annotate examples/ZeroCrossing.cpp @ 47:be8fdfe25693

* Change input buffers arg to process from float ** to const float *const * to avoid plugins modifying their input data * Some improvements to comments * Fix stupidity in frequency-domain input passing (there are n/2+1 values, not n/2)
author cannam
date Fri, 08 Dec 2006 17:39:32 +0000
parents 3bbe244611bb
children aa64a46320d4
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@0 57 ZeroCrossing::getName() const
cannam@0 58 {
cannam@0 59 return "zerocrossing";
cannam@0 60 }
cannam@0 61
cannam@0 62 string
cannam@0 63 ZeroCrossing::getDescription() const
cannam@0 64 {
cannam@0 65 return "Zero Crossings";
cannam@0 66 }
cannam@0 67
cannam@0 68 string
cannam@0 69 ZeroCrossing::getMaker() const
cannam@0 70 {
cannam@43 71 return "Vamp SDK Example Plugins";
cannam@0 72 }
cannam@0 73
cannam@0 74 int
cannam@0 75 ZeroCrossing::getPluginVersion() const
cannam@0 76 {
cannam@0 77 return 2;
cannam@0 78 }
cannam@0 79
cannam@0 80 string
cannam@0 81 ZeroCrossing::getCopyright() const
cannam@0 82 {
cannam@7 83 return "Freely redistributable (BSD license)";
cannam@0 84 }
cannam@0 85
cannam@0 86 bool
cannam@0 87 ZeroCrossing::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@0 88 {
cannam@0 89 if (channels < getMinChannelCount() ||
cannam@0 90 channels > getMaxChannelCount()) return false;
cannam@0 91
cannam@0 92 m_stepSize = std::min(stepSize, blockSize);
cannam@0 93
cannam@0 94 return true;
cannam@0 95 }
cannam@0 96
cannam@0 97 void
cannam@0 98 ZeroCrossing::reset()
cannam@0 99 {
cannam@0 100 m_previousSample = 0.0f;
cannam@0 101 }
cannam@0 102
cannam@0 103 ZeroCrossing::OutputList
cannam@0 104 ZeroCrossing::getOutputDescriptors() const
cannam@0 105 {
cannam@0 106 OutputList list;
cannam@0 107
cannam@0 108 OutputDescriptor zc;
cannam@0 109 zc.name = "counts";
cannam@0 110 zc.unit = "crossings";
cannam@0 111 zc.description = "Zero Crossing Counts";
cannam@9 112 zc.hasFixedBinCount = true;
cannam@9 113 zc.binCount = 1;
cannam@0 114 zc.hasKnownExtents = false;
cannam@0 115 zc.isQuantized = true;
cannam@0 116 zc.quantizeStep = 1.0;
cannam@0 117 zc.sampleType = OutputDescriptor::OneSamplePerStep;
cannam@0 118 list.push_back(zc);
cannam@0 119
cannam@0 120 zc.name = "zerocrossings";
cannam@0 121 zc.unit = "";
cannam@0 122 zc.description = "Zero Crossings";
cannam@9 123 zc.hasFixedBinCount = true;
cannam@9 124 zc.binCount = 0;
cannam@0 125 zc.sampleType = OutputDescriptor::VariableSampleRate;
cannam@0 126 zc.sampleRate = m_inputSampleRate;
cannam@0 127 list.push_back(zc);
cannam@0 128
cannam@0 129 return list;
cannam@0 130 }
cannam@0 131
cannam@0 132 ZeroCrossing::FeatureSet
cannam@47 133 ZeroCrossing::process(const float *const *inputBuffers,
cannam@47 134 Vamp::RealTime timestamp)
cannam@0 135 {
cannam@0 136 if (m_stepSize == 0) {
cannam@0 137 cerr << "ERROR: ZeroCrossing::process: "
cannam@0 138 << "ZeroCrossing has not been initialised"
cannam@0 139 << endl;
cannam@0 140 return FeatureSet();
cannam@0 141 }
cannam@0 142
cannam@0 143 float prev = m_previousSample;
cannam@0 144 size_t count = 0;
cannam@0 145
cannam@0 146 FeatureSet returnFeatures;
cannam@0 147
cannam@0 148 for (size_t i = 0; i < m_stepSize; ++i) {
cannam@0 149
cannam@0 150 float sample = inputBuffers[0][i];
cannam@0 151 bool crossing = false;
cannam@0 152
cannam@0 153 if (sample <= 0.0) {
cannam@0 154 if (prev > 0.0) crossing = true;
cannam@0 155 } else if (sample > 0.0) {
cannam@0 156 if (prev <= 0.0) crossing = true;
cannam@0 157 }
cannam@0 158
cannam@0 159 if (crossing) {
cannam@0 160 ++count;
cannam@0 161 Feature feature;
cannam@0 162 feature.hasTimestamp = true;
cannam@0 163 feature.timestamp = timestamp +
cannam@0 164 Vamp::RealTime::frame2RealTime(i, (size_t)m_inputSampleRate);
cannam@0 165 returnFeatures[1].push_back(feature);
cannam@0 166 }
cannam@0 167
cannam@0 168 prev = sample;
cannam@0 169 }
cannam@0 170
cannam@0 171 m_previousSample = prev;
cannam@0 172
cannam@0 173 Feature feature;
cannam@0 174 feature.hasTimestamp = false;
cannam@0 175 feature.values.push_back(count);
cannam@0 176
cannam@0 177 returnFeatures[0].push_back(feature);
cannam@0 178 return returnFeatures;
cannam@0 179 }
cannam@0 180
cannam@0 181 ZeroCrossing::FeatureSet
cannam@0 182 ZeroCrossing::getRemainingFeatures()
cannam@0 183 {
cannam@0 184 return FeatureSet();
cannam@0 185 }
cannam@0 186