Install FFmpeg
Open a terminal or command prompt
Go to the folder containing the M4B file
Check chapter markers with:
`ffprobe -i input.m4b`
Split by chapters into separate files with:
`ffmpeg -i input.m4b -f segment -segment_time 600 -c copy output_%03d.mp3`
If the M4B has chapters, export each chapter to MP3 with a script or chapter-based command
Use a chapter-splitting tool such as:
`mp3splt`
`Chapter and Verse`
`Audiobook Cutter`
Convert the whole file to MP3 with:
`ffmpeg -i input.m4b -codec:a libmp3lame -q:a 2 output.mp3`
Split the MP3 into multiple files with an audio editor if chapter-based splitting is not available
Use a batch script to automate chapter extraction and MP3 conversion
Verify each output file plays correctly