Codebox Software

This shell script extracts still frames from video files, and uses them to generate Video Barcode images like these:

Star Wars

The Empire Strikes Back

Return of the Jedi

The script should work on Linux and Mac OSX, and has dependencies on ffmpeg and ImageMagick. It is based on an idea by Benoît Romito but uses a different technique to create the images, explained below. The source code for this script is shown below, and is also available on GitHub

#!/bin/bash

# Set things up...
INFILE=$1
if [[ -z "$INFILE" || ! -f $INFILE ]]; then
    echo Please supply the location of a video file
    exit 1
fi
OUTFILE=$INFILE.jpg
STEP=1
CURR=1
TMPDIR=./tmp
if [ ! -d $TMPDIR ]; then
    mkdir $TMPDIR
fi

# Find the duration of the video, in seconds
LEN_TXT=`ffmpeg -i $INFILE 2>&1|grep Duration|cut -f4 -d' '|cut -f1 -d'.'| sed 's/:0/:/g' | sed 's/:/ \\* 3600 + /'|sed 's/:/ \\* 60 + /'`
let "LEN=$LEN_TXT"
echo "Duration=$LEN seconds"

# Ctrl-C to stop
function stopnow(){
    echo Processing halted, re-execute script with the same file to resume
    exit 2
}
trap stopnow 2

FILENAME=`basename $INFILE`

# Make the thumbnail images, and squash them into vertical bars
while [ $CURR -le $LEN ]
do
    PADDED_NUM=`printf "%05d" $CURR`
    THUMBFILE=$TMPDIR/$FILENAME.$PADDED_NUM.jpg
    BARFILE=$TMPDIR/$FILENAME.bar$PADDED_NUM.jpg
    if [ ! -f $BARFILE ]; then
        echo Processing $CURR of $LEN
        ffmpeg -ss $CURR -i $INFILE -vcodec mjpeg -vframes 1 -y -an -f rawvideo -s 320x240 $THUMBFILE >/dev/null 2>&1 
        convert $THUMBFILE -resize 1x400\! $BARFILE >/dev/null 2>&1 
    fi    
    let CURR+=STEP
done

# Stitch the vertical bars together to make the barcode
convert $TMPDIR/$FILENAME.bar* +append $OUTFILE

echo Finished.

makebarcode.sh starwars.avi

The script extracts still frames from the video at one-second intervals, and saves them as JPEG image files (to change the interval between stills, and therefore the length of the barcode, adjust the STEP variable). Each image is then squashed to be only 1 pixel wide, and 400 pixels high, and these squashed images are stitched together horizontally to form a barcode.