GIF animation script to cut a piece of video and produce a frame-accurate optimized GIF with a precise framerate.

gifcreate

#!/bin/sh

help () {
    log "Usage: `basename $0` [-h] [-n] [-a] [-u] [-s hh:mm:ss] [-d ss] [-w px] [-f n] [-S n] [-b n] [-t subtitle.sub] [-c default | basic | fontsize | fontstyle | full] <filename> [result.gif]
    
-h              show this help
-n              turn off subtitles
-a              don't open directory with frames in filemanager
-u              update this script from gist. Create .gifupd file in the script's directory to automatically check for updates once per day or put the number of seconds in the file to check with that period.
-s              start time in seconds or as hours:minutes:seconds, default: 0
-d              duration in seconds or as hh:mm:ss, default: 5
-w              resulting width in pixels (height is set according to the aspect), default: 320
-f              use every nth frame to get smaller file; use 2-3 for anime, default: 2
-S              use nth subtitles track
-b              use n fake (dithered) bits for color, you can also use form r,g,b specifying number of levels per channel (0-255), default: 24
-t              add subtitles from the file
-c              create (and replace) the subtitles file with a template of the chosen type
-p              set FPS manually
<filename>      input filename
result.gif      optional output filename. If not specified, random name will be used.
"
    update
    exit 0
}

log () {
    if [ -z "$2" ]
    then
        echo "$1" >&2
    else
        if [ $1 -le $DEBUG ]
        then
            echo "$2" >&2
        fi
    fi
}

update () {
    PERIOD=86400
    if [ "$1" != "do" ]
    then
        if [ ! -f "$UPDFILE" ]
        then
            log 5 "No update file found"
            return
        fi
        FILEPERIOD=$( cat "$UPDFILE" )
        if [ -n "$FILEPERIOD" ]
        then
            PERIOD=$FILEPERIOD
        fi
        log 5 "Update file found, PERIOD=$PERIOD"
        NOW=$( date +%s )
        THEN=$( stat -c %Y "$UPDFILE" )
        DIFF=$(( NOW - THEN ))
        log 5 "Now: $NOW, Then: $THEN, Diff: $DIFF"
    else
        DIFF=86401
    fi
    if [ $DIFF -ge $PERIOD ]
    then
        touch "$UPDFILE"
        NEWFILE=`mktemp "/tmp/gcupdXXXXXX"`
        trap "rm $NEWFILE 2>/dev/null" INT TERM EXIT
        log 5 "NEWFILE: $NEWFILE"
        wget -qO "$NEWFILE" "$UPDURL"
        if [ $? -eq 0 -a -n "`cat $NEWFILE`" ]
        then
            DIFFTEXT=$( diff -u "$FULLSELFPATH" "$NEWFILE" )
            if [ -n "$DIFFTEXT" ]
            then
                log "\033[1m***New version available***\033[0m"
                if [ "$1" = "do" ]
                then
                    log "Diff:\n\n$DIFFTEXT"
                    read -p "Perform updating? (y/N)" UPD
                    if [ "$UPD" = "y" -o "$UPD" = "Y" ]
                    then
                        log "Updating..."
                        cp "$NEWFILE" "$FULLSELFPATH"
                        log "Done."
                    fi
                    exit 0
                else
                    log 5 "Update found, doing nothing."
                fi
            else
                log 5 "No difference found in update"
            fi
        else
            log 2 "Error downloading update."
        fi
    else
        log 5 "Diff is less than $PERIOD seconds"
    fi
    rm $NEWFILE 2>/dev/null
}

