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Diffstat (limited to 'third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h')
-rw-r--r-- | third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h b/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h new file mode 100644 index 0000000000..08b676f5fd --- /dev/null +++ b/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h @@ -0,0 +1,48 @@ +/* + * 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_ |