Merge pull request #18756 from andy-held:add_ueye_capture

CMakeLists.txt

@@ -367,6 +367,9 @@ OCV_OPTION(WITH_MSMF_DXVA "Enable hardware acceleration in Media Foundation back
 OCV_OPTION(WITH_XIMEA "Include XIMEA cameras support" OFF
   VISIBLE_IF NOT ANDROID AND NOT WINRT
   VERIFY HAVE_XIMEA)
+OCV_OPTION(WITH_UEYE "Include UEYE camera support" OFF
+  VISIBLE_IF NOT ANDROID AND NOT APPLE AND NOT WINRT
+  VERIFY HAVE_UEYE)
 OCV_OPTION(WITH_XINE "Include Xine support (GPL)" OFF
   VISIBLE_IF UNIX AND NOT APPLE AND NOT ANDROID
   VERIFY HAVE_XINE)
@@ -1380,6 +1383,10 @@ if(WITH_XIMEA OR HAVE_XIMEA)
   status("    XIMEA:" HAVE_XIMEA THEN YES ELSE NO)
 endif()
 
+if(WITH_UEYE OR HAVE_UEYE)
+  status("    uEye:" HAVE_UEYE THEN YES ELSE NO)
+endif()
+
 if(WITH_XINE OR HAVE_XINE)
   status("    Xine:"           HAVE_XINE           THEN "YES (ver ${XINE_VERSION})"     ELSE NO)
 endif()

modules/videoio/CMakeLists.txt

@@ -138,6 +138,15 @@ if(TARGET ocv.3rdparty.ximea)
   list(APPEND tgts ocv.3rdparty.ximea)
 endif()
 
+if(TARGET ocv.3rdparty.ueye)
+  if("ueye" IN_LIST VIDEOIO_PLUGIN_LIST OR VIDEOIO_PLUGIN_LIST STREQUAL "all")
+    ocv_create_builtin_videoio_plugin("opencv_videoio_ueye" ocv.3rdparty.ueye "cap_ueye.cpp")
+  else()
+    list(APPEND videoio_srcs ${CMAKE_CURRENT_LIST_DIR}/src/cap_ueye.cpp)
+    list(APPEND tgts ocv.3rdparty.ueye)
+  endif()
+endif()
+
 if(TARGET ocv.3rdparty.ffmpeg)
   if(HAVE_FFMPEG_WRAPPER)
     list(APPEND tgts ocv.3rdparty.ffmpeg)

modules/videoio/cmake/detect_ueye.cmake

@@ -0,0 +1,25 @@
+if(NOT HAVE_UEYE)
+  if(WIN32)
+    if(X86_64)
+      set(_WIN_LIB_SUFFIX "_64")
+    endif()
+  endif()
+  find_path(UEYE_INCLUDE "ueye.h"
+    PATHS "${UEYE_ROOT}" ENV UEYE_ROOT "/usr" "C:/Program Files/IDS/uEye/Develop"
+    HINTS "${regpath}"
+    PATH_SUFFIXES "include")
+  find_library(UEYE_LIBRARY ueye_api${_WIN_LIB_SUFFIX}
+    PATHS "${UEYE_ROOT}" ENV UEYE_ROOT "/usr" "C:/Program Files/IDS/uEye/Develop"
+    HINTS "${regpath}"
+    PATH_SUFFIXES "lib")
+  if(UEYE_INCLUDE AND UEYE_LIBRARY)
+    set(HAVE_UEYE TRUE)
+  endif()
+endif()
+unset(_WIN_LIB_SUFFIX)
+
+if(HAVE_UEYE)
+  ocv_add_external_target(ueye "${UEYE_INCLUDE}" "${UEYE_LIBRARY}" "HAVE_UEYE")
+endif()
+
+set(HAVE_UEYE ${HAVE_UEYE} PARENT_SCOPE)

