Android 플랫폼에서 "전면 카메라"를 열려면 어떻게합니까?

Android 플랫폼에서 "전면 카메라"를 열려면 어떻게합니까?

---

일반적으로 장치에 내장 카메라가 두 개 이상있는 경우 특히 그중 하나를 초기화하는 방법이 있습니까?

Android 참조 문서에서 찾지 못했습니다.

• https://developer.android.com/reference/android/hardware/Camera.html
• https://developer.android.com/reference/android/hardware/camera2/package-summary.html
• https://developer.android.com/reference/android/hardware/camera2/CameraManager.html

삼성 SHW-M100S에는 두 대의 카메라가 있습니다. 두 대의 카메라 사용에 대한 언급이 없다면 삼성이 어떻게했는지 알 수 있습니까?

---

private Camera openFrontFacingCameraGingerbread() {
    int cameraCount = 0;
    Camera cam = null;
    Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
    cameraCount = Camera.getNumberOfCameras();
    for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
        Camera.getCameraInfo(camIdx, cameraInfo);
        if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
            try {
                cam = Camera.open(camIdx);
            } catch (RuntimeException e) {
                Log.e(TAG, "Camera failed to open: " + e.getLocalizedMessage());
            }
        }
    }

    return cam;
}

AndroidManifest.xml파일에 다음 권한을 추가 하십시오.

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" android:required="false" />
<uses-feature android:name="android.hardware.camera.front" android:required="false" />

참고 : 이 기능은 Gingerbread (2.3) 이상 Android 버전에서 사용할 수 있습니다.

---

API 21부터는 Camera 2 API 를 사용해야 하기 때문에 모든 이전 답변의 메서드는 Google에서 더 이상 사용하지 않습니다 (이와 같은 문제로 인해) .

이 클래스는 API 레벨 21에서 더 이상 사용되지 않습니다. 새 애플리케이션에는 새 android.hardware.camera2 API를 사용하는 것이 좋습니다.

에서 새로운 API , 당신은 거의 완벽한 전력 안드로이드 장치 카메라 및 문서에 명시 적으로 조언 이상을

String[] getCameraIdList()

그런 다음 얻은 CameraId를 사용하여 카메라를 엽니 다.

void openCamera(String cameraId, CameraDevice.StateCallback callback, Handler handler)

이에 따라 전면 카메라의 99 %는 id = "1"이고 후면 카메라 id = "0"입니다 .

비 이동식 카메라는 식별자로 0부터 시작하는 정수를 사용하는 반면, 이동식 카메라는 동일한 모델이더라도 각 개별 장치에 대해 고유 한 식별자를 사용합니다.

However, this means if device situation is rare like just 1-frontal -camera tablet you need to count how many embedded cameras you have, and place the order of the camera by its importance ("0"). So CAMERA_FACING_FRONT == 1 CAMERA_FACING_BACK == 0, which implies that the back camera is more important than frontal.

I don't know about a uniform method to identify the frontal camera on all Android devices. Simply said, the Android OS inside the device can't really find out which camera is exactly where for some reasons: maybe the only camera hardcoded id is an integer representing its importance or maybe on some devices whichever side you turn will be .. "back".

Documentation: https://developer.android.com/reference/android/hardware/camera2/package-summary.html

Explicit Examples: https://github.com/googlesamples/android-Camera2Basic

---

For the older API (it is not recommended, because it will not work on modern phones newer Android version and transfer is a pain-in-the-arse). Just use the same Integer CameraID (1) to open frontal camera like in this answer:

cam = Camera.open(1);

---

If you trust OpenCV to do the camera part:

Inside

    <org.opencv.android.JavaCameraView
    ../>

use the following for the frontal camera:

        opencv:camera_id="1"

---

As of Android 2.1, Android only supports a single camera in its SDK. It is likely that this will be added in a future Android release.

