Data file formats

This page is about the various file formats that the XO may encounter.

Introduction

Because the OLPC has limited storage and limited RAM, it is not a good idea to support every data format used on regular PCs. It makes more sense to use our PCs to convert data than to put that burden on the OLPC.

The libraries and packages in the build support various file formats. Some of this support is exposed through the various Activities and the files they are able to load. Most activities list the mime types they support in their activity.info file. In a Terminal activity,

 cat ~olpc/Activities/Activity name.activity/activity/activity.info

and there will be a mime_types line.

On some activities' wiki pages the infobox lists some of the mime types they support, e.g. Browse.

List of supported formats

TODO: This should become a table of format - mime-type - activities supporting the format - a link to sample files for each file format.

• Image file formats
  • JPEG 2000 (? does not work in Browse). Sample file
  • GIF
  • JPEG
  • PNG
  • SVG (in Browse, also directly by Sugar for icons). Sample files (not all work in Browse
  • TIFF (in Paint and in Read via Evince). Sample files. Multipage TIFFs don't work in Read (<trac>7166</trac>) or Paint.
  • DVI? (might work in Read via Evince).

• eBook formats
  • HTML in Browse. Note Browse uses the XULRunner engine from Firefox, which supports advanced CSS 3 feature for nicer layout (sample book and sample chapter).
  • DJVU (coming some day to Read, see <trac>6223</trac>). Sample files
  • PDF (in Read via Evince)
• Multimedia formats:
  • Browse supports advanced "HTML 5" capabilities such as the <canvas> tag for interactive rendering, though slowly (see HTML canvas performance).
  • Sound formats
    • Ogg Vorbis (supported by the Totem plugin for Browse).Sample file, also there are sample files in some OLPC builds in OLPC Library > media > music (equivalent web version. (The version of Browse in Release notes/8.2.0 uses a XULRunner engine that does not yet support the <audio> and <video> tags.)
    • WAV (supported by the Totem plugin for Browse). Sample files
    • the Totem and Gnash plugins for Browse claim to support other formats, enter about:plugins in the Browse location field.

• • Video formats
    • Ogg Theora (supported by the Totem plugin for Browse)
    • DV format ? (/usr/lib/libdv present)

• General formats
  • XML
  • SQLite (a lightweight relational database that is included in Python 2.5)
  • Gnu gdbm (supported by Python's dbm module)
  • Berkeley db version 4.3.0.1 (supported by Python's bsddb module)

• Compression formats
  • Uncompressed (this is listed because the JFFS2 filesystem on the OLPC will compress all compressable files)
  • GNU Zip (supported by Python's zlib module, Etoys, and the implementation of the jar: URL protocol in XULRunner that powers Browse)

• OLPC-specific formats
  • Activities are made available to download as ".xo" bundles
  • Content is a made available to download as ".xol" bundles
  • Journal entry bundles (a zip file with the ".xoj" extension and mime type 'application/vnd.olpc-journal-entry')

See also

• Category:mimetype and other mimetype category assignments of Activities
• Image file formats