Add SDL Video Capture, with back-end for linux/macos/ios/android

CMakeLists.txt

@@ -343,6 +343,7 @@ set_option(SDL_METAL               "Enable Metal support" ${APPLE})
 set_option(SDL_KMSDRM              "Use KMS DRM video driver" ${UNIX_SYS})
 dep_option(SDL_KMSDRM_SHARED       "Dynamically load KMS DRM support" ON "SDL_KMSDRM" OFF)
 set_option(SDL_OFFSCREEN           "Use offscreen video driver" ON)
+dep_option(SDL_VIDEO_CAPTURE       "Enable video capturing" ON SDL_VIDEO OFF)
 option_string(SDL_BACKGROUNDING_SIGNAL "number to use for magic backgrounding signal or 'OFF'" OFF)
 option_string(SDL_FOREGROUNDING_SIGNAL "number to use for magic foregrounding signal or 'OFF'" OFF)
 dep_option(SDL_HIDAPI              "Enable the HIDAPI subsystem" ON "NOT VISIONOS" OFF)
@@ -2047,6 +2048,10 @@ elseif(APPLE)
     set(HAVE_SDL_FILE TRUE)
   endif()
 
+  if(IOS OR TVOS OR MACOSX OR DARWIN)
+    sdl_sources("${SDL3_SOURCE_DIR}/src/video/SDL_video_capture_apple.m")
+  endif()
+
   if(SDL_MISC)
     if(IOS OR TVOS OR VISIONOS)
       sdl_glob_sources("${SDL3_SOURCE_DIR}/src/misc/ios/*.m")
@@ -2230,6 +2235,10 @@ elseif(APPLE)
 
   # Actually load the frameworks at the end so we don't duplicate include.
   if(SDL_FRAMEWORK_COREVIDEO)
+    find_library(COREMEDIA CoreMedia)
+    if(COREMEDIA)
+      sdl_link_dependency(corevideo LINK_OPTIONS "-Wl,-framework,CoreMedia")
+    endif()
     sdl_link_dependency(corevideo LINK_OPTIONS "-Wl,-framework,CoreVideo")
   endif()
   if(SDL_FRAMEWORK_COCOA)