diff options
Diffstat (limited to 'src/audio_core/algorithm/filter.cpp')
-rw-r--r-- | src/audio_core/algorithm/filter.cpp | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/src/audio_core/algorithm/filter.cpp b/src/audio_core/algorithm/filter.cpp deleted file mode 100644 index 96e37991f..000000000 --- a/src/audio_core/algorithm/filter.cpp +++ /dev/null @@ -1,79 +0,0 @@ -// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project -// SPDX-License-Identifier: GPL-2.0-or-later - -#define _USE_MATH_DEFINES - -#include <algorithm> -#include <array> -#include <cmath> -#include <vector> -#include "audio_core/algorithm/filter.h" -#include "common/common_types.h" - -namespace AudioCore { - -Filter Filter::LowPass(double cutoff, double Q) { - const double w0 = 2.0 * M_PI * cutoff; - const double sin_w0 = std::sin(w0); - const double cos_w0 = std::cos(w0); - const double alpha = sin_w0 / (2 * Q); - - const double a0 = 1 + alpha; - const double a1 = -2.0 * cos_w0; - const double a2 = 1 - alpha; - const double b0 = 0.5 * (1 - cos_w0); - const double b1 = 1.0 * (1 - cos_w0); - const double b2 = 0.5 * (1 - cos_w0); - - return {a0, a1, a2, b0, b1, b2}; -} - -Filter::Filter() : Filter(1.0, 0.0, 0.0, 1.0, 0.0, 0.0) {} - -Filter::Filter(double a0_, double a1_, double a2_, double b0_, double b1_, double b2_) - : a1(a1_ / a0_), a2(a2_ / a0_), b0(b0_ / a0_), b1(b1_ / a0_), b2(b2_ / a0_) {} - -void Filter::Process(std::vector<s16>& signal) { - const std::size_t num_frames = signal.size() / 2; - for (std::size_t i = 0; i < num_frames; i++) { - std::rotate(in.begin(), in.end() - 1, in.end()); - std::rotate(out.begin(), out.end() - 1, out.end()); - - for (std::size_t ch = 0; ch < channel_count; ch++) { - in[0][ch] = signal[i * channel_count + ch]; - - out[0][ch] = b0 * in[0][ch] + b1 * in[1][ch] + b2 * in[2][ch] - a1 * out[1][ch] - - a2 * out[2][ch]; - - signal[i * 2 + ch] = static_cast<s16>(std::clamp(out[0][ch], -32768.0, 32767.0)); - } - } -} - -/// Calculates the appropriate Q for each biquad in a cascading filter. -/// @param total_count The total number of biquads to be cascaded. -/// @param index 0-index of the biquad to calculate the Q value for. -static double CascadingBiquadQ(std::size_t total_count, std::size_t index) { - const auto pole = - M_PI * static_cast<double>(2 * index + 1) / (4.0 * static_cast<double>(total_count)); - return 1.0 / (2.0 * std::cos(pole)); -} - -CascadingFilter CascadingFilter::LowPass(double cutoff, std::size_t cascade_size) { - std::vector<Filter> cascade(cascade_size); - for (std::size_t i = 0; i < cascade_size; i++) { - cascade[i] = Filter::LowPass(cutoff, CascadingBiquadQ(cascade_size, i)); - } - return CascadingFilter{std::move(cascade)}; -} - -CascadingFilter::CascadingFilter() = default; -CascadingFilter::CascadingFilter(std::vector<Filter> filters_) : filters(std::move(filters_)) {} - -void CascadingFilter::Process(std::vector<s16>& signal) { - for (auto& filter : filters) { - filter.Process(signal); - } -} - -} // namespace AudioCore |