cropfinder

#!/usr/bin/env bash

# trap ctrl-c and call ctrl_c()
trap ctrl_c INT

function ctrl_c() {
    echo "Exiting."
    exit 1
}

usage() {
cat - <<EOF
Usage: $NAME -i <INPUT FILE>

-h|--help:     show this help message
-i|--input:    file name for input
-s|--samples:  number of crop samples to take
-d|--debug:    output results continuously

EOF
}

while [ $# -gt 0 ]; do
    OPT="$1"
    case "${OPT}" in
    -i|--input)
            shift
            INPUT="${1}"
            shift;;
    -s|--samples)
            shift
            SAMPLES="${1}"
            shift;;
    -d|--debug)
            DEBUG=1
            shift;;
    -h|--help)
            usage
            exit;;
    *)
            echo "$0: invalid option ${1}"
            echo "$0 -h for usage options"
            usage
            exit 1;;
    esac
done

# Check for tool dependencies
SELF_FULLPATH=$(realpath $0)
SELF_DIR=$(dirname $SELF_FULLPATH)
# Override default tool list
TOOLS=(ffmpeg ffprobe grep awk sort uniq head tail)
# Does not depend on any other scripts
SCRIPTS=NONE
if [ ! -r $SELF_DIR/toolchecker ]; then
    echo "toolchecker not found."
    exit 1
else
    . $SELF_DIR/toolchecker
fi

if [ -z "$INPUT" ]; then
    echo "Must supply input (-i/--input) file"
    usage
    exit 1
fi

if [ ! -s "$INPUT" ]; then
    echo "Error reading input file: $INPUT"
    exit 1
fi

if [ ! -z "$SAMPLES" ]; then
    if [ ! $SAMPLES -gt 0 ]; then
        echo "Invalid sample count. Using defaults."
        SAMPLES=10
    fi
else
    SAMPLES=10
fi

DUR=$($FFPROBE "$INPUT" 2>&1 | $GREP -e DURATION -e Duration | $HEAD -n1 | $AWK -F': ' '{print $2}' | $AWK -F: '{ print ($1 * 3600) + ($2 * 60) + $3 }' | $AWK -F. '{print $1}')
[ $DEBUG ] && echo "Duration: $DUR"
if [ $DUR -le 0 ]; then
    echo "Unknown duration."
    exit 1
fi
DUR_TRIM=$((DUR - 600))
SPLIT=$(($DUR_TRIM / $SAMPLES))
[ $DEBUG ] && echo "Sample length: $SPLIT"
#CROPDETECT="cropdetect=24:16:0"
CROPDETECT="cropdetect=.1:16:0"
ALL_CROPS=""
for i in $(seq 1 $SAMPLES); do
    START=$(($SPLIT * ${i}))
    CROP=$($FFMPEG -ss $START -i "$INPUT" -vframes 360 -vf "$CROPDETECT" -f null -max_muxing_queue_size 9999 - 2>&1 | $GREP -o crop=.* | $SORT | $UNIQ -c | $SORT -n | $TAIL -n1 | $AWK '{print $2}')
    [ $DEBUG ] && echo -e "Segment start: $START\t$CROP"
    ALL_CROPS="$ALL_CROPS"$'\n'"$CROP"
done
CROP=$(echo "$ALL_CROPS" | $SORT -t "=" -k 2 | $UNIQ -c | $SORT -n | $TAIL -n1 | $AWK '{print $2}')
echo "$CROP"