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-rw-r--r--libavcodec/fft-internal.h14
-rw-r--r--libavcodec/fft.c3
-rw-r--r--libavcodec/fft.h5
-rw-r--r--libavcodec/mdct_fixed.c44
4 files changed, 63 insertions, 3 deletions
diff --git a/libavcodec/fft-internal.h b/libavcodec/fft-internal.h
index 1f240dbd18..d30571b733 100644
--- a/libavcodec/fft-internal.h
+++ b/libavcodec/fft-internal.h
@@ -39,6 +39,8 @@
#include "libavutil/intmath.h"
#include "mathops.h"
+void ff_mdct_calcw_c(FFTContext *s, FFTDouble *output, const FFTSample *input);
+
#define SCALE_FLOAT(a, bits) lrint((a) * (double)(1 << (bits)))
#define FIX15(a) av_clip(SCALE_FLOAT(a, 15), -32767, 32767)
@@ -49,11 +51,17 @@
y = (a + b) >> 1; \
} while (0)
-#define CMUL(dre, dim, are, aim, bre, bim) do { \
- (dre) = (MUL16(are, bre) - MUL16(aim, bim)) >> 15; \
- (dim) = (MUL16(are, bim) + MUL16(aim, bre)) >> 15; \
+#define CMULS(dre, dim, are, aim, bre, bim, sh) do { \
+ (dre) = (MUL16(are, bre) - MUL16(aim, bim)) >> sh; \
+ (dim) = (MUL16(are, bim) + MUL16(aim, bre)) >> sh; \
} while (0)
+#define CMUL(dre, dim, are, aim, bre, bim) \
+ CMULS(dre, dim, are, aim, bre, bim, 15)
+
+#define CMULL(dre, dim, are, aim, bre, bim) \
+ CMULS(dre, dim, are, aim, bre, bim, 0)
+
#endif /* CONFIG_FFT_FLOAT */
#define ff_imdct_calc_c FFT_NAME(ff_imdct_calc_c)
diff --git a/libavcodec/fft.c b/libavcodec/fft.c
index ff5d34baf3..19da4830a9 100644
--- a/libavcodec/fft.c
+++ b/libavcodec/fft.c
@@ -123,6 +123,9 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
if (ARCH_ARM) ff_fft_init_arm(s);
if (HAVE_ALTIVEC) ff_fft_init_altivec(s);
if (HAVE_MMX) ff_fft_init_mmx(s);
+ if (CONFIG_MDCT) s->mdct_calcw = s->mdct_calc;
+#else
+ if (CONFIG_MDCT) s->mdct_calcw = ff_mdct_calcw_c;
#endif
for(j=4; j<=nbits; j++) {
diff --git a/libavcodec/fft.h b/libavcodec/fft.h
index 2f13e5fdb3..0f324cf5a2 100644
--- a/libavcodec/fft.h
+++ b/libavcodec/fft.h
@@ -53,6 +53,10 @@ typedef struct FFTContext FFTContext;
#endif /* CONFIG_FFT_FLOAT */
+typedef struct FFTDComplex {
+ FFTDouble re, im;
+} FFTDComplex;
+
/* FFT computation */
struct FFTContext {
@@ -77,6 +81,7 @@ struct FFTContext {
void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
+ void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input);
int fft_permutation;
#define FF_FFT_PERM_DEFAULT 0
#define FF_FFT_PERM_SWAP_LSBS 1
diff --git a/libavcodec/mdct_fixed.c b/libavcodec/mdct_fixed.c
index 19c8039e04..94527f9e85 100644
--- a/libavcodec/mdct_fixed.c
+++ b/libavcodec/mdct_fixed.c
@@ -18,3 +18,47 @@
#define CONFIG_FFT_FLOAT 0
#include "mdct.c"
+
+/* same as ff_mdct_calcw_c with double-width unscaled output */
+void ff_mdct_calcw_c(FFTContext *s, FFTDouble *out, const FFTSample *input)
+{
+ int i, j, n, n8, n4, n2, n3;
+ FFTDouble re, im;
+ const uint16_t *revtab = s->revtab;
+ const FFTSample *tcos = s->tcos;
+ const FFTSample *tsin = s->tsin;
+ FFTComplex *x = s->tmp_buf;
+ FFTDComplex *o = (FFTDComplex *)out;
+
+ n = 1 << s->mdct_bits;
+ n2 = n >> 1;
+ n4 = n >> 2;
+ n8 = n >> 3;
+ n3 = 3 * n4;
+
+ /* pre rotation */
+ for(i=0;i<n8;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 = 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]);
+ }
+
+ s->fft_calc(s, x);
+
+ /* post rotation */
+ for(i=0;i<n8;i++) {
+ FFTDouble r0, i0, r1, i1;
+ CMULL(i1, r0, x[n8-i-1].re, x[n8-i-1].im, -tsin[n8-i-1], -tcos[n8-i-1]);
+ CMULL(i0, r1, x[n8+i ].re, x[n8+i ].im, -tsin[n8+i ], -tcos[n8+i ]);
+ o[n8-i-1].re = r0;
+ o[n8-i-1].im = i0;
+ o[n8+i ].re = r1;
+ o[n8+i ].im = i1;
+ }
+}