public class VideoActivity extends Activity implements SurfaceHolder.Callback {
    private Button start;// 开始录制按钮
    private Button stop;// 停止录制按钮
    private MediaRecorder mediarecorder;// 录制视频的类
    private SurfaceView surfaceview;// 显示视频的控件
    private SurfaceHolder surfaceHolder;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        requestWindowFeature(Window.FEATURE_NO_TITLE);// 去掉标题栏
//        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
//                WindowManager.LayoutParams.FLAG_FULLSCREEN);// 设置全屏
////         设置横屏显示
//        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
////         选择支持半透明模式,在有surfaceview的activity中使用。
//        getWindow().setFormat(PixelFormat.TRANSLUCENT);
        setContentView(R.layout.video);
        init();
    }
    private void init() {
        start = (Button) this.findViewById(R.id.start);
        stop = (Button) this.findViewById(R.id.stop);
        start.setOnClickListener(new TestVideoListener());
        stop.setOnClickListener(new TestVideoListener());
        surfaceview = (SurfaceView) this.findViewById(R.id.surfaceview);
        SurfaceHolder holder = surfaceview.getHolder();// 取得holder
        holder.addCallback(this); // holder加入回调接口
        // setType必须设置，要不出错.
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }
    Camera camera;
    class TestVideoListener implements OnClickListener {
        @Override
        public void onClick(View v) {
            if (v == start) {
                mediarecorder = new MediaRecorder();// 创建mediarecorder对象
                // 设置录制视频源为Camera(相机)
                camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
                if (camera != null) {
//                    camera.setDisplayOrientation(90);//摄像图旋转90度
                    camera.unlock();
                    mediarecorder.setCamera(camera);
                }
                mediarecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
                mediarecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
                mediarecorder.setPreviewDisplay(surfaceHolder.getSurface());
//                mediarecorder.setOrientationHint(90);//视频旋转90度，没有用
                System.out.println("手机默认地址：" + Environment.getExternalStorageDirectory());
                // 设置视频文件输出的路径
                mediarecorder.setOutputFile(Environment.getExternalStorageDirectory() + "/" + "test.mp4");
                try {
                    // 准备录制
                    mediarecorder.prepare();
                    // 开始录制
                    mediarecorder.start();
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (v == stop) {
                if (mediarecorder != null) {
                    // 停止录制
                    mediarecorder.stop();
                    // 释放资源
                    mediarecorder.release();
                    mediarecorder = null;
                }
            }
        }
    }
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
                               int height) {
        // 将holder，这个holder为开始在oncreat里面取得的holder，将它赋给surfaceHolder
        surfaceHolder = holder;
    }
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // 将holder，这个holder为开始在oncreat里面取得的holder，将它赋给surfaceHolder
        surfaceHolder = holder;
    }
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // surfaceDestroyed的时候同时对象设置为null
        surfaceview = null;
        surfaceHolder = null;
        mediarecorder = null;
    }
}

像做朋友圈视频那样的，竖着拿手机，然后压缩显示出横着拿手机拍摄的效果，现在代码显示出的还是竖屏拍摄结果，设置camera.setDisplayOrientation(90)现实的虽然是横屏，但明显是把竖屏给纵向压缩了，比例都变了。