modules/videoio/cmake/init.cmake

@@ -38,6 +38,7 @@ add_backend("msdk" WITH_MFX)
 add_backend("openni2" WITH_OPENNI2)
 add_backend("pvapi" WITH_PVAPI)
 add_backend("realsense" WITH_LIBREALSENSE)
+add_backend("ueye" WITH_UEYE)
 add_backend("ximea" WITH_XIMEA)
 add_backend("xine" WITH_XINE)
 

modules/videoio/include/opencv2/videoio.hpp

@@ -121,6 +121,7 @@ enum VideoCaptureAPIs {
        CAP_OPENCV_MJPEG = 2200,         //!< Built-in OpenCV MotionJPEG codec
        CAP_INTEL_MFX    = 2300,         //!< Intel MediaSDK
        CAP_XINE         = 2400,         //!< XINE engine (Linux)
+       CAP_UEYE         = 2500,         //!< uEye Camera API
      };
 
 /** @brief %VideoCapture generic properties identifier.

modules/videoio/src/cap_interface.hpp

@@ -301,6 +301,8 @@ Ptr<IVideoCapture> create_PvAPI_capture( int index );
 Ptr<IVideoCapture> create_XIMEA_capture_cam( int index );
 Ptr<IVideoCapture> create_XIMEA_capture_file( const std::string &serialNumber );
 
+Ptr<IVideoCapture> create_ueye_camera(int camera);
+
 Ptr<IVideoCapture> create_Aravis_capture( int index );
 
 Ptr<IVideoCapture> createMotionJpegCapture(const std::string& filename);

