Java ImageFormat.getBitsPerPixel方法代碼示例

import android.graphics.ImageFormat; //導入方法依賴的package包/類
/**
 * Creates one buffer for the camera preview callback.  The size of the buffer is based off of
 * the camera preview size and the format of the camera image.
 *
 * @return a new preview buffer of the appropriate size for the current camera settings
 */
private byte[] createPreviewBuffer(Size previewSize) {
    int bitsPerPixel = ImageFormat.getBitsPerPixel(ImageFormat.NV21);
    long sizeInBits = previewSize.getHeight() * previewSize.getWidth() * bitsPerPixel;
    int bufferSize = (int) Math.ceil(sizeInBits / 8.0d) + 1;

    //
    // NOTICE: This code only works when using play services v. 8.1 or higher.
    //

    // Creating the byte array this way and wrapping it, as opposed to using .allocate(),
    // should guarantee that there will be an array to work with.
    byte[] byteArray = new byte[bufferSize];
    ByteBuffer buffer = ByteBuffer.wrap(byteArray);
    if (!buffer.hasArray() || (buffer.array() != byteArray)) {
        // I don't think that this will ever happen.  But if it does, then we wouldn't be
        // passing the preview content to the underlying detector later.
        throw new IllegalStateException("Failed to create valid buffer for camera source.");
    }

    mBytesToByteBuffer.put(byteArray, buffer);
    return byteArray;
}
 

import android.graphics.ImageFormat; //導入方法依賴的package包/類
/**
 * Creates one buffer for the camera preview callback.  The size of the buffer is based off of
 * the camera preview size and the format of the camera image.
 *
 * @return a new preview buffer of the appropriate size for the current camera settings
 */
private byte[] createPreviewBuffer(Size previewSize) {
    int bitsPerPixel = ImageFormat.getBitsPerPixel(ImageFormat.NV21);
    long sizeInBits = previewSize.getHeight() * previewSize.getWidth() * bitsPerPixel;
    int bufferSize = (int) Math.ceil(sizeInBits / 8.0d) + 1;
    //
    // NOTICE: This code only works when using play services v. 8.1 or higher.
    //
    // Creating the byte array this way and wrapping it, as opposed to using .allocate(),
    // should guarantee that there will be an array to work with.
    byte[] byteArray = new byte[bufferSize];
    ByteBuffer buffer = ByteBuffer.wrap(byteArray);
    if (!buffer.hasArray() || (buffer.array() != byteArray)) {
        // I don't think that this will ever happen.  But if it does, then we wouldn't be
        // passing the preview content to the underlying detector later.
        throw new IllegalStateException("Failed to create valid buffer for camera source.");
    }
    mBytesToByteBuffer.put(byteArray, buffer);
    return byteArray;
}
 

import android.graphics.ImageFormat; //導入方法依賴的package包/類
public void openCamera(boolean facingFront) {
    synchronized (this) {
        int facing=facingFront? Camera.CameraInfo.CAMERA_FACING_FRONT:Camera.CameraInfo.CAMERA_FACING_BACK;
        currentCameraId=getCameraIdWithFacing(facing);
        camera = Camera.open(currentCameraId);
        camera.setPreviewCallbackWithBuffer(this);
        initRotateDegree(currentCameraId);
        if (camera != null) {
            mParams = camera.getParameters();
            List<Camera.Size> supportedPictureSizesList=mParams.getSupportedPictureSizes();
            List<Camera.Size> supportedVideoSizesList=mParams.getSupportedVideoSizes();
            List<Camera.Size> supportedPreviewSizesList=mParams.getSupportedPreviewSizes();
            Logger.logCameraSizes(supportedPictureSizesList);
            Logger.logCameraSizes(supportedVideoSizesList);
            Logger.logCameraSizes(supportedPreviewSizesList);

            previewSize=choosePreferredSize(supportedPreviewSizesList,preferredRatio);
            Camera.Size photoSize=choosePreferredSize(supportedPictureSizesList,preferredRatio);

            frameHeight=previewSize.width;
            frameWidth=previewSize.height;
            Log.d(TAG, "openCamera: choose preview size"+previewSize.height+"x"+previewSize.width);
            mParams.setPreviewSize(frameHeight,frameWidth);

            mParams.setPictureSize(photoSize.width,photoSize.height);
            Log.d(TAG, "openCamera: choose photo size"+photoSize.height+"x"+photoSize.width);

