cooleshow_android/musicMerge/src/main/java/com/cooleshow/musicmerge/widget/MusicFrequencyView.java

package com.cooleshow.musicmerge.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.media.audiofx.Visualizer;
import android.util.AttributeSet;
import android.view.View;

import com.cooleshow.base.utils.LOG;
import com.cooleshow.base.utils.SizeUtils;
import com.cooleshow.musicmerge.R;

import androidx.annotation.Nullable;

/**
 *
 * on 2021/4/13
 * 自定义组件：音乐频谱显示组件
 * API-> setMediaPlayer()  外层设置路径 播放之后 自动显示频谱效果
 */
public class MusicFrequencyView extends View {
    private static final String TAG = "MusicFrequencyView";
    private int LUMP_COUNT = 120;
    private int LUMP_WIDTH = SizeUtils.dp2px(1.5f);
    ;
    private int LUMP_SPACE = SizeUtils.dp2px(3);
    private int LUMP_SIZE = LUMP_WIDTH + LUMP_SPACE;
    private int LUMP_MAX_HEIGHT = SizeUtils.dp2px(80);
    private int LUMP_MIN_HEIGHT = SizeUtils.dp2px(3);
    private float SCALE = 0.95f;
    private int widthsize;
    private int heightsize;
    private Visualizer visualizer;
    private int itemColor = Color.WHITE;
    private Paint paint1;
    protected RectF mRect;

    public MusicFrequencyView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.musicView);
        itemColor = ta.getColor(R.styleable.musicView_itemColor, Color.WHITE);
        mRect = new RectF();
        waveData = new float[LUMP_COUNT];
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        widthsize = MeasureSpec.getSize(widthMeasureSpec);
        heightsize = MeasureSpec.getSize(heightMeasureSpec);
        setMeasuredDimension(widthsize, heightsize);
        init();
    }


    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        mRect.set(0, 0, getWidth(), getHeight());
    }


    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //因为外部宽度是写死的,不调整坐标算法,最后一个可能绘制不全,暂时不绘制最后一个吧
        for (int i = 1; i <= LUMP_COUNT-1; i++) {
//            canvas.drawLine(mRect.width() * i / LUMP_COUNT, mRect.height() / 2, mRect.width() * i / LUMP_COUNT, -LUMP_MIN_HEIGHT + mRect.height() / 2 - SCALE * waveData[i], paint1);
//            canvas.drawLine(mRect.width() * i / LUMP_COUNT, mRect.height() / 2, mRect.width() * i / LUMP_COUNT, LUMP_MIN_HEIGHT + mRect.height() / 2 + SCALE * waveData[i], paint1);
            canvas.drawLine(mRect.width() * i / LUMP_COUNT, -LUMP_MIN_HEIGHT + mRect.height() / 2 - SCALE * waveData[i-1], mRect.width() * i / LUMP_COUNT, LUMP_MIN_HEIGHT + mRect.height() / 2 + SCALE * waveData[i - 1], paint1);
        }
    }

    private Path getPath(float startX, float startY, float endX, float endY, Paint paint) {
        Path path = new Path();
        paint.setStrokeCap(Paint.Cap.SQUARE);
        path.moveTo(startY, startY);
        path.lineTo(endX / 2, endY / 2);
        paint.setStrokeCap(Paint.Cap.ROUND);
        path.lineTo(endX, endY);
        return path;
    }


    private Visualizer.OnDataCaptureListener dataCaptureListener = new Visualizer.OnDataCaptureListener() {
        @Override
        public void onWaveFormDataCapture(Visualizer visualizer, byte[] waveform, int samplingRate) {
        }

        @Override
        public void onFftDataCapture(Visualizer visualizer, byte[] fft, int samplingRate) {
            setWaveData(fft);
        }
    };

    private float[] waveData;

    private void setWaveData(byte[] fft) {
        waveData = readyData(fft);
//        LOG.i(TAG, "setWaveData:" + waveData);
        invalidate();
    }

    /**
     * 预处理数据
     *
     * @return
     */
    private float[] readyData(byte[] fft) {
        float[] model = new float[fft.length / 2 + 1];
        model[0] = (float) Math.abs(fft[1]);
        int j = 1;

        for (int i = 2; i < LUMP_COUNT * 2; ) {

            model[j] = (float) Math.hypot(fft[i], fft[i + 1]);
            i += 2;
            j++;
            model[j] = Math.abs(model[j]);
        }
//        LOG.i(TAG,"model:"+model.length);
        float[] results = hananianWindow(model, 2);
//        LOG.i(TAG,"results:"+results.length);
        return results;
    }

    public static float[] hananianWindow(float[] data, int windowSize) {
        float[] windowData = new float[data.length - windowSize + 1];
        for (int i = 0; i < windowData.length; i++) {
            float sum = 0;
            for (int j = 0; j < windowSize; j++) {
                sum += data[i + j];
            }
            windowData[i] = sum / windowSize;
        }
        return windowData;
    }

    /**
     * 只需传入 mediaPlayer 即可
     *
     * @param
     */
    public void setMediaPlayer(final int audioSessionId) {
        try {
            if (visualizer == null) {
                visualizer = new Visualizer(audioSessionId);

                int captureSize = Visualizer.getCaptureSizeRange()[1];
                int captureRate = Visualizer.getMaxCaptureRate() / 2;
                // 3：设置参数
                visualizer.setCaptureSize(captureSize);
                visualizer.setDataCaptureListener(dataCaptureListener, captureRate, false, true);
                visualizer.setScalingMode(Visualizer.SCALING_MODE_NORMALIZED);
                visualizer.setEnabled(true);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setVisualizerEnable(boolean isEnable) {
        if (visualizer != null) {
            visualizer.setEnabled(isEnable);
        }
    }

    public void release() {
        if (visualizer != null) {
            visualizer.release();
        }
    }


    /**
     * 设置频率数据
     *
     * @param data
     */
    public void setMusicData(int[] data) {

    }

    /**
     * 初始化画笔
     */
    void init() {
        paint1 = new Paint();
        paint1.setStrokeWidth(LUMP_WIDTH);
        paint1.setColor(itemColor);
        paint1.setStrokeCap(Paint.Cap.ROUND);
        paint1.setAntiAlias(true);
        paint1.setStyle(Paint.Style.FILL);
        paint1.setStrokeJoin(Paint.Join.BEVEL);
//        paint1.setMaskFilter(new BlurMaskFilter(5, BlurMaskFilter.Blur.SOLID));
    }
}