Android 实时视频采集—Camera预览采集

        /*【SurfaceHolder.Callback 回调函数】*/
        public void surfaceCreated(SurfaceHolder holder)
        // SurfaceView启动时/初次实例化，预览界面被创建时，该方法被调用。
         {
         // TODO Auto-generated method stub 
          mCamera = Camera.open();// 开启摄像头（2.3版本后支持多摄像头,需传入参数） 
         try
          {
           Log.i(TAG, "SurfaceHolder.Callback：surface Created");
           mCamera.setPreviewDisplay(mSurfaceHolder);//set the surface to be used for live preview
          } catch (Exception ex)
          {
          if(null != mCamera)
           {
            mCamera.release();
            mCamera = null;
           }
           Log.i(TAG+"initCamera", ex.getMessage());
          }
         }
        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
        // 当SurfaceView/预览界面的格式和大小发生改变时，该方法被调用
         {
         // TODO Auto-generated method stub 
          Log.i(TAG, "SurfaceHolder.Callback：Surface Changed");
         //mPreviewHeight = height;
         //mPreviewWidth = width;
          initCamera();
         }
        public void surfaceDestroyed(SurfaceHolder holder)
        // SurfaceView销毁时，该方法被调用
         {
         // TODO Auto-generated method stub
          Log.i(TAG, "SurfaceHolder.Callback：Surface Destroyed");
         if(null != mCamera)
          {
           mCamera.setPreviewCallback(null); //！！这个必须在前，不然退出出错
           mCamera.stopPreview();
           bIfPreview = false;
           mCamera.release();
           mCamera = null;
          }
         }
    
   

核心子函数:　　相机预览

        /*【2】【相机预览】*/
         private void initCamera()//surfaceChanged中调用
          {
           Log.i(TAG, "going into initCamera");
          if (bIfPreview)
           {
            mCamera.stopPreview();//stopCamera();
           }
          if(null != mCamera)
           {
           try
            {
            /* Camera Service settings*/
             Camera.Parameters parameters = mCamera.getParameters();
            // parameters.setFlashMode("off"); // 无闪光灯
             parameters.setPictureFormat(PixelFormat.JPEG); //Sets the image format for picture 设定相片格式为JPEG，默认为NV21 
             parameters.setPreviewFormat(PixelFormat.YCbCr_420_SP); //Sets the image format for preview picture，默认为NV21
            /*【ImageFormat】JPEG/NV16(YCrCb format，used for Video)/NV21(YCrCb format，used for Image)/RGB_565/YUY2/YU12*/
            // 【调试】获取caera支持的PictrueSize，看看能否设置？？
             List<Size> pictureSizes = mCamera.getParameters().getSupportedPictureSizes();
             List<Size> previewSizes = mCamera.getParameters().getSupportedPreviewSizes();
             List<Integer> previewFormats = mCamera.getParameters().getSupportedPreviewFormats();
             List<Integer> previewFrameRates = mCamera.getParameters().getSupportedPreviewFrameRates();
             Log.i(TAG+"initCamera", "cyy support parameters is ");
            Size psize = null;
            for (int i = 0; i < pictureSizes.size(); i++)
             {
              psize = pictureSizes.get(i);
              Log.i(TAG+"initCamera", "PictrueSize,width: " + psize.width + " height" + psize.height);
             }
            for (int i = 0; i < previewSizes.size(); i++)
             {
              psize = previewSizes.get(i);
              Log.i(TAG+"initCamera", "PreviewSize,width: " + psize.width + " height" + psize.height);
             }
            Integer pf = null;
            for (int i = 0; i < previewFormats.size(); i++)
             {
              pf = previewFormats.get(i);
              Log.i(TAG+"initCamera", "previewformates:" + pf);
             }
            // 设置拍照和预览图片大小
             parameters.setPictureSize(640, 480); //指定拍照图片的大小
             parameters.setPreviewSize(mPreviewWidth, mPreviewHeight); // 指定preview的大小 
        //这两个属性 如果这两个属性设置的和真实手机的不一样时，就会报错
        // 横竖屏镜头自动调整
            if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE)
             {
              parameters.set("orientation", "portrait"); //
              parameters.set("rotation", 90); // 镜头角度转90度（默认摄像头是横拍） 
              mCamera.setDisplayOrientation(90); // 在2.2以上可以使用
             } else// 如果是横屏
             {
              parameters.set("orientation", "landscape"); //
              mCamera.setDisplayOrientation(0); // 在2.2以上可以使用
             }
            /* 视频流编码处理 */
            //添加对视频流处理函数
        // 设定配置参数并开启预览
             mCamera.setParameters(parameters); // 将Camera.Parameters设定予Camera 
             mCamera.startPreview(); // 打开预览画面
             bIfPreview = true;
            // 【调试】设置后的图片大小和预览大小以及帧率
             Camera.Size csize = mCamera.getParameters().getPreviewSize();
             mPreviewHeight = csize.height; //
             mPreviewWidth = csize.width;
             Log.i(TAG+"initCamera", "after setting, previewSize:width: " + csize.width + " height: " + csize.height);
             csize = mCamera.getParameters().getPictureSize();
             Log.i(TAG+"initCamera", "after setting, pictruesize:width: " + csize.width + " height: " + csize.height);
             Log.i(TAG+"initCamera", "after setting, previewformate is " + mCamera.getParameters().getPreviewFormat());
             Log.i(TAG+"initCamera", "after setting, previewframetate is " + mCamera.getParameters().getPreviewFrameRate());
            } catch (Exception e)
            {
             e.printStackTrace();
            }
           }
          }