speedup4o () {
    orig="$1"
    new="${orig%.mp4}s4.mp4"
    ffmpeg -i "$orig" -filter_complex '[0:v]setpts=0.25*PTS[v];[0:a]atempo=4[a]' -map '[v]' -map '[a]' -ac 2 -ar 48000 "$new"
}

speedup4 () {
    orig="$1"
    new="${orig%.mp4}s4.mp4"
    ffmpeg -i "$orig" -filter_complex '[0:v]setpts=0.25*PTS[v];[0:a]atempo=4[a]' -r 120 -map '[v]' -map '[a]' -ac 2 -ar 48000 "$new"
}

smooth60fps () {
    orig="$1"
    new="${orig%.mp4}s.mp4"
    ffmpeg -i "$orig" -c:a copy -filter:v "minterpolate='mi_mode=mci:mc_mode=aobmc:vsbmc=1:fps=60'" "$new"
}

addsoundtrack () {
    orig="$1"
    strack="$2"
    new="${orig%.mp4}f.mp4"
    ffmpeg -i "$orig" -i "$strack" -c:v copy -map 0:v:0 -filter_complex "[0:a][1:a]amerge=inputs=2,pan=stereo|c0<c0+c2|c1<c1+c3[a]" -map "[a]" "$new"
}