Merge pull request opencv#26063 from mshabunin:fix-config-and-doc

build/doc: disabled libdc1394 by default, documented framebuffer options

Author: asmorkalov

CMakeLists.txt

@@ -248,7 +248,7 @@ OCV_OPTION(BUILD_ITT                "Build Intel ITT from source"
 
 # Optional 3rd party components
 # ===================================================
-OCV_OPTION(WITH_1394 "Include IEEE1394 support" ON
+OCV_OPTION(WITH_1394 "Include IEEE1394 support" OFF
   VISIBLE_IF NOT ANDROID AND NOT IOS AND NOT XROS AND NOT WINRT
   VERIFY HAVE_DC1394_2)
 OCV_OPTION(WITH_AVFOUNDATION "Use AVFoundation for Video I/O (iOS/visionOS/Mac)" ON

doc/tutorials/introduction/config_reference/config_reference.markdown

@@ -393,7 +393,7 @@ There are multiple less popular frameworks which can be used to read and write v
 
 | Option | Default | Description |
 | ------ | ------- | ----------- |
-| `WITH_1394` | _ON_ | [IIDC IEEE1394](https://en.wikipedia.org/wiki/IEEE_1394#IIDC) support using DC1394 library |
+| `WITH_1394` | _OFF_ | [IIDC IEEE1394](https://en.wikipedia.org/wiki/IEEE_1394#IIDC) support using DC1394 library |
 | `WITH_OPENNI` | _OFF_ | [OpenNI](https://en.wikipedia.org/wiki/OpenNI) can be used to capture data from depth-sensing cameras. Deprecated. |
 | `WITH_OPENNI2` | _OFF_ | [OpenNI2](https://structure.io/openni) can be used to capture data from depth-sensing cameras. |
 | `WITH_PVAPI` | _OFF_ | [PVAPI](https://www.alliedvision.com/en/support/software-downloads.html) is legacy SDK for Prosilica GigE cameras. Deprecated. |
@@ -455,6 +455,8 @@ OpenCV relies on various GUI libraries for window drawing.
 | `WITH_WIN32UI` | _ON_ | Windows | [WinAPI](https://en.wikipedia.org/wiki/Windows_API) is a standard GUI API in Windows. |
 | N/A | _ON_ | macOS | [Cocoa](https://en.wikipedia.org/wiki/Cocoa_(API)) is a framework used in macOS. |
 | `WITH_QT` | _OFF_ | Cross-platform | [Qt](https://en.wikipedia.org/wiki/Qt_(software)) is a cross-platform GUI framework. |
+| `WITH_FRAMEBUFFER` | _OFF_ | Linux | Experimental backend using [Linux framebuffer](https://en.wikipedia.org/wiki/Linux_framebuffer). Have limited functionality but does not require dependencies. |
+| `WITH_FRAMEBUFFER_XVFB` | _OFF_ | Linux | Enables special output mode of the FRAMEBUFFER backend compatible with [xvfb](https://en.wikipedia.org/wiki/Xvfb) tool. Requires some X11 headers. |
 
 @note OpenCV compiled with Qt support enables advanced _highgui_ interface, see @ref highgui_qt for details.
 

doc/tutorials/introduction/env_reference/env_reference.markdown

@@ -329,6 +329,9 @@ Some external dependencies can be detached into a dynamic library, which will be
 |------|------|---------|-------------|
 | OPENCV_LEGACY_WAITKEY | non-null | | switch `waitKey` return result (default behavior: `return code & 0xff` (or -1), legacy behavior: `return code`) |
 | $XDG_RUNTIME_DIR | | | Wayland backend specific - create shared memory-mapped file for interprocess communication (named `opencv-shared-??????`) |
+| OPENCV_HIGHGUI_FB_MODE | string | `FB` | Selects output mode for the framebuffer backend (`FB` - regular frambuffer, `EMU` - emulation, perform internal checks but does nothing, `XVFB` - compatible with _xvfb_ virtual frambuffer) |
+| OPENCV_HIGHGUI_FB_DEVICE | file path | | Path to frambuffer device to use (will be checked first) |
+| FRAMEBUFFER | file path | `/dev/fb0` | Same as OPENCV_HIGHGUI_FB_DEVICE, commonly used variable for the same purpose (will be checked second) |
 
 
 ## imgproc