---

public void surfaceCreated(SurfaceHolder holder) {
    try {
        mCamera = Camera.open();
        mCamera.setDisplayOrientation(90);
        mCamera.setPreviewDisplay(holder);

        Camera.Parameters p = mCamera.getParameters();
        p.set("camera-id",2);
        mCamera.setParameters(p);   
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

---

For API 21 (5.0) and later you can use the CameraManager API's

try {
    String desiredCameraId = null;
    for(String cameraId : mCameraIDsList) {
        CameraCharacteristics chars =  mCameraManager.getCameraCharacteristics(cameraId);
        List<CameraCharacteristics.Key<?>> keys = chars.getKeys();
        try {
            if(CameraCharacteristics.LENS_FACING_FRONT == chars.get(CameraCharacteristics.LENS_FACING)) {
               // This is the one we want.
               desiredCameraId = cameraId;
               break;
            }
        } catch(IllegalArgumentException e) {
            // This key not implemented, which is a bit of a pain. Either guess - assume the first one
            // is rear, second one is front, or give up.
        }
    }
}

---

With the release of Android 2.3 (Gingerbread), you can now use the android.hardware.Camera class to get the number of cameras, information about a specific camera, and get a reference to a specific Camera. Check out the new Camera APIs here.

---

build.gradle

 dependencies {
       compile 'com.google.android.gms:play-services-vision:9.4.0+'
    }

Set View

CameraSourcePreview mPreview = (CameraSourcePreview) findViewById(R.id.preview);

GraphicOverlay mGraphicOverlay = (GraphicOverlay) findViewById(R.id.faceOverlay);

CameraSource mCameraSource = new CameraSource.Builder(context, detector)
                            .setRequestedPreviewSize(640, 480)
                            .setFacing(CameraSource.CAMERA_FACING_FRONT)
                            .setRequestedFps(30.0f)
                            .build();

           mPreview.start(mCameraSource, mGraphicOverlay);

---

To open the back camera:-

val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
startActivityForResult(cameraIntent, REQUEST_CODE_CAMERA)

To open the front camera:-

val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
when {
     Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1 && Build.VERSION.SDK_INT < Build.VERSION_CODES.O -> {
         cameraIntent.putExtra("android.intent.extras.CAMERA_FACING", CameraCharacteristics.LENS_FACING_FRONT)  // Tested on API 24 Android version 7.0(Samsung S6)
     }
     Build.VERSION.SDK_INT >= Build.VERSION_CODES.O -> {
         cameraIntent.putExtra("android.intent.extras.CAMERA_FACING", CameraCharacteristics.LENS_FACING_FRONT) // Tested on API 27 Android version 8.0(Nexus 6P)
         cameraIntent.putExtra("android.intent.extra.USE_FRONT_CAMERA", true)
     }
     else -> cameraIntent.putExtra("android.intent.extras.CAMERA_FACING", 1)  // Tested API 21 Android version 5.0.1(Samsung S4)
}
startActivityForResult(cameraIntent, REQUEST_CODE_CAMERA)

I could not make it work for API 28 and above. Also, opening the front camera directly is not possible in some devices(depends on the manufacturer).

---

Camera camera;   
if (Camera.getNumberOfCameras() >= 2) {

    //if you want to open front facing camera use this line   
    camera = Camera.open(CameraInfo.CAMERA_FACING_FRONT);

    //if you want to use the back facing camera
    camera = Camera.open(CameraInfo.CAMERA_FACING_BACK);                
}

try {
    camera.setPreviewDisplay("your surface holder here");
    camera.startPreview();      
} catch (Exception e) {  
    camera.release();
}

/* This is not the proper way, this is a solution for older devices that run Android 4.0 or older. This can be used for testing purposes, but not recommended for main development. This solution can be considered as a temporary solution only. But this solution has helped many so I don't intend to delete this answer*/

참고URL : https://stackoverflow.com/questions/2779002/how-do-i-open-the-front-camera-on-the-android-platform