如何让这个脉冲波在 Java 中的占空比样本之间有更好的转换

Question

我正在构建一个扩展方波发生器的脉冲波发生器。

我的问题是我希望脉宽调制过渡更平滑我试图使波峰和波谷之间的中间样本在调制宽度时平滑地上下移动。这是如此高的声音，例如 2093 Hz 的 C7 在调制占空比时听起来不会发出咔哒声。

需要做什么？

采样率为 44100 比特率为 16 ampLimit 是最高可能值。持续时间是以秒为单位的波形长度占空比是波形的起始周期

public class PulseGenerator extends SquareGenerator {

    // constants
    public static final double DEF_MIN_DUTY_CYCLE = 0.05;
    public static final double DEF_MAX_DUTY_CYCLE = 0.95;
    public static final double DEF_CYCLE_FREQ = 2;
    public static final double DEF_HOLD_CYCLE = 0;

    // instance variables
    double minDutyCycle; // minimum value of duty cycle
    double maxDutyCycle; // maximum value of duty cycle
    double cycleFreq;
    double holdCycle; // if more than zero, the wave will hold the modulation for that period
    double dutyCycleRange;  // maxDutyCycle - minDutyCycle
    boolean setDirection;

    // constructor
    public PulseGenerator(double amplitude, double frequency, int bitRate,
            double duration, double dutyCycle, double minDutyCycle,
            double maxDutyCycle, double cycleFreq, double holdCycle) {
        super(amplitude, frequency, bitRate, duration, dutyCycle);
        // sample data
        squareSample = new int[sampleLength];
        calculateAmpLimit();
        this.dutyCycle = dutyCycle;
        waveLength = SAMPLE_RATE / this.frequency;
        this.minDutyCycle = minDutyCycle;
        this.maxDutyCycle = maxDutyCycle;
        this.cycleFreq = cycleFreq * SAMPLE_RATE;
        this.holdCycle = holdCycle * SAMPLE_RATE;
        dutyCycleRange = this.maxDutyCycle - this.minDutyCycle;
        setDirection = false;
    }

    // one arg cunstructor
    public PulseGenerator(double frequency) {
        this(AMPLITUDE, frequency, BIT_RATE, DURATION, DEF_DUTY_CYCLE,
                DEF_MIN_DUTY_CYCLE, DEF_MAX_DUTY_CYCLE, DEF_CYCLE_FREQ,
                DEF_HOLD_CYCLE);
    }

    // no args constructor
    public PulseGenerator() {
        this(AMPLITUDE, FREQUENCY, BIT_RATE, DURATION, DEF_DUTY_CYCLE,
                DEF_MIN_DUTY_CYCLE, DEF_MAX_DUTY_CYCLE, DEF_CYCLE_FREQ,
                DEF_HOLD_CYCLE);
    }

    // generate waveform method
    @Override
    public int[] generateWaveForm() {

        // define cycle point
        int cyclePoint = (int)(cycleFreq / 2 * ((dutyCycle * dutyCycleRange) + minDutyCycle));

        // generate the actual waveform
        for (int i = 0, j = 0; i < sampleLength; i++, j++) {

            double waveCycleRatio = waveLength * dutyCycle;

            // same as square generate method
            if (j - waveCycleRatio < 0.0) {
                finePoint = 1.0;
            } else if (j - waveCycleRatio >= 0.0 
                    && j - waveCycleRatio < 1) {
                finePoint = 1 - (j - waveCycleRatio);
            } else if (j - waveLength < 0.0) {
                finePoint = -1.0;
            } else if (j - waveLength >= 0.0) {
                finePoint = -1 + (waveLength - j);
            }
            if (j >= waveLength) {
                j = 1;
            }
            point = (int)finePoint * ampLimit;
            squareSample[i] = point;

            if (holdCycle > 0) {
                holdCycle--;
            } else {
                dutyCycle = (cyclePoint / (cycleFreq / 2) * dutyCycleRange)
                        + minDutyCycle;
                if (cyclePoint < cycleFreq / 2 && !setDirection) {
                    cyclePoint++;
                } else if (cyclePoint >= cycleFreq / 2 && !setDirection) {
                    cyclePoint--;
                    setDirection = true;
                } else if (cyclePoint > 0 && setDirection) {
                    cyclePoint--;
                } else if (cyclePoint <= 0 && setDirection) {
                    cyclePoint++;
                    setDirection = false;
                }
            }
        }

        // return the sample data
        return squareSample;
    }

}

Answer 1

我实际上发现了问题所在，首先我将精细点转换为整数，然后再将其乘以安培限制。其次，精细点的代码需要重新定位并乘以二。

// generate the actual waveform
        for (int i = 0, j = 0; i < sampleLength; i++, j++) {

            double waveCycleRatio = waveLength * dutyCycle;

            // same as square
            if (j - waveCycleRatio < 0.0) {
                finePoint = 1.0;
            } else if (j - waveCycleRatio >= 0.0 
                    && j - waveCycleRatio < 1) {
                finePoint = 0 - (j - waveCycleRatio - 0.5) * 2;
            } else if (j - waveLength < 0.0) {
                finePoint = -1.0;
            } else if (j - waveLength >= 0.0) {
                finePoint = (j - waveLength - 0.5) * 2;
            }
            if (j >= waveLength) {
                j = 1;
            }
            point = (int)(finePoint * ampLimit);
            squareSample[i] = point;

            if (holdCycle > 0) {
                holdCycle--;
            } else {
                dutyCycle = (cyclePoint / (cycleFreq / 2) * dutyCycleRange)
                        + minDutyCycle;
                if (cyclePoint < cycleFreq / 2 && !setDirection) {
                    cyclePoint++;
                } else if (cyclePoint >= cycleFreq / 2 && !setDirection) {
                    cyclePoint--;
                    setDirection = true;
                } else if (cyclePoint > 0 && setDirection) {
                    cyclePoint--;
                } else if (cyclePoint <= 0 && setDirection) {
                    cyclePoint++;
                    setDirection = false;
                }
            }
        }

如何让这个脉冲波在 Java 中的占空比样本之间有更好的转换

How to get this pulse wave to to have a finer transtion between duty cycle samples in Java

java

waveform