How to help

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This page is intended to collect ideas and areas where new participants can contribute to Xiph.org initiatives. Because this is an open wiki not all of these points have been reviewed with core Xiph developers. It is always best to coordinate your efforts on the relevant Xiph mailing lists and IRC channels.

One of the best ways people can contribute is by using the tools and formats. This accomplishes two primary goals:

  1. By providing materials in free formats you help lower the barriers to adoption for others
  2. By using the tools you will discover problems which you can report contributing to further development and refinement


OggDSF specific activities

Directshow is the windows video codec API, OggDSF provides support for Vorbis/Theora/Speex/Flac and Ogg in directshow.

Places to discuss development: Theora mailing list; #theora on irc.freenode.net

  • Testing. Much of the Xiph.org community are run various unix-like operating systems. While OggDSF is widely used, it isn't frequently used by much of the more experienced Xiph.org community and hasn't has sufficient scrutiny.

Software outreach

Xiph.org software often reaches users via other software. E.g. Few people run libtheora by itself, many people use libtheora through other tools like VLC, Firefox, or gstreamer. These tools are maintained by other projects but the reliability and robustness of the free format support in these applications is critical to the public's ability to use Xiph.org formats.

Relevant contribution areas:

  1. Testing, e.g. TheoraTestsuite and reporting bugs into the relevant bug trackers
  2. Cross porting features
  3. Updating tools to support the latest features in the Xiph.org implementations (e.g. two-pass encoding for video tools)

Theora specific activities

Places to discuss development: Theora mailing list; #theora on irc.freenode.net

  • Identifying videos where 1.1 or 1.2-development (ptalarbvorm) produce significantly worse results than prior versions. (These case is important compared to "works worse than some random format" because the differences are more likely to be actionable rather than just chance consequences related to differences in the encoders overall behaviour)
  • Decoder assembly optimization for additional platforms (MIPS64; PPC)
    • Skills required: optimization and development experience on the relevant platform.
  • Decoder general performance improvements
    • Skills required: C language; Use of a profiler. Optionally: SIMD assembly on relevant platforms.

Vorbis specific activities

Places to discuss development: Vorbis mailing list; #vorbis on irc.freenode.net


  • Identifying test samples where Vorbis encodings at very high quality are not completely transparent under careful listening tests.
  • Identifying test cases that exemplify the improvements in the current AoTuV development. (Helps with AoTuV merging)
  • Identifying test samples where Vorbis performs worse than other formats.

Skeleton specific activities

Places to discuss development: Theora mailing list; #theora on irc.freenode.net

Liboggz specific activities

Places to discuss development: Theora mailing list; #theora on irc.freenode.net

Cortado specific activities

Places to discuss development: Theora mailing list; #theora on irc.freenode.net

Cortado is contains Java implementation of Vorbis/Theora/Kate/Ogg and an applet that allows playback of these formats on the web. It is the most popular fallback for HTML5 Ogg video, allowing users on legacy browsers (as old as Netscape 4) to play modern web video.

Additional tools work

  • Build and refine fall-back tools for HTML5 video based on Cortado, Flash vorbis, and the upcoming Silverlight applet support. Many existing fallback tools require users to adopt H.264.

PR and organizational matters

  • Participate in external promotional activities such as PlayOgg!