OpenShot Audio Library | OpenShotAudio: juce_FIRFilter.h Source File

OpenShot Audio Library | OpenShotAudio 0.4.0 |

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juce_FIRFilter.h
1/*
2 ==============================================================================
3
4 This file is part of the JUCE library.
5 Copyright (c) 2022 - Raw Material Software Limited
6
7 JUCE is an open source library subject to commercial or open-source
8 licensing.
9
10 By using JUCE, you agree to the terms of both the JUCE 7 End-User License
11 Agreement and JUCE Privacy Policy.
12
13 End User License Agreement: www.juce.com/juce-7-licence
14 Privacy Policy: www.juce.com/juce-privacy-policy
15
16 Or: You may also use this code under the terms of the GPL v3 (see
17 www.gnu.org/licenses).
18
19 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
20 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
21 DISCLAIMED.
22
23 ==============================================================================
24*/
25
29 namespace juce::dsp::FIR
30{
31 template <typename NumericType>
32 struct Coefficients;
33
34 //==============================================================================
48 template <typename SampleType>
49 class Filter
50 {
51 public:
55 using NumericType = typename SampleTypeHelpers::ElementType<SampleType>::Type;
56
58 using CoefficientsPtr = typename Coefficients<NumericType>::Ptr;
59
60 //==============================================================================
62 Filter() : coefficients (new Coefficients<NumericType>) { reset(); }
63
65 Filter (CoefficientsPtr coefficientsToUse) : coefficients (std::move (coefficientsToUse)) { reset(); }
66
67 Filter (const Filter&) = default;
68 Filter (Filter&&) = default;
69 Filter& operator= (const Filter&) = default;
70 Filter& operator= (Filter&&) = default;
71
72 //==============================================================================
74 inline void prepare ([[maybe_unused]] const ProcessSpec& spec) noexcept
75 {
76 // This class can only process mono signals. Use the ProcessorDuplicator class
77 // to apply this filter on a multi-channel audio stream.
78 jassert (spec.numChannels == 1);
79 reset();
80 }
81
87 void reset()
88 {
89 if (coefficients != nullptr)
90 {
91 auto newSize = coefficients->getFilterOrder() + 1;
92
93 if (newSize != size)
94 {
95 memory.malloc (1 + jmax (newSize, size, static_cast<size_t> (128)));
96
97 fifo = snapPointerToAlignment (memory.getData(), sizeof (SampleType));
98 size = newSize;
99 }
100
101 for (size_t i = 0; i < size; ++i)
102 fifo[i] = SampleType {0};
103 }
104 }
105
106 //==============================================================================
113 typename Coefficients<NumericType>::Ptr coefficients;
114
115 //==============================================================================
117 template <typename ProcessContext>
118 void process (const ProcessContext& context) noexcept
119 {
120 static_assert (std::is_same_v<typename ProcessContext::SampleType, SampleType>,
121 "The sample-type of the FIR filter must match the sample-type supplied to this process callback");
122 check();
123
124 auto&& inputBlock = context.getInputBlock();
125 auto&& outputBlock = context.getOutputBlock();
126
127 // This class can only process mono signals. Use the ProcessorDuplicator class
128 // to apply this filter on a multi-channel audio stream.
129 jassert (inputBlock.getNumChannels() == 1);
130 jassert (outputBlock.getNumChannels() == 1);
131
132 auto numSamples = inputBlock.getNumSamples();
133 auto* src = inputBlock .getChannelPointer (0);
134 auto* dst = outputBlock.getChannelPointer (0);
135
136 auto* fir = coefficients->getRawCoefficients();
137 size_t p = pos;
138
139 if (context.isBypassed)
140 {
141 for (size_t i = 0; i < numSamples; ++i)
142 {
143 fifo[p] = dst[i] = src[i];
144 p = (p == 0 ? size - 1 : p - 1);
145 }
146 }
147 else
148 {
149 for (size_t i = 0; i < numSamples; ++i)
150 dst[i] = processSingleSample (src[i], fifo, fir, size, p);
151 }
152
153 pos = p;
154 }
155
156
160 SampleType JUCE_VECTOR_CALLTYPE processSample (SampleType sample) noexcept
161 {
162 check();
163 return processSingleSample (sample, fifo, coefficients->getRawCoefficients(), size, pos);
164 }
165
166 private:
167 //==============================================================================
168 HeapBlock<SampleType> memory;
169 SampleType* fifo = nullptr;
170 size_t pos = 0, size = 0;
171
172 //==============================================================================
173 void check()
174 {
175 jassert (coefficients != nullptr);
176
177 if (size != (coefficients->getFilterOrder() + 1))
178 reset();
179 }
180
181 static SampleType JUCE_VECTOR_CALLTYPE processSingleSample (SampleType sample, SampleType* buf,
182 const NumericType* fir, size_t m, size_t& p) noexcept
183 {
184 SampleType out (0);
185
186 buf[p] = sample;
187
188 size_t k;
189 for (k = 0; k < m - p; ++k)
190 out += buf[(p + k)] * fir[k];
191
192 for (size_t j = 0; j < p; ++j)
193 out += buf[j] * fir[j + k];
194
195 p = (p == 0 ? m - 1 : p - 1);
