feat(media): the audiobook relayout, filed by the book Plex matched

The audiobook tree is the one library Jellyfin does not read at all and Plex
reads completely: 58,975 chapters matched into Artist/Album/Track, where the
album is the BOOK and the book's single artist row is the NARRATOR. That is the
authority the new planner files by, never the collection folder a pack made.

  Audiobooks/<Narrator>/<Book> (<year>)/<the file's own name>

Two laws are the opposite of the music tool's, both forced by the rows: files
are never renumbered (72% of the books carry chapters with no usable index, and
playback order comes from the embedded track tag either way, so an invented
number can only lie), and the shelf is the narrator, not the author (every book
has exactly one artist row; the author survives in 10% of album titles and in no
column Plex stores, so one rule beats a shelf half authors and half narrators).

media-census.py gains the audiobooks export: the chapters Plex matched under a
root, host paths straight through, nothing outside the root and nothing Plex
deleted. 22 tests in tests/media_audiobooks.bats pin the export's join and the
plan's output.

scripts/media-audiobooks.py

@@ -0,0 +1,379 @@
+#!/usr/bin/env python3
+r"""media-audiobooks.py — a plan that re-files the audiobook library into one folder per book.
+
+    media-audiobooks.py --root DIR --enum TSV --rows TSV [--out TSV] [--exceptions FILE]
+
+Plex reads this library and Jellyfin does not: its music scanner has no audiobook
+concept, and the tree is indexed entirely by Plex, which matched 58,975 of the
+62,879 files here into its Artist/Album/Track shape. So the authority is
+`scripts/media-census.py audiobooks` — the BOOK (album row), its NARRATOR (that
+book's single artist row) and its CHAPTERS (track rows) — and never the folder a
+release pack made. The plan is:
+
+    Audiobooks/<Narrator>/<Book> (<year>)/<the file's own name>.<ext>
+                     ... the same folder, " (2)" on the name, when two chapters
+                         of one book carry the same name
+
+What that buys is the one property both media servers' book scanners assume: a
+folder holds exactly one book. Today 212 top-level folders are a mix of
+author-named shelves and collection packs, and the books inside the packs are
+split across `… [Part 1]`, `… [Part 2]` folders three or four deep.
+
+Three laws here are the opposite of what a music shelf does, and each is forced
+by what the rows actually hold:
+
+ * A chapter is NEVER renumbered. 7,556 of the 10,485 books contain at least one
+   chapter whose index Plex does not know, so a number written into a name would
+   be invented — and it would buy nothing, because both servers order playback by
+   the embedded track tag, not by the file name. A wrong number in a name is worse
+   than none: it is the number a human later trusts. A file already carrying its
+   own number keeps it, untouched.
+ * The shelf is the NARRATOR, not the author. Every book has exactly one artist row
+   and it is the narrator; the author survives only inside 10% of the album titles
+   (`Kryptos by Graham McNeill`) and in no column Plex stores, so deriving the
+   author would mean parsing titles for one book in ten and inventing it for the
+   rest. One rule that always resolves beats a shelf that is half author and half
+   narrator; the author stays visible in the book folder's own name, which is the
+   title Plex shows.
+ * Nothing is guessed at. A chapter row with no book or no narrator parks, an audio
+   file Plex never matched parks, a video container parks, and a loose file in a
+   folder holding two books parks: nothing says which book owns it.
+
+Nothing is deleted and nothing is overwritten. The output is a list of rename(2)
+intents for `scripts/media-apply.py`, whose preflight refuses any target that is
+already claimed and whose journal is the rollback.
+"""
+import argparse
+import csv
+import os
+import re
+import sys
+from collections import Counter, defaultdict
+
+# What a chapter file can be. .m4b is the audiobook container; the rest are the
+# audio a pack ships when it was ripped as music.
+AUDIO_EXT = {".mp3", ".m4a", ".m4b", ".ogg", ".oga", ".opus", ".wav", ".flac",
+             ".wma", ".aiff", ".aif", ".m4v", ".aac", ".mka"}
+# Never an audiobook, whatever the library it sits in says: Plex reads these as
+# video, and renaming one into an audio extension would claim it is a chapter.
+VIDEO_EXT = {".mkv", ".mp4", ".webm", ".avi", ".mov", ".mpg", ".mpeg", ".ts",
+             ".m2ts", ".vob", ".ifo", ".wmv", ".iso", ".img", ".bdmv", ".ogm",
+             ".divx"}
+# The characters Plex documents as breaking playback. They are dropped, not
+# substituted: a replacement character is a guess at what the title meant.
+BAD_CHARS = set('<>:"/\\|?*')
+TRASH_DIR = re.compile(r"(^|/)(\.AGENTTRASH|\.thumbnails|\.Trash-\d+|@eaDir"
+                       r"|lost\+found)(/|$)")
