contrib: add vpx rules and patches

Dependency required by libav.

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

Change-Id: I7d29d51feeff97349fdbe341cbba07f068e79521

contrib/src/vpx/SHA512SUMS

+af26766a3336155c5bc7b8cce7c23228de054287b990f9cacdc35273384a7af4999c01bb623d12143f40107036308a8b3207081efe67936748503c30c985fd6b  libvpx-v1.3.0.tar.bz2

contrib/src/vpx/libvpx-mac.patch

+libvpx's configure script hard-codes the SDK location of previous Xcode release in the /Developer folder. However, starting with Xcode 4.3, the SDKs moved to /Applications/Xcode.app/blabla
+VLC's contrib system is clever enough to detect this, but libvpx fails miserably. However, they are providing a work-around for iOS and Android, which is expanded by this patch.
+
+diff -ru libvpx/build/make/configure.sh libvpx/build/make/configure.sh
+--- libvpx/build/make/configure.sh	2012-06-08 10:26:47.000000000 +0200
++++ libvpx-fixed/build/make/configure.sh	2012-06-08 10:26:07.000000000 +0200
+@@ -628,6 +628,11 @@
+     if [ -d "/Developer/SDKs/MacOSX10.7.sdk" ]; then
+         osx_sdk_dir="/Developer/SDKs/MacOSX10.7.sdk"
+     fi
++    if [ -d "${sdk_path}" ]; then
++        case "${sdk_path}" in
++           darwin*) osx_sdk_dir=${sdk_path} ;;
++        esac
++    fi
+ 
+     case ${toolchain} in
+         *-darwin8-*)

contrib/src/vpx/libvpx-no-cross.patch

+--- libvpx-v1.0.0/build/make/configure.sh.orig	2012-01-29 04:59:36.976441000 -0500
++++ libvpx-v1.0.0/build/make/configure.sh	2012-01-29 04:59:46.684441001 -0500
+@@ -680,7 +680,6 @@
+ 
+         case ${tgt_cc} in
+         gcc)
+-            CROSS=${CROSS:-arm-none-linux-gnueabi-}
+             link_with_cc=gcc
+             setup_gnu_toolchain
+             arch_int=${tgt_isa##armv}

contrib/src/vpx/libvpx-sysroot.patch

+Our contrib system already passes the correct sysroot to the compiler, so there
+is no need to set an alternate libc path. If that path is empty the script will
+try to look for it in some fashion, but since the SDKROOT may be in a
+non standard location the look up may fail.
+
+This patch avoids that case and relies on the user configuration for the
+correct sysroot.
+
+See also https://code.google.com/p/webm/issues/detail?id=809
+
+diff --git a/build/make/configure.sh b/build/make/configure.sh
+index d4124c7..c420d25 100755
+--- a/build/make/configure.sh
++++ b/build/make/configure.sh
+@@ -939,8 +939,11 @@ EOF
+                           awk '{ print $1 }' | tail -1`
+             fi
+ 
+-            add_cflags "--sysroot=${alt_libc}"
+-            add_ldflags "--sysroot=${alt_libc}"
++            # this may happen if toolchain binaries are outside the ndk dir
++            if [ "${alt_libc}" ]; then
++                add_cflags "--sysroot=${alt_libc}"
++                add_ldflags "--sysroot=${alt_libc}"
++            fi
+ 
+             # linker flag that routes around a CPU bug in some
+             # Cortex-A8 implementations (NDK Dev Guide)
+-- 
+1.8.3.2
+

contrib/src/vpx/rules.mak

+# libvpx
+
+VPX_VERSION := v1.3.0
+VPX_URL := http://webm.googlecode.com/files/libvpx-$(VPX_VERSION).tar.bz2
+
+$(TARBALLS)/libvpx-$(VPX_VERSION).tar.bz2:
+	$(call download,$(VPX_URL))
+
+.sum-vpx: libvpx-$(VPX_VERSION).tar.bz2
+
+vpx: libvpx-$(VPX_VERSION).tar.bz2 .sum-vpx
+	$(UNPACK)
+	$(APPLY) $(SRC)/vpx/libvpx-sysroot.patch
+	$(APPLY) $(SRC)/vpx/libvpx-no-cross.patch
+	$(APPLY) $(SRC)/vpx/libvpx-mac.patch
+	$(MOVE)
+
+DEPS_vpx =
+
+ifdef HAVE_CROSS_COMPILE
+VPX_CROSS := $(HOST)-
+else
+VPX_CROSS :=
+endif
+
+ifeq ($(ARCH),arm)
+VPX_ARCH := armv7
+else ifeq ($(ARCH),i386)
+VPX_ARCH := x86
+else ifeq ($(ARCH),mips)
+VPX_ARCH := mips32
+else ifeq ($(ARCH),ppc)
+VPX_ARCH := ppc32
+else ifeq ($(ARCH),ppc64)
+VPX_ARCH := ppc64
+else ifeq ($(ARCH),sparc)
+VPX_ARCH := sparc
+else ifeq ($(ARCH),x86_64)
+VPX_ARCH := x86_64
+endif
+
+ifdef HAVE_ANDROID
+VPX_OS := android
+else ifdef HAVE_LINUX
+VPX_OS := linux
+else ifdef HAVE_DARWIN_OS
+ifeq ($(ARCH),arm)
+VPX_OS := darwin
+else
+ifeq ($(OSX_VERSION),10.5)
+VPX_OS := darwin9
+else
+VPX_OS := darwin10
+endif
+endif
+else ifdef HAVE_SOLARIS
+VPX_OS := solaris
+else ifdef HAVE_WIN64 # must be before WIN32
+VPX_OS := win64
+else ifdef HAVE_WIN32
+VPX_OS := win32
+else ifdef HAVE_BSD
+VPX_OS := linux
+endif
+
+VPX_TARGET := generic-gnu
+ifdef VPX_ARCH
+ifdef VPX_OS
+VPX_TARGET := $(VPX_ARCH)-$(VPX_OS)-gcc
+endif
+endif
+
+VPX_CONF := \
+	--enable-runtime-cpu-detect \
+	--disable-install-bins \
+	--disable-install-docs \
+	--disable-examples \
+	--disable-unit-tests \
+	--disable-vp8-decoder \
+	--disable-vp9-decoder
+ifndef HAVE_WIN32
+VPX_CONF += --enable-pic
+endif
+ifdef HAVE_MACOSX
+VPX_CONF += --sdk-path=$(MACOSX_SDK)
+endif
+ifdef HAVE_IOS
+VPX_CONF += --sdk-path=$(SDKROOT)
+endif
+ifdef HAVE_ANDROID
+# vpx configure.sh overrides our sysroot and it looks for it itself, and
+# uses that path to look for the compiler (which we already know)
+VPX_CONF += --sdk-path=$(shell dirname $(shell which $(HOST)-gcc))
+# needed for cpu-features.h
+VPX_CONF += --extra-cflags="-I $(ANDROID_NDK)/sources/cpufeatures/"
+endif
+
+.vpx: vpx
+	cd $< && CROSS=$(VPX_CROSS) ./configure --target=$(VPX_TARGET) \
+		$(VPX_CONF) --prefix=$(PREFIX)
+	cd $< && $(MAKE)
+	cd $< && ../../../contrib/src/pkg-static.sh vpx.pc
+	cd $< && $(MAKE) install
+	touch $@