Comment by MawKKe

You can instruct ffprobe to output the metadata in JSON (-print_format json), removing the need for manual parsing. Although you already utilize "-print_format compact" - was this a deliberate choice?

Also, you don't have to do manual stdout buffering. Have a look at ReadChapters function in here: https://github.com/MawKKe/audiobook-split-ffmpeg-go/blob/f95... (fyi it's my own repo)