opencv/modules/videoio/src/plugin_api.hpp

// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.

#ifndef PLUGIN_API_HPP
#define PLUGIN_API_HPP

#include <opencv2/core/cvdef.h>
#include <opencv2/core/llapi/llapi.h>

// increase for backward-compatible changes, e.g. add new function
// Main API <= Plugin API -> plugin is compatible
#define API_VERSION 0 // preview
// increase for incompatible changes, e.g. remove function argument
// Main ABI == Plugin ABI -> plugin is compatible
#define ABI_VERSION 0 // preview

#ifdef __cplusplus
extern "C" {
#endif

typedef CvResult (CV_API_CALL *cv_videoio_retrieve_cb_t)(int stream_idx, unsigned const char* data, int step, int width, int height, int cn, void* userdata);

typedef struct CvPluginCapture_t* CvPluginCapture;
typedef struct CvPluginWriter_t* CvPluginWriter;

typedef struct OpenCV_VideoIO_Plugin_API_preview
{
    OpenCV_API_Header api_header;

    /** OpenCV capture ID (VideoCaptureAPIs)
    @note API-ENTRY 1, API-Version == 0
     */
    int captureAPI;

    /** @brief Open video capture

    @param filename File name or NULL to use camera_index instead
    @param camera_index Camera index (used if filename == NULL)
    @param[out] handle pointer on Capture handle

    @note API-CALL 2, API-Version == 0
     */
    CvResult (CV_API_CALL *Capture_open)(const char* filename, int camera_index, CV_OUT CvPluginCapture* handle);

    /** @brief Release Capture handle

    @param handle Capture handle

    @note API-CALL 3, API-Version == 0
     */
    CvResult (CV_API_CALL *Capture_release)(CvPluginCapture handle);

    /** @brief Get property value

    @param handle Capture handle
    @param prop Property index
    @param[out] val property value

    @note API-CALL 4, API-Version == 0
     */
    CvResult (CV_API_CALL *Capture_getProperty)(CvPluginCapture handle, int prop, CV_OUT double* val);

    /** @brief Set property value

    @param handle Capture handle
    @param prop Property index
    @param val property value

    @note API-CALL 5, API-Version == 0
     */
    CvResult (CV_API_CALL *Capture_setProperty)(CvPluginCapture handle, int prop, double val);

    /** @brief Grab frame

    @param handle Capture handle

    @note API-CALL 6, API-Version == 0
     */
    CvResult (CV_API_CALL *Capture_grab)(CvPluginCapture handle);

    /** @brief Retrieve frame

    @param handle Capture handle
    @param stream_idx stream index to retrieve (BGR/IR/depth data)
    @param callback retrieve callback (synchronous)
    @param userdata callback context data

    @note API-CALL 7, API-Version == 0
     */
    CvResult (CV_API_CALL *Capture_retreive)(CvPluginCapture handle, int stream_idx, cv_videoio_retrieve_cb_t callback, void* userdata);


    /** @brief Try to open video writer

    @param filename File name or NULL to use camera_index instead
    @param camera_index Camera index (used if filename == NULL)
    @param[out] handle pointer on Writer handle

    @note API-CALL 8, API-Version == 0
     */
    CvResult (CV_API_CALL *Writer_open)(const char* filename, int fourcc, double fps, int width, int height, int isColor,
                                         CV_OUT CvPluginWriter* handle);

    /** @brief Release Writer handle

    @param handle Writer handle

    @note API-CALL 9, API-Version == 0
     */
    CvResult (CV_API_CALL *Writer_release)(CvPluginWriter handle);

    /** @brief Get property value

    @param handle Capture handle
    @param prop Property index
    @param[out] val property value

    @note API-CALL 10, API-Version == 0
     */
    CvResult (CV_API_CALL *Writer_getProperty)(CvPluginWriter handle, int prop, CV_OUT double* val);

    /** @brief Set property value

    @param handle Capture handle
    @param prop Property index
    @param val property value

    @note API-CALL 11, API-Version == 0
     */
    CvResult (CV_API_CALL *Writer_setProperty)(CvPluginWriter handle, int prop, double val);

    /** @brief Write frame

    @param handle Capture handle
    @param data Capture handle
    @param step step in bytes
    @param width frame width in pixels
    @param height frame height
    @param cn number of channels per pixel

    @note API-CALL 12, API-Version == 0
     */
    CvResult (CV_API_CALL *Writer_write)(CvPluginWriter handle, const unsigned char *data, int step, int width, int height, int cn);

} OpenCV_VideoIO_Plugin_API_preview;

#ifdef BUILD_PLUGIN

#ifndef CV_PLUGIN_EXPORTS
#if (defined _WIN32 || defined WINCE || defined __CYGWIN__)
#  define CV_PLUGIN_EXPORTS __declspec(dllexport)
#elif defined __GNUC__ && __GNUC__ >= 4
#  define CV_PLUGIN_EXPORTS __attribute__ ((visibility ("default")))
#endif
#endif

CV_PLUGIN_EXPORTS
const OpenCV_VideoIO_Plugin_API_preview* CV_API_CALL opencv_videoio_plugin_init_v0
        (int requested_abi_version, int requested_api_version, void* reserved /*NULL*/) CV_NOEXCEPT;

#else  // BUILD_PLUGIN
typedef const OpenCV_VideoIO_Plugin_API_preview* (CV_API_CALL *FN_opencv_videoio_plugin_init_t)
        (int requested_abi_version, int requested_api_version, void* reserved /*NULL*/);
#endif  // BUILD_PLUGIN


#ifdef __cplusplus
}
#endif

#endif // PLUGIN_API_HPP