modules/videoio/src/cap_ueye.cpp

@@ -0,0 +1,499 @@
+// 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.
+
+/*
+This file adds support for uEye cameras in OpenCV.
+
+Cameras can be opened by ID. If 0 is passed as ID the first available camera
+will be used. For any other number, the camera associated with that ID will be
+opened (c.f. IDS documentation for is_InitCamera).
+
+Images are double buffered in a ring buffer of size 2 (called 'image memory
+sequence' in the uEye SDK c.f. is_AddToSequence). The memory is locked on a
+'grab' call and copied and unlocked during 'retrieve'. The image queue provided
+in the uEye SDK is not used since it automatically locks the buffers when a new
+image arrives, which means the buffer can fill up when frames are retrieved too
+slowly.
+*/
+
+#include "precomp.hpp"
+
+#include <ueye.h>
+
+#include <array>
+#include <chrono>
+#include <cstdlib>
+#include <memory>
+#include <thread>
+
+namespace cv
+{
+namespace
+{
+struct image_buffer
+{
+    char* data;
+    INT id;
+};
+}
+#define ASSERT_UEYE(expr) { UINT expr_result = expr; if(IS_SUCCESS != expr_result) CV_Error_(Error::StsAssert, ("%s %s %d: failed with code %u", #expr, __FILE__, __LINE__, expr_result)); }
+#define PRINT_ON_UEYE_ERROR( expr ) { UINT expr_result = expr; if(IS_SUCCESS != expr_result) CV_LOG_ERROR(NULL, "VIDEOIO(UEYE:" << cam_id << "): " << #expr << " " << __FILE__ << " " << __LINE__ << ": failed with code " << expr_result); }
+
+struct VideoCapture_uEye CV_FINAL: public IVideoCapture
+{
+    int getCaptureDomain() CV_OVERRIDE
+    {
+        return cv::CAP_UEYE;
+    }
+
+    VideoCapture_uEye(int camera);
+
+    bool isOpened() const CV_OVERRIDE
+    {
+        return 255 != cam_id;
+    }
+
+    ~VideoCapture_uEye() CV_OVERRIDE
+    {
+        close();
+    }
+
+    double getProperty(int property_id) const CV_OVERRIDE;
+    bool setProperty(int property_id, double value) CV_OVERRIDE;
+    bool grabFrame() CV_OVERRIDE;
+    bool retrieveFrame(int outputType, OutputArray frame) CV_OVERRIDE;
+
+    void close();
+    void start_camera();
+    void stop_camera();
+
+    void unlock_image_buffer();
+
+    HIDS cam_id = 255;
+    SENSORINFO sensor_info;
+    double fps;
+    int width;
+    int height;
+    int pitch;
+    std::array<image_buffer, 2> ring_buffer = {{{nullptr, 0}, {nullptr, 0}}};
+    char* locked_image = nullptr;
+};
+
+Ptr<IVideoCapture> create_ueye_camera(int camera)
+{
+    return cv::makePtr<VideoCapture_uEye>(camera);
+}
+
+namespace
+{
+std::vector<IMAGE_FORMAT_INFO> get_freerun_formats(HIDS cam_id)
+{
+    UINT count;
+    ASSERT_UEYE(is_ImageFormat(cam_id, IMGFRMT_CMD_GET_NUM_ENTRIES, &count, sizeof(count)));
+    UINT sizeof_list = sizeof(IMAGE_FORMAT_LIST) + (count - 1) * sizeof(IMAGE_FORMAT_INFO);
+    std::unique_ptr<IMAGE_FORMAT_LIST> list(new (std::malloc(sizeof_list)) IMAGE_FORMAT_LIST);
+
+    list->nSizeOfListEntry = sizeof(IMAGE_FORMAT_INFO);
+    list->nNumListElements = count;
+    ASSERT_UEYE(is_ImageFormat(cam_id, IMGFRMT_CMD_GET_LIST, list.get(), sizeof_list));
+
+    // copy to vector and filter out non-live modes
+    std::vector<IMAGE_FORMAT_INFO> formats;
+    formats.reserve(count + 1);
+    std::copy_if(list->FormatInfo, list->FormatInfo+count, std::back_inserter(formats), [](const IMAGE_FORMAT_INFO& format)
+    {
+        return (format.nSupportedCaptureModes & CAPTMODE_FREERUN);
+    });
+
+    return formats;
+}
+
+void set_matching_format(HIDS cam_id, const SENSORINFO& sensor_info, int width, int height)
+{
+    // uEye camera formats sometimes do not include the native resolution (without binning, subsampling or AOI)
+    if(width == int(sensor_info.nMaxWidth) && height == int(sensor_info.nMaxHeight))
+    {
+        ASSERT_UEYE(is_SetBinning(cam_id, IS_BINNING_DISABLE));
+        ASSERT_UEYE(is_SetSubSampling(cam_id, IS_SUBSAMPLING_DISABLE));
