signal/src/fft_auto_scale.h

/* Copyright 2023 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/

#ifndef SIGNAL_SRC_FFT_AUTO_SCALE_H_
#define SIGNAL_SRC_FFT_AUTO_SCALE_H_

#include <stddef.h>
#include <stdint.h>

// TODO(b/286250473): remove namespace once de-duped libraries
namespace tflite {
namespace tflm_signal {

// Auto scales `input` and write the result to `output`
// Elements in `input` are left shifted to maximize the amplitude without
// clipping,
// * both `input` and `output` must be of size `size`
int FftAutoScale(const int16_t* input, int size, int16_t* output);

}  // namespace tflm_signal
}  // namespace tflite

#endif  // SIGNAL_SRC_FFT_AUTO_SCALE_H_