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deckcraft/docs/file-format-parity.md
T
Nikita Rakitin 184b76e2a7 Round-trip text effects, layout, fills, bevels and connectors
An owned corpus of those kinds survives open, save and reopen. A run's
inner shadow, reflection and soft edge were dropped, and a bevel preset
with no kept 3-D XML was not written back, so import and export now keep
them.
2026-10-14 00:04:22 +03:00

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File-format parity with PowerPoint

Last reviewed: 2026-10-13 · Last updated: 2026-10-13 · Change: minor (owned corpus for text effects, body layout, theme effects, fills, bevels and connectors; a run's inner shadow, reflection and soft edge, and a bevel preset with no kept 3-D XML, survive a save; previous: trivial, groups with a small legacy child coordinate space) · Target: Microsoft PowerPoint for Mac 16.113 (Microsoft 365)

Every format PowerPoint reads or writes, DeckCraft's support, fidelity and how it is tested. Gaps are itemized in gaps.md. Dimension score: ~58% ready (estimated), 60–110 h to parity.

Weights inside this dimension: PPTX 70%, PDF export 10%, image export 5%, legacy binary formats 5%, everything else (templates, shows, macros, ODP, video, GIF, outline) 10%.

Documents

From /Applications/Microsoft PowerPoint.app/Contents/Info.plist CFBundleDocumentTypes (Editor = PowerPoint opens and saves; Viewer = opens only).

Format PowerPoint DeckCraft read DeckCraft write Fidelity / notes Tested by
.pptx presentation Editor yes yes Broad (see below); an owned corpus covers text effects, autofit, columns, vertical and RTL text, tabs, line spacing, theme effects, gradient and pattern fills, bevels and connectors. A corpus of decks from outside this repo is still open crates/pptx/tests/roundtrip.rs, corpus_style.rs, sample.rs, malformed.rs, sniff.rs; opened in PowerPoint by hand 2026-10-06
.potx template Editor yes (as a presentation) no: written with the .pptx content type file.saveTemplate is Save As under another name none
.ppsx slide show Editor yes (as a presentation) no: written as .pptx content Doesn't start in show mode none
.pptm / .potm / .ppsm macro-enabled Editor no no Should open and keep vbaProject.bin without running it none
.ppt / .pot / .pps 97–2003 binary Editor no no Owner decision; import only would be enough none
.odp OpenDocument Editor no no none
.thmx Office theme Viewer no no Browse for themes is a P2 row none
.deckcraft native (zip + JSON) n/a yes (also .slidecraft) yes Lossless for the DeckCraft model, forward compatible crates/format tests
PDF export no yes Slides, notes pages, handouts (1–9); real-text layer with embedded subsets, links, bookmarks. Slide artwork is a raster image at print resolution, not vector crates/pdf tests
Outline .rtf / .txt export (RTF), import (outline) .txt/.md outline (slide.fromOutline) .txt outline No RTF engine tests
PNG / JPEG slide images export n/a yes (file.export, deckcraft-cli render) Matches the editor's renderer render tests
TIFF / BMP / GIF slide images export n/a no Easy (the image crate writes them) none
Animated GIF of the deck export n/a no none
MP4 / MOV video of the deck export n/a no Needs timeline render + H.264 encode none
Print yes n/a no PR #66 (browser) open none

Pictures and media inside decks

Kind PowerPoint DeckCraft Notes
PNG, JPEG, GIF (animated), BMP, TIFF, WebP yes yes image 0.25; animated GIFs play since #39
SVG yes (with PNG fallback) no The PNG fallback shows; SVG files can't be inserted
EMF / WMF yes partial Drawn as vectors (paths, pens, pattern and hatch brushes, bitmaps, text in the document's fonts with the file's character advances); clip regions and EMF+ records are not drawn. Legacy OLE objects (VML preview) and ActiveX controls show their pictures
HEIC yes (macOS) no
Audio: MP3, AAC/M4A, ALAC, WAV, AIFF, CAF, FLAC, Ogg Vorbis, Opus yes (Ogg/Opus partly) yes Pure-Rust decoders in crates/media, crates/opus
WMA yes (Windows) embedded, not playable
Video: H.264, HEVC in MP4/MOV yes yes Pure-Rust, software decode
Video: VP9, AV1 in WebM/MKV partly (OS codecs) yes Ahead of PowerPoint for Mac
WMV yes (Windows) embedded, not playable
Online video (YouTube embeds) yes no Cloud feature
Embedded OLE objects yes kept on round trip (opaque), not insertable or editable ShapeKind::Opaque
3-D models (.glb) yes no
Embedded fonts yes no p:embeddedFontLst ignored

PPTX coverage (PresentationML / DrawingML)

What crates/pptx reads and writes, from ECMA-376. "Kept" means the XML is preserved untouched for the round trip even though DeckCraft doesn't model it.