+        IS_RECT rectAOI = {0, 0, width, height};
+        ASSERT_UEYE(is_AOI(cam_id, IS_AOI_IMAGE_SET_AOI, &rectAOI, sizeof(rectAOI)));
+        return;
+    }
+    auto formats = get_freerun_formats(cam_id);
+    CV_Assert(formats.size() > 0);
+    auto calc_err = [=](const IMAGE_FORMAT_INFO& format)
+    {
+        return format.nWidth - width + format.nHeight - height + (sensor_info.nMaxWidth - width)/2 - format.nX0 + (sensor_info.nMaxHeight - height)/2 - format.nY0;
+    };
+
+    std::sort(formats.begin(), formats.end(), [=](const IMAGE_FORMAT_INFO& f0, const IMAGE_FORMAT_INFO& f1)
+    {
+        return calc_err(f0) < calc_err(f1);
+    });
+
+    ASSERT_UEYE(is_ImageFormat(cam_id, IMGFRMT_CMD_SET_FORMAT, &formats.front().nFormatID, sizeof(UINT)));
+}
+}
+
+
+VideoCapture_uEye::VideoCapture_uEye(int camera)
+{
+    CV_Assert(camera >= 0);
+    CV_Assert(camera < 255); // max camera id is 254
+    cam_id = static_cast<HIDS>(camera);
+    CV_LOG_DEBUG(NULL, "VIDEOIO(UEYE:" << cam_id << "): opening...");
+    ASSERT_UEYE(is_InitCamera(&cam_id, nullptr));
+
+    IS_INIT_EVENT init_event = {IS_SET_EVENT_FRAME, FALSE, FALSE};
+    ASSERT_UEYE(is_Event(cam_id, IS_EVENT_CMD_INIT, &init_event, sizeof(init_event)));
+    UINT frame_event = IS_SET_EVENT_FRAME;
+    ASSERT_UEYE(is_Event(cam_id, IS_EVENT_CMD_ENABLE, &frame_event, sizeof(frame_event)));
+
+    ASSERT_UEYE(is_ResetToDefault(cam_id));
+
+    ASSERT_UEYE(is_SetFrameRate(cam_id, IS_GET_FRAMERATE, &fps));
+
+    start_camera();
+}
+
+double VideoCapture_uEye::getProperty(int property_id) const
+{
+    auto value = 0.;
+    switch (property_id)
+    {
+    case CAP_PROP_FRAME_WIDTH:
+        value = width;
+        break;
+    case CAP_PROP_FRAME_HEIGHT:
+        value = height;
+        break;
+    case CAP_PROP_FPS:
+        value = fps;
+        break;
+    }
+    return value;
+}
+
+bool VideoCapture_uEye::setProperty(int property_id, double value)
+{
+    if(!isOpened())
+        return false;
+    try
+    {
+        bool set_format = false;
+        switch (property_id)
+        {
+        case CAP_PROP_FRAME_WIDTH:
+            if(width == value)
+                break;
+            width = static_cast<int>(value);
+            set_format = true;
+            break;
+        case CAP_PROP_FRAME_HEIGHT:
+            if(height == value)
+                break;
+            height = static_cast<int>(value);
+            set_format = true;
+            break;
+        case CAP_PROP_FPS:
+            if(fps == value)
+                break;
+            ASSERT_UEYE(is_SetFrameRate(cam_id, value, &fps));
+            break;
+        }
+        if(set_format)
+        {
+            set_matching_format(cam_id, sensor_info, width, height);
+            start_camera();
+        }
+    }
+    catch(const cv::Exception& e)
+    {
+        CV_LOG_ERROR(NULL, "VIDEOIO(UEYE:" << cam_id << "): " <<  e.what());
+        return false;
+    }
+
+    return true;
+}
+
+bool VideoCapture_uEye::grabFrame()
+{
+    if (!isOpened())
+        return false;
+
+    try
+    {
+        IS_WAIT_EVENT wait_event{IS_SET_EVENT_FRAME, static_cast<UINT>(3*1000/fps), 0, 0}; // wait for the time it should take to get 3 frames
+        ASSERT_UEYE(is_Event(cam_id, IS_EVENT_CMD_WAIT, &wait_event, sizeof(wait_event)));
+        INT current_buffer_id;
+        char* current_buffer;
+        char* last;
+        ASSERT_UEYE(is_GetActSeqBuf(cam_id, &current_buffer_id, &current_buffer, &last));
+
+        const int lock_tries = 4;
+        std::chrono::milliseconds lock_time_out(static_cast<int>(1000/(fps*4))); // wait for a quarter of a frame if not lockable, should not occur in event mode
+        UINT ret;
+        for(int i = 0; i < lock_tries; i++) // try locking the buffer
+        {
