audiobookConverter

A Python script that converts directories of audio files into single chaptered .m4b audiobook files, with automatic metadata and cover art fetching.

Features

• Converts MP3, M4A, M4B, AAC, OGG, OPUS, FLAC, WAV, and WMA files
• Merges multi-disc/multi-part audiobooks into a single file
• Fetches metadata (title, author, description, cover art) from iTunes, Google Books, and Open Library
• Embeds chapter markers from individual tracks
• Skips already-converted books via fuzzy duplicate detection
• Stream-copies AAC files (no re-encode) when possible
• Progress bars for transcoding and assembly

Requirements

• Python 3.10+
• ffmpeg and ffprobe

Install ffmpeg on Debian/Ubuntu:

sudo apt install ffmpeg

Usage

python3 ab.py <input_dir> [-o <output_dir>] [-b <bitrate>] [--auto-lookup] [--no-lookup] [--dry-run]

Arguments

Argument	Description
input	Directory containing audiobook folders
-o, --output	Output directory (default: current directory)
-b, --bitrate	AAC bitrate for transcoding (default: 192k)
-n, --dry-run	Scan and report without writing any files
--auto-lookup	Automatically select the top metadata result
--no-lookup	Skip all online metadata lookups

Examples

Preview what would be converted without writing anything:

python3 ab.py /path/to/audiobooks -o /path/to/output --dry-run --no-lookup

Convert everything, auto-selecting metadata:

python3 ab.py /path/to/audiobooks -o /path/to/output --auto-lookup

Convert with interactive metadata selection:

python3 ab.py /path/to/audiobooks -o /path/to/output

How It Works

1. Scans the input directory recursively for audiobook folders
2. Groups multi-disc folders (e.g. Book Title Disc 1, Book Title Disc 2) into a single book
3. Probes audio files with ffprobe to read existing metadata
4. Searches iTunes, Google Books, and Open Library for the best metadata match
5. Transcodes non-AAC files to AAC (or stream-copies if already AAC)
6. Assembles everything into a single .m4b with embedded chapters, cover art, and metadata