webrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h
Alex Loiko a05ee82c4c Fixed Digital mode of AGC2 implementation finished.
This CL adds the GainCurveApplier (GCA). It owns a
FixedDigitalLevelEstimator (LE) and an InterpolatedGainCurve
(IGC). The GCA uses the LE to compute the input signal level, looks up
a gain from IGC and applies it on the signal.

The other IGC and LE submodules were added in previous CLs [1] and
[2].

This CL also turns on AGC2 in the APM fuzzer.

[1] https://webrtc-review.googlesource.com/c/src/+/51920
[2] https://webrtc-review.googlesource.com/c/src/+/52381

Bug: webrtc:7949
Change-Id: Idb10cc3ca9d6d2e4ac5824cc3391ed8aa680f6cd
Reviewed-on: https://webrtc-review.googlesource.com/54361
Commit-Queue: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22103}
2018-02-20 15:59:25 +00:00

48 lines
1.8 KiB
C++

/*
* 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_