contrib: add x264 rules

Dependency required by libav.

Based on VideoLan code by Rémi Denis-Courmont et al.
Refs: #46617

Change-Id: Ib7f893bc1ff13a4fa90b2f4a73279288569c9474

contrib/src/x264/rules.mak

+# x264
+
+X264_GITURL := git://git.videolan.org/x264.git
+X264_SNAPURL := http://git.videolan.org/?p=x264.git;a=snapshot;h=HEAD;sf=tgz
+X262_GITURL := git://git.videolan.org/x262.git
+
+ifeq ($(call need_pkg,"x264 >= 0.86"),)
+PKGS_FOUND += x264
+endif
+
+
+X264CONF = --prefix="$(PREFIX)" \
+           --host="$(HOST)"     \
+           --enable-static      \
+           --disable-avs        \
+           --disable-lavf       \
+           --disable-cli        \
+           --disable-ffms
+
+ifndef HAVE_WIN32
+X264CONF += --enable-pic
+else
+X264CONF += --enable-win32thread
+endif
+ifdef HAVE_CROSS_COMPILE
+X264CONF += --cross-prefix="$(HOST)-"
+endif
+
+$(TARBALLS)/x264-git.tar.xz:
+	$(call download_git,$(X264_GITURL))
+
+$(TARBALLS)/x264-git.tar.gz:
+	$(call download,$(X264_SNAPURL))
+
+.sum-x264: x264-git.tar.gz
+	$(warning $@ not implemented)
+	touch $@
+
+x264: x264-git.tar.gz .sum-x264
+	rm -Rf $@-git
+	mkdir -p $@-git
+	$(ZCAT) "$<" | (cd $@-git && tar xv --strip-components=1)
+	$(UPDATE_AUTOCONFIG)
+	$(MOVE)
+
+.x264: x264
+	cd $< && $(HOSTVARS) ./configure $(X264CONF)
+	cd $< && $(MAKE) install
+	touch $@