+
+ARGS = None
+HELD = {}                            # path -> (bytes, ext)
+ROWS = {}                            # path -> the chapter row Plex matched
+PLACED = {}                          # chapter path -> the destination the plan gave it
+CLAIMED = set()                      # every destination path the plan has handed out
+MOVES, KEEPS = [], []
+PARKED = defaultdict(list)           # reason -> [path]
+NOTES = defaultdict(list)            # section -> [line]
+AUDIO_BY_DIR = defaultdict(set)      # source dir -> chapter files a row names
+CHILD_OF = defaultdict(set)          # dir -> the dirs directly below it holding chapters
+FOLDERS_SEEN = {}                    # (dir, depth) -> book folders placed below it
+SUBTREE_DEPTH = 2                    # how far below a folder its chapters may sit
+BOOKS = {}                           # (narrator, book, year) -> the book group
+
+AMBIGUOUS = object()
+
+
+def dominant(values):
+    """The spelling the rows mostly agree on: the most frequent value, ties broken
+    by sort so the answer never depends on the order rows arrived in."""
+    counts = Counter(values)
+    return min(counts.items(), key=lambda kv: (-kv[1], kv[0]))[0]
+
+
+def rel(path):
+    """The path as seen from the library root."""
+    return os.path.relpath(path, ARGS.root)
+
+
+def safe(name):
+    """A name every client can carry: no reserved character, nothing unprintable,
+    no trailing dot or space, and short enough to rename."""
+    out = "".join(c for c in (name or "")
+                  if c not in BAD_CHARS and (c.isprintable() or c == " "))
+    out = re.sub(r"\s+", " ", out).strip().rstrip(". ")
+    while out and len(out.encode("utf-8", "ignore")) > 200:
+        out = out[:-4].rstrip()
+    return out
+
+
+def assign(src, folder, name, ext, kind, note):
+    """Book one file into `folder` under `name`, renamed if that exact destination
+    is already taken — by another file in the plan, or by a file standing there
+    today. Two files claiming one path is the fault that costs a re-run of a 60k
+    plan, and so is a plan that only works if the renames happen in the right
+    order: the executor refuses any target that is occupied, so an occupied path
+    is never a destination, even when its occupant is scheduled to leave.
+    A file already standing where the contract puts it is a keep, not a move."""
+    stem = safe(name) or "file"
+    dst = os.path.join(folder, stem + ext)
+    if dst == src:
+        CLAIMED.add(dst.lower())          # it is standing on its own target
+        KEEPS.append((src, dst, kind))
+        return dst
+    # A file already in this folder under this name — or under the numbered
+    # variant the collision rule gives it — keeps the name it has. Renumbering it
+    # every run would turn the plan into a shuffle instead of a fixed point.
+    base = os.path.splitext(os.path.basename(src))[0]
+    if os.path.dirname(src) == folder and (base == stem
+                                           or base.startswith(stem + " (")):
+        CLAIMED.add(src.lower())
+        KEEPS.append((src, src, kind))
+        return src
+    n = 1
+    while dst.lower() in CLAIMED:
+        n += 1
+        dst = os.path.join(folder, f"{stem} ({n}){ext}")
+    if n > 1:
+        NOTES[note].append(rel(dst))
+    CLAIMED.add(dst.lower())
+    MOVES.append((src, dst, kind))
+    return dst
+
+
+def park(path, reason):
+    """Hold a file where it is, under the park folder, keeping its relative path."""
+    PARKED[reason].append(path)
+    dst = os.path.join(ARGS.park_dir, rel(path))
+    if dst != path:
+        CLAIMED.add(dst.lower())
+        MOVES.append((path, dst, "park"))
+
+
+def under_park(path):
+    """True for a file already parked: that pile is for a human to review, and
+    re-parking it every run would only push it deeper."""
+    return path.startswith(ARGS.park_dir + os.sep)
+
+
+# ------------------------------------------------------------------------ books
+def group_books():
+    """Every matched chapter into one group per (narrator, book, year).
+
+    The key is the identity Plex asserts in its own database, not the folder the
+    file sits in: one book arrives as four part folders inside a collection pack,
+    and two copies of one book in one pack are one book to Plex, whose album item
+    IS that narrator, title and year. The year is part of the key so a 1965
+    recording and a 2020 recording that share a title stay two books.
+    """
+    for path, r in sorted(ROWS.items()):
+        if path not in HELD or under_park(path) or TRASH_DIR.search(path):
+            continue
+        d = os.path.dirname(path)
+        AUDIO_BY_DIR[d].add(path)
+        CHILD_OF[os.path.dirname(d)].add(d)   # so a cover above Part 1/Part 2 sees both
+        narrator = (r["narrator"] or "").strip()
+        book = (r["book"] or "").strip()
+        if not book:
