Merge from branches/mdctexp - faster ifft+imdct in codec lib

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24712 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 64 insertions, 0 deletions

diff --git a/apps/codecs/lib/fft.h b/apps/codecs/lib/fft.h
new file mode 100644
index 0000000000..302a3b3996
--- /dev/null
+++ b/apps/codecs/lib/fft.h
@@ -0,0 +1,64 @@
+/*
+ * WMA compatible decoder
+ * Copyright (c) 2002 The FFmpeg Project.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#ifndef CODECLIB_FFT_H_INCLUDED
+#define CODECLIB_FFT_H_INCLUDED
+ 
+#include <inttypes.h>
+typedef int32_t fixed32; 
+typedef int64_t fixed64;
+
+#define FFT_FIXED
+
+#ifdef FFT_FIXED
+typedef fixed32 FFTSample;
+#else /* FFT_FIXED */
+typedef float   FFTSample;
+#endif /* FFT_FIXED */
+
+typedef struct FFTComplex {
+    FFTSample re, im;
+} FFTComplex;
+
+typedef struct FFTContext {
+    int nbits;
+    int inverse;
+    uint16_t *revtab;
+    int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
+    int mdct_bits; /* n = 2^nbits */
+    /* pre/post rotation tables */
+    FFTSample *tcos;
+    FFTSample *tsin;
+    void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
+    void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
+    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);
+    int split_radix;
+    int permutation;
+#define FF_MDCT_PERM_NONE       0
+#define FF_MDCT_PERM_INTERLEAVE 1
+} FFTContext;
+
+// internal api  (fft<->mdct)
+//int fft_calc_unscaled(FFTContext *s, FFTComplex *z);
+//void ff_fft_permute_c(FFTContext *s, FFTComplex *z); // internal only?
+void ff_fft_calc_c(int nbits, FFTComplex *z);
+
+#endif // CODECLIB_FFT_H_INCLUDED
+