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Unverified Commit 860226d1 authored by Luca Stefani's avatar Luca Stefani
Browse files

Eleven: Fix visualizer capture 

First of all the capture size must be queried at runtime and can vary
from device to device, we now use the minimum capture size supported.

Now the data points are a factor of the capture size instead of the
hardcoded 32 points.

Fix the magnitude to DB function to multiply by 20 instead of 10.

Calculate the first magnitude properly, as FFT[0] is always real since
the signal is real.

We ignore n/2 magnitude as we only sample 1/4 of the signal to
visualize.

Change-Id: If53213fee3bb45aec4783896947fe64a1d162db2
parent b1325202

src/org/lineageos/eleven/widgets/VisualizerView.java

+24 −19
Original line number Diff line number Diff line
@@ -40,12 +40,15 @@ public class VisualizerView extends View { 
    private static final long DURATION_LINK = 800;

    private static final long DURATION_UNLINK = 600;



    private static final int CAPTURE_SIZE = Visualizer.getCaptureSizeRange()[0];

    private static final int POINTS_SIZE = CAPTURE_SIZE / 4;



    private Paint mPaint;

    private Visualizer mVisualizer;

    private ObjectAnimator mVisualizerColorAnimator;



    private final ValueAnimator[] mValueAnimators = new ValueAnimator[32];

    private final float[] mFFTPoints = new float[128];

    private final ValueAnimator[] mValueAnimators = new ValueAnimator[POINTS_SIZE];

    private final float[] mFFTPoints = new float[CAPTURE_SIZE];



    private boolean mVisible = false;

    private boolean mPlaying = false;
@@ -56,9 +59,9 @@ public class VisualizerView extends View { 


    private final Visualizer.OnDataCaptureListener mVisualizerListener =

            new Visualizer.OnDataCaptureListener() {

                byte rfk, ifk;

                int dbValue;

                float magnitude;

                private float magnitudeToDB(float magnitude) {

                    return magnitude > 0 ? (float) (20 * Math.log10(magnitude)) : 0;

                }



                @Override

                public void onWaveFormDataCapture(Visualizer visualizer, byte[] bytes,
@@ -69,17 +72,19 @@ public class VisualizerView extends View { 
                @Override

                public void onFftDataCapture(Visualizer visualizer, byte[] fft,

                                             int samplingRate) {

                    for (int i = 0; i < 32; i++) {

                        mValueAnimators[i].cancel();



                        rfk = fft[i * 2 + 2];

                        ifk = fft[i * 2 + 3];

                        magnitude = rfk * rfk + ifk * ifk;

                        dbValue = magnitude > 0 ? (int) (10 * Math.log10(magnitude)) : 0;

                    float[] decibels = new float[POINTS_SIZE];

                    decibels[0] = magnitudeToDB((float) Math.abs(fft[0]));

                    for (int k = 1; k < POINTS_SIZE; k++) {

                        int i = k * 2;

                        float magnitude = (float) Math.hypot(fft[i], fft[i + 1]);

                        decibels[k] = magnitudeToDB(magnitude);

                    }



                    for (int i = 0; i < POINTS_SIZE; i++) {

                        mValueAnimators[i].cancel();

                        mValueAnimators[i].setFloatValues(

                                mFFTPoints[i * 4 + 1],

                                mFFTPoints[3] - (dbValue * 16f));

                                mFFTPoints[3] - decibels[i] * 16f);

                        mValueAnimators[i].start();

                    }

                }
@@ -96,7 +101,7 @@ public class VisualizerView extends View { 
            }



            mVisualizer.setEnabled(false);

            mVisualizer.setCaptureSize(66);

            mVisualizer.setCaptureSize(CAPTURE_SIZE);

            mVisualizer.setDataCaptureListener(mVisualizerListener, Visualizer.getMaxCaptureRate(),

                    false, true);

            mVisualizer.setEnabled(true);
@@ -145,12 +150,12 @@ public class VisualizerView extends View { 
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {

        super.onSizeChanged(w, h, oldw, oldh);



        float barUnit = w / 32f;

        float barUnit = w / (float) POINTS_SIZE;

        float barWidth = barUnit * 8f / 9f;

        barUnit = barWidth + (barUnit - barWidth) * 32f / 31f;

        barUnit = barWidth + (barUnit - barWidth) * (float) POINTS_SIZE / (POINTS_SIZE - 1f);

        mPaint.setStrokeWidth(barWidth);



        for (int i = 0; i < 32; i++) {

        for (int i = 0; i < POINTS_SIZE; i++) {

            mFFTPoints[i * 4] = mFFTPoints[i * 4 + 2] = i * barUnit + (barWidth / 2);

            mFFTPoints[i * 4 + 1] = h;

            mFFTPoints[i * 4 + 3] = h;
@@ -173,10 +178,10 @@ public class VisualizerView extends View { 
        mPaint.setAntiAlias(true);

        mPaint.setColor(mColor);



        for (int i = 0; i < 32; i++) {

        for (int i = 0; i < POINTS_SIZE; i++) {

            final int j = i * 4 + 1;

            mValueAnimators[i] = new ValueAnimator();

            mValueAnimators[i].setDuration(128);

            mValueAnimators[i].setDuration(CAPTURE_SIZE);

            mValueAnimators[i].addUpdateListener(animation ->

                    mFFTPoints[j] = (float) animation.getAnimatedValue());

        }