Camera2 Preview Rotation

MainActivity.java

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public class MainActivity extends Activity {

    private CameraDevice mCameraDevice;
    private TextureView mTextureView;
    private Handler mBackgroundHandler = new Handler();
    private CameraCaptureSession mCaptureSession = null;

    private CaptureRequest.Builder mPreviewRequestBuilder;
    private CaptureRequest mPreviewRequest;

    private ImageReader mImageReader;

    // E/CameraDevice-0-LE: Surface with size (w=180, h=180) and format 0x21 is not valid, size not in valid set: [5248x3936, 5248x2952, 3840x2160, 3264x2448, 2048x1536, 1920x1080, 1280x720, 640x480, 480x320, 320x240]
// 09-10 01:32:02.632 6585-6585/com.example.woshidan.cameratest W/CameraDevice-JV-0: Stream configuration failed
    private final int IMAGE_WIDTH  = 320;
    private final int IMAGE_HEIGHT = 240;
    private final int MAX_IMAGES = 5;

    private ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
        // Surfaceから画像が利用できるようになった時に呼び出される
        @Override
        public void onImageAvailable(ImageReader reader) {
            // Imageは各種コーデック(圧縮方法みたいなもの)で圧縮したりする、画像のByteBufferを扱うためのオブジェクト
            Image image = reader.acquireLatestImage();
            // 何枚か画像を扱うことができて(?)、それぞれはPlanesに入っている
            // この辺のコードは https://developer.android.com/things/training/doorbell/camera-input.html のサンプルより
            ByteBuffer imageBuf = image.getPlanes()[0].getBuffer();
            final byte[] imageBytes = new byte[imageBuf.remaining()];
            imageBuf.get(imageBytes);
            image.close();

            final Bitmap bitmap = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);

            MainActivity.this.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    ImageView imageView = (ImageView) findViewById(R.id.picture);
                    imageView.setImageBitmap(bitmap);
                }
            });
        }
    };

    @TargetApi(Build.VERSION_CODES.M)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // ImageReaderインスタンスの初期化
        // MAX_IMAGES個だけ同時にImageオブジェクトが取得できる
        mImageReader = ImageReader.newInstance(IMAGE_WIDTH, IMAGE_HEIGHT, ImageFormat.JPEG, MAX_IMAGES);

        // imageAvailableListener -> 画像準備できた時反応するくん
        // backgroundHandler -> Listenerが実行された時に呼び出されるHandler
        // (に対応したLooperって形で処理を実行するバックグラウンドスレッドの指定)
        mImageReader.setOnImageAvailableListener(mOnImageAvailableListener, mBackgroundHandler);

        mTextureView = (TextureView) findViewById(R.id.texture);
        mTextureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
            @Override
            public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
                // 先ほどのカメラを開く部分をメソッド化した
                openCamera();
            }

            @Override
            public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {

            }

            @Override
            public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
                return true;
            }

            @Override
            public void onSurfaceTextureUpdated(SurfaceTexture surface) {

            }
        });

        Button capture = (Button) findViewById(R.id.button_capture);
        capture.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(mTextureView.isAvailable()) {
                    copyPreview();
                }
            }
        });
    }

    private void copyPreview() {
        // ImageViewへ静止画を送るためのCaptureRequestを作る
        // 静止画を送ってもらうためのリクエストのビルダーですよ
        CaptureRequest.Builder copyPreviewRequestBuilder = null;
        try {
            copyPreviewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
        // 送り先はImageReaderにしてね
        copyPreviewRequestBuilder.addTarget(mImageReader.getSurface());
        CaptureRequest copyPreviewRequest = copyPreviewRequestBuilder.build();

        // (プレビュー時にセッションは開いたままで、)追加で静止画送ってくれリクエストを送る
        try {
            mCaptureSession.capture(copyPreviewRequest, null, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    private void openCamera() {
        CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        String selectedCameraId = "";
        try {
            selectedCameraId = manager.getCameraIdList()[0];

            // https://github.com/googlesamples/android-Camera2Basic/blob/5dad16c103715b5e7e3c001cc5f6067f8d23f29e/Application/src/main/java/com/example/android/camera2basic/Camera2BasicFragment.java#L499
            // あたりにあるのですが、顔用カメラを使いたくないなどがあれば、CameraCharacteristicsを経由して確認可能
            //            CameraCharacteristics characteristics
            //                    = manager.getCameraCharacteristics(selectedCameraId);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }

        try {
            manager.openCamera(selectedCameraId, mStateCallback, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    private final CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {
        @Override
        public void onOpened(CameraDevice cameraDevice) {
            mCameraDevice = cameraDevice;
            createCameraPreviewSession();
        }

        @Override
        public void onDisconnected(CameraDevice cameraDevice) {
            cameraDevice.close();
            mCameraDevice = null;
        }

        @Override
        public void onError(CameraDevice cameraDevice, int error) {
            cameraDevice.close();
            mCameraDevice = null;
        }

    };

    private void createCameraPreviewSession() {
        // Landscapeのアプリの場合、カメラの向きとプレビューの向きがずれるっぽい
        // https://stackoverflow.com/questions/34536798/android-camera2-preview-is-rotated-90deg-while-in-landscape
        Matrix rotate = new Matrix();
        rotate.postRotate(270); // デバイスの向きとアプリの向きの差分から決めると良い
        // 関連: https://github.com/googlesamples/android-Camera2Basic/blob/master/Application/src/main/java/com/example/android/camera2basic/Camera2BasicFragment.java#L520-L541
        rotate.postTranslate(0, mTextureView.getWidth());
        rotate.postScale((1.0f * IMAGE_WIDTH / IMAGE_HEIGHT) * (mTextureView.getWidth() / mTextureView.getHeight()), (1.0f * IMAGE_HEIGHT / IMAGE_WIDTH) * (mTextureView.getWidth() / mTextureView.getHeight()));
        mTextureView.setTransform(rotate);
        SurfaceTexture texture = mTextureView.getSurfaceTexture();
        texture.setDefaultBufferSize(IMAGE_WIDTH, IMAGE_HEIGHT); // 自分の手元のデバイスで決めうちしてます
        Surface surface = new Surface(texture);

        try {
            mPreviewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            mPreviewRequestBuilder.addTarget(surface);
            mPreviewRequest = mPreviewRequestBuilder.build();
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }

        try {
            mCameraDevice.createCaptureSession(Arrays.asList(surface , mImageReader.getSurface()), new CameraCaptureSession.StateCallback() {
                @Override
                public void onConfigured(CameraCaptureSession session) {
                    // カメラがcloseされている場合
                    if (null == mCameraDevice) {
                        return;
                    }

                    mCaptureSession = session;

                    try {
                        session.setRepeatingRequest(mPreviewRequest, null, null);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onConfigureFailed(CameraCaptureSession session) {

                }
            }, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }
}