Image_Reader.h

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef OPENCV_NDK_IMAGE_READER_H
#define OPENCV_NDK_IMAGE_READER_H

#include "Util.h"
#include <media/NdkImageReader.h>
#include <opencv2/core.hpp>

class Image_Reader {
public:
    explicit Image_Reader(ImageFormat *res, enum AIMAGE_FORMATS format);

    ~Image_Reader();

    /**
     * Report cached ANativeWindow, which was used to create camera's capture
     * session output.
     */
    ANativeWindow *GetNativeWindow(void);

    /**
     * Retrieve Image on the top of Reader's queue
     */
    AImage *GetNextImage(void);

    /**
    * Retrieve Image on the bottom of Reader's queue
    */
    AImage *GetLatestImage(void);

    int32_t GetMaxImage(void);

    /**
     * Delete Image
     * @param image {@link AImage} instance to be deleted
     */
    void DeleteImage(AImage *image);

    /**
     * AImageReader callback handler. Called by AImageReader when a frame is
     * captured
     * (Internal function, not to be called by clients)
     */
    void ImageCallback(AImageReader *reader);

    /**
     * DisplayImage()
     *   Present camera image to the given display buffer. Avaliable image is
     * converted
     *   to display buffer format. Supported display format:
     *      WINDOW_FORMAT_RGBX_8888
     *      WINDOW_FORMAT_RGBA_8888
     *   @param buf {@link ANativeWindow_Buffer} for image to display to.
     *   @param image a {@link AImage} instance, source of image conversion.
     *            it will be deleted via {@link AImage_delete}
     *   @return true on success, false on failure
     */
    bool DisplayImage(ANativeWindow_Buffer *buf, AImage *image);

    /**
     * Configure the rotation angle necessary to apply to
     * Camera image when presenting: all rotations should be accumulated:
     *    CameraSensorOrientation + Android Device Native Orientation +
     *    Human Rotation (rotated degree related to Phone native orientation
     */
    void SetPresentRotation(int32_t angle);

private:
    int32_t presentRotation_;
    AImageReader *reader_;

    void PresentImage(ANativeWindow_Buffer *buf, AImage *image);

    void PresentImage90(ANativeWindow_Buffer *buf, AImage *image);

    void PresentImage180(ANativeWindow_Buffer *buf, AImage *image);

    void PresentImage270(ANativeWindow_Buffer *buf, AImage *image);

    int32_t imageHeight_;
    int32_t imageWidth_;

    uint8_t *imageBuffer_;

    int32_t yStride, uvStride;
    uint8_t *yPixel, *uPixel, *vPixel;
    int32_t yLen, uLen, vLen;
    int32_t uvPixelStride;
};

#endif  // OPENCV_NDK_IMAGE_READER_H