roadmap: Query I/O API backends registry (#1237)

videoio: Query I/O API backends registry

ROADMAP.md

@@ -81,17 +81,17 @@ Your pull requests will be greatly appreciated!
 
 - [X] **imgcodecs. Image file reading and writing.**
 - [ ] **videoio. Video I/O - WORK STARTED**
-    - [ ] Query I/O API backends registry:
-        - [ ] [getBackendName](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga6723e68832186e20bd44cd3c2b0d8c60)
-        - [ ] [getBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga973abd27c3ea165472f789fa511d9f7b)
-        - [ ] [getCameraBackendPluginVersion](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gab36e3e19ab2396410b74046de141323c)
-        - [ ] [getCameraBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga043347faf6f5590b867a8b621906f7a9)
-        - [ ] [getStreamBackendPluginVersion](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gadf3c0c355f0917ccf754ac1af79d605a)
-        - [ ] [getStreamBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga29296d4c06ed9a9ff8bddae9fe581de1)
-        - [ ] [getWriterBackendPluginVersion](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gac41a544552a08bf3dc8142d687fbe4e5)
-        - [ ] [getWriterBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gaed03e49e6a45ca5b20afe1b9f78955e0)
-        - [ ] [hasBackend](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga9068310d50ef430c2f5f6b185a99a24b)
-        - [ ] [isBackendBuiltIn](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gadf24ec0854bb893a75591306ad9f3878)
+    - [X] Query I/O API backends registry:
+        - [X] [getBackendName](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga6723e68832186e20bd44cd3c2b0d8c60)
+        - [X] [getBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga973abd27c3ea165472f789fa511d9f7b)
+        - [X] [getCameraBackendPluginVersion](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gab36e3e19ab2396410b74046de141323c)
+        - [X] [getCameraBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga043347faf6f5590b867a8b621906f7a9)
+        - [X] [getStreamBackendPluginVersion](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gadf3c0c355f0917ccf754ac1af79d605a)
+        - [X] [getStreamBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga29296d4c06ed9a9ff8bddae9fe581de1)
+        - [X] [getWriterBackendPluginVersion](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gac41a544552a08bf3dc8142d687fbe4e5)
+        - [X] [getWriterBackends](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gaed03e49e6a45ca5b20afe1b9f78955e0)
+        - [X] [hasBackend](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga9068310d50ef430c2f5f6b185a99a24b)
+        - [X] [isBackendBuiltIn](https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gadf24ec0854bb893a75591306ad9f3878)
 
 - [X] **highgui. High-level GUI**
 - [ ] **video. Video Analysis - WORK STARTED**

videoio.cpp

@@ -1,3 +1,4 @@
+#include <stdexcept>
 #include "videoio.h"
 