subtitle () {
    sed -e "s/^\s*\(.*\)$/\1/" -e "/^$/d" -e "/^;.*/d" $SUBTITLE | (
        FONTSIZE=20
        FONT=DejaVu-Sans-Bold
        COLOR=white
        STROKECOLOR='#000c'
        STROKEWIDTH=2
        read TYPE
        log 5 "Subtitles type is: $TYPE"
        case $TYPE in
            basic)
                read FONT FONTSIZE COLOR STROKECOLOR STROKEWIDTH
                log 5 "Set up basic subtitles defaults."
                ;;
            fontsize)
                read FONT COLOR STROKECOLOR STROKEWIDTH
                log 5 "Set up font subtitles defaults."
                ;;
            fontstyle)
                read STROKECOLOR STROKEWIDTH
                log 5 "Set up font subtitles defaults"
                ;;
        esac
        log 5 "Set up subtitles defaults. FONT: $FONT FONTSIZE: $FONTSIZE COLOR: $COLOR STROKECOLOR: $STROKECOLOR STROKEWIDTH: $STROKEWIDTH"
        FROM=
        for FRAME in `ls "$TEMP"`
        do
            FRAMENUM=${FRAME%.png}
            log 5 "Processing frame $FRAMENUM"
            if [ -z "$FROM" ]
            then
                case $TYPE in
                    basic | default)
                        log 5 "Reading subline of default or basic type"
                        read FROM TO GRAVITY GEOMETRY TEXT
                        ;;
                    fontsize)
                        log 5 "Reading subline of fontsize type"
                        read FROM TO GRAVITY GEOMETRY FONTSIZE TEXT
                        ;;
                    fontstyle)
                        log 5 "Reading subline of fontstyle type"
                        read FROM TO GRAVITY GEOMETRY FONT FONTSIZE COLOR TEXT
                        ;;
                    full)
                        log 5 "Reading subline of full type"
                        read FROM TO GRAVITY GEOMETRY FONT FONTSIZE COLOR STROKECOLOR STROKEWIDTH TEXT
                        ;;
                esac
                log 5 "FROM: $FROM TO: $TO GRAVITY: $GRAVITY GEOMETRY: $GEOMETRY TEXT: $TEXT"
            fi
            if [ -n "$FROM" ]
            then
                if [ $FRAMENUM -ge $FROM -a $FRAMENUM -le $TO ]
                then
                    log 5 "Adding subtitle to $FRAMENUM"
                    mogrify -gravity $GRAVITY -pointsize $FONTSIZE -font $FONT -stroke $STROKECOLOR -strokewidth $STROKEWIDTH -annotate $GEOMETRY "$TEXT" -stroke none -fill $COLOR -annotate $GEOMETRY "$TEXT" $FRAME
                fi
                if [ $FRAMENUM -ge $TO ]
                then
                    # load next line
                    FROM=
                fi
            fi
        done
    )
}

gentemplate () {
    TEMPLATE=";This is a subtitle file. Comments start with semicolon.\n;The first non-comment line sets dynamic parameters which can be specified for each subtitle line.\n;The second non-comment line sets other (static) parameters which can't be changed elsewhere.\n;Then your actual subtitles go. Fields are separated by spaces. From/to frame numbers are actual PNG file names in the temporary directory.\n;Refer to http://www.imagemagick.org/script/command-line-options.php and look for parameters -fill, -gravity, -pointsize, -font, -stroke, -strokewidth and -annotate.\n"
    case $SUBTITLETYPE in
        default)
            TEMPLATE="${TEMPLATE}default\n;Defaults are: fontsize 20, font DejaVu-Sans-Bold, color white, strokecolor '#000c', strokewidth 2\n;Fields order: from to gravity geometry text\n0 30 south 0 Hello world!\n35 50 north -50+50 Subtitles are working!"
            ;;
        basic)
            TEMPLATE="${TEMPLATE}basic\n;In basic type we should specify the font, its size, its color and stroke color and width\nDejaVu-Sans-Bold 25 yellow #000066aa 5\n;Fields order: from to gravity geometry text\n0 30 south 0 Hello world!\n35 50 north -50+50 Subtitles are working!"
            ;;
        fontsize)
            TEMPLATE="${TEMPLATE}fontsize\n;In fontsize type we should specify the font, its color and stroke color and width\nDejaVu-Sans-Bold yellow #000066aa 5\n;Fields order: from to gravity geometry fontsize text\n0 30 south 0 20 Hello world!\n35 50 north -50+50 30 Subtitles are working!"
            ;;
        fontstyle)
            TEMPLATE="${TEMPLATE}fontstyle\n;In fontstyle type we should only specify the stroke color and width\n#000066aa 5\n;Fields order: from to gravity geometry font fontsize color text\n0 30 south 0 DejaVu-Sans-Condensed 20 yellow Hello world!\n35 50 north -50+50 DejaVu-Serif-Italic 30 green Subtitles are working!"
            ;;
        full)
            TEMPLATE="${TEMPLATE}full\n;In full type we should not specify anything after the style type\n\n;Fields order: from to gravity geometry font fontsize color strokecolor strokewidth text\n0 30 south 0 DejaVu-Sans-Condensed 20 yellow #000c 2 Hello world!\n35 50 north -50+50 DejaVu-Serif-Italic 30 green blue 5 Subtitles are working!"
            ;;
        *)
            log "Invalid template type. Valid types are: default, basic, fontsize, fontstyle and full"
            exit 1
            ;;
    esac
    echo "$TEMPLATE" > $SUBTITLE
}

