Ogg

Ogg codecs

Ogg is only a container format. The actual music or video encoded by a codec will be stored inside an Ogg container. Ogg containers may contain streams encoded with multiple codecs, for example, an audio video file may contain data encoded by both an audio codec and a video codec.

Being a Container format, Ogg can embed audio and video in various formats (such as MPEG-4, Dirac (codec)|Dirac, MP3 and others) but usually Ogg is used with the following:

• Audio codecs
  • lossy
    • Speex: handles voice data at low bitrates (~8-32 kbit/s/channel)
    • Vorbis: handles general audio data at mid- to high-level variable bitrates (~16-500 kbit/s/channel)
  • lossless
    • FLAC: handles archival and high fidelity audio data

• Text codec
  • Writ: a text codec designed to embed subtitles or captions

• Video codecs
  • Theora: based upon On2's VP3, it is targeted at competing with MPEG-4 video (for example, encoded with DivX or Xvid), RealVideo, or Windows Media Video.
  • Tarkin: an experimental codec utilizing 3D wavelet transforms. It has been put on hold, with Theora becoming the main focus for video encoding.
  • Dirac: an experimental codec developed by the BBC as the basis of a new codec for the transmission of video over the Internet. The Schrödinger project aims to provide portable libraries, written in C, that implement the Dirac codec. It also allows to embed Dirac inside the Ogg container format.
  • OggUVS

• Subtitle structures
  • Annodex: An open source set of standards developed by CSIRO to annotate and index networked media.

Ogg clients

• Ogg Vorbis clients

Proprietary alternatives

Various components of the project are intended to stand as alternatives to proprietary codecs such as:

• MP3 and Advanced Audio Coding
• RealAudio and RealVideo
• QuickTime streaming format and its codecs
• The RIFF format and its derivatives such as WAV and AVI and their respective codecs
• The Advanced Streaming Format with its Windows Media Audio and Windows Media Video codecs

References

• Wikipedia - Ogg

External Links

• Xiph.org Foundation's Ogg page