audio cli tools and compositions

audio tools and compositions

-- ffmpeg batch convert mp3 to 128k mp3
for i in *.mp3; do ffmpeg -i "$i" -codec:a libmp3lame -b:a 128k "${i%.*}128.mp3"; done  

-- ffmpeg batch convert audio files from flac to wav 
for i in *.flac; do ffmpeg -i "$i" "${i%.*}.wav"; done

-- batch convert aiff to wav with sox
find -E . -maxdepth 1 -iregex '.*\.(aif|aiff)' -exec bash -c '$0 "$1" "${1%.*}.wav"' sox {} \;

-- ffmpeg john cage 4'33 
ffmpeg -f lavfi -i anullsrc=r=44100:cl=stereo -t 273 -q:a 9 -acodec libmp3lame johncage.mp3

-- sox batch convert audio files in subdirectories to 44.1khz and add headroom, and store in new directory mirroring directory structure
-- useful for preparing samples for hardware samplers not supporting frequencies > 44.1khz
baseDir="${PWD##*/}_44100" && mkdir ../"$baseDir" && for d in */ ; do
    (cd "$d" && mkdir converted && for i in *.{wav,aif}; do sox "$i" converted/"${i%.*}.wav" gain -3 rate -L -s 44100; done && mv converted ../../"$baseDir"/"${PWD##*/}");
done

-- like above batch convert but just for files in current directory
mkdir ../"${PWD##*/}_44100" && for i in *.{wav,aif}; do sox "$i" ../"${PWD##*/}_44100"/"${i%.*}.wav" gain -3 rate -L -s 44100; done