Create a public API for FFT family of functions

Originally committed as revision 22291 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/APIchanges

@@ -12,6 +12,9 @@ libavutil:   2009-03-08
 
 API changes, most recent first:
 
+2010-03-07 - r22291 - lavc 52.56.0 - avfft.h
+  Add public FFT interface.
+
 2010-03-06 - r22251 - lavu 50.11.0 - av_stristr()
   Add av_stristr().
 

libavcodec/Makefile

@@ -3,7 +3,7 @@ include $(SUBDIR)../config.mak
 NAME = avcodec
 FFLIBS = avutil
 
-HEADERS = avcodec.h dxva2.h opt.h vaapi.h vdpau.h xvmc.h
+HEADERS = avcodec.h avfft.h dxva2.h opt.h vaapi.h vdpau.h xvmc.h
 
 OBJS = allcodecs.o                                                      \
        audioconvert.o                                                   \
@@ -30,7 +30,7 @@ OBJS-$(CONFIG_ENCODERS)                += faandct.o jfdctfst.o jfdctint.o
 OBJS-$(CONFIG_DCT)                     += dct.o
 OBJS-$(CONFIG_DXVA2)                   += dxva2.o
 FFT-OBJS-$(CONFIG_HARDCODED_TABLES)    += cos_tables.o
-OBJS-$(CONFIG_FFT)                     += fft.o $(FFT-OBJS-yes)
+OBJS-$(CONFIG_FFT)                     += avfft.o fft.o $(FFT-OBJS-yes)
 OBJS-$(CONFIG_GOLOMB)                  += golomb.o
 OBJS-$(CONFIG_LPC)                     += lpc.o
 OBJS-$(CONFIG_LSP)                     += lsp.o

libavcodec/avcodec.h

@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 52
-#define LIBAVCODEC_VERSION_MINOR 55
+#define LIBAVCODEC_VERSION_MINOR 56
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

libavcodec/avfft.c

@@ -0,0 +1,142 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/mem.h"
+#include "avfft.h"
+#include "fft.h"
+
+/* FFT */
+
+FFTContext *av_fft_init(int nbits, int inverse)
+{
+    FFTContext *s = av_malloc(sizeof(*s));
+
+    if (s)
+        ff_fft_init(s, nbits, inverse);
+
+    return s;
+}
+
+void av_fft_permute(FFTContext *s, FFTComplex *z)
+{
+    s->fft_permute(s, z);
+}
+
+void av_fft_calc(FFTContext *s, FFTComplex *z)
+{
+    s->fft_calc(s, z);
+}
+
+void av_fft_end(FFTContext *s)
+{
+    if (s) {
+        ff_fft_end(s);
+        av_free(s);
+    }
+}
+
+#if CONFIG_MDCT
+
+FFTContext *av_mdct_init(int nbits, int inverse, double scale)
+{
+    FFTContext *s = av_malloc(sizeof(*s));
+
+    if (s)
+        ff_mdct_init(s, nbits, inverse, scale);
+
+    return s;
+}
+
+void av_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input)
+{
+    s->imdct_calc(s, output, input);
+}
+
+void av_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input)
+{
+    s->imdct_half(s, output, input);
+}
+
+void av_mdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input)
+{
+    s->mdct_calc(s, output, input);
+}
+
+void av_mdct_end(FFTContext *s)
+{
+    if (s) {
+        ff_mdct_end(s);
+        av_free(s);
+    }
+}
+
+#endif /* CONFIG_MDCT */
+
+#if CONFIG_RDFT
+
+RDFTContext *av_rdft_init(int nbits, enum RDFTransformType trans)
+{
+    RDFTContext *s = av_malloc(sizeof(*s));
+
+    if (s)
+        ff_rdft_init(s, nbits, trans);
+
+    return s;
+}
+
+void av_rdft_calc(RDFTContext *s, FFTSample *data)
+{
+    ff_rdft_calc(s, data);
+}
+
+void av_rdft_end(RDFTContext *s)
+{
+    if (s) {
+        ff_rdft_end(s);
+        av_free(s);
+    }
+}
+
+#endif /* CONFIG_RDFT */
+
+#if CONFIG_DCT
+
+DCTContext *av_dct_init(int nbits, int inverse)
+{
+    DCTContext *s = av_malloc(sizeof(*s));
+
+    if (s)
+        ff_dct_init(s, nbits, inverse);
+
+    return s;
+}
+
+void av_dct_calc(DCTContext *s, FFTSample *data)
+{
+    ff_dct_calc(s, data);
+}
+
+void av_dct_end(DCTContext *s)
+{
+    if (s) {
+        ff_dct_end(s);
+        av_free(s);
+    }
+}
+
+#endif /* CONFIG_DCT */

