blob: 8f32418d6c8dad394dfa0d8a58de524559e8da0c [file] [log] [blame]
/*
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "common_audio/signal_processing/include/real_fft.h"
#include <stdlib.h>
#include "common_audio/signal_processing/include/signal_processing_library.h"
struct RealFFT {
int order;
};
struct RealFFT* WebRtcSpl_CreateRealFFT(int order) {
struct RealFFT* self = NULL;
// This constraint comes from ComplexFFT().
if (order > 10 || order < 0) {
return NULL;
}
self = malloc(sizeof(struct RealFFT));
self->order = order;
return self;
}
void WebRtcSpl_FreeRealFFT(struct RealFFT* self) {
free(self);
}
// WebRtcSpl_ComplexFFT and WebRtcSpl_ComplexIFFT use in-place algorithm,
// so copy data from data_in to data_out in the next two functions.
int WebRtcSpl_RealForwardFFTC(struct RealFFT* self,
const int16_t* data_in,
int16_t* data_out) {
memcpy(data_out, data_in, sizeof(int16_t) * (1 << (self->order + 1)));
WebRtcSpl_ComplexBitReverse(data_out, self->order);
return WebRtcSpl_ComplexFFT(data_out, self->order, 1);
}
int WebRtcSpl_RealInverseFFTC(struct RealFFT* self,
const int16_t* data_in,
int16_t* data_out) {
memcpy(data_out, data_in, sizeof(int16_t) * (1 << (self->order + 1)));
WebRtcSpl_ComplexBitReverse(data_out, self->order);
return WebRtcSpl_ComplexIFFT(data_out, self->order, 1);
}
#if defined(WEBRTC_DETECT_ARM_NEON) || defined(WEBRTC_ARCH_ARM_NEON)
// TODO(kma): Replace the following function bodies into optimized functions
// for ARM Neon.
int WebRtcSpl_RealForwardFFTNeon(struct RealFFT* self,
const int16_t* data_in,
int16_t* data_out) {
return WebRtcSpl_RealForwardFFTC(self, data_in, data_out);
}
int WebRtcSpl_RealInverseFFTNeon(struct RealFFT* self,
const int16_t* data_in,
int16_t* data_out) {
return WebRtcSpl_RealInverseFFTC(self, data_in, data_out);
}
#endif