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/*
* Copyright (c) 2020 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.
*/
#include "modules/audio_processing/agc2/rnn_vad/rnn_fc.h"
#include <algorithm>
#include <numeric>
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "third_party/rnnoise/src/rnn_activations.h"
#include "third_party/rnnoise/src/rnn_vad_weights.h"
namespace webrtc {
namespace rnn_vad {
namespace {
std::vector<float> GetScaledParams(rtc::ArrayView<const int8_t> params) {
std::vector<float> scaled_params(params.size());
std::transform(params.begin(), params.end(), scaled_params.begin(),
[](int8_t x) -> float {
return ::rnnoise::kWeightsScale * static_cast<float>(x);
});
return scaled_params;
}
// TODO(bugs.chromium.org/10480): Hard-code optimized layout and remove this
// function to improve setup time.
// Casts and scales `weights` and re-arranges the layout.
std::vector<float> PreprocessWeights(rtc::ArrayView<const int8_t> weights,
int output_size) {
if (output_size == 1) {
return GetScaledParams(weights);
}
// Transpose, scale and cast.
const int input_size = rtc::CheckedDivExact(
rtc::dchecked_cast<int>(weights.size()), output_size);
std::vector<float> w(weights.size());
for (int o = 0; o < output_size; ++o) {
for (int i = 0; i < input_size; ++i) {
w[o * input_size + i] = rnnoise::kWeightsScale *
static_cast<float>(weights[i * output_size + o]);
}
}
return w;
}
rtc::FunctionView<float(float)> GetActivationFunction(
ActivationFunction activation_function) {
switch (activation_function) {
case ActivationFunction::kTansigApproximated:
return ::rnnoise::TansigApproximated;
case ActivationFunction::kSigmoidApproximated:
return ::rnnoise::SigmoidApproximated;
}
}
} // namespace
FullyConnectedLayer::FullyConnectedLayer(
const int input_size,
const int output_size,
const rtc::ArrayView<const int8_t> bias,
const rtc::ArrayView<const int8_t> weights,
ActivationFunction activation_function,
const AvailableCpuFeatures& cpu_features,
absl::string_view layer_name)
: input_size_(input_size),
output_size_(output_size),
bias_(GetScaledParams(bias)),
weights_(PreprocessWeights(weights, output_size)),
vector_math_(cpu_features),
activation_function_(GetActivationFunction(activation_function)) {
RTC_DCHECK_LE(output_size_, kFullyConnectedLayerMaxUnits)
<< "Insufficient FC layer over-allocation (" << layer_name << ").";
RTC_DCHECK_EQ(output_size_, bias_.size())
<< "Mismatching output size and bias terms array size (" << layer_name
<< ").";
RTC_DCHECK_EQ(input_size_ * output_size_, weights_.size())
<< "Mismatching input-output size and weight coefficients array size ("
<< layer_name << ").";
}
FullyConnectedLayer::~FullyConnectedLayer() = default;
void FullyConnectedLayer::ComputeOutput(rtc::ArrayView<const float> input) {
RTC_DCHECK_EQ(input.size(), input_size_);
rtc::ArrayView<const float> weights(weights_);
for (int o = 0; o < output_size_; ++o) {
output_[o] = activation_function_(
bias_[o] + vector_math_.DotProduct(
input, weights.subview(o * input_size_, input_size_)));
}
}
} // namespace rnn_vad
} // namespace webrtc