[FFmpeg-devel] [PATCH 2/3] Create a public API for FFT family of functions
Mans Rullgard
mans
Sat Mar 6 04:38:06 CET 2010
---
libavcodec/Makefile | 4 +-
libavcodec/avfft.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++
libavcodec/avfft.h | 89 ++++++++++++++++++++++++++++++++
libavcodec/fft.h | 28 +++--------
4 files changed, 240 insertions(+), 23 deletions(-)
create mode 100644 libavcodec/avfft.c
create mode 100644 libavcodec/avfft.h
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index aed14ab..5eeb143 100644
--- a/libavcodec/Makefile
+++ b/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
diff --git a/libavcodec/avfft.c b/libavcodec/avfft.c
new file mode 100644
index 0000000..c49c9de
--- /dev/null
+++ b/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 */
diff --git a/libavcodec/avfft.h b/libavcodec/avfft.h
new file mode 100644
index 0000000..f3e1d6e
--- /dev/null
+++ b/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 {
+ RDFT,
+ IRDFT,
+ RIDFT,
+ IRIDFT,
+};
+
+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 */
diff --git a/libavcodec/fft.h b/libavcodec/fft.h
index 67e0fd8..f7fddf5 100644
--- a/libavcodec/fft.h
+++ b/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 {
- RDFT,
- IRDFT,
- RIDFT,
- IRIDFT,
-};
-
-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.
--
1.7.0
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