            //mParams.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
            int size = frameWidth*frameHeight;
            size = size * ImageFormat.getBitsPerPixel(mParams.getPreviewFormat()) / 8;
            if (mBuffer==null || mBuffer.length!=size)
                mBuffer = new byte[size];
            mFrameChain[0].init(size);
            mFrameChain[1].init(size);
            camera.addCallbackBuffer(mBuffer);
            camera.setParameters(mParams);
            cameraOpened=true;
        }
    }
}
 

import android.graphics.ImageFormat; //導入方法依賴的package包/類
public static int frameSize(int width, int height, int imageFormat) {
  if (imageFormat != ImageFormat.NV21) {
    throw new UnsupportedOperationException("Don't know how to calculate "
        + "the frame size of non-NV21 image formats.");
  }
  return (width * height * ImageFormat.getBitsPerPixel(imageFormat)) / 8;
}
 

import android.graphics.ImageFormat; //導入方法依賴的package包/類
@Override
public void surfaceCreated(SurfaceHolder holder) {
    if (safeCameraOpen(mCurrentFacingId)) {
        try {
            mCamera.setPreviewDisplay(holder);

            int degree = getDeviceRotationDegree(mContext);
            Camera.CameraInfo camInfo = new Camera.CameraInfo();
            Camera.getCameraInfo(mCurrentFacingId, camInfo);
            int orientation;
            if (mCurrentFacingId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                orientation = (camInfo.orientation + degree) % 360;
                mCameraPreviewDegree = orientation;
                orientation = (360 - orientation) % 360;  // compensate the mirror
            } else {  // back-facing
                orientation = (camInfo.orientation - degree + 360) % 360;
                mCameraPreviewDegree = orientation;
            }
            mCamera.setDisplayOrientation(orientation);

            Camera.Parameters params = mCamera.getParameters();
            params.setPreviewFormat(ImageFormat.NV21);

            final Camera.Size previewSize = params.getPreviewSize();
            List<Camera.Size> sizes = mCamera.getParameters().getSupportedPreviewSizes();
            for (Camera.Size size : sizes) {
                if (size.width == DEFAULT_VIDEO_WIDTH && size.height == DEFAULT_VIDEO_HEIGHT) {
                    previewSize.width = size.width;
                    previewSize.height = size.height;
                    break;
                }
            }
            params.setPreviewSize(previewSize.width, previewSize.height);
            mCamera.setParameters(params);

            final int bitsPerPixel = ImageFormat.getBitsPerPixel(params.getPreviewFormat());
            final int previewBufferSize = (previewSize.width * previewSize.height * bitsPerPixel) / 8;
            for (int i = 0; i < MAX_CALLBACK_BUFFER_NUM; i++) {
                mCamera.addCallbackBuffer(new byte[previewBufferSize]);
            }

            mPreviewWidth = previewSize.width;
            mPreviewHeight = previewSize.height;

            mCamera.setPreviewCallbackWithBuffer(this);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}
 

import android.graphics.ImageFormat; //導入方法依賴的package包/類
public void openCamera(CameraSetup cameraSetup) throws Exception {

        // Check camera setup
        cameraSetup.checkSetup();

        // Gets back camera
        Pair<Camera.CameraInfo, Integer> backCamera = getBackCamera();
        final int backCameraId = backCamera.second;
        mBackCameraInfo = backCamera.first;

        // Tries to open camera
        mCamera = Camera.open(backCameraId);

        // Check display orientation and fixes camera image.
        // Without this fix, for example, in landscape mode you would get a stretched preview
        setDisplayOrientation();

        // Sets up preview surface
        mCamera.setPreviewDisplay(cameraSetup.holder);

        // Sets up callback for camera, that will get input YUV NV21 bytes
        mCamera.setPreviewCallbackWithBuffer(cameraSetup.previewCallback);

        mCameraParameters = mCamera.getParameters();

        // Gets supported previews sizes and uses chooseOptimalPreviewSize to set maximum preview
        // size and ratio.
        List<Camera.Size> supportedPreviewSizes = mCameraParameters.getSupportedPreviewSizes();
        mCameraSize = chooseOptimalPreviewSize(supportedPreviewSizes, cameraSetup.maxPreviewSize.x, cameraSetup.maxPreviewSize.y);

        // Calculates expected camera bytes length, as YUV image uses compressed stored image.
        expectedCameraBytes = mCameraSize.width * mCameraSize.height *
                ImageFormat.getBitsPerPixel(ImageFormat.NV21) / 8;

        int bufferSize = expectedCameraBytes;

        // For each camera buffer, adds corresponding byte array.
        // Camera buffers are used to store temporarily images to process in an async way.
        for (int i = 0; i < cameraSetup.cameraBuffersCount; i++) {
            byte[] cameraBuffer = new byte[bufferSize];
            mCamera.addCallbackBuffer(cameraBuffer);
        }

        // Forces camera preview size, as got earlier.
        mCameraParameters.setPreviewSize(mCameraSize.width, mCameraSize.height);

        // Sets previously set camera parameters
        mCamera.setParameters(mCameraParameters);

        // Starts preview
        mCamera.startPreview();

    }