Write flexible programs that work together!

dbar, ffmpeg and mpv sitting in a tree, F.O.S.S.I.N.G.

dbar ffmpeg mpv

Here's the crop-df script I showcased in the video. Keep in mind this code is much better suited to a "proper" programming language. If you are so inclined, extract the code into a better language, tweak the ffmpeg settings, use json to communicate with mpv, and figure out how to play a sample length's worth of video without calling sleep 😬.

#! /usr/bin/bash

if [ $# -ne 2 ]; then
    echo "Error: must provide 2 parameters (INPUT OUTPUT)"
    exit 1
fi

get_time() {
    length=2

    if [ "$1" == "start" ]; then
        i=0.0
        v="%v"
    else
        i=1.0
        v="%(v-$length)"
    fi

    seconds=$(dbar -f -v -i $i -C "echo \"seek $v absolute\" | socat - /tmp/mpvsocket && echo 'set pause no' | socat - /tmp/mpvsocket; sleep $length; echo 'set pause yes' | socat - /tmp/mpvsocket" -t "RET to confirm $1 time (seconds)" $2 $duration)

    [ -z $seconds ] && echo 'quit' | socat - /tmp/mpvsocket && exit 0
    time=$(echo $seconds | awk '{printf("%02d:%02d:%g",($1/60/60),($1/60%60),($1%60))}')
}

infile=$1
outfile=$2
duration=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 $infile)

# attach mpv instance to socket
mpv $infile --input-ipc-server=/tmp/mpvsocket --pause --keep-open --keep-open-pause=no --really-quiet &

get_time start 0
start=$time
get_time end $seconds
end=$time

# close mpv
echo 'quit' | socat - /tmp/mpvsocket

ffmpeg -y -i $infile -ss $start -to $end $outfile