根据播放音乐显示不同频谱案例

Android应用源码音乐实时跳动频谱显示Demo/build.gradle

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+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 22
+    buildToolsVersion "23.0.2"
+
+    defaultConfig {
+        applicationId "com.terry.AudioFx"
+        minSdkVersion 15
+        targetSdkVersion 22
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
+        }
+    }
+}

Android应用源码音乐实时跳动频谱显示Demo/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.terry.AudioFx"
+    android:versionCode="1"
+    android:versionName="1.0" >
+
+    <application
+        android:icon="@drawable/icon"
+        android:label="@string/app_name" >
+        <activity
+            android:label="@string/app_name"
+            android:name=".AudioFxActivity" >
+            <intent-filter >
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+    <uses-sdk android:minSdkVersion="10" />
+
+    <uses-permission android:name="android.permission.RECORD_AUDIO" ></uses-permission>
+
+</manifest>

Android应用源码音乐实时跳动频谱显示Demo/src/main/java/com/terry/AudioFx/AudioFxActivity.java

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+package com.terry.AudioFx;
+
+import android.app.Activity;
+import android.media.AudioManager;
+import android.media.MediaPlayer;
+import android.media.audiofx.Visualizer;
+import android.os.Bundle;
+
+public class AudioFxActivity extends Activity
+{
+
+	private static final String TAG = "AudioFxActivity";
+
+
+	private MediaPlayer mMediaPlayer;
+	private Visualizer mVisualizer;
+
+	private  BaseVisualizerView mBaseVisualizerView;
+
+	public void onCreate(Bundle savedInstanceState)
+	{
+		super.onCreate(savedInstanceState);
+		setVolumeControlStream(AudioManager.STREAM_MUSIC);
+
+
+		setContentView(R.layout.main);
+		mBaseVisualizerView = (BaseVisualizerView) findViewById(R.id.visualizerview);
+
+		mMediaPlayer = MediaPlayer.create(this, R.raw.z8806c);
+
+
+
+
+		mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
+			@Override
+			public void onPrepared(MediaPlayer mp) {
+				mMediaPlayer.start();
+				setupVisualizerFxAndUi();
+			}
+		});
+
+
+		mMediaPlayer.setLooping(true);
+
+	}
+
+
+	/**
+	 * 生成一个VisualizerView对象，使音频频谱的波段能够反映到 VisualizerView上
+	 */
+	private void setupVisualizerFxAndUi()
+	{
+
+		int audioSessionid = mMediaPlayer.getAudioSessionId();
+		System.out.println("audioSessionid=="+audioSessionid);
+		mVisualizer = new Visualizer(audioSessionid);
+		// 参数内必须是2的位数
+		mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
+		// 设置允许波形表示，并且捕获它
+		mBaseVisualizerView.setVisualizer(mVisualizer);
+		mVisualizer.setEnabled(true);
+	}
+
+	@Override
+	protected void onPause()
+	{
+		super.onPause();
+		if (isFinishing() && mMediaPlayer != null)
+		{
+			mVisualizer.release();
+			mMediaPlayer.release();
+			mMediaPlayer = null;
+		}
+	}
+
+}

Android应用源码音乐实时跳动频谱显示Demo/src/main/java/com/terry/AudioFx/BaseVisualizerView.java