 // VideoWriter
@@ -94,3 +95,100 @@ int VideoWriter_IsOpened(VideoWriter vw) {
 void VideoWriter_Write(VideoWriter vw, Mat img) {
     *vw << *img;
 }
+
+char* Videoio_Registry_GetBackendName(int api) {
+    cv::String name;
+
+    name = cv::videoio_registry::getBackendName((cv::VideoCaptureAPIs)(api));
+
+    return strdup(name.c_str());
+}
+
+IntVector Videio_Registry_GetBackends() {
+    IntVector c_backs;
+
+    std::vector<cv::VideoCaptureAPIs> backs = cv::videoio_registry::getBackends();
+
+    c_backs.val = new int[backs.size()];
+    c_backs.length = backs.size();
+
+    for(int i = 0; i < c_backs.length; i++) {
+        c_backs.val[i] = backs[i];
+    }
+
+    return c_backs;
+}
+
+char* Videoio_Registry_GetCameraBackendPluginVersion(int api, int* version_ABI, int* version_API) {
+
+    std::string desc = cv::videoio_registry::getCameraBackendPluginVersion((cv::VideoCaptureAPIs)(api), *version_ABI, *version_API);
+
+    return strdup(desc.c_str());
+}
+
+IntVector Videoio_Registry_GetCameraBackends() {
+    IntVector c_backs;
+
+    std::vector<cv::VideoCaptureAPIs> backs = cv::videoio_registry::getCameraBackends();
+
+    c_backs.val = new int[backs.size()];
+    c_backs.length = backs.size();
+
+    for(int i = 0; i < c_backs.length; i++) {
+        c_backs.val[i] = backs[i];
+    }
+
+    return c_backs;
+}
+
+char* Videoio_Registry_GetStreamBackendPluginVersion(int api, int* version_ABI, int* version_API){
+
+    std::string desc = cv::videoio_registry::getStreamBackendPluginVersion((cv::VideoCaptureAPIs)(api), *version_ABI, *version_API);
+
+    return strdup(desc.c_str());
+}
+
+IntVector Videoio_Registry_GetStreamBackends() {
+    IntVector c_backs;
+
+    std::vector<cv::VideoCaptureAPIs> backs = cv::videoio_registry::getStreamBackends();
+
+    c_backs.val = new int[backs.size()];
+    c_backs.length = backs.size();
+
+    for(int i = 0; i < c_backs.length; i++) {
+        c_backs.val[i] = backs[i];
+    }
+
+    return c_backs;
+}
+
+char* Videoio_Registry_GetWriterBackendPluginVersion(int api, int* version_ABI, int* version_API){
+
+    std::string desc = cv::videoio_registry::getWriterBackendPluginVersion((cv::VideoCaptureAPIs)(api), *version_ABI, *version_API);
+
+    return strdup(desc.c_str());
+}
+
+IntVector Videoio_Registry_GetWriterBackends() {
+    IntVector c_backs;
+
+    std::vector<cv::VideoCaptureAPIs> backs = cv::videoio_registry::getWriterBackends();
+
+    c_backs.val = new int[backs.size()];
+    c_backs.length = backs.size();
+
+    for(int i = 0; i < c_backs.length; i++) {
+        c_backs.val[i] = backs[i];
+    }
+
+    return c_backs;
+}
+
+bool Videoio_Registry_HasBackend(int api) {
+    return cv::videoio_registry::hasBackend((cv::VideoCaptureAPIs)(api));
+}
+
+bool Videoio_Registry_IsBackendBuiltIn(int api) {
+    return cv::videoio_registry::isBackendBuiltIn((cv::VideoCaptureAPIs)(api));
+}

