annotate examples/ZeroCrossing.cpp @ 78:6bf198e06d72 vamp-plugin-sdk-v1.1

* doc updates
author cannam
date Thu, 23 Aug 2007 10:31:46 +0000
parents aa64a46320d4
children 1982246a3902
rev   line source
cannam@0 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
cannam@0 2
cannam@0 3 /*
cannam@0 4 Vamp
cannam@0 5
cannam@0 6 An API for audio analysis and feature extraction plugins.
cannam@0 7
cannam@0 8 Centre for Digital Music, Queen Mary, University of London.
cannam@0 9 Copyright 2006 Chris Cannam.
cannam@0 10
cannam@0 11 Permission is hereby granted, free of charge, to any person
cannam@0 12 obtaining a copy of this software and associated documentation
cannam@0 13 files (the "Software"), to deal in the Software without
cannam@0 14 restriction, including without limitation the rights to use, copy,
cannam@0 15 modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@0 16 of the Software, and to permit persons to whom the Software is
cannam@0 17 furnished to do so, subject to the following conditions:
cannam@0 18
cannam@0 19 The above copyright notice and this permission notice shall be
cannam@0 20 included in all copies or substantial portions of the Software.
cannam@0 21
cannam@0 22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@0 23 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@0 24 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@6 25 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@0 26 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@0 27 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@0 28 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@0 29
cannam@0 30 Except as contained in this notice, the names of the Centre for
cannam@0 31 Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@0 32 shall not be used in advertising or otherwise to promote the sale,
cannam@0 33 use or other dealings in this Software without prior written
cannam@0 34 authorization.
cannam@0 35 */
cannam@0 36
cannam@0 37 #include "ZeroCrossing.h"
cannam@0 38
cannam@0 39 using std::string;
cannam@0 40 using std::vector;
cannam@0 41 using std::cerr;
cannam@0 42 using std::endl;
cannam@0 43
cannam@0 44
cannam@0 45 ZeroCrossing::ZeroCrossing(float inputSampleRate) :
cannam@0 46 Plugin(inputSampleRate),
cannam@0 47 m_stepSize(0),
cannam@0 48 m_previousSample(0.0f)
cannam@0 49 {
cannam@0 50 }
cannam@0 51
cannam@0 52 ZeroCrossing::~ZeroCrossing()
cannam@0 53 {
cannam@0 54 }
cannam@0 55
cannam@0 56 string
cannam@49 57 ZeroCrossing::getIdentifier() const
cannam@0 58 {
cannam@0 59 return "zerocrossing";
cannam@0 60 }
cannam@0 61
cannam@0 62 string
cannam@49 63 ZeroCrossing::getName() const
cannam@49 64 {
cannam@49 65 return "Zero Crossings";
cannam@49 66 }
cannam@49 67
cannam@49 68 string
cannam@0 69 ZeroCrossing::getDescription() const
cannam@0 70 {
cannam@49 71 return "Detect and count zero crossing points";
cannam@0 72 }
cannam@0 73
cannam@0 74 string
cannam@0 75 ZeroCrossing::getMaker() const
cannam@0 76 {
cannam@43 77 return "Vamp SDK Example Plugins";
cannam@0 78 }
cannam@0 79
cannam@0 80 int
cannam@0 81 ZeroCrossing::getPluginVersion() const
cannam@0 82 {
cannam@0 83 return 2;
cannam@0 84 }
cannam@0 85
cannam@0 86 string
cannam@0 87 ZeroCrossing::getCopyright() const
cannam@0 88 {
cannam@7 89 return "Freely redistributable (BSD license)";
cannam@0 90 }
cannam@0 91
cannam@0 92 bool
