42 lines
1.4 KiB
C
42 lines
1.4 KiB
C
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// Copyright 2016 Citra Emulator Project
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// Licensed under GPLv2 or any later version
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// Refer to the license.txt file included.
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#pragma once
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#include <array>
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#include <vector>
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#include "common/common_types.h"
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namespace AudioInterp {
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/// A variable length buffer of signed PCM16 stereo samples.
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using StereoBuffer16 = std::vector<std::array<s16, 2>>;
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struct State {
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// Two historical samples.
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std::array<s16, 2> xn1 = {}; ///< x[n-1]
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std::array<s16, 2> xn2 = {}; ///< x[n-2]
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};
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/**
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* No interpolation. This is equivalent to a zero-order hold. There is a two-sample predelay.
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* @param input Input buffer.
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* @param rate_multiplier Stretch factor. Must be a positive non-zero value.
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* rate_multiplier > 1.0 performs decimation and rate_multipler < 1.0 performs upsampling.
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* @return The resampled audio buffer.
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*/
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StereoBuffer16 None(State& state, const StereoBuffer16& input, float rate_multiplier);
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/**
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* Linear interpolation. This is equivalent to a first-order hold. There is a two-sample predelay.
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* @param input Input buffer.
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* @param rate_multiplier Stretch factor. Must be a positive non-zero value.
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* rate_multiplier > 1.0 performs decimation and rate_multipler < 1.0 performs upsampling.
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* @return The resampled audio buffer.
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*/
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StereoBuffer16 Linear(State& state, const StereoBuffer16& input, float rate_multiplier);
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} // namespace AudioInterp
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