Allow re-targeting of naclports install

libraries/ffmpeg-0.5/nacl-ffmpeg-0.5.sh

 #!/bin/bash
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # nacl-ffmpeg-0.5.sh
 #
 # usage:  nacl-ffmpeg-0.5.sh
 #
 # this script downloads, patches, and builds ffmpeg for Native Client 
 #
 
 readonly URL=http://commondatastorage.googleapis.com/nativeclient-mirror/nacl/ffmpeg-0.5.tar.bz2
 #readonly URL=http://ffmpeg.org/releases/ffmpeg-0.5.tar.bz2
 readonly PATCH_FILE=nacl-ffmpeg-0.5.patch
 readonly PACKAGE_NAME=ffmpeg-0.5
 
 source ../../build_tools/common.sh
 
 
 CustomConfigureStep() {
-  export PKG_CONFIG_PATH=${NACL_SDK_USR_LIB}/pkgconfig
-  export PKG_CONFIG_LIBDIR=${NACL_SDK_USR_LIB}
+  export PKG_CONFIG_PATH=${NACLPORTS_LIBDIR}/pkgconfig
+  export PKG_CONFIG_LIBDIR=${NACLPORTS_LIBDIR}
   export PATH=${NACL_BIN_PATH}:${PATH};
   MakeDir ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}/${PACKAGE_NAME}-build
   ChangeDir ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}/${PACKAGE_NAME}-build
   local extra_args=""
   if [ "${NACL_ARCH}" = pnacl ]; then
     extra_args="--cc=pnacl-clang --arch=pnacl"
   fi
   ../configure \
     --cross-prefix=${NACL_CROSS_PREFIX}- \
     ${extra_args} \
@@ skipping 11 matching lines @@
     --disable-protocols \
     --disable-network \
     --enable-protocol=file \
     --enable-libmp3lame \
     --enable-libvorbis \
     --enable-libtheora \
     --disable-ffplay \
     --disable-ffserver \
     --disable-demuxer=rtsp \
     --disable-demuxer=image2 \
-    --prefix=${NACL_SDK_USR} \
-    --libdir=${NACL_SDK_USR_LIB}
+    --prefix=${NACLPORTS_PREFIX} \
+    --libdir=${NACLPORTS_LIBDIR}
 }
 
 
 CustomPostConfigureStep() {
   touch strings.h
 }
 
 
 CustomBuildAndInstallStep() {
   DefaultBuildStep
   make install
   DefaultTouchStep
 }
 
 
 CustomPackageInstall() {
   DefaultPreInstallStep
   DefaultDownloadBzipStep
   DefaultExtractBzipStep
   DefaultPatchStep
   CustomConfigureStep
   CustomPostConfigureStep
   CustomBuildAndInstallStep
   DefaultCleanUpStep
 }
 
 
 CustomPackageInstall
 exit 0