(转)安卓模拟示波器



先来看看本文程序运行的效果图(屏幕录像速度较慢,真机实际运行起来会更加流畅):

(转)安卓模拟示波器

       本文程序使用8000hz的采样率,对X轴方向绘图的实时性要求较高,如果不降低X轴的分辨率,程序的实时性较差,因此程序对X轴数据缩小区间为8倍~16倍。由于采用16位采样,因此Y轴数据的高度相对于手机屏幕来说也偏大,程序也对Y轴数据做缩小,区间为1倍~10倍。在SurfaceView的OnTouchListener方法里加入了波形基线的位置调节,直接在SurfaceView控件上触摸即可控制整体波形偏上或偏下显示。

main.xml源码如下:

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
        android:orientation="vertical" android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <linearlayout android:id="@+id/LinearLayout01" 
                android:layout_height="wrap_content" android:layout_width="fill_parent"
                android:orientation="horizontal">
                <button android:layout_height="wrap_content" android:id="@+id/btnStart" 
                        android:text="开始" android:layout_width="80dip">
                <button android:layout_height="wrap_content" android:text="停止" 
                        android:id="@+id/btnExit" android:layout_width="80dip">
                <zoomcontrols android:layout_width="wrap_content" 
                        android:layout_height="wrap_content" android:id="@+id/zctlX">
                <zoomcontrols android:layout_width="wrap_content" 
                        android:layout_height="wrap_content" android:id="@+id/zctlY">
        
        <surfaceview android:id="@+id/SurfaceView01" 
                android:layout_height="fill_parent" android:layout_width="fill_parent">

ClsOscilloscope.java是实现示波器的类库,包含AudioRecord操作线程和SurfaceView绘图线程的实现,两个线程同步操作,代码如下:

package com.testOscilloscope;
import java.util.ArrayList;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.media.AudioRecord;
import android.view.SurfaceView;
public class ClsOscilloscope {
        private ArrayList inBuf = new ArrayList();
        private boolean isRecording = false;// 线程控制标记
        /**
         * X轴缩小的比例
         */
        public int rateX = 4;
        /**
         * Y轴缩小的比例
         */
        public int rateY = 4;
        /**
         * Y轴基线
         */
        public int baseLine = 0;
        /**
         * 初始化
         */
        public void initOscilloscope(int rateX, int rateY, int baseLine) {
                this.rateX = rateX;
                this.rateY = rateY;
                this.baseLine = baseLine;
        }
        /**
         * 开始
         * 
         * @param recBufSize
         *            AudioRecord的MinBufferSize
         */
        public void Start(AudioRecord audioRecord, int recBufSize, SurfaceView sfv,
                        Paint mPaint) {
                isRecording = true;
                new RecordThread(audioRecord, recBufSize).start();// 开始录制线程
                new DrawThread(sfv, mPaint).start();// 开始绘制线程
        }
        /**
         * 停止
         */
        public void Stop() {
                isRecording = false;
                inBuf.clear();// 清除
        }
        /**
         * 负责从MIC保存数据到inBuf
         * 
         * @author GV
         * 
         */
        class RecordThread extends Thread {
                private int recBufSize;
                private AudioRecord audioRecord;
                public RecordThread(AudioRecord audioRecord, int recBufSize) {
                        this.audioRecord = audioRecord;
                        this.recBufSize = recBufSize;
                }
                public void run() {
                        try {
                                short[] buffer = new short[recBufSize];
                                audioRecord.startRecording();// 开始录制
                                while (isRecording) {
                                        // 从MIC保存数据到缓冲区
                                        int bufferReadResult = audioRecord.read(buffer, 0,
                                                        recBufSize);
                                        short[] tmpBuf = new short[bufferReadResult / rateX];
                                        for (int i = 0, ii = 0; i < tmpBuf.length; i++, ii = i
                                                        * rateX) {
                                                tmpBuf[i] = buffer[ii];
                                        }
                                        synchronized (inBuf) {//
                                                inBuf.add(tmpBuf);// 添加数据
                                        }
                                }
                                audioRecord.stop();
                        } catch (Throwable t) {
                        }
                }
        };
        /**
         * 负责绘制inBuf中的数据
         * 
         * @author GV
         * 
         */
        class DrawThread extends Thread {
                private int oldX = 0;// 上次绘制的X坐标
                private int oldY = 0;// 上次绘制的Y坐标
                private SurfaceView sfv;// 画板
                private int X_index = 0;// 当前画图所在屏幕X轴的坐标
                private Paint mPaint;// 画笔
                public DrawThread(SurfaceView sfv, Paint mPaint) {
                        this.sfv = sfv;
                        this.mPaint = mPaint;
                }
                public void run() {
                        while (isRecording) {
                                ArrayList buf = new ArrayList();
                                synchronized (inBuf) {
                                        if (inBuf.size() == 0)
                                                continue;
                                        buf = (ArrayList) inBuf.clone();// 保存
                                        inBuf.clear();// 清除
                                }
                                for (int i = 0; i < buf.size(); i++) {
                                        short[] tmpBuf = buf.get(i);
                                        SimpleDraw(X_index, tmpBuf, rateY, baseLine);// 把缓冲区数据画出来
                                        X_index = X_index + tmpBuf.length;
                                        if (X_index > sfv.getWidth()) {
                                                X_index = 0;
                                        }
                                }
                        }
                }
                /**
                 * 绘制指定区域
                 * 
                 * @param start
                 *            X轴开始的位置(全屏)
                 * @param buffer
                 *            缓冲区
                 * @param rate
                 *            Y轴数据缩小的比例
                 * @param baseLine
                 *            Y轴基线
                 */
                void SimpleDraw(int start, short[] buffer, int rate, int baseLine) {
                        if (start == 0)
                                oldX = 0;
                        Canvas canvas = sfv.getHolder().lockCanvas(
                                        new Rect(start, 0, start + buffer.length, sfv.getHeight()));// 关键:获取画布
                        canvas.drawColor(Color.BLACK);// 清除背景
                        int y;
                        for (int i = 0; i < buffer.length; i++) {// 有多少画多少
                                int x = i + start;
                                y = buffer[i] / rate + baseLine;// 调节缩小比例,调节基准线
                                canvas.drawLine(oldX, oldY, x, y, mPaint);
                                oldX = x;
                                oldY = y;
                        }
                        sfv.getHolder().unlockCanvasAndPost(canvas);// 解锁画布,提交画好的图像
                }
        }
}

