e36e8bbf6d
The FixedGainController (FGC) applies a fixed gain. It will also control the limiter. The limiter will be landed over the next several CLs. The GainController2 is a 'private submodule' of APM. It will control the new automatic gain controller (AGC). It controls the AGC through Initialize() and ApplyConfig(). This CL contains * build changes to make modules/audio_processing/agc2 an independent target * a new MutableFloatAudioFrame which is the audio interface between AGC2 and APM * move of the fixed gain application from GainController2 to FixedGainController. If you are a googler, there is more information in this doc: https://docs.google.com/document/d/1RV2Doet3MZtUPAHVva61Vjo20iyd1bmmm3aR8znWpzo/edit# Bug: webrtc:7949 Change-Id: Ief95cbbce83c3aafe54638fd2ab881c9fb8bdc3a Reviewed-on: https://webrtc-review.googlesource.com/50440 Commit-Queue: Alex Loiko <aleloi@webrtc.org> Reviewed-by: Oskar Sundbom <ossu@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22046}
91 lines
3.1 KiB
C++
91 lines
3.1 KiB
C++
/*
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* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/audio_processing/agc2/fixed_gain_controller.h"
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#include <algorithm>
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#include <cmath>
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#include "api/array_view.h"
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#include "common_audio/include/audio_util.h"
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#include "modules/audio_processing/agc2/agc2_common.h"
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#include "modules/audio_processing/logging/apm_data_dumper.h"
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#include "rtc_base/checks.h"
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#include "rtc_base/logging.h"
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#include "rtc_base/numerics/safe_minmax.h"
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namespace webrtc {
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namespace {
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// Returns true when the gain factor is so close to 1 that it would
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// not affect int16 samples.
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bool CloseToOne(float gain_factor) {
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return 1.f - 1.f / kMaxSampleValue <= gain_factor &&
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gain_factor <= 1.f + 1.f / kMaxSampleValue;
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}
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} // namespace
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FixedGainController::FixedGainController(ApmDataDumper* apm_data_dumper)
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: apm_data_dumper_(apm_data_dumper) {
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RTC_DCHECK_LT(0.f, gain_to_apply_);
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RTC_DLOG(LS_INFO) << "Gain to apply: " << gain_to_apply_;
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}
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void FixedGainController::SetGain(float gain_to_apply_db) {
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// Changes in gain_to_apply_ cause discontinuities. We assume
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// gain_to_apply_ is set in the beginning of the call. If it is
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// frequently changed, we should add interpolation between the
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// values.
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gain_to_apply_ = DbToRatio(gain_to_apply_db);
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}
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void FixedGainController::SetSampleRate(size_t sample_rate_hz) {
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// TODO(aleloi): propagate the new sample rate to the GainCurveApplier.
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}
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void FixedGainController::EnableLimiter(bool enable_limiter) {
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enable_limiter_ = enable_limiter;
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}
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void FixedGainController::Process(AudioFrameView<float> signal) {
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// Apply fixed digital gain; interpolate if necessary. One of the
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// planned usages of the FGC is to only use the limiter. In that
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// case, the gain would be 1.0. Not doing the multiplications speeds
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// it up considerably. Hence the check.
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if (!CloseToOne(gain_to_apply_)) {
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for (size_t k = 0; k < signal.num_channels(); ++k) {
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rtc::ArrayView<float> channel_view = signal.channel(k);
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for (auto& sample : channel_view) {
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sample *= gain_to_apply_;
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}
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}
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}
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// Use the limiter (if configured to).
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if (enable_limiter_) {
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// TODO(aleloi): Process the signal with the
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// GainCurveApplier. This will be done in the upcoming CLs.
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// Dump data for debug.
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const auto channel_view = signal.channel(0);
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apm_data_dumper_->DumpRaw("agc2_fixed_digital_gain_curve_applier",
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channel_view.size(), channel_view.data());
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}
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// Hard-clipping.
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for (size_t k = 0; k < signal.num_channels(); ++k) {
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rtc::ArrayView<float> channel_view = signal.channel(k);
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for (auto& sample : channel_view) {
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sample = rtc::SafeClamp(sample, kMinSampleValue, kMaxSampleValue);
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}
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}
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}
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} // namespace webrtc
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