后台服务采取与摄像头像素

本文介绍了后台服务采取与摄像头像素的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 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); }