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/*
* Copyright (c) 2018 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_COMPUTE_INTERPOLATED_GAIN_CURVE_H_
#define MODULES_AUDIO_PROCESSING_AGC2_COMPUTE_INTERPOLATED_GAIN_CURVE_H_
#include <array>
#include "modules/audio_processing/agc2/agc2_common.h"
namespace webrtc {
namespace test {
// Parameters for interpolated gain curve using under-approximation to
// avoid saturation.
//
// The saturation gain is defined in order to let hard-clipping occur for
// those samples having a level that falls in the saturation region. It is an
// upper bound of the actual gain to apply - i.e., that returned by the
// limiter.
// Knee and beyond-knee regions approximation parameters.
// The gain curve is approximated as a piece-wise linear function.
// `approx_params_x_` are the boundaries between adjacent linear pieces,
// `approx_params_m_` and `approx_params_q_` are the slope and the y-intercept
// values of each piece.
struct InterpolatedParameters {
std::array<float, kInterpolatedGainCurveTotalPoints>
computed_approximation_params_x;
std::array<float, kInterpolatedGainCurveTotalPoints>
computed_approximation_params_m;
std::array<float, kInterpolatedGainCurveTotalPoints>
computed_approximation_params_q;
};
InterpolatedParameters ComputeInterpolatedGainCurveApproximationParams();
} // namespace test
} // namespace webrtc
#endif // MODULES_AUDIO_PROCESSING_AGC2_COMPUTE_INTERPOLATED_GAIN_CURVE_H_