From f02dfce6e6c34b3d8a7b8a0e784b506178e331fa Mon Sep 17 00:00:00 2001
From: "erdgeist@erdgeist.org" <erdgeist@bauklotz.fritz.box>
Date: Thu, 4 Jul 2019 23:26:09 +0200
Subject: stripdown of version 0.9

---
 codec2_fft.h | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 codec2_fft.h

(limited to 'codec2_fft.h')

diff --git a/codec2_fft.h b/codec2_fft.h
new file mode 100644
index 0000000..c741202
--- /dev/null
+++ b/codec2_fft.h
@@ -0,0 +1,104 @@
+/*
+ * codec2_fft.h
+ *
+ *  Created on: 17.09.2016
+ *      Author: danilo
+ */
+
+#ifndef DRIVERS_FREEDV_CODEC2_FFT_H_
+#define DRIVERS_FREEDV_CODEC2_FFT_H_
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
+#ifdef FDV_ARM_MATH
+  #include "fdv_arm_math.h"
+#else
+    #define USE_KISS_FFT
+#endif
+
+#include "defines.h"
+#include "comp.h"
+
+
+typedef COMP    codec2_fft_cpx;
+#include "kiss_fftr.h"
+
+#ifdef USE_KISS_FFT
+    #include "kiss_fft.h"
+    typedef kiss_fftr_cfg codec2_fftr_cfg;
+    typedef kiss_fft_cfg codec2_fft_cfg;
+    typedef kiss_fft_scalar codec2_fft_scalar;
+#else
+  typedef float32_t codec2_fft_scalar;
+  typedef struct {
+      arm_rfft_fast_instance_f32* instance;
+      int inverse;
+  } codec2_fftr_struct;
+
+  typedef codec2_fftr_struct* codec2_fftr_cfg;
+
+  typedef struct {
+        const arm_cfft_instance_f32* instance;
+        int inverse;
+    } codec2_fft_struct;
+  typedef codec2_fft_struct* codec2_fft_cfg;
+#endif
+
+
+
+static inline void codec2_fftr(codec2_fftr_cfg cfg, codec2_fft_scalar* in, codec2_fft_cpx* out)
+{
+
+#ifdef USE_KISS_FFT
+      kiss_fftr(cfg, in, (kiss_fft_cpx*)out);
+#else
+    arm_rfft_fast_f32(cfg->instance,in,(float*)out,cfg->inverse);
+    out->imag = 0; // remove out[FFT_ENC/2]->real stored in out[0].imag
+#endif
+}
+
+static inline void codec2_fftri(codec2_fftr_cfg cfg, codec2_fft_cpx* in, codec2_fft_scalar* out)
+{
+#ifdef USE_KISS_FFT
+      kiss_fftri(cfg, (kiss_fft_cpx*)in, out);
+#else
+    arm_rfft_fast_f32(cfg->instance,(float*)in,out,cfg->inverse);
+    // arm_scale_f32(out,cfg->instance->fftLenRFFT,out,cfg->instance->fftLenRFFT);
+#endif
+
+}
+
+codec2_fft_cfg codec2_fft_alloc(int nfft, int inverse_fft, void* mem, size_t* lenmem);
+codec2_fftr_cfg codec2_fftr_alloc(int nfft, int inverse_fft, void* mem, size_t* lenmem);
+void codec2_fft_free(codec2_fft_cfg cfg);
+void codec2_fftr_free(codec2_fftr_cfg cfg);
+
+
+static inline void codec2_fft(codec2_fft_cfg cfg, codec2_fft_cpx* in, codec2_fft_cpx* out)
+{
+
+#ifdef USE_KISS_FFT
+      kiss_fft(cfg, (kiss_fft_cpx*)in, (kiss_fft_cpx*)out);
+#else
+    memcpy(out,in,cfg->instance->fftLen*2*sizeof(float));
+    arm_cfft_f32(cfg->instance,(float*)out,cfg->inverse, 1);
+    // TODO: this is not nice, but for now required to keep changes minimal
+    // however, since main goal is to reduce the memory usage
+    // we should convert to an in place interface
+    // on PC like platforms the overhead of using the "inplace" kiss_fft calls
+    // is neglectable compared to the gain in memory usage on STM32 platforms
+    if (cfg->inverse)
+    {
+        arm_scale_f32((float*)out,cfg->instance->fftLen,(float*)out,cfg->instance->fftLen*2);
+    }
+#endif
+}
+
+void codec2_fft_inplace(codec2_fft_cfg cfg, codec2_fft_cpx* inout);
+
+
+#endif
-- 
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