@@ -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)

@@ -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++) {

@@ -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

@@ -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;

+    }

+}