Part / feature Read Write Notes
OPC package, content types, relationships yes yes Content types found anywhere in the zip (#19); zip bombs capped; relationship cycles bounded
Presentation, slide size, sections (p14), custom shows yes yes
Slide masters, layouts, placeholders and inheritance yes yes
Themes: colour, font (Latin/EA/CS), effect schemes, background styles yes yes Unknown theme parts kept
Notes slides and notes master yes yes No notes-master editing view
Handout master no no
Shapes: preset geometry (~180 presets), custom geometry, groups, connectors yes yes Presets re-derived in crates/geom/src/preset.rs (and preset/extra.rs). Outlines, dashes, arrowheads and ink inside a group, and text, keep their size in points whatever the group's child-coordinate scale (#233).
Fills: solid, gradient, picture (stretch/tile/crop), pattern, group yes yes
Lines: dash, compound, caps, joins, arrowheads yes yes
Effects: shadow, glow, soft edges, reflection yes yes On a run, inner shadow, reflection and soft edges are kept along with the outer shadow and glow
3-D: scene3d, sp3d kept kept A bevel preset with no sp3d of its own is written back on shapes and theme effect styles. Bevels, cameras and face lighting draw approximately; extrusion does not
Text: runs, paragraphs, bullets, numbering, levels, autofit, columns, vertical, RTL, script fonts, fields, hyperlinks yes yes Round-trip tests incl. justLow, date fields, gradient and outline on a run, autofit, columns, vertical and RTL text, tab stops and line spacing (corpus_style.rs)
Text warp (prstTxWarp) yes yes All 40 presets rendered (crates/geom/src/warp.rs); adjust values (avLst) round-trip
Pictures with crop, recolour, duotone, alpha, luminance yes yes
Tables with styles yes yes
Charts (c:chartSpace) yes yes Original XML kept in Chart.raw
Charts (cx: chartex: waterfall, funnel, treemap, sunburst, histogram, box) no no
SmartArt (dgm) drawing part only, as a group as shapes Diagram data model lost on save
Equations (OMML, a14:m) no no PR #55 open
Audio / video (p14:media, trim, fades, bookmarks) yes partly Playback options lost on save (#74)
Ink (contentPart) yes as a group of freeform lines PowerPoint sees shapes, not ink
Transitions incl. p14/p15 (Vortex, Morph…) all 48 all 48 every_transition_kind_round_trips
Animations: timing tree, build paragraphs, triggers, motion paths yes (flattened to the Animation Pane list) yes (rebuilt) every_animation_effect_survives; rewind lost (#77)
Comments: legacy yes yes
Comments: modern threaded (p188) yes no (written as legacy) Replies and resolved state lost (#70)
Unknown slide-level elements (graphicFrame OLE, extensions, mc:AlternateContent) kept kept Rendered as a labelled placeholder with the preview picture when present
Tags, custom XML, VBA no / no / no
Embedded fonts no no
Encryption (password to open) no no

What would move the PPTX number

  1. An owned corpus of real-world-shaped decks (corporate templates, SmartArt, chartex charts, EMF, embedded fonts, every transition and animation) in a corpus repo, with import → render → export → re-import checks in CI and a PowerPoint reference render for each (owner runs PowerPoint).
  2. The round-trip losses above (#70, #74, #77).
  3. SVG rendering, and clip regions inside EMF/WMF.

Revision history

Date Change Summary
2026-10-13 minor Owned corpus for text effects, body layout, theme effects, fills, bevels and connectors. A run's inner shadow, reflection and soft edge, and a bevel preset with no kept 3-D XML, survive a save
2026-10-12 minor EMF/WMF text and pattern brushes drawn; OLE (VML) and ActiveX previews read
2026-10-12 minor Text warps rendered; their adjust values read and written
2026-10-12 trivial Groups with a small legacy child coordinate space draw outlines, dashes, arrowheads and ink at their own width (#233)
2026-10-10 major Created from PowerPoint 16.113.4's CFBundleDocumentTypes, crates/pptx reader/writer and tests, and the open round-trip issues