+            ret = is_LockSeqBuf(cam_id, IS_IGNORE_PARAMETER, last);
+            if(IS_SEQ_BUFFER_IS_LOCKED == ret)
+                std::this_thread::sleep_for(lock_time_out);
+            else
+                break;
+        }
+        ASSERT_UEYE(ret);
+        locked_image = last;
+    }
+    catch(const cv::Exception& e)
+    {
+        CV_LOG_ERROR(NULL, "VIDEOIO(UEYE:" << cam_id << "): " <<  e.what());
+        close();
+        return false;
+    }
+    return true;
+}
+
+bool VideoCapture_uEye::retrieveFrame(int /*outputType*/, OutputArray frame)
+{
+    if(!locked_image)
+        return false;
+    Mat(height, width, CV_8UC3, locked_image, pitch).copyTo(frame);
+    try
+    {
+        unlock_image_buffer();
+    }
+    catch(const cv::Exception& e)
+    {
+        CV_LOG_ERROR(NULL, "VIDEOIO(UEYE:" << cam_id << "): " <<  e.what());
+        return false;
+    }
+
+    return true;
+}
+
+void VideoCapture_uEye::start_camera()
+{
+    stop_camera();
+
+    IS_RECT aoi;
+    ASSERT_UEYE(is_AOI(cam_id, IS_AOI_IMAGE_GET_AOI, &aoi, sizeof(aoi)));
+
+    UINT x_is_abs_pos;
+    UINT y_is_abs_pos;
+
+    ASSERT_UEYE(is_AOI(cam_id, IS_AOI_IMAGE_GET_POS_X_ABS, &x_is_abs_pos , sizeof(x_is_abs_pos)));
+    ASSERT_UEYE(is_AOI(cam_id, IS_AOI_IMAGE_GET_POS_Y_ABS, &y_is_abs_pos , sizeof(y_is_abs_pos)));
+
+    ASSERT_UEYE(is_GetSensorInfo(cam_id, &sensor_info));
+    width  = x_is_abs_pos? sensor_info.nMaxWidth: aoi.s32Width;
+    height = y_is_abs_pos? sensor_info.nMaxHeight: aoi.s32Height;
+
+    // allocate ring_buffer
+    int bpp = 24;
+    for(auto& image_memory: ring_buffer)
+    {
+        ASSERT_UEYE(is_AllocImageMem(cam_id, width, height, bpp, &image_memory.data, &image_memory.id));
+        ASSERT_UEYE(is_AddToSequence(cam_id, image_memory.data, image_memory.id));
+    }
+
+    // TODO: this could be set according to sensor_info.nColorMode and CAP_PROP_FOURCC
+    ASSERT_UEYE(is_SetColorMode(cam_id, IS_CM_BGR8_PACKED));
+    ASSERT_UEYE(is_GetImageMemPitch (cam_id, &pitch));
+
+    ASSERT_UEYE(is_CaptureVideo(cam_id, IS_DONT_WAIT));
+}
+
+void VideoCapture_uEye::stop_camera()
+{
+    if(is_CaptureVideo(cam_id, IS_GET_LIVE))
+        ASSERT_UEYE(is_StopLiveVideo(cam_id, IS_FORCE_VIDEO_STOP));
+
+    if(locked_image)
+        unlock_image_buffer();
+    ASSERT_UEYE(is_ClearSequence(cam_id));
+    for(auto buffer: ring_buffer)
+    {
+        if(buffer.data)
+        {
+            ASSERT_UEYE(is_FreeImageMem(cam_id, buffer.data, buffer.id));
+            buffer.data = nullptr;
+        }
+    }
+}
+
+void VideoCapture_uEye::close()
+{
+    if(!isOpened())
+        return;
+    CV_LOG_DEBUG(NULL, "VIDEOIO(UEYE:" << cam_id << "): closing...");
+    // During closing we do not care about correct error handling as much.
+    // Either something has gone wrong already or it has been called from the
+    // destructor. Just make sure that all calls are done.
+    try
+    {
+        stop_camera();
+    }
+    catch(const cv::Exception& e)
+    {
+        CV_LOG_ERROR(NULL, "VIDEOIO(UEYE:" << cam_id << "): " <<  e.what());
+    }
+    UINT frame_event = IS_SET_EVENT_FRAME;
+    PRINT_ON_UEYE_ERROR(is_Event(cam_id, IS_EVENT_CMD_DISABLE, &frame_event, sizeof(frame_event)));
+    PRINT_ON_UEYE_ERROR(is_Event(cam_id, IS_EVENT_CMD_EXIT, &frame_event, sizeof(frame_event)));
+    PRINT_ON_UEYE_ERROR(is_ExitCamera(cam_id));
+    cam_id = 255;
+}
+
+void VideoCapture_uEye::unlock_image_buffer()
+{
+    char* tmp_buffer = nullptr;
+    std::swap(locked_image, tmp_buffer);
+    ASSERT_UEYE(is_UnlockSeqBuf(cam_id, IS_IGNORE_PARAMETER, tmp_buffer));
+}
+} // namespace cv
+
+// plugin glue
+#if defined(BUILD_PLUGIN)
+
+#include "plugin_api.hpp"
+
+namespace cv
+{
+
+namespace
+{
+#define CV_PLUGIN_NULL_FAIL(ptr) if(!ptr) return CV_ERROR_FAIL;
+#define CV_PLUGIN_CALL_BEGIN CV_PLUGIN_NULL_FAIL(handle) try {
