chromium/third_party/webrtc/modules/audio_processing/agc2/gain_map_internal.h

/*
 *  Copyright (c) 2013 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.
 */

#ifndef MODULES_AUDIO_PROCESSING_AGC2_GAIN_MAP_INTERNAL_H_
#define MODULES_AUDIO_PROCESSING_AGC2_GAIN_MAP_INTERNAL_H_

namespace webrtc {

static constexpr int kGainMapSize = …;
// Maps input volumes, which are values in the [0, 255] range, to gains in dB.
// The values below are generated with numpy as follows:
// SI = 2                        # Initial slope.
// SF = 0.25                     # Final slope.
// D = 8/256                     # Quantization factor.
// x = np.linspace(0, 255, 256)  # Input volumes.
// y = (SF * x + (SI - SF) * (1 - np.exp(-D*x)) / D - 56).round()
static const int kGainMap[kGainMapSize] = …;

}  // namespace webrtc

#endif  // MODULES_AUDIO_PROCESSING_AGC2_GAIN_MAP_INTERNAL_H_