#!/bin/sh # Usage: version.sh <ffmpeg-root-dir> <output-version.h> <extra-version> # check for git short hashif ! test "$revision"; then    if (cd "$1" && grep git RELEASE 2> /dev/null >/dev/null) ; then        revision=$(cd "$1" && git describe --tags --match N 2> /dev/null)    else        revision=$(cd "$1" && git describe --tags --always 2> /dev/null)    fifi # Shallow Git clones (--depth) do not have the N tag:# use 'git-YYYY-MM-DD-hhhhhhh'.test "$revision" || revision=$(cd "$1" &&  git log -1 --pretty=format:"git-%cd-%h" --date=short 2> /dev/null) # Snapshots from gitweb are in a directory called ffmpeg-hhhhhhh or# ffmpeg-HEAD-hhhhhhh.if [ -z "$revision" ]; then  srcdir=$(cd "$1" && pwd)  case "$srcdir" in    */ffmpeg-[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f])      git_hash="${srcdir##*-}";;    */ffmpeg-HEAD-[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f])      git_hash="${srcdir##*-}";;  esacfi # no revision number foundtest "$revision" || revision=$(cd "$1" && cat RELEASE 2> /dev/null) # Append the Git hash if we have onetest "$revision" && test "$git_hash" && revision="$revision-$git_hash" # releases extract the version number from the VERSION fileversion=$(cd "$1" && cat VERSION 2> /dev/null)test "$version" || version=$revision test -n "$3" && version=$version-$3 if [ -z "$2" ]; then    echo "$version"    exitfi NEW_REVISION="#define FFMPEG_VERSION \"$version\""OLD_REVISION=$(cat "$2" 2> /dev/null | head -4 | tail -1) # String used for preprocessor guardGUARD=$(echo "$2" | sed 's/\//_/' | sed 's/\./_/' | tr '[:lower:]' '[:upper:]' | sed 's/LIB//') # Update version header only on revision changes to avoid spurious rebuildsif test "$NEW_REVISION" != "$OLD_REVISION"; then    cat << EOF > "$2"/* Automatically generated by version.sh, do not manually edit! */#ifndef $GUARD#define $GUARD$NEW_REVISION#endif /* $GUARD */EOFfi