framedumper

#!/usr/bin/env bash

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

-h|--help:      show this help message
-i|--input:     file name for input
-f|--frames:    number of frames to fetch
-d|--debug:     print all commands and wait for keypress to continue

EOF
}

while [ $# -gt 0 ]; do
    OPT="$1"
    case "${OPT}" in
    -i|--input)
            shift
            INPUT="${1}"
            shift;;
    -f|--frames)
            shift
            FRAMES="${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, we only need these two
TOOLS=(ffmpeg ffprobe mediainfo)
# 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 "$FRAMES" ]; then
    if [ ! $FRAMES -gt 0 ]; then
        echo "Invalid sample count. Using defaults."
        FRAMES=50
    fi
else
    FRAMES=50
fi

FRAMECOUNT=`$MEDIAINFO --Output="Video;%FrameCount%" "$INPUT"`
RAWFRAMERATE=`$MEDIAINFO --Output="Video;%FrameRate%" "$INPUT"`
FRAMERATE=`printf "%.${2:-0}f" $RAWFRAMERATE`
FRAMESKIP=$(( $FRAMECOUNT / $FRAMES ))
SPF=$(( $FRAMESKIP / $FRAMERATE ))
FRAMEDIR=`basename "$INPUT" .mkv`
if [ $DEBUG ]; then
    echo "Framecount: $FRAMECOUNT"
    echo "Framerate: $FRAMERATE"
    echo "Frameskip: $FRAMESKIP"
    echo "Seconds per frame: $SPF"
    echo "Framedir: $FRAMEDIR"
    exit
fi
mkdir "$FRAMEDIR"
#echo "$FFMPEG -i \"$INPUT\" -vf select=\"not(mod(n\,$FRAMESKIP))\",setpts=N/TB -r 1 -vframes $FRAMES ${FRAMEDIR}/inputframes%03d.png"
#$FFMPEG -i "$INPUT" -vf select="not(mod(n\,$FRAMESKIP))",setpts=N/TB -r 1 -vframes $FRAMES "${FRAMEDIR}/inputframes%03d.png"
$FFMPEG -i "$INPUT" -vf fps=1/$SPF "${FRAMEDIR}/frame%04d.png"