后台服务采取与摄像头像素 [英] Background Service to take picture with Camera

问题描述

我知道有很多关于这个问题，但我想我面临的问题是不以任何人处理。
从各种不同的问题，我写了这个服务。问题是我在onStartCommand方法所有的try-catch块获得成功，但在回调方法（ShutterCallback和PictureCallback）日志没有得到处理。
我认为这意味着拍摄照片，但回调不叫，这是奇怪的。

 照相机凸轮;
参数参数;
PictureCallback rawCallback =新PictureCallback（）{
    公共无效onPictureTaken（字节[]数据，相机摄像头）{
        Log.d（照相机，onPictureTaken  - 原始）;
    }
};ShutterCallback shutterCallback =新ShutterCallback（）{
    公共无效onShutter（）{
        Log.i（照相机，onShutter'd）;
    }
};@覆盖
公众的IBinder onBind（意向为arg0）{
    // TODO自动生成方法存根
    返回null;
}@覆盖
公众诠释onStartCommand（意向意图，诠释标志诠释startId）{
    尝试{
        凸轮= Camera.open（）;
        Log.i（照相机，成功）;
    }赶上（RuntimeException的E）{
        Log.e（照相机，摄像机当前不可用）;
        e.printStackTrace（）;
    }
    尝试{
        参数= cam.getParameters（）;
        cam.setParameters（参数）;
        Log.i（照相机，成功）;
    }赶上（例外E1）{
        Log.e（照相机，参数问题）;
        e1.printStackTrace（）;
    }
    尝试{
        SurfaceView视图=新SurfaceView（本）;
        cam.set previewDisplay（view.getHolder（））;
        cam.start preVIEW（）;
        Log.i（照相机，成功）;
    }赶上（例外五）{
        Log.e（照相机，表面问题）;
        e.printStackTrace（）;
    }
    尝试{
        cam.takePicture（shutterCallback，rawCallback，NULL）;
        Log.i（照相机，成功）;
    }赶上（例外五）{
        Log.e（照相机，点击失败）;
        e.printStackTrace（）;
    }
    cam.release（）;
    返回super.onStartCommand（意向，旗帜，startId）;
}
 

解决方案

您不应该调用takePicture方法后立即释放相机。你需要给镜头足够的时间来执行回调。顺便说一句，你最好也加JPG回调。同时停止preVIEW可以释放相机之前被调用。您code可能看起来像如下：

 照相机凸轮;
参数参数;
PictureCallback rawCallback =新PictureCallback（）{
    公共无效onPictureTaken（字节[]数据，相机摄像头）{
        Log.d（照相机，onPictureTaken  - 原始）;
        camera.stop preVIEW（）;
        camera.release（）;
    }
};PictureCallback jpgCallback =新PictureCallback（）{
    公共无效onPictureTaken（字节[]数据，相机摄像头）{
        Log.d（照相机，onPictureTaken  -  JPG）;
        camera.stop preVIEW（）;
        camera.release（）;
    }
};ShutterCallback shutterCallback =新ShutterCallback（）{
    公共无效onShutter（）{
        Log.i（照相机，onShutter'd）;
    }
};@覆盖
公众的IBinder onBind（意向为arg0）{
    // TODO自动生成方法存根
    返回null;
}@覆盖
公众诠释onStartCommand（意向意图，诠释标志诠释startId）{
    尝试{
        凸轮= Camera.open（）;
        Log.i（照相机，成功）;
    }赶上（RuntimeException的E）{
        Log.e（照相机，摄像机当前不可用）;
        e.printStackTrace（）;
    }
    尝试{
        参数= cam.getParameters（）;
        cam.setParameters（参数）;
        Log.i（照相机，成功）;
    }赶上（例外E1）{
        Log.e（照相机，参数问题）;
        e1.printStackTrace（）;
    }
    尝试{
        SurfaceView视图=新SurfaceView（本）;
        cam.set previewDisplay（view.getHolder（））;
        cam.start preVIEW（）;
        Log.i（照相机，成功）;
    }赶上（例外五）{
        Log.e（照相机，表面问题）;
        e.printStackTrace（）;
    }
    尝试{
        cam.takePicture（shutterCallback，rawCallback，NULL）;
        Log.i（照相机，成功）;
    }赶上（例外五）{
        Log.e（照相机，点击失败）;
        e.printStackTrace（）;
    }
    //注释掉以下行和移动到你的回调
    //cam.release（）;
    返回super.onStartCommand（意向，旗帜，startId）;
}
 

