m4b-tool

m4b-tool is a command line utility to merge, split and chapterize audiobook files such as mp3, ogg, flac, m4a or m4b

parallel m4b-tool jobs

use the --jobs flag to run conversions in parallel

m4b-tool merge -v --jobs=4

convert a folder of mp3 to m4b

…using docker:

• it'll mount the current folder into /input/ and will save the m4b file in /mnt/media/audiobooks

docker run -it --rm -v "$(pwd)"/:/input/ -v /mnt/media/audiobooks/:/output/ sandreas/m4b-tool merge -v /input/ --output-file="/output/filename.m4b"

convert a bunch of folders with mp3 files to m4b

do the same as above, just with a bunch of folders. assuming you're in /data with multiple subfolders containing mp3 files:

for i in *; do docker run -it --rm -v "$(pwd)/$i"/:/input/ -v /mnt/media/audiobooks/:/output/ sandreas/m4b-tool merge -v /input/ --output-file="/output/$i.m4b"; done