if [ -z $DEBUG ]
then
    DEBUG=1
fi
FPS=
UPDFILENAME=".gifupd"
UPDURL=https://gist.github.com/raw/4463793/gifcreate
FULLSELFPATH=$( readlink -f "$0" )
UPDFILE=$( dirname "$FULLSELFPATH" )/$UPDFILENAME
STARTTIME=0
DURATION=5
WIDTH=320
FRAMESTEP=2
RUNFM=1
FAKEBITS=24
OUTPUT=$( mktemp -u /tmp/videoXXXXXX.gif )
if [ $# -eq 0 ]
then
    help
fi
OPTS=
while getopts hnaus:d:w:f:o:S:b:t:c:p: flag
do
    case $flag in
        h)
            help
            ;;
        n)
            OPTS="-nosub -noautosub $OPTS"
            ;;
        a)
            RUNFM=
            ;;
        u)
            update "do"
            exit 0
            ;;
        s)
            STARTTIME=$OPTARG
            ;;
        d)
            DURATION=$OPTARG
            ;;
        w)
            WIDTH=$OPTARG
            ;;
        f)
            FRAMESTEP=$OPTARG
            ;;
        S)
            OPTS="-sid $OPTARG $OPTS"
            ;;
        b)
            FAKEBITS=$OPTARG
            ;;
        t)
            SUBTITLE=$OPTARG
            ;;
        c)
            SUBTITLETYPE=$OPTARG
            ;;
        p)
            FPS=$OPTARG
            ;;
    esac
done
update & # do background update check
shift $(( OPTIND-1 ))
if [ -n "$SUBTITLETYPE" -a -n "$SUBTITLE" ]
then
    gentemplate
    exit
fi
if [ -n "$SUBTITLETYPE" ]
then
    log "Specify the subtitle file with -t to create a template."
    exit 1
fi
if [ -z "$1" ]
then
    log "No input file specified."
    exit 1
fi
if [ -z "$2" ]
then
    log "No output file specified. The resulting GIF will be saved as $OUTPUT"
else
    OUTPUT=$( readlink -f "$2" )
fi
SUBTITLE=$( readlink -f "$SUBTITLE" )
TEMP=`mktemp -d /tmp/mpgifXXXXXX`
trap "rm -rf \"$TEMP\"; exit" INT TERM EXIT
FILENAME=$( readlink -f "$1" )
cd "$TEMP"
MPOUT=$( ffmpeg "$FILENAME" $OPTS -ss $STARTTIME -endpos $DURATION -vf scale=$WIDTH:-2,framestep=$FRAMESTEP -nosound -vo png:z=9 -speed 100 2>&1 )
log 5 "Mplayer output: $MPOUT"
[ -z "$FPS" ] && FPS=$( echo "$MPOUT" | sed -n 's/.* \([0-9]*\)\.[0-9]* fps .*/\1/p' | head -n 1 )
log 5 "FPS: $FPS"
DELAY=$(( 100 * FRAMESTEP / FPS ))
log 5 "Delay: $DELAY"
if [ -n "$RUNFM" ]
then
    xdg-open "$TEMP"
    read -p "Now remove any excessive frames and press Enter to combine them to a nice gif." null
fi
if [ -n "$SUBTITLE" ]
then
    log "Adding subtitles..."
    subtitle
fi
log "Rendering the final gif..."
convert -delay $DELAY "$TEMP/*.png" -ordered-dither o8x8,$FAKEBITS -layers optimize-transparency "$OUTPUT"

Let's add options, help and stuff.

Speed it up!

Adding ordered dithering to fight black artifacts and decrease the GIF size a lot.

HOROSHO SDELALY BATYA DOVOLEN

Logs and autoupdating. WTF am I doing, huh?

Now publish it on Steam and make truckload of money.

>autoupdating
You're do it wrong.

That's ok though autoupdating was implemented a little too late. I dunno what to add to this. Anyway, new features always appear when you're using the tool to its max.