实例教程十四：视频刻录（调用前置摄像头）

        android:id\="@+id/btnStop"

        android:layout\_width\="wrap\_content"

        android:layout\_height\="wrap\_content"

        android:layout\_alignTop\="@id/btnRecord"

        android:layout\_marginRight\="20dp"

        android:layout\_toLeftOf\="@id/btnRecord"

        android:onClick\="record"

        android:text\="@string/btnStop" /> 

</RelativeLayout> 

<manifest xmlns:android="schemas.android.com/apk/res/and…"

package\="cn.itcast.recorder"

android:versionCode\="1"

android:versionName\="1.0" > 



<uses-sdk android:minSdkVersion="8" /> 



<application 

    android:icon\="@drawable/ic\_launcher"

    android:label\="@string/app\_name" > 

    <activity 

        android:name\=".MainActivity"

        android:label\="@string/app\_name"

        android:screenOrientation\="landscape" > 

        <intent-filter> 

            <action android:name="android.intent.action.MAIN" /> 



            <category android:name="android.intent.category.LAUNCHER" /> 

        </intent-filter> 

    </activity> 

</application> 

  

<uses-permission android:name="android.permission.RECORD\_AUDIO"/> 

<uses-permission android:name="android.permission.CAMERA" /> 

<!-- 在SDCard中创建与删除文件权限 --> 

<uses-permission android:name="android.permission.MOUNT\_UNMOUNT\_FILESYSTEMS" /> 

<!-- 在SDCard中写入数据权限 --> 

<uses-permission android:name="android.permission.WRITE\_EXTERNAL\_STORAGE" /> 

package cn.itcast.recorder;

import java.io.File;

import android.app.Activity;

import android.hardware.Camera;

import android.media.MediaRecorder;

import android.os.Bundle;

import android.os.Environment;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

import android.view.View;

import android.view.Window;

import android.view.WindowManager;

import android.widget.Button;

import android.widget.RelativeLayout;

import android.hardware.Camera.Parameters;

public class MainActivity extends Activity {

    private SurfaceView sfvShow; 

    private RelativeLayout btnLayout; 

    private Button btnRecord; 

    private Button btnStop; 

    private MediaRecorder mediaRecorder; 



    private Camera camera = null;         

    private Camera.CameraInfo cameraInfo; 

    private int cameraCount = 0; 



    @Override

    public void onCreate(Bundle savedInstanceState) { 

            super.onCreate(savedInstanceState); 



            requestWindowFeature(Window.FEATURE\_NO\_TITLE); //设置窗口无标题 

            getWindow().setFlags(WindowManager.LayoutParams.FLAG\_FULLSCREEN,  

                            WindowManager.LayoutParams.FLAG\_FULLSCREEN); //设置全屏 

            setContentView(R.layout.main); 



            initView(); 

    } 



    private void initView(){ 

            btnRecord \= (Button)this.findViewById(R.id.btnRecord); 

            btnStop \= (Button)this.findViewById(R.id.btnStop); 



            btnLayout \= (RelativeLayout)this.findViewById(R.id.btnLayout); 

            sfvShow \= (SurfaceView)this.findViewById(R.id.sfvShow); 



            sfvShow.getHolder().setType(SurfaceHolder.SURFACE\_TYPE\_PUSH\_BUFFERS); 

            sfvShow.getHolder().setFixedSize(176, 144); 

            sfvShow.getHolder().setKeepScreenOn(true); //使摄像头一直保持高亮 

    } 



    //触摸屏幕事件 

    @Override

    public boolean onTouchEvent(MotionEvent event) { 

            if(event.getAction() == MotionEvent.ACTION\_DOWN){ 

                    btnLayout.setVisibility(View.VISIBLE); 

            } 

            return super.onTouchEvent(event); 

    } 



    public void record(View v){ 

            switch(v.getId()){ 

            case R.id.btnRecord: 

                    try{ 

                            initCamera(); //调用前置摄像头--注意，要在MediaRecorder设置参数之前就调用unlock来获得camera的控制权。camera是单例的嘛。如果不调用，程序就挂 

                            File videofile = new File(Environment.getExternalStorageDirectory(), System.currentTimeMillis() + ".3gp"); 

                            mediaRecorder \= new MediaRecorder(); 

                            mediaRecorder.setCamera(camera); //如果需要前置摄像头，则加上，反之，这句话不需要存在 

                            //设置声音从哪个设备获取 

                            mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); 

                            //设置画面从哪个设备获取 

                            mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA); 

                            //设置输入的格式 

                            mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE\_GPP); 

                            //设置视频大小 

                            mediaRecorder.setVideoSize(320, 240); 

                            //设置每秒获取几帧，5帧比较清晰 

                            mediaRecorder.setVideoFrameRate(5); 

                            //设置音频编码格式 

                            mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR\_NB); 

                            //设置视频编码格式 

                            mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264); 

                            //设置文件存放位置 

                            mediaRecorder.setOutputFile(videofile.getAbsolutePath()); 

                            //显示画面 

                            mediaRecorder.setPreviewDisplay(sfvShow.getHolder().getSurface()); //预览输入 

                            //缓冲 

                            mediaRecorder.prepare(); 

                            //开始刻录 

                            mediaRecorder.start(); 

                    }catch(Exception e){ 

                            e.printStackTrace(); 

                    } 

                    btnRecord.setEnabled(false); 

                    btnStop.setEnabled(true); 



                    break; 

            case R.id.btnStop: 

                    if(mediaRecorder != null){ 

                            //停止记录 

                            mediaRecorder.stop(); 

                            //释放该对象 

                            mediaRecorder.release(); 

                    } 



                    btnRecord.setEnabled(true); 

                    btnStop.setEnabled(false); 

                    break; 

            default: 

                    break; 

            } 

    } 



    private void initCamera(){ 

            Camera.CameraInfo cameraInfo \= new Camera.CameraInfo();   

            cameraCount \= Camera.getNumberOfCameras(); // get cameras number