Enable libva on Windows

I was not able to get the driver to work at all.
It just crashes a lot, but since it has no averse side-effects
(hopefully), let's just enable it by default.

scripts.d/50-vaapi/50-libva.sh

@@ -4,7 +4,10 @@ SCRIPT_REPO="https://github.com/intel/libva.git"
 SCRIPT_COMMIT="7d6c7d482b9d2330b1f3a8bac13a6a3205f33382"
 
 ffbuild_enabled() {
-    [[ $TARGET != linux* ]] && return -1
+    [[ $ADDINS_STR == *4.4* && $TARGET == win* ]] && return -1
+    [[ $ADDINS_STR == *5.0* && $TARGET == win* ]] && return -1
+    [[ $ADDINS_STR == *5.1* && $TARGET == win* ]] && return -1
+    [[ $ADDINS_STR == *6.0* && $TARGET == win* ]] && return -1
     [[ $TARGET == linuxarm64 ]] && return -1
     return 0
 }
@@ -12,25 +15,35 @@ ffbuild_enabled() {
 ffbuild_dockerbuild() {
     cd "$FFBUILD_DLDIR/$SELF"
 
-    autoreconf -i
+    # This works around an issue of our libxcb-dri3 implib-wrapper not exporting data symbols.
+    # Under normal circumstances, this would break horribly.
+    # But we only want to generate another import lib for libva, so it doesn't matter.
+    echo "#include <xcb/xcbext.h>" >> va/x11/va_dri3.c
+    echo "xcb_extension_t xcb_dri3_id;" >> va/x11/va_dri3.c
+
+    mkdir mybuild && cd mybuild
 
     local myconf=(
         --prefix="$FFBUILD_PREFIX"
-        --enable-shared
+        --buildtype=release
-        --disable-static
+        --default-library=shared
-        --with-pic
+        -Denable_docs=false
-        --disable-docs
-        --enable-drm
-        --enable-x11
-        --disable-glx
-        --disable-wayland
     )
 
     if [[ $TARGET == linux64 ]]; then
         myconf+=(
-            --host="$FFBUILD_TOOLCHAIN"
+            --cross-file=/cross.meson
-            --with-drivers-path="/usr/lib/x86_64-linux-gnu/dri"
             --sysconfdir="/etc"
+            -Ddriverdir="/usr/lib/x86_64-linux-gnu/dri"
+            -Ddisable_drm=false
+            -Dwith_x11=yes
+            -Dwith_glx=no
+            -Dwith_wayland=no
+        )
+    elif [[ $TARGET == win* ]]; then
+        myconf+=(
+            --cross-file=/cross.meson
+            -Dwith_win32=yes
         )
     else
         echo "Unknown target"
@@ -40,16 +53,27 @@ ffbuild_dockerbuild() {
     export CFLAGS="$RAW_CFLAGS"
     export LDFLAFS="$RAW_LDFLAGS"
 
-    ./configure "${myconf[@]}"
+    meson "${myconf[@]}" ..
-    make -j$(nproc)
+    ninja -j"$(nproc)"
-    make install
+    ninja install
 
-    gen-implib "$FFBUILD_PREFIX"/lib/{libva.so.2,libva.a}
+    if [[ $TARGET == linux* ]]; then
-    gen-implib "$FFBUILD_PREFIX"/lib/{libva-drm.so.2,libva-drm.a}
+        gen-implib "$FFBUILD_PREFIX"/lib/{libva.so.2,libva.a}
-    gen-implib "$FFBUILD_PREFIX"/lib/{libva-x11.so.2,libva-x11.a}
+        gen-implib "$FFBUILD_PREFIX"/lib/{libva-drm.so.2,libva-drm.a}
-    rm "$FFBUILD_PREFIX"/lib/libva{,-drm,-x11}{.so*,.la}
+        gen-implib "$FFBUILD_PREFIX"/lib/{libva-x11.so.2,libva-x11.a}
+        rm "$FFBUILD_PREFIX"/lib/libva{,-drm,-x11}.so*
 
-    echo "Libs: -ldl" >> "$FFBUILD_PREFIX"/lib/pkgconfig/libva.pc
+        echo "Libs: -ldl" >> "$FFBUILD_PREFIX"/lib/pkgconfig/libva.pc
+    elif [[ $TARGET == win* ]]; then
+        "$FFBUILD_CROSS_PREFIX"gendef - "$FFBUILD_PREFIX"/bin/libva.dll > libva.def
+        "$FFBUILD_CROSS_PREFIX"gendef - "$FFBUILD_PREFIX"/bin/libva_win32.dll > libva_win32.def
+        "$FFBUILD_CROSS_PREFIX"dlltool --input-def libva.def --output-delaylib "$FFBUILD_PREFIX"/lib/libva.a
+        "$FFBUILD_CROSS_PREFIX"dlltool --input-def libva_win32.def --output-delaylib "$FFBUILD_PREFIX"/lib/libva_win32.a
+        rm "$FFBUILD_PREFIX"/bin/libva*.dll "$FFBUILD_PREFIX"/lib/libva*.dll.a
+    else
+        echo "Unknown target"
+        return -1
+    fi
 }
 
 ffbuild_configure() {

scripts.d/50-vaapi/99-finalize.sh

@@ -3,7 +3,6 @@
 SCRIPT_SKIP="1"
 
 ffbuild_enabled() {
-    [[ $TARGET != linux* ]] && return -1
     return 0
 }
 
@@ -12,6 +11,8 @@ ffbuild_dockerdl() {
 }
 
 ffbuild_dockerbuild() {
-    rm "$FFBUILD_PREFIX"/lib/lib*.so* || true
+    if [[ $TARGET == linux* ]]; then
-    rm "$FFBUILD_PREFIX"/lib/*.la || true
+        rm "$FFBUILD_PREFIX"/lib/lib*.so* || true
+        rm "$FFBUILD_PREFIX"/lib/*.la || true
+    fi
 }