+            park(path, "a chapter row no book names — Plex has the file but no "
+                       "album item to put it in")
+            continue
+        if not narrator:
+            park(path, "a chapter row no narrator names — the book has no artist "
+                       "row, so no shelf owns it")
+            continue
+        key = (narrator.casefold(), book.casefold(), (r["year"] or "").strip())
+        g = BOOKS.setdefault(key, {"narrators": [], "books": [], "year": key[2],
+                                   "members": [], "indexed": 0})
+        g["members"].append(path)
+        g["narrators"].append(narrator)
+        g["books"].append(book)
+        if str(r["track"] or "").isdigit():
+            g["indexed"] += 1
+
+
+def book_folder(g):
+    name = safe(dominant(g["books"])) or "Untitled"
+    return os.path.join(ARGS.root, safe(dominant(g["narrators"])) or "Unknown Narrator",
+                        f"{name} ({g['year']})" if g["year"] else name)
+
+
+def place_books():
+    """One folder per book; every chapter keeps the name it has today."""
+    for key in sorted(BOOKS):
+        g = BOOKS[key]
+        folder = book_folder(g)
+        for path in sorted(g["members"]):
+            ext = HELD[path][1]
+            base = os.path.splitext(os.path.basename(path))[0]
+            # The name the ripper wrote, unchanged: the track tag inside the file
+            # is what orders playback, and 72% of the books here have chapters no
+            # row numbers, so any number added here would be invented.
+            PLACED[path] = assign(path, folder, base, ext, "chapter",
+                                  "two chapters of one book carried the same name")
+
+
+# --------------------------------------------------------------------- sidecars
+def folders_below(d, depth):
+    """The book folders the chapters in `d`, or within `depth` directories below
+    it, were placed in. Memoised, because every loose file in a big collection
+    folder asks the same question about it."""
+    if (d, depth) not in FOLDERS_SEEN:
+        seen = {os.path.dirname(PLACED[a]) for a in AUDIO_BY_DIR.get(d, ())
+                if a in PLACED}
+        if depth:
+            for child in CHILD_OF.get(d, ()):
+                seen |= folders_below(child, depth - 1)
+        FOLDERS_SEEN[(d, depth)] = seen
+    return FOLDERS_SEEN[(d, depth)]
+
+
+def owner_folder(d):
+    """The book folder that owns this directory — the first place up the tree
+    where chapters sit, in the directory itself or within SUBTREE_DEPTH levels
+    below it, which is how a pack whose parts are `… [Part 1]`/`… [Part 2]` owns
+    the cover art lying above them. None when no chapter is near enough to say,
+    AMBIGUOUS when the chapters there belong to more than one book."""
+    while d.startswith(ARGS.root + os.sep) and d != ARGS.root:
+        folders = folders_below(d, SUBTREE_DEPTH)
+        if folders:
+            return next(iter(folders)) if len(folders) == 1 else AMBIGUOUS
+        d = os.path.dirname(d)
+    return None
+
+
+def place_other():
+    """Everything that is not a chapter Plex matched: covers, booklets, EPUBs,
+    logs, checksums, playlists — and the clutter that is none of those."""
+    for path, (_size, ext) in sorted(HELD.items()):
+        if path in ROWS or under_park(path) or TRASH_DIR.search(path):
+            continue
+        d = os.path.dirname(path)
+        base = os.path.splitext(os.path.basename(path))[0]
+        if ext in VIDEO_EXT:
+            park(path, "a video container inside the audiobook library: Plex reads "
+                       "it as video, and renaming it would claim it is a chapter")
+        elif ext in AUDIO_EXT:
+            park(path, "an audio file no chapter row names — it is not in the "
+                       "library Plex matched, so nothing says which book it is")
+        else:
+            owner = owner_folder(d)
+            if owner is AMBIGUOUS:
+                park(path, "a file whose folder holds more than one book, so "
+                           "nothing says which one it belongs to")
+            elif owner:
+                assign(path, owner, base, ext,
+                       "playlist" if ext in (".m3u", ".m3u8") else "sidecar",
+                       "one book folder would have carried two files of the same"
+                       " sidecar name")
+            else:
+                park(path, "not an audiobook file, and no book's folder lies with"
+                           " it to carry it")
+
+
+# ---------------------------------------------------------------------- outputs
+def write_plan():
+    """mkdir rows for every destination folder and its whole chain, then the moves.
+    Parents first: the executor creates directories in the order they are listed."""
+    chain = set()
+    for _s, dst, _k in MOVES:
+        d = os.path.dirname(dst)
+        while d and d != ARGS.root and d != os.path.dirname(d):
+            chain.add(d)
