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.

//
// DEPRECATED. Do not use in new plugins
//

#ifndef PLUGIN_API_HPP
#define PLUGIN_API_HPP

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

#if !defined(BUILD_PLUGIN)

/// increased for backward-compatible changes, e.g. add new function
/// Caller API <= Plugin API -> plugin is fully compatible
/// Caller API > Plugin API -> plugin is not fully compatible, caller should use extra checks to use plugins with older API
#define API_VERSION 1 // preview

/// increased for incompatible changes, e.g. remove function argument
/// Caller ABI == Plugin ABI -> plugin is compatible
/// Caller ABI > Plugin ABI -> plugin is not compatible, caller should use shim code to use old ABI plugins (caller may know how lower ABI works, so it is possible)
/// Caller ABI < Plugin ABI -> plugin can't be used (plugin should provide interface with lower ABI to handle that)
#define ABI_VERSION 0 // preview

#else // !defined(BUILD_PLUGIN)

#if !defined(ABI_VERSION) || !defined(API_VERSION)
#error "Plugin must define ABI_VERSION and API_VERSION before including plugin_api.hpp"
#endif

#endif // !defined(BUILD_PLUGIN)


#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;

struct OpenCV_VideoIO_Plugin_API_v0_0_api_entries
{
    /** 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 Destination location
    @param fourcc FOURCC code
    @param fps FPS
    @param width frame width
    @param height frame height
    @param isColor true if video stream should save color frames
    @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 Writer 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 Writer 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 Writer handle
    @param data frame data
    @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_v0_0_api_entries

struct OpenCV_VideoIO_Plugin_API_v0_1_api_entries
{
    /** @brief Try to open video writer

    @param filename Destination location
    @param fourcc FOURCC code
    @param fps FPS
    @param width frame width
    @param height frame height
    @param params pointer on 2*n_params array of 'key,value' pairs
    @param n_params number of passed parameters
    @param[out] handle pointer on Writer handle

    @note API-CALL 13, API-Version == 1
     */
    CvResult (CV_API_CALL* Writer_open_with_params)(
        const char* filename, int fourcc, double fps, int width, int height,
        int* params, unsigned n_params,
        CV_OUT CvPluginWriter* handle
    );
}; // OpenCV_VideoIO_Plugin_API_v0_1_api_entries

typedef struct OpenCV_VideoIO_Plugin_API_preview_v0
{
    OpenCV_API_Header api_header;
    struct OpenCV_VideoIO_Plugin_API_v0_0_api_entries v0;
} OpenCV_VideoIO_Plugin_API_preview_v0;

typedef struct OpenCV_VideoIO_Plugin_API_preview_v1
{
    OpenCV_API_Header api_header;
    struct OpenCV_VideoIO_Plugin_API_v0_0_api_entries v0;
    struct OpenCV_VideoIO_Plugin_API_v0_1_api_entries v1;
} OpenCV_VideoIO_Plugin_API_preview_v1;


#if ABI_VERSION == 0 && API_VERSION == 1
typedef struct OpenCV_VideoIO_Plugin_API_preview_v1 OpenCV_VideoIO_Plugin_API_preview;
#elif ABI_VERSION == 0 && API_VERSION == 0
typedef struct OpenCV_VideoIO_Plugin_API_preview_v0 OpenCV_VideoIO_Plugin_API_preview;
#else
#error "Not supported configuration: check ABI_VERSION/API_VERSION"
#endif

#ifdef BUILD_PLUGIN

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