Fix Windows RC flags and OHOS SDK discovery

Author: zzzhr1990

.github/workflows/ffmpeg-dependencies.yml

@@ -131,11 +131,22 @@ jobs:
       - name: Initialize pinned vcpkg
         run: git submodule update --init ffmpeg/vcpkg
 
+      - name: Locate OHOS SDK 23
+        run: |
+          sdk_root="${OHOS_SDK_ROOT:-$HOME/Library/OpenHarmony/Sdk/23}"
+          toolchain="$sdk_root/native/build/cmake/ohos.toolchain.cmake"
+          if [[ ! -f "$toolchain" ]]; then
+            echo "::error::OHOS SDK 23 toolchain not found at $toolchain"
+            exit 1
+          fi
+          echo "OHOS_SDK_ROOT=$sdk_root" >> "$GITHUB_ENV"
+
       - name: Check OHOS host tools
         run: |
-          test -n "$OHOS_SDK_ROOT"
-          test -f "$OHOS_SDK_ROOT/native/build/cmake/ohos.toolchain.cmake"
-          command -v patchelf
+          if ! command -v patchelf >/dev/null 2>&1; then
+            echo "::error::macOS-native patchelf is required; install it with: brew install patchelf"
+            exit 1
+          fi
 
       - name: Restore vcpkg binary cache
         uses: actions/cache@v4

ffmpeg/README.md

@@ -123,5 +123,5 @@ Windows when a different artifact directory is needed.
 
 `.github/workflows/ffmpeg-dependencies.yml` builds Android and OHOS on a
 self-hosted macOS arm64 runner and Windows on a self-hosted Visual Studio
-runner. The macOS runner service environment must provide `OHOS_SDK_ROOT` and
-macOS-native `patchelf`.
+runner. The OHOS job uses `OHOS_SDK_ROOT` when set and otherwise checks
+`$HOME/Library/OpenHarmony/Sdk/23`; macOS-native `patchelf` must be installed.

ffmpeg/triplets/toolchains/windows-clang-cl.cmake

@@ -44,4 +44,10 @@ if(NOT _QTAV_WINDOWS_CLANG_CL_TOOLCHAIN)
     set(CMAKE_CXX_COMPILER "${QTAV_CLANG_CL}" CACHE FILEPATH "" FORCE)
 
     include("${CMAKE_CURRENT_LIST_DIR}/../../vcpkg/scripts/toolchains/windows.cmake")
+
+    # CMake's cmcldeps passes resource-compiler flags through clang-cl while
+    # scanning .rc dependencies. clang-cl treats rc.exe's /c65001 option as a
+    # file name, so retain the Windows define without that RC-only codepage
+    # switch. C and C++ sources still receive vcpkg's /utf-8 option.
+    set(CMAKE_RC_FLAGS "/DWIN32" CACHE STRING "" FORCE)
 endif()