| name | multi-format-book-extractor |
| description | Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files. Use when extracting non-EPUB books. PDF uses pymupdf with TOC-based chapter splitting and auto-OCR fallback (Gemini) for scanned/image-only PDFs; MOBI/AZW3 routes through calibre then epub-chapter-extractor. |
| allowed-tools | ["Bash"] |
| user-invocable | true |
Multi-Format Book Extractor
Extract chapters from PDF, MOBI, and AZW3 files into individual numbered markdown files.
Mirrors the epub-chapter-extractor pattern for non-EPUB formats.
Dependencies
Single Book
cd $PROJECT_ROOT/.claude/skills/multi-format-book-extractor && \
uv run --with pymupdf --with requests python extract_book.py "/path/to/book.pdf" [output_dir]
If output_dir is omitted, creates a folder named after the file in the same directory.
Scanned / Image-Only PDFs (auto-OCR)
Some PDFs are pure page scans with no text layer — pymupdf extracts nothing
and would silently write empty files. extract_book.py now samples the text layer
first (_has_text_layer) and, when a PDF looks image-only, automatically routes it
to Gemini 2.5 Flash OCR (ocr_pdf.py).
- Renders each page to PNG (~180 DPI), batches pages per API call, transcribes
verbatim to Markdown (preserves verse line breaks, Sanskrit/Tibetan diacritics,
footnotes), and writes
NN_pages-S-E.md chunk files.
- Resumable: re-running skips chunk files already written (≥200 chars), so an
interrupted long book picks up where it left off.
- Cost is ~$0.002/page on Flash (a 300-page book ≈ $0.60).
Run OCR directly (e.g. to tune params or force it):
cd $PROJECT_ROOT/.claude/skills/multi-format-book-extractor && \
uv run --with pymupdf --with requests python ocr_pdf.py "/path/to/scan.pdf" [output_dir] \
[--model gemini-2.5-flash] [--dpi 180] [--pages-per-call 5] [--pages-per-file 20] [--concurrency 6]
Batch Extraction (Parallel)
Extract all PDFs, MOBIs, and AZW3s from a directory in parallel:
SKILL="$PROJECT_ROOT/.claude/skills/multi-format-book-extractor"
UVX="uv"
DIR="/path/to/books"
for book in "$DIR"/*.{pdf,mobi,azw3}; do
[ -f "$book" ] || continue
stem="${book%.*}"
[ -d "$stem" ] && echo "Skipping: $(basename "$book") (already extracted)" && continue
echo "Starting: $(basename "$book")"
(cd "$SKILL" && $UVX run --with pymupdf --with requests python extract_book.py "$book") &
done
wait
echo "All done"
Output Format
Each book gets a subfolder named after the file (without extension):
book-name/
├── 01_introduction.md
├── 02_chapter-one.md
└── ...
- PDF with TOC: one file per chapter (uses level-1 TOC; falls through to level-2 if < 5 top-level entries, e.g. books structured as Parts)
- PDF without TOC: 20-page chunks (
01_pages-1-20.md, etc.)
- Scanned / image-only PDF: auto-routed to Gemini OCR → 20-page chunks (
01_pages-1-20.md) with <!-- page N --> markers
- MOBI / AZW3: same output quality as epub-chapter-extractor (converts via calibre first)
After Extraction
open /path/to/books/