+            d = os.path.dirname(d)
+    dirs = sorted(chain, key=lambda p: (p.count("/"), p))
+    with open(ARGS.out, "w") as fh:
+        fh.write("action\tsrc\tdst\tkind\n")
+        for d in dirs:
+            fh.write(f"mkdir\t\t{d}\tdir\n")
+        for src, dst, kind in sorted(MOVES, key=lambda m: (m[1], m[0])):
+            fh.write(f"move\t{src}\t{dst}\t{kind}\n")
+        for src, dst, kind in sorted(KEEPS, key=lambda m: (m[1], m[0])):
+            fh.write(f"keep\t{src}\t{dst}\t{kind}\n")
+    parked = [m for m in MOVES if m[2] == "park"]
+    sized = sum(HELD[s][0] for s, _d, _k in MOVES if s in HELD)
+    print(f"plan: {len(MOVES) - len(parked)} moves, {len(parked)} parked"
+          f" ({sized / 2**40:.2f} TiB touched), {len(KEEPS)} already placed,"
+          f" {len(dirs)} folders -> {ARGS.out}")
+
+
+def write_exceptions():
+    with open(ARGS.exceptions, "w") as fh:
+        fh.write(f"Audiobook relayout exceptions for {ARGS.root}\n\n")
+        fh.write(f"Everything below is parked under {ARGS.park_dir}, keeping the\n"
+                 "relative path it has today. Nothing is deleted and nothing is\n"
+                 "overwritten: a parked file is one rename from wherever the plan is\n"
+                 "pointed next.\n\n")
+        for reason in sorted(PARKED, key=lambda r: -len(PARKED[r])):
+            rs = PARKED[reason]
+            fh.write(f"{len(rs):>6} files  {reason}\n")
+            for p in sorted(rs, key=rel)[:400]:
+                fh.write(f"          {rel(p)}\n")
+            if len(rs) > 400:
+                fh.write(f"          … and {len(rs) - 400} more\n")
+            fh.write("\n")
+        for section in sorted(NOTES, key=lambda s: -len(NOTES[s])):
+            lines = sorted(set(NOTES[section]))
+            fh.write(f"{len(lines):>6}  {section}\n")
+            for line in lines[:200]:
+                fh.write(f"          {line}\n")
+            if len(lines) > 200:
+                fh.write(f"          … and {len(lines) - 200} more\n")
+            fh.write("\n")
+        unindexed = sorted(f"{safe(dominant(g['narrators']))}/{safe(dominant(g['books']))}"
+                           for g in BOOKS.values()
+                           if 0 < g["indexed"] < len(g["members"]))
+        if unindexed:
+            fh.write(f"{len(unindexed):>6} books have chapters Plex does not number. Their\n")
+            fh.write("       files keep the names they carry: playback order comes from the\n"
+                     "       track tag inside each file, and a number written here would be\n"
+                     "       invented for the chapters with no index. Fix it in the tags, not\n"
+                     "       in the names — Plex re-reads tags on a scan and never names files.\n\n")
+        fh.write("       Playlists move with their book and their contents are never\n"
+                 "       rewritten: the paths inside an .m3u go stale.\n")
+    print(f"exceptions -> {ARGS.exceptions}")
+
+
+def main():
+    global ARGS
+    ap = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    ap.add_argument("--root", default=os.environ.get("MEDIA_AUDIOBOOKS_ROOT",
+                                                     "/mnt/entropy/Audiobooks"))
+    ap.add_argument("--enum", default="/tmp/audiobooks-enum.tsv",
+                    help="the enumerate TSV (bytes, ext, path)")
+    ap.add_argument("--rows", default="/tmp/plex-audiobooks.tsv",
+                    help="the chapter rows scripts/media-census.py audiobooks wrote")
+    ap.add_argument("--out", default="/tmp/audiobooks-plan.tsv")
+    ap.add_argument("--exceptions", default="/tmp/audiobooks-exceptions.txt")
+    ap.add_argument("--park", default="_unsorted",
+                    help="the folder inside the root that holds what cannot be filed")
+    ARGS = ap.parse_args()
+    ARGS.root = os.path.normpath(ARGS.root)
+    ARGS.park_dir = os.path.join(ARGS.root, ARGS.park)
+    read_inputs()
+    # Every path a file occupies today is claimed before a single destination is
+    # handed out: the executor refuses an occupied target, so a plan that aimed at
+    # one would only fail after the renames that were supposed to clear it.
+    CLAIMED.update(p.lower() for p in HELD)
+    group_books()
+    place_books()
+    place_other()
+    write_plan()
+    write_exceptions()
+
+
+def read_inputs():
+    with open(ARGS.enum) as fh:
+        for line in fh:
+            parts = line.rstrip("\n").split("\t")
+            if len(parts) >= 3:
+                HELD[parts[2]] = (int(parts[0]), parts[1].lower())
+    with open(ARGS.rows, newline="") as fh:
+        for row in csv.DictReader(fh, delimiter="\t"):
+            if row.get("file"):
+                ROWS[row["file"]] = row
+    gone = [p for p in ROWS if p not in HELD]
+    if gone:
+        NOTES["a chapter row whose file the census no longer sees"].extend(gone)
+
+
+if __name__ == "__main__":
+    main()

