* Copyright (c) 2002 Fabrice Bellard
* Partly based on libdjbfft by D. J. Bernstein
*
- * Licensed under the GNU Lesser General Public License.
- * For licencing details see COPYING.LIB.
+ * Licensed under the GNU Lesser General Public License, see file COPYING.LIB.
*/
/**
* \file imdct.c Inverse modified discrete cosine transform.
*/
-#include <inttypes.h>
#include <math.h>
-#include <string.h>
-#include <stdlib.h>
#include <regex.h>
#include "para.h"
struct fft_context fft;
};
-/** cos(2 * pi * x / n) for 0 <= x <= n / 4, followed by its reverse */
+/** \cond cosine_tabs */
+
+/* cos(2 * pi * x / n) for 0 <= x <= n / 4, followed by its reverse */
#define COSINE_TAB(n) static fftsample_t cos_ ## n[n / 2] __a_aligned(16)
COSINE_TAB(16);
cos_16, cos_32, cos_64, cos_128, cos_256, cos_512, cos_1024, cos_2048,
cos_4096, cos_8192, cos_16384, cos_32768, cos_65536,
};
+/** \endcond cosine_tabs */
-static int split_radix_permutation(int i, int n)
+__a_const static int split_radix_permutation(int i, int n)
{
int m;
if (n <= 2)
}
/* z[0...8n - 1], w[1...2n - 1] */
-#define PASS(name)\
-static void name(struct fft_complex *z, const fftsample_t *wre, unsigned int n)\
-{\
- fftsample_t t1, t2, t3, t4, t5, t6;\
- int o1 = 2 * n;\
- int o2 = 4 * n;\
- int o3 = 6 * n;\
- const fftsample_t *wim = wre + o1;\
- n--;\
-\
- TRANSFORM_ZERO(z[0], z[o1], z[o2], z[o3]);\
- TRANSFORM(z[1], z[o1 + 1], z[o2 + 1], z[o3 + 1], wre[1], wim[-1]);\
- do {\
- z += 2;\
- wre += 2;\
- wim -= 2;\
- TRANSFORM(z[0], z[o1], z[o2], z[o3], wre[0], wim[0]);\
- TRANSFORM(z[1], z[o1 + 1], z[o2 + 1], z[o3 + 1], wre[1], wim[-1]);\
- } while (--n);\
+static void pass(struct fft_complex *z, const fftsample_t *wre, unsigned int n)
+{
+ fftsample_t t1, t2, t3, t4, t5, t6;
+ int o1 = 2 * n;
+ int o2 = 4 * n;
+ int o3 = 6 * n;
+ const fftsample_t *wim = wre + o1;
+
+ n--;
+ TRANSFORM_ZERO(z[0], z[o1], z[o2], z[o3]);
+ TRANSFORM(z[1], z[o1 + 1], z[o2 + 1], z[o3 + 1], wre[1], wim[-1]);
+ do {
+ z += 2;
+ wre += 2;
+ wim -= 2;
+ TRANSFORM(z[0], z[o1], z[o2], z[o3], wre[0], wim[0]);
+ TRANSFORM(z[1], z[o1 + 1], z[o2 + 1], z[o3 + 1], wre[1], wim[-1]);
+ } while (--n);
}
-PASS(pass)
#undef BUTTERFLIES
#define BUTTERFLIES BUTTERFLIES_BIG
fft(&s->fft, z);
/* post rotation + reordering */
- output += n4;
for (k = 0; k < n8; k++) {
fftsample_t r0, i0, r1, i1;
CMUL(r0, i1, z[n8 - k - 1].im, z[n8 - k - 1].re,