posters.sh

#!/bin/bash

root=$( cd -P "$( dirname "${BASH_SOURCE[0]}" )/.." && pwd)

usage="
Usage: `basename $0` [source] [ratio]

Generate video poster images.

Arguments
=========
    source: Source video folder or file.
        Defaults to $root/project/media/movies
    ratio: Scene ratio. 
    
Try adjusting ratio (down from 24) if you get black images.
"


MOVIEDIR=${1:-$root/project/media/movies}
RATIO=${2:-500}

if [ ! -e $MOVIEDIR ] ; then
    echo "Folder does not exist: $MOVIEDIR"
    echo -e "$usage"
    exit 1
fi

if [ -f $MOVIEDIR ] ; then
    FILES=$MOVIEDIR
    MOVIEDIR=$(dirname $FILES)
fi

POSTERDIR=$MOVIEDIR/poster

# Find an appropriate VLC command
for cmd in 'cvlc' 'vlc -I "dummy"' '/Applications/VLC.app/Contents/MacOS/VLC -I rc'; do
    type -P $cmd &>/dev/null
    if [ $? == 0  ]; then
        CMD="$cmd"
        break
    fi
done


if [ "$CMD" = "" ]; then
    echo "vlc not found. Not able to generate screenshots"
    exit 1
fi

if [ "$FILES" = "" ]; then
    FILES=$(shopt -s nullglob; echo $MOVIEDIR/*)
fi
if  test ! -n "$FILES"; then
    echo "No video files found."
    exit 1
fi

if [ ! -e $POSTERDIR ]; then
    mkdir $POSTERDIR
fi

for FILE in $FILES; do
    if [ -f $FILE ] ; then
        echo "Generating poster for $FILE"

        NAME=$(basename $FILE)
        NAME=${NAME%.*}

        $CMD $FILE --rate=1 --video-filter=scene --vout=dummy --start-time=1 --stop-time=2 --scene-format=png --scene-ratio=$RATIO --scene-prefix=$NAME --scene-path=$POSTERDIR vlc://quit

        # Tidy file names
        #POSTERS=$(shopt -s nullglob; echo $POSTERDIR/${NAME}0*)
        LASTPOSTER=$(printf '%.5d' $[RATIO + 1])
        POSTERS=$(shopt -s nullglob; echo ${POSTERDIR}/${NAME}{$LASTPOSTER,00001}.png)
        for POSTER in $POSTERS; do
            if [ -e $POSTER ]; then
                mv "$POSTER" "${POSTERDIR}/${NAME}.png"
                rm $POSTERDIR/${NAME}0*.png
                break
            fi
        done
    fi
done