Ogg Vorbis is a new audio compression format. It is roughly comparable to other formats used to store and play digital music, such as MP3, VQF, AAC, and other digital audio formats. It is different from these other formats because it is completely free, open, and unpatented.
Xiph.org has a page explaining the sources and meanings of the names and logos.
application/ogg.
The official mimetype was approved in February 2003. The experimental
application/x-ogg may still be out there, though.
Ogg Vorbis has been designed to completely replace all proprietary, patented audio formats. That means that you can encode all your music or audio content in Vorbis and never look back.
There are a couple of reasons:
Because Vorbis provides a high-quality format for you to listen to your music.
Epic Games (the makers of Unreal Tournament, et. al.) have used Vorbis in their games ever since releasing Unreal Tournament 2003 to compress game music without having per-game license fees sap profits from every game sold. Vorbis saves developers money by avoiding patent-license fees.
Epic isn't alone; other Vorbis users include:
Interested? see our developer site.
The Ogg Vorbis specification is in the public domain. It is completely free for commercial or noncommercial use. That means that commercial developers may independently write Ogg Vorbis software which is compatible with the specification for no charge and without restrictions of any kind. However, the software packages we have developed are available under various free/open-source software licenses with varying allowances and restrictions.
Most (but not all) of our utility software is released under the terms of the GNU GPL. The libraries and SDKs are released under our BSD-like license.
Note that developers are still free to use the specification to write implementations of Ogg Vorbis licensed under other terms.
Again, there are no licensing fees for any use of the Ogg Vorbis specification. As a commercial developer, you are free to create and sell (or give away) open or closed source implementations of Vorbis encoders, decoders, or other tools. However, if you use our software rather than writing an independent implementation, you must respect the terms of the license. Our libraries are available under our BSD-like license and can be used whole or in part by closed source applications.
No.
The benefits of a patent-free, license-free format outweigh the concerns of making money directly from the format. The Vorbis format will always be free and in the public domain. Xiph.org is investigating a variety of models for funding development, some of which may include licensing non-free Vorbis-related programs and libraries to commercial projects. Nevertheless, the reference encoder and decoder will always be open source and third parties will always be free to modify or reimplement them.
There are two broad classes of compression algorithms:
Yes, definitely. Naturally, we invite you to judge this for yourself.
Vorbis sounds better. Vorbis is open, so you're free to use it on your favorite platform. Vorbis doesn't have intellectual property restrictions to get in the way. And Vorbis doesn't just try to sound better, it tries to do things fundamentally better in all the ways that it can.
You can convert any audio format to Ogg Vorbis. However, converting from one lossy format, like MP3, to another lossy format, like Vorbis, is generally a bad idea. Both MP3 and Vorbis encoders achieve high compression ratios by throwing away parts of the audio waveform that you probably won't hear. However, the MP3 and Vorbis codecs are very different, so they each will throw away different parts of the audio, although there certainly is some overlap. Converting a MP3 to Vorbis involves decoding the MP3 file back to an uncompressed format, like WAV, and recompressing it using the Ogg Vorbis encoder. The decoded MP3 will be missing the parts of the original audio that the MP3 encoder chose to discard. The Ogg Vorbis encoder will then discard other audio components when it compresses the data. At best, the result will be an Ogg file that sounds the same as your original MP3, but it is most likely that the resulting file will sound worse than your original MP3. In no case will you get a file that sounds better than the original MP3.
Since many music players can play both MP3 and Ogg files, there is no reason that you should have to switch all of your files to one format or the other. If you like Ogg Vorbis, then we would encourage you to use it when you encode from original, lossless audio sources (like CDs). When encoding from originals, you will find that you can make Ogg files that are smaller or of better quality (or both) than your MP3s.
While the Vorbis file format is standardized, the Vorbis encoder has undergone several beta and prerelease testing cycles. If the files you heard were encoded using an earlier version encoder, they might contain serious audio quality bugs that have already been fixed. Try re-encoding from the source audio using the latest encoder. If you still think you've got a bug that produces unreasonable artifacts, please e-mail the vorbis-dev list with the details.
Vorbis' audio quality is not best measured in kilobits per second, but on a scale from -1 to 10 called "quality". This change in terminology was brought about by a tuning of the variable-bitrate algorithm that produces better sound quality for a given average bitrate, but which does not adhere as strictly to that average as a target.
This new scale of measurement is not tied to a quantifiable characteristic of the stream, like bitrate, so it's a fairly subjective metric, but provides a more stable basis of comparison to other codecs and is relatively future-proof. As Segher Boessenkool explained, “if you upgrade to a new vorbis encoder, and you keep the same quality setting, you will get smaller files which sound the same. If you keep the same nominal bitrate, you get about the same size files, which sound somewhat better.” The former behavior is the aim of the quality metric, so encoding to a target bitrate is now officially deprecated for all uses except streaming over bandwidth-critical connections.
For now, quality 0 is roughly equivalent to 64kbps average, 5 is roughly 160kbps, and 10 gives about 400kbps. Most people seeking very-near-CD-quality audio encode at a quality of 5 or, for lossless stereo coupling, 6. The default setting is quality 3, which at approximately 110kbps gives a smaller filesize and significantly better fidelity than .mp3 compression at 128kbps.
As always, if you need CD-quality sound, neither Vorbis nor MP3 (nor any other lossy audio codec) can provide exact reproduction; instead, consider using a lossless audio compression scheme like FLAC.
It works well, but is generally not the optimal solution. Vorbis is designed for the compression of music and general purpose audio. Special purpose codecs can achieve much greater compression of speech than Vorbis. Vorbis also tends to have a latency that is too high for telephony, a common use of speech codecs. Read the Speech Coding and Compression FAQ for more details. Those looking for an open-source, patent-free speech codec should take a look at Speex.
Yes, Vorbis includes a flexible, complete comment field for song and artist info, as well as other track data. The official encoder, oggenc, allows you to enter comment info at encode time. Other tools tools also let you enter and edit track data.
If you're interested in our progress on a video codec, check out Theora at theora.org.
Ogg Vorbis is easily streamable. Icecast, our streaming audio server, is capable of streaming Ogg Vorbis to players like XMMS, Winamp 2, and foobar2000.
Many programs support Ogg Vorbis encoding and playback; it's included in popular players such as Winamp an foobar2000 for Windows, and Whamb for OS X. It's also supported in popular audio applications such as CDex and GoldWave. For a more complete list, refer to our software page.
Our wiki has notes on hardware support for Vorbis.
Yes. The Ogg container format was designed to allow different media types to be multiplexed together; Theora will be mixed with Vorbis audio in an Ogg container to encode movies.
In addition, FLAC can be embedded in Ogg and some preliminary work has been done to put MNG and MIDI content into Ogg files as well.Experimental code is available in the ogg-tools module in the Xiph.org CVS repository. Programmers working on such extensions can discuss issues and questions on the vorbis-dev mailing list.
It is important to first become familiar with current development efforts. The best ways to do this are:
Once you have seen what others are doing, you will have a better chance to find a project to work on.
It's been done for the decoder.
Tremor is a fixed-point implementation of the Vorbis decoder suitable for chips found on portable devices. However, a fixed-point encoder has not been written.
There are archived mailing lists for advocacy, user discussion, and development at Xiph.org's mailing list page, as well as #vorbis on irc.freenode.net, an IRC channel.
Xiph.org's mailing list page also has subscription info and archives of the vorbis mailing list. Contributions and discussion are welcome there.
It was updated on October 3, 2003.