使用android.hardware.camera2访问摄像头

Question

我想创建一个应用程序，允许我控制相机上的闪光灯，但是我对如何做到这一点的研究导致了一堆使用最近贬值的android.hardware.camera api的例子。有人能指出我在正确的方向，我将如何使用androird.hardware.camera2，使一个简单的手电筒应用程序?

Answer 1

如果你只是想做一个简单的手电筒应用程序，你应该编辑你的问题。用新的安卓硬件的摄像头。Camera2更复杂。

我曾尝试使用android studio和nexus lg 5x制作相机预览应用程序，但没有成功。

如果你只想打开闪光灯，代码如下:

void torch(){
    /* turn on the flash light */
    CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    try {
        String[] cameraID = new String[]{};
        cameraID = cameraManager.getCameraIdList();
        for(int i = 0; i<cameraID.length; i++){
            Log.e(TAG,cameraID[i]);
        }
        /* camera id is 0 and 1. 0 is the back camera, 1 is the front camera */
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            cameraManager.setTorchMode(cameraID[0],true); 
            //true means turned on, false, means turned off.
        }
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

清单:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test">
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-feature android:name="android.hardware.camera2.full" />
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/MaterialTheme">
    <activity
        android:name=".MainActivity"
        android:screenOrientation="portrait"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

</application>

MainActivity.java:

package com.example.test;
import android.app.Activity;
import android.graphics.Camera;
import android.hardware.camera2.params.InputConfiguration;
import android.os.Build;
import android.os.Bundle;
public class MainActivity extends Activity {
private final static String TAG = "Camera2testJ";
private Size mPreviewSize;
private TextureView mTextureView;
private CameraDevice mCameraDevice;
private CaptureRequest.Builder mPreviewBuilder;
private CameraCaptureSession mPreviewSession;
private Button mBtnShot;
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_main);
    mTextureView = (TextureView)findViewById(R.id.texture);
    mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
    mBtnShot = (Button)findViewById(R.id.btn_takepicture);
    mBtnShot.setOnClickListener(new OnClickListener(){
        @Override
        public void onClick(View v) {
            Log.e(TAG, "mBtnShot clicked");
            torch();
        }
    });
}
void torch(){
    /* try the flash light */
    CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);;
    try {
        String[] cameraID = new String[]{};
        cameraID = cameraManager.getCameraIdList();
        for(int i = 0; i<cameraID.length; i++){
            Log.e(TAG,cameraID[i]);
        }
        /* camera id is 0 and 1. which one is the front or the back camera? */
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            cameraManager.setTorchMode(cameraID[0],true);
        }
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

布局activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextureView
        android:id="@+id/texture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true" />
    <Button
        android:id="@+id/btn_takepicture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="@string/picture"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true" />
</RelativeLayout>

Answer 2

您应该学习https://github.com/googlesamples/android-Camera2Basic示例。这里展示了一种使用

控制flash的方法

mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE,
                                    CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);

我一直在研究一种方法来获得预览纹理中显示的所有帧来做一些图像处理，如果你找到一种方法请告诉我= d

Answer 3

android.hardware。相机已弃用。但你仍然可以利用它它在lollipop和pre-lollipop中都有效

几天前我试过http://www.androidsources.com/index.php/2015/09/19/android-flashlight-app-tutorial/