testOscilloscope.java是主程序,控制UI和ClsOscilloscope,代码如下:

package com.testOscilloscope;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.Paint;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.ZoomControls;
public class testOscilloscope extends Activity {
    /** Called when the activity is first created. */
        Button btnStart,btnExit;
        SurfaceView sfv;
    ZoomControls zctlX,zctlY;
    
    ClsOscilloscope clsOscilloscope=new ClsOscilloscope();
    
        static final int frequency = 8000;//分辨率
        static final int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO;
        static final int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
        static final int xMax = 16;//X轴缩小比例最大值,X轴数据量巨大,容易产生刷新延时
        static final int xMin = 8;//X轴缩小比例最小值
        static final int yMax = 10;//Y轴缩小比例最大值
        static final int yMin = 1;//Y轴缩小比例最小值
        
        int recBufSize;//录音最小buffer大小
        AudioRecord audioRecord;
        Paint mPaint;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //录音组件
                recBufSize = AudioRecord.getMinBufferSize(frequency,
                                channelConfiguration, audioEncoding);
                audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency,
                                channelConfiguration, audioEncoding, recBufSize);
                //按键
                btnStart = (Button) this.findViewById(R.id.btnStart);
                btnStart.setOnClickListener(new ClickEvent());
                btnExit = (Button) this.findViewById(R.id.btnExit);
                btnExit.setOnClickListener(new ClickEvent());
                //画板和画笔
                sfv = (SurfaceView) this.findViewById(R.id.SurfaceView01); 
                sfv.setOnTouchListener(new TouchEvent());
        mPaint = new Paint();  
        mPaint.setColor(Color.GREEN);// 画笔为绿色  
        mPaint.setStrokeWidth(1);// 设置画笔粗细 
        //示波器类库
        clsOscilloscope.initOscilloscope(xMax/2, yMax/2, sfv.getHeight()/2);
        
        //缩放控件,X轴的数据缩小的比率高些
                zctlX = (ZoomControls)this.findViewById(R.id.zctlX);
                zctlX.setOnZoomInClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                if(clsOscilloscope.rateX>xMin)
                                        clsOscilloscope.rateX--;
                                setTitle("X轴缩小"+String.valueOf(clsOscilloscope.rateX)+"倍"
                                                +","+"Y轴缩小"+String.valueOf(clsOscilloscope.rateY)+"倍");
                        }
                });
                zctlX.setOnZoomOutClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                if(clsOscilloscope.rateX<xmax)
                                        clsOscilloscope.rateX++;        
                                setTitle("X轴缩小"+String.valueOf(clsOscilloscope.rateX)+"倍"
                                                +","+"Y轴缩小"+String.valueOf(clsOscilloscope.rateY)+"倍");
                        }
                });
                zctlY = (ZoomControls)this.findViewById(R.id.zctlY);
                zctlY.setOnZoomInClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                if(clsOscilloscope.rateY>yMin)
                                        clsOscilloscope.rateY--;
                                setTitle("X轴缩小"+String.valueOf(clsOscilloscope.rateX)+"倍"
                                                +","+"Y轴缩小"+String.valueOf(clsOscilloscope.rateY)+"倍");
                        }
                });
                
                zctlY.setOnZoomOutClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                if(clsOscilloscope.rateY<ymax)
                                        clsOscilloscope.rateY++;        
                                setTitle("X轴缩小"+String.valueOf(clsOscilloscope.rateX)+"倍"
                                                +","+"Y轴缩小"+String.valueOf(clsOscilloscope.rateY)+"倍");
                        }
                });
    }
        @Override
        protected void onDestroy() {
                super.onDestroy();
                android.os.Process.killProcess(android.os.Process.myPid());
        }
        
        /**
         * 按键事件处理
         * @author GV
         *
         */
        class ClickEvent implements View.OnClickListener {
                @Override
                public void onClick(View v) {
                        if (v == btnStart) {
                                clsOscilloscope.baseLine=sfv.getHeight()/2;
                                clsOscilloscope.Start(audioRecord,recBufSize,sfv,mPaint);
                        } else if (v == btnExit) {
                                clsOscilloscope.Stop();
                        }
                }
        }
        /**
         * 触摸屏动态设置波形图基线
         * @author GV
         *
         */
        class TouchEvent implements OnTouchListener{
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                        clsOscilloscope.baseLine=(int)event.getY();
                        return true;
                }
                
        }
}



(转)安卓模拟示波器

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