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+package com.terry.AudioFx;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Paint.Cap;
+import android.graphics.Paint.Join;
+import android.media.audiofx.Visualizer;
+import android.util.AttributeSet;
+import android.view.View;
+
+public class BaseVisualizerView extends View implements Visualizer.OnDataCaptureListener{
+
+    private static final int DN_W = 480;
+    private static final int DN_H = 160;
+    private static final int DN_SL =14;
+    private static final int DN_SW = 6;
+
+    private int hgap = 0;
+    private int vgap = 0;
+    private int levelStep = 0;
+    private float strokeWidth = 0;
+    private float strokeLength = 0;
+
+    /**
+     * It is the max level.
+     */
+    protected final static int MAX_LEVEL = 13;
+
+    /**
+     * It is the cylinder number.
+     */
+    protected final static int CYLINDER_NUM = 20;
+
+    /**
+     * It is the visualizer.
+     */
+    protected Visualizer mVisualizer = null;
+
+    /**
+     * It is the paint which is used to draw to visual effect. 
+     */
+    protected Paint mPaint = null;
+
+    /**
+     * It is the buffer of fft.
+     */
+    protected byte[] mData = new byte[CYLINDER_NUM];
+
+    boolean mDataEn = true;
+    /**
+     * It constructs the base visualizer view.
+     * @param context It is the context of the view owner.
+     */
+    public BaseVisualizerView(Context context) {
+        super(context);
+
+        initView();
+    }
+
+    private void initView() {
+        mPaint = new Paint();
+        mPaint.setAntiAlias(true);
+        mPaint.setColor(Color.GREEN);
+//        mPaint.setColor(0xFFd60d25);
+        mPaint.setStrokeJoin(Join.ROUND);
+        mPaint.setStrokeCap(Cap.ROUND);
+    }
+
+    public BaseVisualizerView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        initView();
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        super.onLayout(changed, left, top, right, bottom);
+
+        float w, h, xr, yr;
+        w = right - left;
+        h = bottom - top;
+        xr = w / (float)DN_W;
+        yr = h / (float)DN_H;
+
+        strokeWidth = DN_SW * yr;
+        strokeLength = DN_SL * xr;
+        hgap = (int)((w - strokeLength * CYLINDER_NUM) / (CYLINDER_NUM + 1) );
+        vgap = (int)(h / (MAX_LEVEL + 2));
+
+        mPaint.setStrokeWidth(strokeWidth);
+    }
+
+    protected void drawCylinder(Canvas canvas, float x, byte value) {
+        if (value < 0) value = 0;
+        for (int i = 0; i < value; i++) {
+            float y = getHeight() - i * vgap - vgap;
+            canvas.drawLine(x, y, x + strokeLength, y, mPaint);
+        }
+    }
+
+    @Override
+    public void onDraw(Canvas canvas) {
+        for (int i = 0; i < CYLINDER_NUM; i ++) {
+            drawCylinder(canvas, strokeWidth / 2 + hgap + i * (hgap + strokeLength), mData[i]);
+        }
+    }
+
+    /**
+     * It sets the visualizer of the view. DO set the viaulizer to null when exit the program.
+     * @parma visualizer It is the visualizer to set.
+     */
+    public void setVisualizer(Visualizer visualizer) {
+        if (visualizer != null) {
+            if (!visualizer.getEnabled()) {
+                visualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[0]);
+            }
+            levelStep = 128 / MAX_LEVEL;
+            visualizer.setDataCaptureListener(this, Visualizer.getMaxCaptureRate() / 2, false, true);
+
+        } else {
+
+            if (mVisualizer != null) {
+                mVisualizer.setEnabled(false);
+                mVisualizer.release();
+            }
+        }
+        mVisualizer = visualizer;
+    }
+
+    @Override
+    public void onFftDataCapture(Visualizer visualizer, byte[] fft,
+            int samplingRate) {
+        byte[] model = new byte[fft.length / 2 + 1];
+        if (mDataEn) {
+
+            model[0] = (byte) Math.abs(fft[1]);  
+            int j = 1;  
+            for (int i = 2; i < fft.length;) {
+                model[j] = (byte) Math.hypot(fft[i], fft[i + 1]);  
+                i += 2;  
+                j++;  
+            }
+        } else {
+            for (int i = 0; i < CYLINDER_NUM; i ++) {
+                model[i] = 0;
+            }
+        }
+        for (int i = 0; i < CYLINDER_NUM; i ++) {
+            final byte a = (byte)(Math.abs(model[CYLINDER_NUM  - i]) / levelStep);
+
+            final byte b = mData[i];
+            if (a > b) {
+                mData[i] = a;
+            } else {
+                if (b > 0) {
+                    mData[i]--;
+                }
+            }
+        }
+        postInvalidate();
+    }
+
+    @Override
+    public void onWaveFormDataCapture(Visualizer visualizer, byte[] waveform,
+            int samplingRate) {
+        // Do nothing.
+    }
+
+    /**
+     * It enables or disables the data processs.
+     * @param en If this value is true it enables the data process..
+     */
+    public void enableDataProcess(boolean en) {
+        mDataEn = en;
+    }
+}

Android应用源码音乐实时跳动频谱显示Demo/src/main/res/layout/main.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:orientation="vertical">
+
+    <com.terry.AudioFx.BaseVisualizerView
+        android:id="@+id/visualizerview"
+        android:layout_width="fill_parent"
+        android:layout_height="100dp"
+        />
+</LinearLayout>

Android应用源码音乐实时跳动频谱显示Demo/src/main/res/values/strings.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="hello">Hello World, AudioFxActivity!</string>
+    <string name="app_name">android跳动频谱</string>
+</resources>