public void startRecord() {

        mediarecorder = new MediaRecorder();// 创建mediarecorder对象

        mCamera = getCameraInstance();

        Parameters parameters = mCamera.getParameters();

        mCamera.autoFocus(null);

        // 解锁camera

        mCamera.setDisplayOrientation(90);

        mCamera.unlock();

        mediarecorder.setCamera(mCamera);

        List<Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes();

        for(int i=0;i<supportedPreviewSizes.size();i++)

        {

            Log.v("startRecord", "width="+supportedPreviewSizes.get(i).width+";height="+supportedPreviewSizes.get(i).height);

        }

        // 设置录制视频源为Camera(相机)

//        mediarecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);

        mediarecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

        // 设置录制文件质量，格式，分辨率之类，这个全部包括了

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_480P));  //7.43M  10frame

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_1080P));   //70.94M  10frame

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_CIF));  // 2.6M  5frame/10frame

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_QCIF));  //0.76M   30frame  模糊

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_QVGA));  //2.1M

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_TIME_LAPSE_CIF));  //不支持

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_LOW));  //766KB  还行  比QUALITY_QCIF好

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_TIME_LAPSE_LOW));  //1M 质量类似LOW

//        mediarecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_TIME_LAPSE_480P));  //480p效果

//        mediarecorder.setAudioEncoder(MediaRecorder.AudioEncoder.);

//        mediarecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);

//        boolean isSupQUALITY_TIME_LAPSE_CIF = CamcorderProfile.hasProfile(CamcorderProfile.QUALITY_TIME_LAPSE_CIF);

//        boolean isSupQUALITY_LOW = CamcorderProfile.hasProfile(CamcorderProfile.QUALITY_LOW);

//        Log.v("startRecord", "isSupQUALITY_TIME_LAPSE_CIF="+isSupQUALITY_TIME_LAPSE_CIF+";isSupQUALITY_LOW="+isSupQUALITY_LOW);

//

//        mediarecorder.setVideoFrameRate(30);

      //start实现录像静音

        mediarecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);

//        mediarecorder.setVideoSize(640,480);

        mediarecorder.setVideoSize(1280,720);

        //设置编码比特率,不设置会使视频图像模糊

//        mediarecorder.setVideoEncodingBitRate(5*1024*1024);  //清晰     512*1024(不清楚)

        mediarecorder.setVideoEncodingBitRate(900*1024); //较为清晰，且文件大小为3.26M(30秒)

        mediarecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);  //H263的貌似有点不清晰

//        mediarecorder.setVideoFrameRate(10);  //设置无效

        //end

        mediarecorder.setPreviewDisplay(surfaceHolder.getSurface());

        // 设置视频文件输出的路径

        mediarecorder.setOutputFile(Environment.getExternalStorageDirectory().getAbsolutePath() + "/data/data/"+System.currentTimeMillis()+".mp4");

        try {

            // 准备录制

            mediarecorder.prepare();

            // 开始录制

            mediarecorder.start();

        } catch (Exception e) {

            e.printStackTrace();

        }

    }