rafp

A GNOME desktop application for reading and inspecting AFP (Advanced Function Presentation / MO:DCA) files, written in Rust.

The window splits in two panes that are linked together:

• Inspector: the full structured-field table.
  • Each field shows its offset, ID, name, token and size, plus a readable one-line decode: PTX/NOP/TLE text, page and image geometry, font metrics, code pages and object maps.
  • Select a field to jump to its page and flash the content it produced; expand it (arrow, double-click or Enter) to see its decoded triplets.
  • Filter by field type (several types at once).
  • Find text in PTX, NOP or TLE fields, or by field type, with a case toggle and previous/next.
• Render: each page, rasterized with resvg.
  • Navigation, zoom (fit width, fit height, 50–400 %, or 10–800 % with Ctrl + wheel), and the pointer position in millimetres.
  • Copy the page's text, export all text to .txt, export the document or the page as PDF (vector, with selectable text), or the page as SVG or PNG (300 dpi).
  • Optional fidelity notes overlay, which explains where the render approximates the original (substitute fonts, estimated sizes, omitted glyphs, fallback code pages, CMYK compositing).
  • Clicking rendered text selects the field that produced it.

The interface is a native GTK 4 / libadwaita application. Open a file from the ☰ menu (or Ctrl+O), by dropping it on the window, or by passing its path to ./run.sh. The ☰ menu (top right) holds Open AFP File, the default text encoding, the small-font option and About; the button at the top left shows or hides the inspector. Document details (pages, fields, size, declared code pages) are shown in the footer under the page.

Keys	Action
Ctrl+O	Open a file
Ctrl+F	Find (shows the inspector if hidden)
Enter / Shift+Enter	Next / previous match
F9	Show or hide the inspector
Page Down / Page Up	Next / previous page (pointer or focus in the page pane)
Ctrl+plus / Ctrl+minus / Ctrl+0	Zoom in / out / real size (also Ctrl + wheel, or a touchpad pinch)
Enter or double-click on a field	Expand its triplets
F10	Main menu
Ctrl+Q	Quit
Banners warn about page-less AFP resources (fonts, overlays, images) and
about missing resources (fonts the document references but does not embed).

What it decodes

Architecture	Coverage
MO:DCA	Structured fields, triplets (about 15 decoded in detail), MCF format 1 and 2, MDR, MPO, IPO, IPS, IOB, object containers
PTOCA	Positioning, rules, colors (STC/SEC), STO rotation, SVI justification, MCF/MDR fonts and code pages, implicit pagination of loose text
IOCA	Uncompressed bilevel, grayscale and RGB; IBM MMR (G4); TIFF LZW; JPEG; banded CMYK (JPEG or LZW)
IM image	Simple and celled IM/1 rasters
BCOCA	QR Code (other symbologies are reported and skipped)
GOCA	Lines, boxes, full and partial arcs, Bézier curves, fillets, area fills, colors, line types
FOCA	Raster fonts; Adobe Type 1 and CFF / CID-keyed outline fonts; specimen pages for font resources; document text drawn in the file's own embedded fonts
Code pages	EBCDIC cp037, cp273, cp424, cp500, cp875, cp1026, cp1047, cp1140, cp1141; DOS/Windows single-byte pages; UTF-8, UTF-16BE, Latin-1, Shift-JIS, GBK, EUC-KR, Big5

Install

Download the .deb package from the latest release, then:

sudo apt install ./rafp_*_amd64.deb

It adds rafp to the applications menu and opens .afp files from the file manager.

Supported distributions

The package is built for 64-bit x86 (amd64) and needs GTK 4.12+, libadwaita 1.5+ and glibc 2.39+:

Distribution	Versions
Ubuntu	24.04 LTS and later
Debian	13 (trixie) and later
Based on Ubuntu 24.04 or later	e.g. Linux Mint 22, Pop!_OS 24.04, elementary OS 8

Debian 12 and Ubuntu 22.04 ship an older GTK 4 and are not supported. On other distributions, build from source (see below).

Build and run

You need Rust 1.92 or later, and the GTK 4 (4.12+) and libadwaita (1.5+) development files. On Debian / Ubuntu:

sudo apt install libgtk-4-dev libadwaita-1-dev gettext

./run.sh [path/to/file.afp]   # builds if needed, then launches

To get a menu entry on Linux (it installs ~/.local/bin/rafp, its translations, its icon, the AFP file type so that .afp files open with rafp, and a .desktop file named after the application id, org.delaunois.Rafp):

tools/install-desktop-linux.sh

To build the Debian package (into target/debian/), with cargo-deb and dpkg-dev installed:

tools/build-deb.sh

Pushing a tag such as v0.1.0 (matching the version in Cargo.toml) builds the package on GitHub and attaches it to a release.

Command-line dump

afp-dump prints the same analysis without a window:

cargo run --release -p afp-dump -- file.afp            # field list with decoded summaries
cargo run --release -p afp-dump -- --text file.afp     # extracted text
cargo run --release -p afp-dump -- --svg out/ file.afp # one SVG per page
cargo run --release -p afp-dump -- --pdf out.pdf file.afp # all pages as one PDF
cargo run --release -p afp-dump -- --json file.afp     # full inspector + page model

--codepage CP sets the code page for text whose font declares none (default cp500), and --embed-small-fonts draws small text in the file's embedded raster fonts, like the viewer's option.

Environment variables

Variable	Effect
RAFP_START_DIR	Folder the file dialogs start in until a file is opened (run.sh sets it to the current folder)
RAFP_LOCALEDIR	Folder with the compiled translations, instead of the installed or built ones
RAFP_SCREENSHOT	Capture the window to this PNG once the page is rendered, then quit (see crates/afp-viewer/src/screenshot.rs for its options)
RUST_LOG	Log level (warn by default)

Translations

The interface is available in English and French, following the desktop language. AFP content (field names, decoded summaries, fidelity notes) stays in English, the language of the AFP specifications. Translations use gettext:

tools/update-po.sh     # extract the strings into po/rafp.pot and merge po/*.po

To add a language, add its code to po/LINGUAS, run tools/update-po.sh, then translate the new po/<code>.po.

Project layout

crates/
  afp-core/     library: parsing, decoding, page model, SVG rendering (no UI)
    src/parser.rs        MO:DCA structured fields and their IDs (parser::sf)
    src/triplets.rs      triplets and MCF helpers
    src/codepages/       code page tables (tables.rs is generated)
    src/inspect.rs       inspector rows, summaries, resource diagnostics
    src/dump.rs          JSON view of an inspection (afp-dump --json, snapshots)
    src/ptoca/           text interpreter (text.rs) and page extraction (pages.rs)
    src/ioca.rs ccitt.rs imimage.rs goca.rs bcoca.rs foca.rs type1.rs cff.rs
    src/outline.rs       outline glyphs shared by the Type 1 and CFF interpreters
    src/render_svg.rs    page → SVG
    src/raster.rs        SVG → pixels with resvg (feature `raster`)
    src/pdf.rs           pages → PDF with krilla (feature `pdf`)
  afp-viewer/   the GTK 4 / libadwaita desktop application (binary `rafp`)
  afp-dump/     command-line dump
po/             translations (gettext)
data/           desktop entry and file type templates, icons, screenshots
tools/          code page table generator, translation update, installer, Debian package

License

Copyright (c) 2026 Cédric de Launois MIT - see LICENSE.

Acknowledgements

Initially ported from readAFP by Keith Lutz. Coded with Claude Code.