OpenShot Library | OpenShotAudio  0.2.1
juce_Convolution.h
1 
2 /** @weakgroup juce_dsp-frequency
3  * @{
4  */
5 /*
6  ==============================================================================
7 
8  This file is part of the JUCE library.
9  Copyright (c) 2017 - ROLI Ltd.
10 
11  JUCE is an open source library subject to commercial or open-source
12  licensing.
13 
14  By using JUCE, you agree to the terms of both the JUCE 5 End-User License
15  Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
16  27th April 2017).
17 
18  End User License Agreement: www.juce.com/juce-5-licence
19  Privacy Policy: www.juce.com/juce-5-privacy-policy
20 
21  Or: You may also use this code under the terms of the GPL v3 (see
22  www.gnu.org/licenses).
23 
24  JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
25  EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
26  DISCLAIMED.
27 
28  ==============================================================================
29 */
30 
31 namespace juce
32 {
33 namespace dsp
34 {
35 
36 /**
37  Performs stereo uniform-partitioned convolution of an input signal with an
38  impulse response in the frequency domain, using the juce FFT class.
39 
40  It provides some thread-safe functions to load impulse responses as well,
41  from audio files or memory on the fly without any noticeable artefacts,
42  performing resampling and trimming if necessary.
43 
44  The processing is equivalent to the time domain convolution done in the
45  class FIRFilter, with a FIRFilter::Coefficients object having as
46  coefficients the samples of the impulse response. However, it is more
47  efficient in general to do frequency domain convolution when the size of
48  the impulse response is higher than 64 samples.
49 
50  @see FIRFilter, FIRFilter::Coefficients, FFT
51 
52  @tags{DSP}
53 */
55 {
56 public:
57  //==============================================================================
58  /** Initialises an object for performing convolution in the frequency domain. */
59  Convolution();
60 
61  /** Destructor. */
62  ~Convolution();
63 
64  //==============================================================================
65  /** Must be called before loading any impulse response, to provide to the
66  convolution the maximumBufferSize to handle, and the sample rate useful for
67  optional resampling.
68  */
69  void prepare (const ProcessSpec&);
70 
71  /** Resets the processing pipeline, ready to start a new stream of data. */
72  void reset() noexcept;
73 
74  /** Performs the filter operation on the given set of samples, with optional
75  stereo processing.
76  */
77  template <typename ProcessContext>
78  void process (const ProcessContext& context) noexcept
79  {
80  static_assert (std::is_same<typename ProcessContext::SampleType, float>::value,
81  "Convolution engine only supports single precision floating point data");
82 
83  processSamples (context.getInputBlock(), context.getOutputBlock(), context.isBypassed);
84  }
85 
86  //==============================================================================
87  /** This function loads an impulse response audio file from memory, added in a
88  JUCE project with the Projucer as binary data. It can load any of the audio
89  formats registered in JUCE, and performs some resampling and pre-processing
90  as well if needed.
91 
92  Note: Obviously, don't try to use this function on float samples, since the
93  data is supposed to be an audio file in its binary format, and be sure that
94  the original data is not going to move at all its memory location during the
95  process !!
96 
97  @param sourceData the block of data to use as the stream's source
98  @param sourceDataSize the number of bytes in the source data block
99  @param wantsStereo requests to process both stereo channels or only one mono channel
100  @param wantsTrimming requests to trim the start and the end of the impulse response
101  @param size the expected size for the impulse response after loading, can be
102  set to 0 for requesting maximum original impulse response size
103  @param wantsNormalisation requests to normalise the impulse response amplitude
104  */
105  void loadImpulseResponse (const void* sourceData, size_t sourceDataSize,
106  bool wantsStereo, bool wantsTrimming, size_t size,
107  bool wantsNormalisation = true);
108 
109  /** This function loads an impulse response from an audio file on any drive. It
110  can load any of the audio formats registered in JUCE, and performs some
111  resampling and pre-processing as well if needed.
112 
113  @param fileImpulseResponse the location of the audio file
114  @param wantsStereo requests to process both stereo channels or only one mono channel
115  @param wantsTrimming requests to trim the start and the end of the impulse response
116  @param size the expected size for the impulse response after loading, can be
117  set to 0 for requesting maximum original impulse response size
118  @param wantsNormalisation requests to normalise the impulse response amplitude
119  */
120  void loadImpulseResponse (const File& fileImpulseResponse,
121  bool wantsStereo, bool wantsTrimming, size_t size,
122  bool wantsNormalisation = true);
123 
124  /** This function loads an impulse response from an audio buffer, which is
125  copied before doing anything else. Performs some resampling and
126  pre-processing as well if needed.
127 
128  @param buffer the AudioBuffer to use
129  @param bufferSampleRate the sampleRate of the data in the AudioBuffer
130  @param wantsStereo requests to process both stereo channels or only one mono channel
131  @param wantsTrimming requests to trim the start and the end of the impulse response
132  @param wantsNormalisation requests to normalise the impulse response amplitude
133  @param size the expected size for the impulse response after loading, can be
134  set to 0 for requesting maximum original impulse response size
135  */
136  void copyAndLoadImpulseResponseFromBuffer (AudioBuffer<float>& buffer, double bufferSampleRate,
137  bool wantsStereo, bool wantsTrimming, bool wantsNormalisation,
138  size_t size);
139 
140  /** This function loads an impulse response from an audio block, which is
141  copied before doing anything else. Performs some resampling and
142  pre-processing as well if needed.
143 
144  @param block the AudioBlock to use
145  @param bufferSampleRate the sampleRate of the data in the AudioBuffer
146  @param wantsStereo requests to process both stereo channels or only one channel
147  @param wantsTrimming requests to trim the start and the end of the impulse response
148  @param wantsNormalisation requests to normalise the impulse response amplitude
149  @param size the expected size for the impulse response after loading,
150  -1 for maximum length
151  */
152  void copyAndLoadImpulseResponseFromBlock (AudioBlock<float> block, double bufferSampleRate,
153  bool wantsStereo, bool wantsTrimming, bool wantsNormalisation,
154  size_t size);
155 
156 
157 private:
158  //==============================================================================
159  struct Pimpl;
160  std::unique_ptr<Pimpl> pimpl;
161 
162  //==============================================================================
163  void processSamples (const AudioBlock<const float>&, AudioBlock<float>&, bool isBypassed) noexcept;
164 
165  //==============================================================================
166  double sampleRate;
167  bool currentIsBypassed = false;
168  bool isActive = false;
169  SmoothedValue<float> volumeDry[2], volumeWet[2];
170  AudioBlock<float> dryBuffer;
171  HeapBlock<char> dryBufferStorage;
172 
173  //==============================================================================
174  JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Convolution)
175 };
176 
177 } // namespace dsp
178 } // namespace juce
179 
180 /** @}*/
#define JUCE_API
This macro is added to all JUCE public class declarations.
Manages all the changes requested by the main convolution engine, to minimize the number of calls of ...
Performs stereo uniform-partitioned convolution of an input signal with an impulse response in the fr...
void process(const ProcessContext &context) noexcept
Performs the filter operation on the given set of samples, with optional stereo processing.
Represents a local file or directory.
Definition: juce_File.h:44
This structure is passed into a DSP algorithm&#39;s prepare() method, and contains information about vari...