpha) * scale; + s->tcos[i*tstep] = FIX15(-cos(alpha) * scale); + s->tsin[i*tstep] = FIX15(-sin(alpha) * scale); } return 0; fail: @@ -79,17 +86,6 @@ av_cold int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale) return -1; } -/* complex multiplication: p = a * b */ -#define CMUL(pre, pim, are, aim, bre, bim) \ -{\ - FFTSample _are = (are);\ - FFTSample _aim = (aim);\ - FFTSample _bre = (bre);\ - FFTSample _bim = (bim);\ - (pre) = _are * _bre - _aim * _bim;\ - (pim) = _are * _bim + _aim * _bre;\ -} - /** * Compute the middle half of the inverse MDCT of size N = 2^nbits, * thus excluding the parts that can be derived by symmetry @@ -161,7 +157,7 @@ void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input) void ff_mdct_calc_c(FFTContext *s, FFTSample *out, const FFTSample *input) { int i, j, n, n8, n4, n2, n3; - FFTSample re, im; + FFTDouble re, im; const uint16_t *revtab = s->revtab; const FFTSample *tcos = s->tcos; const FFTSample *tsin = s->tsin; @@ -175,13 +171,13 @@ void ff_mdct_calc_c(FFTContext *s, FFTSample *out, const FFTSample *input) /* pre rotation */ for(i=0;i<n8;i++) { - re = -input[2*i+n3] - input[n3-1-2*i]; - im = -input[n4+2*i] + input[n4-1-2*i]; + re = RSCALE(-input[2*i+n3] - input[n3-1-2*i]); + im = RSCALE(-input[n4+2*i] + input[n4-1-2*i]); j = revtab[i]; CMUL(x[j].re, x[j].im, re, im, -tcos[i], tsin[i]); - re = input[2*i] - input[n2-1-2*i]; - im = -(input[n2+2*i] + input[n-1-2*i]); + re = RSCALE( input[2*i] - input[n2-1-2*i]); + im = RSCALE(-input[n2+2*i] - input[ n-1-2*i]); j = revtab[n8 + i]; CMUL(x[j].re, x[j].im, re, im, -tcos[n8 + i], tsin[n8 + i]); } |