libavcodec/avfft.h

@@ -0,0 +1,89 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_AVFFT_H
+#define AVCODEC_AVFFT_H
+
+typedef float FFTSample;
+
+typedef struct FFTComplex {
+    FFTSample re, im;
+} FFTComplex;
+
+typedef struct FFTContext FFTContext;
+
+/**
+ * Set up a complex FFT.
+ * @param nbits           log2 of the length of the input array
+ * @param inverse         if 0 perform the forward transform, if 1 perform the inverse
+ */
+FFTContext *av_fft_init(int nbits, int inverse);
+
+/**
+ * Do the permutation needed BEFORE calling ff_fft_calc().
+ */
+void av_fft_permute(FFTContext *s, FFTComplex *z);
+
+/**
+ * Do a complex FFT with the parameters defined in av_fft_init(). The
+ * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
+ */
+void av_fft_calc(FFTContext *s, FFTComplex *z);
+
+void av_fft_end(FFTContext *s);
+
+FFTContext *av_mdct_init(int nbits, int inverse, double scale);
+void av_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
+void av_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input);
+void av_mdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
+void av_mdct_end(FFTContext *s);
+
+/* Real Discrete Fourier Transform */
+
+enum RDFTransformType {
+    DFT_R2C,
+    IDFT_C2R,
+    IDFT_R2C,
+    DFT_C2R,
+};
+
+typedef struct RDFTContext RDFTContext;
+
+/**
+ * Set up a real FFT.
+ * @param nbits           log2 of the length of the input array
+ * @param trans           the type of transform
+ */
+RDFTContext *av_rdft_init(int nbits, enum RDFTransformType trans);
+void av_rdft_calc(RDFTContext *s, FFTSample *data);
+void av_rdft_end(RDFTContext *s);
+
+/* Discrete Cosine Transform */
+
+typedef struct DCTContext DCTContext;
+
+/**
+ * Set up (Inverse)DCT.
+ * @param nbits           log2 of the length of the input array
+ * @param inverse         >0 forward transform, <0 inverse transform
+ */
+DCTContext *av_dct_init(int nbits, int inverse);
+void av_dct_calc(DCTContext *s, FFTSample *data);
+void av_dct_end (DCTContext *s);
+
+#endif /* AVCODEC_AVFFT_H */

libavcodec/fft.h

@@ -25,18 +25,11 @@
 #include <stdint.h>
 #include "config.h"
 #include "libavutil/mem.h"
+#include "avfft.h"
 
 /* FFT computation */
 
-/* NOTE: soon integer code will be added, so you must use the
-   FFTSample type */
-typedef float FFTSample;
-
-typedef struct FFTComplex {
-    FFTSample re, im;
-} FFTComplex;
-
-typedef struct FFTContext {
+struct FFTContext {
     int nbits;
     int inverse;
     uint16_t *revtab;
@@ -57,7 +50,7 @@ typedef struct FFTContext {
     int permutation;
 #define FF_MDCT_PERM_NONE       0
 #define FF_MDCT_PERM_INTERLEAVE 1
-} FFTContext;
+};
 
 #if CONFIG_HARDCODED_TABLES
 #define COSTABLE_CONST const
@@ -194,14 +187,7 @@ void ff_mdct_end(FFTContext *s);
 
 /* Real Discrete Fourier Transform */
 
-enum RDFTransformType {
-    DFT_R2C,
-    IDFT_C2R,
-    IDFT_R2C,
-    DFT_C2R,
-};
-
-typedef struct {
+struct RDFTContext {
     int nbits;
     int inverse;
     int sign_convention;
@@ -210,7 +196,7 @@ typedef struct {
     const FFTSample *tcos;
     SINTABLE_CONST FFTSample *tsin;
     FFTContext fft;
-} RDFTContext;
+};
 
 /**
  * Sets up a real FFT.
@@ -223,14 +209,14 @@ void ff_rdft_end(RDFTContext *s);
 
 /* Discrete Cosine Transform */
 
-typedef struct {
+struct DCTContext {
     int nbits;
     int inverse;
     FFTSample *data;
     RDFTContext rdft;
     const float *costab;
     FFTSample *csc2;
-} DCTContext;
+};
 
 /**
  * Sets up (Inverse)DCT.