1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
6 An API for audio analysis and feature extraction plugins.
8 Centre for Digital Music, Queen Mary, University of London.
9 Copyright 2006 Chris Cannam.
11 Permission is hereby granted, free of charge, to any person
12 obtaining a copy of this software and associated documentation
13 files (the "Software"), to deal in the Software without
14 restriction, including without limitation the rights to use, copy,
15 modify, merge, publish, distribute, sublicense, and/or sell copies
16 of the Software, and to permit persons to whom the Software is
17 furnished to do so, subject to the following conditions:
19 The above copyright notice and this permission notice shall be
20 included in all copies or substantial portions of the Software.
22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
26 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
27 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
30 Except as contained in this notice, the names of the Centre for
31 Digital Music; Queen Mary, University of London; and Chris Cannam
32 shall not be used in advertising or otherwise to promote the sale,
33 use or other dealings in this Software without prior written
37 #include "ZeroCrossing.h"
45 ZeroCrossing::ZeroCrossing(float inputSampleRate
) :
46 Plugin(inputSampleRate
),
48 m_previousSample(0.0f
)
52 ZeroCrossing::~ZeroCrossing()
57 ZeroCrossing::getIdentifier() const
59 return "zerocrossing";
63 ZeroCrossing::getName() const
65 return "Zero Crossings";
69 ZeroCrossing::getDescription() const
71 return "Detect and count zero crossing points";
75 ZeroCrossing::getMaker() const
77 return "Vamp SDK Example Plugins";
81 ZeroCrossing::getPluginVersion() const
87 ZeroCrossing::getCopyright() const
89 return "Freely redistributable (BSD license)";
93 ZeroCrossing::initialise(size_t channels
, size_t stepSize
, size_t blockSize
)
95 if (channels
< getMinChannelCount() ||
96 channels
> getMaxChannelCount()) return false;
98 m_stepSize
= std::min(stepSize
, blockSize
);
104 ZeroCrossing::reset()
106 m_previousSample
= 0.0f
;
109 ZeroCrossing::OutputList
110 ZeroCrossing::getOutputDescriptors() const
115 zc
.identifier
= "counts";
116 zc
.name
= "Zero Crossing Counts";
117 zc
.description
= "The number of zero crossing points per processing block";
118 zc
.unit
= "crossings";
119 zc
.hasFixedBinCount
= true;
121 zc
.hasKnownExtents
= false;
122 zc
.isQuantized
= true;
123 zc
.quantizeStep
= 1.0;
124 zc
.sampleType
= OutputDescriptor::OneSamplePerStep
;
127 zc
.identifier
= "zerocrossings";
128 zc
.name
= "Zero Crossings";
129 zc
.description
= "The locations of zero crossing points";
131 zc
.hasFixedBinCount
= true;
133 zc
.sampleType
= OutputDescriptor::VariableSampleRate
;
134 zc
.sampleRate
= m_inputSampleRate
;
140 ZeroCrossing::FeatureSet
141 ZeroCrossing::process(const float *const *inputBuffers
,
142 Vamp::RealTime timestamp
)
144 if (m_stepSize
== 0) {
145 cerr
<< "ERROR: ZeroCrossing::process: "
146 << "ZeroCrossing has not been initialised"
151 float prev
= m_previousSample
;
154 FeatureSet returnFeatures
;
156 for (size_t i
= 0; i
< m_stepSize
; ++i
) {
158 float sample
= inputBuffers
[0][i
];
159 bool crossing
= false;
162 if (prev
> 0.0) crossing
= true;
163 } else if (sample
> 0.0) {
164 if (prev
<= 0.0) crossing
= true;
170 feature
.hasTimestamp
= true;
171 feature
.timestamp
= timestamp
+
172 Vamp::RealTime::frame2RealTime(i
, (size_t)m_inputSampleRate
);
173 returnFeatures
[1].push_back(feature
);
179 m_previousSample
= prev
;
182 feature
.hasTimestamp
= false;
183 feature
.values
.push_back(count
);
185 returnFeatures
[0].push_back(feature
);
186 return returnFeatures
;
189 ZeroCrossing::FeatureSet
190 ZeroCrossing::getRemainingFeatures()