使用onPreviewFrame在服务中拍照

Question

我尝试使用onPreviewFrame方法在服务中拍照。

我保存了一个.jpg文件，但是当我尝试打开该文件时却无法保存，因为图像已损坏。

这是我第一次使用API​​相机和surfaceTexture，我不知道是否需要添加一些配置或其他内容。

有想正确保存照片的想法吗？

服务代码为：

public class ServicioTextureCamara extends Service {
    private final static String TAG = "CameraServiceTexture";
    private Camera mCamera;
    private Bitmap _currentFrame;
    public static final String FACEDETECTIONTHREAD_TAG = "FaceDetectionThread_Tag";


    @Override public int onStartCommand(Intent intent, int flags, int startId) {
        new PictureThread().start();
        return START_STICKY;
    }

    private class PictureThread extends Thread {
        SurfaceTexture texture;
        private byte[] callbackBuffer;
        public void run() {
            mCamera = CameraHelper.getCameraInstance();

            texture = new SurfaceTexture(0);
            texture.setDefaultBufferSize(4, 4);

            try {
                mCamera.setPreviewTexture(texture);
            } catch (IOException e1) {
                e1.printStackTrace();
            }

            Camera.Size previewSize=mCamera.getParameters().getPreviewSize();
            int dataBufferSize=(int)(previewSize.height*previewSize.width*
                    (ImageFormat.getBitsPerPixel(mCamera.getParameters().getPreviewFormat())/8.0));
            callbackBuffer = new byte[dataBufferSize];

            mCamera.addCallbackBuffer(callbackBuffer);
            mCamera.setPreviewCallbackWithBuffer(previewCallback);

            mCamera.startPreview();


            time = System.currentTimeMillis();
        }

        private int mMaxCount = 100;
        private int mCount = 0;
        private long time;

        private final Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() {
            @Override public void onPreviewFrame(byte[] data, Camera camera) {
                long currentTime = System.currentTimeMillis();
                Log.i(TAG, "onPreviewFrame " + data.length + " " + (currentTime - time));
                time = currentTime;
                mCamera.addCallbackBuffer(callbackBuffer);

                File pictureFileDir = getDir(Environment.DIRECTORY_PICTURES, Context.MODE_PRIVATE);
                if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {
                    return;
                }
                SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
                String date = dateFormat.format(new Date());
                String photoFile = "PictureFront_" + "_" + date + ".jpg";
                String filename = pictureFileDir.getPath() + File.separator + photoFile;
                File mainPicture = new File(filename);

                try {
                    FileOutputStream fos = new FileOutputStream(mainPicture);
                    fos.write(data);
                    fos.close();
                    System.out.println("image saved");
                } catch (Exception error) {
                    System.out.println("Image could not be saved");
                }
            }
        };

    }
}