196
197 return out;
198 }
199
200
201 JUCE_LEAK_DETECTOR (Filter)
202 };
203
204 //==============================================================================
212 template <typename NumericType>
213 struct Coefficients : public ProcessorState
214 {
215 //==============================================================================
217 Coefficients() : coefficients ({ NumericType() }) {}
218
220 Coefficients (size_t size) { coefficients.resize ((int) size); }
221
223 Coefficients (const NumericType* samples, size_t numSamples) : coefficients (samples, (int) numSamples) {}
224
225 Coefficients (const Coefficients&) = default;
226 Coefficients (Coefficients&&) = default;
227 Coefficients& operator= (const Coefficients&) = default;
228 Coefficients& operator= (Coefficients&&) = default;
229
233 using Ptr = ReferenceCountedObjectPtr<Coefficients>;
234
235 //==============================================================================
237 size_t getFilterOrder() const noexcept { return static_cast<size_t> (coefficients.size()) - 1; }
238
242 double getMagnitudeForFrequency (double frequency, double sampleRate) const noexcept;
243
247 void getMagnitudeForFrequencyArray (double* frequencies, double* magnitudes,
248 size_t numSamples, double sampleRate) const noexcept;
249
253 double getPhaseForFrequency (double frequency, double sampleRate) const noexcept;
254
258 void getPhaseForFrequencyArray (double* frequencies, double* phases,
259 size_t numSamples, double sampleRate) const noexcept;
260
262 NumericType* getRawCoefficients() noexcept { return coefficients.getRawDataPointer(); }
263
265 const NumericType* getRawCoefficients() const noexcept { return coefficients.begin(); }
266
267 //==============================================================================
269 void normalise() noexcept;
270
271 //==============================================================================
275 Array<NumericType> coefficients;
276 };
277
278} // namespace juce::dsp::FIR
juce::Array
Definition juce_Array.h:56
juce::HeapBlock
Definition juce_HeapBlock.h:87
juce::ReferenceCountedObjectPtr
Definition juce_ReferenceCountedObject.h:247
juce::dsp::FIR::Filter
Definition juce_FIRFilter.h:50
juce::dsp::FIR::Filter::coefficients
Coefficients< NumericType >::Ptr coefficients
Definition juce_FIRFilter.h:113
juce::dsp::FIR::Filter::CoefficientsPtr
typename Coefficients< NumericType >::Ptr CoefficientsPtr
Definition juce_FIRFilter.h:58
juce::dsp::FIR::Filter::process
void process(const ProcessContext &context) noexcept
Definition juce_FIRFilter.h:118
juce::dsp::FIR::Filter::NumericType
typename SampleTypeHelpers::ElementType< SampleType >::Type NumericType
Definition juce_FIRFilter.h:55
juce::dsp::FIR::Filter::processSample
SampleType JUCE_VECTOR_CALLTYPE processSample(SampleType sample) noexcept
Definition juce_FIRFilter.h:160
juce::dsp::FIR::Filter::Filter
Filter(CoefficientsPtr coefficientsToUse)
Definition juce_FIRFilter.h:65
juce::dsp::FIR::Filter::prepare
void prepare(const ProcessSpec &spec) noexcept
Definition juce_FIRFilter.h:74
juce::dsp::FIR::Filter::Filter
Filter()
Definition juce_FIRFilter.h:62
juce::dsp::FIR::Filter::reset
void reset()
Definition juce_FIRFilter.h:87
juce::dsp::FIR
Definition juce_FIRFilter.h:30
juce::dsp::FIR::Coefficients
Definition juce_FIRFilter.h:214
juce::dsp::FIR::Coefficients::normalise
void normalise() noexcept
juce::dsp::FIR::Coefficients::getMagnitudeForFrequencyArray
void getMagnitudeForFrequencyArray(double *frequencies, double *magnitudes, size_t numSamples, double sampleRate) const noexcept
juce::dsp::FIR::Coefficients::getFilterOrder
size_t getFilterOrder() const noexcept
Definition juce_FIRFilter.h:237
juce::dsp::FIR::Coefficients::Coefficients
Coefficients()
Definition juce_FIRFilter.h:217
juce::dsp::FIR::Coefficients::Coefficients
Coefficients(const NumericType *samples, size_t numSamples)
Definition juce_FIRFilter.h:223
juce::dsp::FIR::Coefficients::Coefficients
Coefficients(size_t size)
Definition juce_FIRFilter.h:220
juce::dsp::FIR::Coefficients::getMagnitudeForFrequency
double getMagnitudeForFrequency(double frequency, double sampleRate) const noexcept
juce::dsp::FIR::Coefficients::Ptr
ReferenceCountedObjectPtr< Coefficients > Ptr
Definition juce_FIRFilter.h:233
juce::dsp::FIR::Coefficients::coefficients
Array< NumericType > coefficients
Definition juce_FIRFilter.h:275
juce::dsp::FIR::Coefficients::getPhaseForFrequency
double getPhaseForFrequency(double frequency, double sampleRate) const noexcept
juce::dsp::FIR::Coefficients::getRawCoefficients
NumericType * getRawCoefficients() noexcept
Definition juce_FIRFilter.h:262
juce::dsp::FIR::Coefficients::getRawCoefficients
const NumericType * getRawCoefficients() const noexcept
Definition juce_FIRFilter.h:265
juce::dsp::FIR::Coefficients::getPhaseForFrequencyArray
void getPhaseForFrequencyArray(double *frequencies, double *phases, size_t numSamples, double sampleRate) const noexcept
juce::dsp::ProcessSpec
Definition juce_ProcessContext.h:36
juce::dsp::ProcessorState
Definition juce_ProcessContext.h:68