+#define CV_PLUGIN_CALL_END } catch (...) { return CV_ERROR_FAIL; }
+
+CvResult CV_API_CALL cv_capture_open(const char*, int cam_id, CV_OUT CvPluginCapture* handle)
+{
+    CV_PLUGIN_CALL_BEGIN
+
+    *handle = NULL;
+    std::unique_ptr<VideoCapture_uEye> cap(new VideoCapture_uEye(cam_id));
+    if (cap->isOpened())
+    {
+        *handle = (CvPluginCapture)cap.release();
+        return CV_ERROR_OK;
+    }
+    return CV_ERROR_FAIL;
+
+    CV_PLUGIN_CALL_END
+}
+
+CvResult CV_API_CALL cv_capture_release(CvPluginCapture handle)
+{
+    CV_PLUGIN_NULL_FAIL(handle)
+
+    VideoCapture_uEye* instance = (VideoCapture_uEye*)handle;
+    delete instance;
+    return CV_ERROR_OK;
+}
+
+
+CvResult CV_API_CALL cv_capture_get_prop(CvPluginCapture handle, int prop, CV_OUT double* val)
+{
+    CV_PLUGIN_NULL_FAIL(val)
+    CV_PLUGIN_CALL_BEGIN
+
+    VideoCapture_uEye* instance = (VideoCapture_uEye*)handle;
+    *val = instance->getProperty(prop);
+    return CV_ERROR_OK;
+
+    CV_PLUGIN_CALL_END
+}
+
+CvResult CV_API_CALL cv_capture_set_prop(CvPluginCapture handle, int prop, double val)
+{
+    CV_PLUGIN_CALL_BEGIN
+
+    VideoCapture_uEye* instance = (VideoCapture_uEye*)handle;
+    return instance->setProperty(prop, val) ? CV_ERROR_OK : CV_ERROR_FAIL;
+
+    CV_PLUGIN_CALL_END
+}
+
+CvResult CV_API_CALL cv_capture_grab(CvPluginCapture handle)
+{
+    CV_PLUGIN_CALL_BEGIN
+
+    VideoCapture_uEye* instance = (VideoCapture_uEye*)handle;
+    return instance->grabFrame() ? CV_ERROR_OK : CV_ERROR_FAIL;
+
+    CV_PLUGIN_CALL_END
+}
+
+CvResult CV_API_CALL cv_capture_retrieve(CvPluginCapture handle, int stream_idx, cv_videoio_retrieve_cb_t callback, void* userdata)
+{
+    CV_PLUGIN_CALL_BEGIN
+
+    VideoCapture_uEye* instance = (VideoCapture_uEye*)handle;
+    Mat img;
+    if (instance->retrieveFrame(stream_idx, img))
+        return callback(stream_idx, img.data, (int)img.step, img.cols, img.rows, img.channels(), userdata);
+    return CV_ERROR_FAIL;
+
+    CV_PLUGIN_CALL_END
+}
+
+CvResult CV_API_CALL cv_writer_open(const char* /*filename*/, int /*fourcc*/, double /*fps*/, int /*width*/, int /*height*/, int /*isColor*/,
+                                    CV_OUT CvPluginWriter* /*handle*/)
+{
+    return CV_ERROR_FAIL;
+}
+
+CvResult CV_API_CALL cv_writer_release(CvPluginWriter /*handle*/)
+{
+    return CV_ERROR_FAIL;
+}
+
+CvResult CV_API_CALL cv_writer_get_prop(CvPluginWriter /*handle*/, int /*prop*/, CV_OUT double* /*val*/)
+{
+    return CV_ERROR_FAIL;
+}
+
+CvResult CV_API_CALL cv_writer_set_prop(CvPluginWriter /*handle*/, int /*prop*/, double /*val*/)
+{
+    return CV_ERROR_FAIL;
+}
+
+CvResult CV_API_CALL cv_writer_write(CvPluginWriter /*handle*/, const unsigned char* /*data*/, int /*step*/, int /*width*/, int /*height*/, int /*cn*/)
+{
+    return CV_ERROR_FAIL;
+}
+
+const OpenCV_VideoIO_Plugin_API_preview plugin_api_v0 =
+{
+    {
+        sizeof(OpenCV_VideoIO_Plugin_API_preview), ABI_VERSION, API_VERSION,
+        CV_VERSION_MAJOR, CV_VERSION_MINOR, CV_VERSION_REVISION, CV_VERSION_STATUS,
+        "uEye OpenCV Video I/O plugin"
+    },
+    /*  1*/CAP_UEYE,
+    /*  2*/cv_capture_open,
+    /*  3*/cv_capture_release,
+    /*  4*/cv_capture_get_prop,
+    /*  5*/cv_capture_set_prop,
+    /*  6*/cv_capture_grab,
+    /*  7*/cv_capture_retrieve,
+    /*  8*/cv_writer_open,
+    /*  9*/cv_writer_release,
+    /* 10*/cv_writer_get_prop,
+    /* 11*/cv_writer_set_prop,
+    /* 12*/cv_writer_write
+};
+} // namespace
+} // namespace cv
+
+const OpenCV_VideoIO_Plugin_API_preview* opencv_videoio_plugin_init_v0(int requested_abi_version, int requested_api_version, void* /*reserved=NULL*/) CV_NOEXCEPT
+{
+    if (requested_abi_version != 0)
+        return NULL;
+    if (requested_api_version != 0)
+        return NULL;
+    return &cv::plugin_api_v0;
+}
+
+#endif // BUILD_PLUGIN

