strip all non english audio tracks and all subtitles from mkv

clean_mkv.sh

#!/bin/bash
# keep only audio track 1
# keep no subtitle tracks
# or use -map 0:m:language:eng
LOGLEVEL='warn'
OPTS='-hide_banner -loglevel ${LOGLEVEL}'

for x in *.mkv ; do
    echo ${x}
    ffmpeg ${OPTS} -i "${x}" -map 0:v -map 0:a:0 -map -0:s -c copy "new-${x}"
#    ffmpeg -hide_banner -loglevel info -i "${x}" -map 0:v -map 0:m:language:eng -map -0:s -c copy "new-${x}"
done

rm -fv !(new-*.mkv)

for n in new-*.mmkv ; do
    mv -v "$n" "$(echo "$n" | sed s/new-//)"
done