#!/bin/sh
 

 # check for git short hash

 if ! test "$revision"; then

     revision=$(cd "$1" && git describe --tags --match N 2> /dev/null)

 fi
 

 # no revision number found

 test "$revision" || revision=$(cd "$1" && cat RELEASE 2> /dev/null)

 # releases extract the version number from the VERSION file

 version=$(cd "$1" && cat VERSION 2> /dev/null)

 test "$version" || version=$revision

 test -n "$3" && version=$version-$3
 

 if [ -z "$2" ]; then
     echo "$version"
     exit
 fi
 

 NEW_REVISION="#define FFMPEG_VERSION \"$version\""

 OLD_REVISION=$(cat version.h 2> /dev/null)

 
 # Update version.h only on revision changes to avoid spurious rebuilds
 if test "$NEW_REVISION" != "$OLD_REVISION"; then

     echo "$NEW_REVISION" > "$2"

 fi