音频可视化android代码中的移动线

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.util.AttributeSet;
import android.view.View;

public class AudioVisualizerView extends View {
    private static final int SAMPLE_RATE = 44100; // 采样率
    private static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_MONO; // 单声道
    private static final int AUDIO_FORMAT = AudioFormat.ENCODING_PCM_16BIT; // 16位PCM编码

    private AudioRecord audioRecord;
    private int bufferSize;
    private short[] audioData;
    private Paint linePaint;
    private float[] points;

    public AudioVisualizerView(Context context) {
        super(context);
        init();
    }

    public AudioVisualizerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        bufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL_CONFIG, AUDIO_FORMAT);
        audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, SAMPLE_RATE, CHANNEL_CONFIG, AUDIO_FORMAT, bufferSize);
        audioData = new short[bufferSize];
        linePaint = new Paint();
        linePaint.setColor(Color.RED);
        linePaint.setStrokeWidth(5);
        points = new float[bufferSize * 4];
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        canvas.drawColor(Color.BLACK);

        int bytesRead = audioRecord.read(audioData, 0, bufferSize);
        for (int i = 0; i < bytesRead; i++) {
            points[i * 4] = getWidth() * i / bytesRead;
            points[i * 4 + 1] = getHeight() / 2 + audioData[i] * getHeight() / 4 / Short.MAX_VALUE;
            points[i * 4 + 2] = getWidth() * (i + 1) / bytesRead;
            points[i * 4 + 3] = getHeight() / 2 + audioData[i + 1] * getHeight() / 4 / Short.MAX_VALUE;
        }

        canvas.drawLines(points, linePaint);
        invalidate();
    }

    public void startVisualization() {
        audioRecord.startRecording();
        invalidate();
    }

    public void stopVisualization() {
        audioRecord.stop();
    }
}