modules/videoio/src/videoio_registry.cpp

@@ -51,7 +51,7 @@ namespace {
 - platform specific universal SDK: WINRT, AVFOUNDATION, MSMF/DSHOW, V4L/V4L2
 - RGB-D: OpenNI/OpenNI2, REALSENSE
 - special OpenCV (file-based): "images", "mjpeg"
-- special camera SDKs, including stereo: other special SDKs: FIREWIRE/1394, XIMEA/ARAVIS/GIGANETIX/PVAPI(GigE)
+- special camera SDKs, including stereo: other special SDKs: FIREWIRE/1394, XIMEA/ARAVIS/GIGANETIX/PVAPI(GigE)/uEye
 - other: XINE, gphoto2, etc
 */
 static const struct VideoBackendInfo builtin_backends[] =
@@ -130,6 +130,12 @@ static const struct VideoBackendInfo builtin_backends[] =
     DECLARE_STATIC_BACKEND(CAP_ARAVIS, "ARAVIS", MODE_CAPTURE_BY_INDEX, 0, create_Aravis_capture, 0),
 #endif
 
+#ifdef HAVE_UEYE // uEye
+    DECLARE_STATIC_BACKEND(CAP_UEYE, "UEYE", MODE_CAPTURE_BY_INDEX, 0, create_ueye_camera, 0),
+#elif defined(ENABLE_PLUGINS)
+    DECLARE_DYNAMIC_BACKEND(CAP_UEYE, "UEYE", MODE_CAPTURE_BY_INDEX),
+#endif
+
 #ifdef HAVE_GPHOTO2
     DECLARE_STATIC_BACKEND(CAP_GPHOTO2, "GPHOTO2", MODE_CAPTURE_ALL, createGPhoto2Capture, createGPhoto2Capture, 0),
 #endif