从相机预览回调，保存数据为JPG或YUV格式

@Override
            public void onPreviewFrame(final byte[] data, final Camera camera) {
//                Log.d("eric", "onPreviewFrame");
...

                    Camera.Size size = camera.getParameters().getPreviewSize();
                    YuvImage image = new YuvImage(data,ImageFormat.NV21, size.width, size.height, null);
                    Bitmap bmp = null;
                    Log.d("eric", "count : " + count);
//                        test data if it's valid eric
                        if(count <= 50 && image != null) {
                            Log.d("eric", "enabled");
                            ByteArrayOutputStream stream = new ByteArrayOutputStream();
                            image.compressToJpeg(new Rect(0, 0, size.width, size.height), 80, stream);
                            bmp = BitmapFactory.decodeByteArray(stream.toByteArray(), 0, stream.size());
                            saveBitmap(bmp, "sssssssssssssss");
                            Log.d("eric", "saveBitmap");
                            count ++;
                            try {

                                stream.close();
                            }catch (IOException e) {
                                Log.d("eric", "eeeeeeeeeeeeeeeeeeeeeee " + e.getMessage());
                            }
                        }

                        if(count <= 50) {
                            saveYUV(data);
                            count ++;
                        }

                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                } else {
                    camera.addCallbackBuffer(new byte[calculateFrameSize(ImageFormat.NV21)]);
                }
            }

private void saveYUV(byte[] data) {
    Log.e("eric", "保存YUV");
    File f = getOutputMediaFile(4);
    if (f.exists()) {
        f.delete();
    }
    try {
        FileOutputStream out = new FileOutputStream(f);
        out.write(data);
        out.flush();
        out.close();
        Log.i("eric", "YUV已经保存");
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
/** 保存方法 */
public void saveBitmap(Bitmap bmp, String picName) {
    Log.e("eric", "保存图片");
    File f = getOutputMediaFile(1);
    if (f.exists()) {
        f.delete();
    }
    try {
        FileOutputStream out = new FileOutputStream(f);
        bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
        out.flush();
        out.close();
        Log.i("eric", "已经保存");
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

/** Create a File for saving an image or video */
private File getOutputMediaFile(int type){
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this.

    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES), "MyCameraApp");
    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            Log.d("eric", "failed to create directory");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == 1){
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "IMG_"+ count + ".jpg");
    } else if(type == 2) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "VID_"+ timeStamp + ".mp4");
    } else if(type == 3) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "AVD_"+ count + ".h264");
    }  else if(type == 4) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "YUV_"+ count + ".yuv");
    } else {
        Log.d("eric", "null : ");
        return null;
    }

    Log.d("eric", "path : " + mediaFile.getAbsolutePath());
    return mediaFile;
}