I know there are a lot of questions regarding this, but i think the problem i am facing is not addressed in any of them. From all the different questions i wrote this Service. The problem is that i am getting "Success" in all the try-catch blocks in the onStartCommand method, but the logs in the Callback methods (ShutterCallback and PictureCallback) are not getting processed. Which I think means that the picture is taken but the Callbacks are not called, which is weird.

Camera cam;
Parameters param;
PictureCallback rawCallback = new PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {
        Log.d("CAMERA", "onPictureTaken - raw");
    }
};

ShutterCallback shutterCallback = new ShutterCallback() {
    public void onShutter() {
        Log.i("CAMERA", "onShutter'd");
    }
};

@Override
public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    try {
        cam = Camera.open();
        Log.i("CAMERA", "Success");
    } catch (RuntimeException e) {
        Log.e("CAMERA", "Camera currently unavailable");
        e.printStackTrace();
    }
    try {
        param = cam.getParameters();
        cam.setParameters(param);
        Log.i("CAMERA", "Success");
    } catch (Exception e1) {
        Log.e("CAMERA", "Parameter problem");
        e1.printStackTrace();
    }
    try {
        SurfaceView view = new SurfaceView(this);
        cam.setPreviewDisplay(view.getHolder());
        cam.startPreview();
        Log.i("CAMERA", "Success");
    } catch (Exception e) {
        Log.e("CAMERA", "Surface Problem");
        e.printStackTrace();
    }
    try {
        cam.takePicture(shutterCallback, rawCallback, null);
        Log.i("CAMERA", "Success");
    } catch (Exception e) {
        Log.e("CAMERA", "Click Failure");
        e.printStackTrace();
    }
    cam.release();
    return super.onStartCommand(intent, flags, startId);
}

解决方案

You should not release the camera immediately after calling takePicture method. You need to give the camera enough time to execute the callbacks. BTW, you'd better to also add a JPG callback. Also stopPreview can be called before releasing camera. Your code could look like below:

Camera cam;
Parameters param;
PictureCallback rawCallback = new PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {
        Log.d("CAMERA", "onPictureTaken - raw");
        camera.stopPreview();
        camera.release();
    }
};

PictureCallback jpgCallback = new PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {
        Log.d("CAMERA", "onPictureTaken - jpg");
        camera.stopPreview();
        camera.release();
    }
};

ShutterCallback shutterCallback = new ShutterCallback() {
    public void onShutter() {
        Log.i("CAMERA", "onShutter'd");
    }
};

@Override
public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    try {
        cam = Camera.open();
        Log.i("CAMERA", "Success");
    } catch (RuntimeException e) {
        Log.e("CAMERA", "Camera currently unavailable");
        e.printStackTrace();
    }
    try {
        param = cam.getParameters();
        cam.setParameters(param);
        Log.i("CAMERA", "Success");
    } catch (Exception e1) {
        Log.e("CAMERA", "Parameter problem");
        e1.printStackTrace();
    }
    try {
        SurfaceView view = new SurfaceView(this);
        cam.setPreviewDisplay(view.getHolder());
        cam.startPreview();
        Log.i("CAMERA", "Success");
    } catch (Exception e) {
        Log.e("CAMERA", "Surface Problem");
        e.printStackTrace();
    }
    try {
        cam.takePicture(shutterCallback, rawCallback, null);
        Log.i("CAMERA", "Success");
    } catch (Exception e) {
        Log.e("CAMERA", "Click Failure");
        e.printStackTrace();
    }
    // Commented out following line and moved it into your callbacks
    //cam.release();
    return super.onStartCommand(intent, flags, startId);
}

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