cannam@0 93 ZeroCrossing::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@0 94 {
cannam@0 95 if (channels < getMinChannelCount() ||
cannam@0 96 channels > getMaxChannelCount()) return false;
cannam@0 97
cannam@0 98 m_stepSize = std::min(stepSize, blockSize);
cannam@0 99
cannam@0 100 return true;
cannam@0 101 }
cannam@0 102
cannam@0 103 void
cannam@0 104 ZeroCrossing::reset()
cannam@0 105 {
cannam@0 106 m_previousSample = 0.0f;
cannam@0 107 }
cannam@0 108
cannam@0 109 ZeroCrossing::OutputList
cannam@0 110 ZeroCrossing::getOutputDescriptors() const
cannam@0 111 {
cannam@0 112 OutputList list;
cannam@0 113
cannam@0 114 OutputDescriptor zc;
cannam@49 115 zc.identifier = "counts";
cannam@49 116 zc.name = "Zero Crossing Counts";
cannam@49 117 zc.description = "The number of zero crossing points per processing block";
cannam@0 118 zc.unit = "crossings";
cannam@9 119 zc.hasFixedBinCount = true;
cannam@9 120 zc.binCount = 1;
cannam@0 121 zc.hasKnownExtents = false;
cannam@0 122 zc.isQuantized = true;
cannam@0 123 zc.quantizeStep = 1.0;
cannam@0 124 zc.sampleType = OutputDescriptor::OneSamplePerStep;
cannam@0 125 list.push_back(zc);
cannam@0 126
cannam@49 127 zc.identifier = "zerocrossings";
cannam@49 128 zc.name = "Zero Crossings";
cannam@49 129 zc.description = "The locations of zero crossing points";
cannam@0 130 zc.unit = "";
cannam@9 131 zc.hasFixedBinCount = true;
cannam@9 132 zc.binCount = 0;
cannam@0 133 zc.sampleType = OutputDescriptor::VariableSampleRate;
cannam@0 134 zc.sampleRate = m_inputSampleRate;
cannam@0 135 list.push_back(zc);
cannam@0 136
cannam@0 137 return list;
cannam@0 138 }
cannam@0 139
cannam@0 140 ZeroCrossing::FeatureSet
cannam@47 141 ZeroCrossing::process(const float *const *inputBuffers,
cannam@47 142 Vamp::RealTime timestamp)
cannam@0 143 {
cannam@0 144 if (m_stepSize == 0) {
cannam@0 145 cerr << "ERROR: ZeroCrossing::process: "
cannam@0 146 << "ZeroCrossing has not been initialised"
cannam@0 147 << endl;
cannam@0 148 return FeatureSet();
cannam@0 149 }
cannam@0 150
cannam@0 151 float prev = m_previousSample;
cannam@0 152 size_t count = 0;
cannam@0 153
cannam@0 154 FeatureSet returnFeatures;
cannam@0 155
cannam@0 156 for (size_t i = 0; i < m_stepSize; ++i) {
cannam@0 157
cannam@0 158 float sample = inputBuffers[0][i];
cannam@0 159 bool crossing = false;
cannam@0 160
cannam@0 161 if (sample <= 0.0) {
cannam@0 162 if (prev > 0.0) crossing = true;
cannam@0 163 } else if (sample > 0.0) {
cannam@0 164 if (prev <= 0.0) crossing = true;
cannam@0 165 }
cannam@0 166
cannam@0 167 if (crossing) {
cannam@0 168 ++count;
cannam@0 169 Feature feature;
cannam@0 170 feature.hasTimestamp = true;
cannam@0 171 feature.timestamp = timestamp +
cannam@0 172 Vamp::RealTime::frame2RealTime(i, (size_t)m_inputSampleRate);
cannam@0 173 returnFeatures[1].push_back(feature);
cannam@0 174 }
cannam@0 175
cannam@0 176 prev = sample;
cannam@0 177 }
cannam@0 178
cannam@0 179 m_previousSample = prev;
cannam@0 180
cannam@0 181 Feature feature;
cannam@0 182 feature.hasTimestamp = false;
cannam@0 183 feature.values.push_back(count);
cannam@0 184
cannam@0 185 returnFeatures[0].push_back(feature);
cannam@0 186 return returnFeatures;
cannam@0 187 }
cannam@0 188
cannam@0 189 ZeroCrossing::FeatureSet
cannam@0 190 ZeroCrossing::getRemainingFeatures()
cannam@0 191 {
cannam@0 192 return FeatureSet();
cannam@0 193 }
cannam@0 194