android 拍照及录视频简单的实例

拍照实现步骤：
<1>界面使用SurfaceView控件，显示照相机的画面
<2>SurfaceView接受摄像头界面变化的信息
surfaceView.getHolder().addCallback()
<3>重写三个方法
surfaceDestroyed—>当预览界面关闭时，触发
一般在这里执行销毁照相机的操作，释放内存
camera.stopPreview();
camera.release();
camera = null;
surfaceCreated—–>预览界面被创建时，调用
一般在这里打开照相机和设置照相机的一些参数

        // 打开摄像头
        camera = Camera.open();

        // 给摄像头设置参数
        Parameters parameters = camera.getParameters();
        // 设置每秒3栈
        parameters.setPreviewFrameRate(3);
        // 设置照片的输出格式
        parameters.setPictureFormat(PixelFormat.JPEG);
        // 设置照片的质量
        parameters.set("jpeg-quality", 85);
        // 给照相机设置参数
        camera.setParameters(parameters);
        //将摄像头的画面显示到SurfaceView控件上
        camera.setPreviewDisplay(sv_main_camera.getHolder());
        // 开始预览
        camera.startPreview();
    surfaceChanged----->当预览界面的格式和大小发生改变时，触发
<4>保存
    camera.takePicture
    将照片保存到内存卡(压缩)

2.视频录制
实现步骤：
<1>将视频动画显示到SurfaceView控件上
<2>使用MediaRecorder类进行视频的录制
常用的方法：
mediaRecorder.reset();
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA); //从照相机采集视频
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mediaRecorder.setVideoFrameRate(3); //每秒3帧
mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263); //设置视频编码方式
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
File videoFile = new File(Environment.getExternalStorageDirectory(), System.currentTimeMillis()+”.3gp”);
mediaRecorder.setOutputFile(videoFile.getAbsolutePath());
mediaRecorder.setPreviewDisplay(surfaceView.getHolder().getSurface());
mediaRecorder.prepare();//预期准备
mediaRecorder.start();//开始刻录
mediaRecorder.stop();//停止刻录

注意：权限

<!--打开照相机权限-->
<uses-permission android:name="android.permission.CAMERA" />
<!--创建文件权限-->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<!--写进内存卡权限-->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!--录制视频权限-->
<uses-permission android:name="android.permission.RECORD_AUDIO" />

拍照代码如下:

public class MainActivity extends AppCompatActivity {

    private SurfaceView sv_main_surface;
    private Camera camera;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sv_main_surface = (SurfaceView)findViewById(R.id.sv_main_surface);
        sv_main_surface.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder surfaceHolder) {
                //打开照相机
                camera = Camera.open();
                //设置参数
                Camera.Parameters parameters=camera.getParameters();
                //设置格式
                parameters.setPictureFormat(PixelFormat.JPEG);
                //设置照片质量
                parameters.set("jpeg_quality",85);
                camera.setParameters(parameters);
                //将画面展示到SurfaceView

                 try {
                        camera.setPreviewDisplay(sv_main_surface.getHolder());
                 } catch (IOException e) {
                        e.printStackTrace();
                  }
                //开启预览效果
                camera.startPreview();
                }

            @Override
            public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

            }

            @Override
            public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
                if(camera!=null){
                    camera.stopPreview();
                    camera.release();
                    camera=null;
                }
            }
        });
    }

    public void takePhoto(View view){
        camera.takePicture(null, null, new Camera.PictureCallback() {
            @Override
            public void onPictureTaken(byte[] bytes, Camera camera) {
                //图片压缩技术
                Bitmap bitmap= BitmapFactory.decodeByteArray(bytes,0,bytes.length);
                try {
                    FileOutputStream fos=new FileOutputStream("/mnt/sdcard/G150820_"+System.currentTimeMillis()+".png");
                    bitmap.compress(Bitmap.CompressFormat.PNG,85,fos);
                    camera.stopPreview();
                    camera.startPreview();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }
        });



    }
}

录视频代码：

public class MediarecorderActivity extends AppCompatActivity {

    private SurfaceView sv_recorder_surface;
    private MediaRecorder mediaRecorder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_mediarecorder);
        sv_recorder_surface = (SurfaceView) findViewById(R.id.sv_recorder_surface);
        //实例化媒体录制器
        mediaRecorder = new MediaRecorder();
    }

    public void start(View view){
        mediaRecorder.reset();

        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);

        //设置格式
        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);

        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263);
        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

        //设置保存路径
        mediaRecorder.setOutputFile("/mnt/sdcard/G150820_"+System.currentTimeMillis()+".mp4");

        mediaRecorder.setPreviewDisplay(sv_recorder_surface.getHolder().getSurface());

        try {
            mediaRecorder.prepare();
            mediaRecorder.start();
        } catch (IOException e) {
            e.printStackTrace();
        }



    }

    public void stop(View view){
        if(mediaRecorder!=null){
            mediaRecorder.stop();
            mediaRecorder.release();
            mediaRecorder=null;
        }
    }
}