guide to royalty-free digital multimedia formats

this blog needs to have more technology in it. it's in the description, so I'll have to live up to that

many popular video and audio formats are protected by patents, and oftentimes developers of programs that use these formats must pay fees. here are some popular free formats to explore when creating video or codecs and applications. true, this usually doesn't affect video creators, but I have Linux, and many of the non-free formats aren't available to me

• Ogg is, strictly, a container format developed by the Xiph.Org Foundation <www.xiph.org> that is used to contain a variety of audio and video formats developed by Xiph.Org:
  • Theora, the main video format for Ogg
  • Vorbis, the main audio format
  • Free Lossless Audio Codec (FLAC), originally an independent project, a lossless (duh!) alternative to Vorbis, which is lossy
  • other formats such as Speex, Opus
• Update: please disregard this section. most (if not all) MPEG formats are not free (still protected by patents until they expire); I may have misunderstood the situation. MPEG (Moving Picture Experts Group) formats are developed by the titular organization <mpeg.chiariglione.org>. these are described in a few large standards documents, the main ones of which are MPEG-1, -2, and -4. (you can read all about what happened to MPEG-3 elsewhere.) only some are free, such as:
  • MPEG-2 Video (equivalent: H.262), or "MP2," an older video format that improves on the (even older) MPEG-1 Video format ("MP1")
  • MPEG-1 and -2 Audio Layers I and II, or "MP1" and "MP2" (distinct from the video format), where the two formats are the "layers." MPEG-2 improves the formats from MPEG-1 by introducing, among other things, support for surround sound
  • MPEG-1 and -2 Audio Layer III, the famous MP3 format, which is technically not free, but in practice is most of the time
  • Advanced Audio Coding (AAC), introduced in MPEG-2 and improved in MPEG-4, now the main audio format for MPEG-4
• WebM <www.webmproject.org> is a fairly new format that includes Vorbis for audio, and a video format known as VP8
• Matroska <www.matroska.org> is a container format which, like Ogg, can contain a variety of formats, but is not limited to the Xiph.Org ones. WebM actually uses a derivative of Matroska for its container

some common formats are not free, such as:

• MPEG-4 Advanced Video Coding (AVC) (equivalent: H.264), the most common video format for MPEG-4
• there should be more, and I may update