videoio.go

@@ -560,3 +560,165 @@ func OpenVideoCaptureWithAPIParams(v interface{}, apiPreference VideoCaptureAPI,
 		return nil, errors.New("argument must be int or string")
 	}
 }
+
+type VideoRegistryType struct{}
+
+// VideoRegistry
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html
+var VideoRegistry VideoRegistryType
+
+// GetBackendName Returns backend API name or "UnknownVideoAPI(xxx)".
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga6723e68832186e20bd44cd3c2b0d8c60
+func (VideoRegistryType) GetBackendName(api VideoCaptureAPI) string {
+
+	c_name := C.Videoio_Registry_GetBackendName(C.int(api))
+	defer C.free(unsafe.Pointer(c_name))
+
+	name := C.GoString(c_name)
+	return name
+}
+
+// GetBackends Returns list of all available backends.
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga973abd27c3ea165472f789fa511d9f7b
+func (VideoRegistryType) GetBackends() []VideoCaptureAPI {
+	intVec := C.Videio_Registry_GetBackends()
+	defer C.IntVector_Close(intVec)
+
+	c_ints := unsafe.Slice(intVec.val, int(intVec.length))
+
+	ints := make([]VideoCaptureAPI, len(c_ints))
+
+	for i, val := range c_ints {
+		ints[i] = VideoCaptureAPI(int(val))
+	}
+	return ints
+}
+
+// GetCameraBackendPluginVersion Returns description and ABI/API version of videoio plugin's camera interface.
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gab36e3e19ab2396410b74046de141323c
+func (VideoRegistryType) GetCameraBackendPluginVersion(api VideoCaptureAPI) (string, int, int) {
+	var (
+		version_abi C.int
+		version_api C.int
+	)
+
+	c_desc := C.Videoio_Registry_GetCameraBackendPluginVersion(C.int(api), &version_abi, &version_api)
+	defer C.free(unsafe.Pointer(c_desc))
+	desc := C.GoString(c_desc)
+
+	return desc, int(version_abi), int(version_api)
+}
+
+// GetCameraBackends Returns list of available backends which works via gocv.VideoCapture(int index)
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga043347faf6f5590b867a8b621906f7a9
+func (VideoRegistryType) GetCameraBackends() []VideoCaptureAPI {
+	intVec := C.Videoio_Registry_GetCameraBackends()
+	defer C.IntVector_Close(intVec)
+
+	c_ints := unsafe.Slice(intVec.val, int(intVec.length))
+
+	ints := make([]VideoCaptureAPI, len(c_ints))
+
+	for i, val := range c_ints {
+		ints[i] = VideoCaptureAPI(int(val))
+	}
+	return ints
+}
+
+// GetStreamBackendPluginVersion Returns description and ABI/API version of videoio plugin's stream capture interface
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gadf3c0c355f0917ccf754ac1af79d605a
+func (VideoRegistryType) GetStreamBackendPluginVersion(api VideoCaptureAPI) (string, int, int) {
+	var (
+		version_abi C.int
+		version_api C.int
+	)
+
+	c_desc := C.Videoio_Registry_GetStreamBackendPluginVersion(C.int(api), &version_abi, &version_api)
+	defer C.free(unsafe.Pointer(c_desc))
+	desc := C.GoString(c_desc)
+
+	return desc, int(version_abi), int(version_api)
+}
+
+// GetStreamBackends Returns list of available backends which works via gocv.VideoCapture(filename string)
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga29296d4c06ed9a9ff8bddae9fe581de1
+func (VideoRegistryType) GetStreamBackends() []VideoCaptureAPI {
+	intVec := C.Videoio_Registry_GetStreamBackends()
+	defer C.IntVector_Close(intVec)
+
+	c_ints := unsafe.Slice(intVec.val, int(intVec.length))
+
+	ints := make([]VideoCaptureAPI, len(c_ints))
+
+	for i, val := range c_ints {
+		ints[i] = VideoCaptureAPI(int(val))
+	}
+	return ints
+}
+
+// GetWriterBackendPluginVersion Returns description and ABI/API version of videoio plugin's writer interface.
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gac41a544552a08bf3dc8142d687fbe4e5
+func (VideoRegistryType) GetWriterBackendPluginVersion(api VideoCaptureAPI) (string, int, int) {
+	var (
+		version_abi C.int
+		version_api C.int
+	)
+
+	c_desc := C.Videoio_Registry_GetWriterBackendPluginVersion(C.int(api), &version_abi, &version_api)
+	defer C.free(unsafe.Pointer(c_desc))
+	desc := C.GoString(c_desc)
+
+	return desc, int(version_abi), int(version_api)
+}
+
+// GetWriterBackends Returns list of available backends which works via gocv.VideoWriter()
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gaed03e49e6a45ca5b20afe1b9f78955e0
+func (VideoRegistryType) GetWriterBackends() []VideoCaptureAPI {
+	intVec := C.Videoio_Registry_GetWriterBackends()
+	defer C.IntVector_Close(intVec)
+
+	c_ints := unsafe.Slice(intVec.val, int(intVec.length))
+
+	ints := make([]VideoCaptureAPI, len(c_ints))
+
+	for i, val := range c_ints {
+		ints[i] = VideoCaptureAPI(int(val))
+	}
+	return ints
+}
+
+// HasBackend Returns true if backend is available.
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#ga9068310d50ef430c2f5f6b185a99a24b
+func (VideoRegistryType) HasBackend(api VideoCaptureAPI) bool {
+	b := C.Videoio_Registry_HasBackend(C.int(api))
+	return bool(b)
+}
+
+// IsBackendBuiltIn Returns true if backend is built in (false if backend is used as plugin)
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/de/db1/group__videoio__registry.html#gadf24ec0854bb893a75591306ad9f3878
+func (VideoRegistryType) IsBackendBuiltIn(api VideoCaptureAPI) bool {
+	b := C.Videoio_Registry_IsBackendBuiltIn(C.int(api))
+	return bool(b)
+}

