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/*
* Copyright 2010 Phil Burk, Mobileer Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jsyn.data;
import com.jsyn.unitgen.FixedRateMonoReader;
import com.jsyn.unitgen.FixedRateStereoReader;
import com.jsyn.unitgen.VariableRateMonoReader;
import com.jsyn.unitgen.VariableRateStereoReader;
import com.jsyn.util.SampleLoader;
/**
* Store multi-channel floating point audio data in an interleaved buffer. The values are stored as
* 32-bit floats. You can play samples using one of the readers, for example VariableRateMonoReader.
*
* @author Phil Burk (C) 2010 Mobileer Inc
* @see SampleLoader
* @see FixedRateMonoReader
* @see FixedRateStereoReader
* @see VariableRateMonoReader
* @see VariableRateStereoReader
*/
public class FloatSample extends AudioSample implements Function {
private float[] buffer;
public FloatSample() {
}
/** Constructor for mono samples. */
public FloatSample(int numFrames) {
this(numFrames, 1);
}
/** Constructor for mono samples with data. */
public FloatSample(float[] data) {
this(data.length, 1);
write(data);
}
/** Constructor for multi-channel samples with data. */
public FloatSample(float[] data, int channelsPerFrame) {
this(data.length / channelsPerFrame, channelsPerFrame);
write(data);
}
/**
* Create an silent sample with enough memory to hold the audio data. The number of sample
* numbers in the array will be numFrames*channelsPerFrame.
*
* @param numFrames number of sample groups. A stereo frame contains 2 samples.
* @param channelsPerFrame 1 for mono, 2 for stereo
*/
public FloatSample(int numFrames, int channelsPerFrame) {
allocate(numFrames, channelsPerFrame);
}
/**
* Allocate memory to hold the audio data. The number of sample numbers in the array will be
* numFrames*channelsPerFrame.
*
* @param numFrames number of sample groups. A stereo frame contains 2 samples.
* @param channelsPerFrame 1 for mono, 2 for stereo
*/
@Override
public void allocate(int numFrames, int channelsPerFrame) {
buffer = new float[numFrames * channelsPerFrame];
this.numFrames = numFrames;
this.channelsPerFrame = channelsPerFrame;
}
/**
* Note that in a stereo sample, a frame has two values.
*
* @param startFrame index of frame in the sample
* @param data data to be written
* @param startIndex index of first value in array
* @param numFrames
*/
public void write(int startFrame, float[] data, int startIndex, int numFrames) {
int numSamplesToWrite = numFrames * channelsPerFrame;
int firstSampleIndexToWrite = startFrame * channelsPerFrame;
System.arraycopy(data, startIndex, buffer, firstSampleIndexToWrite, numSamplesToWrite);
}
/**
* Note that in a stereo sample, a frame has two values.
*
* @param startFrame index of frame in the sample
* @param data array to receive the data from the sample
* @param startIndex index of first location in array to start filling
* @param numFrames
*/
public void read(int startFrame, float[] data, int startIndex, int numFrames) {
int numSamplesToRead = numFrames * channelsPerFrame;
int firstSampleIndexToRead = startFrame * channelsPerFrame;
System.arraycopy(buffer, firstSampleIndexToRead, data, startIndex, numSamplesToRead);
}
/**
* Write the entire array to the sample. The sample data must have already been allocated with
* enough room to contain the data.
*
* @param data
*/
public void write(float[] data) {
write(0, data, 0, data.length / getChannelsPerFrame());
}
public void read(float[] data) {
read(0, data, 0, data.length / getChannelsPerFrame());
}
@Override
public double readDouble(int index) {
return buffer[index];
}
@Override
public void writeDouble(int index, double value) {
buffer[index] = (float) value;
}
/*
* @param fractionalIndex must be >=0 and < (size-1)
*/
public double interpolate(double fractionalIndex) {
int index = (int) fractionalIndex;
float phase = (float) (fractionalIndex - index);
float source = buffer[index];
float target = buffer[index + 1];
return ((target - source) * phase) + source;
}
@Override
public double evaluate(double input) {
// Input ranges from -1 to +1
// Map it to range of sample with guard point.
double normalizedInput = (input + 1.0) * 0.5;
// Clip so it does not go out of range of the sample.
if (normalizedInput < 0.0) normalizedInput = 0.0;
else if (normalizedInput > 1.0) normalizedInput = 1.0;
double fractionalIndex = (getNumFrames() - 1.01) * normalizedInput;
return interpolate(fractionalIndex);
}
}
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