scripts/media-census.py

@@ -5,6 +5,7 @@ r"""Read-only census of a media library — the inputs a relayout plan is built
   media-census.py probe     [--enum TSV] [--out TSV] [--jobs N]
   media-census.py plex      [--root DIR] [--db PATH] [--out TSV]
   media-census.py jellyfin  [--root DIR] [--db PATH] [--container PREFIX] [--out TSV]
+  media-census.py audiobooks [--root DIR] [--db PATH] [--out TSV]
 
 Run it on the machine that mounts the library. Nothing here writes inside the
 library and nothing is deleted; the only outputs are the TSVs below, and the
@@ -34,6 +35,14 @@ scripts/media-plan.py and scripts/media-shows.py read them instead of touching m
          album item and the tags' otherwise; `mb` is the album's MusicBrainz
          release group, `performer` the track artist the tags carry
 
+  audiobooks file <TAB> narrator <TAB> book <TAB> year <TAB> track <TAB> chapter
+         (see AB_COLS)
+         one row per chapter Plex matched under the audiobook root: `book` is the
+         album row Plex built from the files' own tags, `narrator` that book's
+         artist row — Plex keeps exactly one artist per book, which is why it, and
+         not an author parsed out of a title, names the shelf. `track` is empty
+         wherever Plex has no chapter number, which is most of this library.
+
 `probe` is the slow step (every container is opened for its header, ~10 min for
 4,800 files on a spindle array at 6 workers) so it is `nice`d: a census beside a
 live service must not starve it. `enumerate` is a stat pass, so re-censusing
@@ -99,6 +108,26 @@ MUSIC_SQL = ("""select b.Path, b.AlbumArtists, b.Artists, b.Album, b.ProductionY
 # release id is one reissue of it.
 MUSIC_PROVIDERS = ("MusicBrainzReleaseGroup", "MusicBrainzAlbum")
 