videoio.h

@@ -3,6 +3,7 @@
 
 #ifdef __cplusplus
 #include <opencv2/opencv.hpp>
+#include <opencv2/videoio/registry.hpp>
 extern "C" {
 #endif
 
@@ -40,6 +41,18 @@ void VideoWriter_Open(VideoWriter vw, const char* name, const char* codec, doubl
 int VideoWriter_IsOpened(VideoWriter vw);
 void VideoWriter_Write(VideoWriter vw, Mat img);
 
+//Videoio Query I/O API backends registry
+char* Videoio_Registry_GetBackendName(int api);
+IntVector Videio_Registry_GetBackends();
+char* Videoio_Registry_GetCameraBackendPluginVersion(int api, int* version_ABI, int* version_API);
+IntVector Videoio_Registry_GetCameraBackends();
+char* Videoio_Registry_GetStreamBackendPluginVersion(int api, int* version_ABI, int* version_API);
+IntVector Videoio_Registry_GetStreamBackends();
+char* Videoio_Registry_GetWriterBackendPluginVersion(int api, int* version_ABI, int* version_API);
+IntVector Videoio_Registry_GetWriterBackends();
+bool Videoio_Registry_HasBackend(int api);
+bool Videoio_Registry_IsBackendBuiltIn(int api);
+
 #ifdef __cplusplus
 }
 #endif

videoio_test.go

@@ -245,3 +245,46 @@ func TestVideoCaptureFile_GrabRetrieve(t *testing.T) {
 		t.Error("Unable to read VideoCaptureFile")
 	}
 }
+
+func TestVideoRegistry(t *testing.T) {
+
+	name := VideoRegistry.GetBackendName(VideoCaptureFFmpeg)
+	t.Log("VideoRegistry.GetBackendName()", name)
+
+	backs := VideoRegistry.GetBackends()
+	for _, b := range backs {
+		t.Log("VideoRegistry.GetBackends()", b.String())
+	}
+
+	cameraBacks := VideoRegistry.GetCameraBackends()
+	for _, b := range cameraBacks {
+		t.Log("VideoRegistry.GetCameraBackends()", b.String())
+		if !VideoRegistry.IsBackendBuiltIn(b) && VideoRegistry.HasBackend(b) {
+
+			description, abiVersion, apiVersion := VideoRegistry.GetCameraBackendPluginVersion(b)
+			t.Log("VideoRegistry.GetCameraBackendPluginVersion()", description, abiVersion, apiVersion)
+		}
+	}
+
+	streamBacks := VideoRegistry.GetStreamBackends()
+	for _, b := range streamBacks {
+		t.Log("VideoRegistry.GetStreamBackends()", b.String())
+		if !VideoRegistry.IsBackendBuiltIn(b) && VideoRegistry.HasBackend(b) {
+
+			description, abiVersion, apiVersion := VideoRegistry.GetStreamBackendPluginVersion(b)
+			t.Log("VideoRegistry.GetStreamBackendPluginVersion()", description, abiVersion, apiVersion)
+		}
+	}
+
+	writerBacks := VideoRegistry.GetWriterBackends()
+
+	for _, b := range writerBacks {
+		t.Log("VideoRegistry.GetWriterBackends()", b.String())
+		if !VideoRegistry.IsBackendBuiltIn(b) && VideoRegistry.HasBackend(b) {
+
+			description, abiVersion, apiVersion := VideoRegistry.GetWriterBackendPluginVersion(b)
+			t.Log("VideoRegistry.GetWriterBackendPluginVersion()", description, abiVersion, apiVersion)
+		}
+	}
+
+}