chunking_strategies_evaluation/backlog/libreoffice-pdf-to-docx-fallback.md

LibreOffice PDF→DOCX fallback

Why deferred

We already convert .doc → .docx via LibreOffice. PDF→DOCX is tempting for “reuse the DOCX parser,” but styles/fonts often come out wrong — fighting the reason we chose PyMuPDF.

Trigger

Heading Reconstruction on PyMuPDF has an unacceptable false-positive/false-negative rate on a representative sample, and bookmarks/fonts are absent.

Approach to try

1. Optional fallback: soffice --headless --convert-to docx then existing parse_docx
2. Compare markdown side-by-side (PyMuPDF vs converted DOCX) in Chunk Preview before making it default
3. Keep as opt-in or auto-fallback only when PDF outline + font variance is below a threshold

Success criteria

• Converted DOCX headings beat PyMuPDF heuristics on the failing sample set
• Conversion time acceptable for upload UX (or async later — currently sync REST)