+# Plex's audiobook tree is the same Artist/Album/Track shape as its music tree:
+# the leaf (10) is a CHAPTER, its parent (9) is the BOOK, and that book's artist
+# (8) is the NARRATOR. The track's own `index` is exported because the exceptions
+# report counts how many books have chapters Plex does not number — the reason the
+# relayout refuses to invent numbers into file names.
+PLEX_ARTIST, PLEX_ALBUM, PLEX_TRACK = 8, 9, 10
+AB_COLS = ["file", "narrator", "book", "year", "track", "chapter"]
+AB_SQL = f"""
+select p.file, coalesce(ar.title,''), coalesce(al.title,''), coalesce(al.year,0),
+       coalesce(mi."index",-1), coalesce(mi.title,'')
+from media_parts p
+join media_items m on m.id = p.media_item_id
+join metadata_items mi on mi.id = m.metadata_item_id
+join metadata_items al on al.id = mi.parent_id and al.metadata_type = {PLEX_ALBUM}
+left join metadata_items ar on ar.id = al.parent_id
+                          and ar.metadata_type = {PLEX_ARTIST}
+where p.file like ? and p.deleted_at is null and mi.deleted_at is null
+  and al.deleted_at is null
+"""
+
 
 def enumerate_lib(root, out):
     """One row per real file under root: size, extension, path."""
@@ -363,6 +392,49 @@ def music(root, db, container, out):
     print(f"tracks={written} outside-root-or-blank={skipped} -> {out}")
 
 
+def audiobooks(root, db, out):
+    """The chapters Plex matched inside the audiobook library, read-only.
+
+    Plex stores HOST paths here (unlike Jellyfin, which stores the container's
+    view), so no prefix mapping is needed: the part's `file` is the path the
+    operator has today. Rows for files outside `root` are skipped, because one
+    Plex library DB carries every library on the box.
+
+    The chapter's `index` is exported as an empty field when Plex has none. That
+    is not a gap to fill in here: three quarters of the books on this box contain
+    at least one un-indexed chapter, so the relayout that reads this file must
+    not renumber anything from it.
+    """
+    uri = f"file:{db}?mode=ro&immutable=1"
+    try:
+        con = sqlite3.connect(uri, uri=True)
+    except sqlite3.Error as e:
+        sys.exit(f"cannot open the Plex database read-only ({db}): {e}\n"
+                 "Plex runs rootless here: run this as the container's owner, never "
+                 "with sudo — rootless storage is per-user, so root sees nothing.")
+    tables = {r[0] for r in con.execute(
+        "select name from sqlite_master where type='table'")}
+    missing = {"media_parts", "media_items", "metadata_items"} - tables
+    if missing:
+        sys.exit(f"{db} is not a Plex library database (no "
+                 f"{', '.join(sorted(missing))})")
+    written = skipped = 0
+    with open(out, "w", newline="") as fh:
+        w = csv.writer(fh, delimiter="\t", lineterminator="\n")
+        w.writerow(AB_COLS)
+        for file, narrator, book, year, track, chapter in con.execute(
+                AB_SQL, (root.rstrip("/") + "/%",)):
+            if not file or not file.startswith(root.rstrip("/") + "/"):
+                skipped += 1              # a row for a file outside this library
+                continue
+            w.writerow([file.replace("\t", " "), narrator.replace("\t", " "),
+                        book.replace("\t", " "), "" if not year else year,
+                        "" if track is None or int(track) < 0 else track,
+                        chapter.replace("\t", " ")])
+            written += 1
+    print(f"chapters={written} outside-root={skipped} -> {out}")
+
+
 def main():
     ap = argparse.ArgumentParser(description=__doc__.splitlines()[0])
     sub = ap.add_subparsers(dest="cmd", required=True)
@@ -399,6 +471,13 @@ def main():
                    help="the in-container prefix that stands for --root"
                         " (default /data/<root's folder name>)")
     m.add_argument("--out", default="/tmp/jellyfin-music.tsv")
+    b = sub.add_parser("audiobooks",
+                       help="export the chapters Plex matched for the audiobook root")
+    b.add_argument("--root", default=os.environ.get("MEDIA_AUDIOBOOKS_ROOT",
+                                                    "/mnt/entropy/Audiobooks"),
+                   help="audiobook library root on the host")
+    b.add_argument("--db", default=PLEX_DB)
+    b.add_argument("--out", default="/tmp/plex-audiobooks.tsv")
     a = ap.parse_args()
     if a.cmd == "enumerate":
         enumerate_lib(a.root, a.out)
@@ -408,6 +487,8 @@ def main():
         plex(a.root, a.db, a.out)
     elif a.cmd == "music":
         music(a.root, a.db, a.container, a.out)
+    elif a.cmd == "audiobooks":
+        audiobooks(a.root, a.db, a.out)
     else:
         jellyfin(a.root, a.db, a.container, a.out)