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Theora

2007-12-29T16:38:06Z

Zdzdzd:

''' [http://free-music-download-0.blogspot.com/ Free Music Downloads] MP3 Music, Music Videos, Lyrics and Music cd '''

'''Theora''' is our video codec, based on the [[VP3]] codec donated by [[On2 Technologies]]. We've refined and extended it, giving it the same future scope for encoder improvement [[Vorbis]] has. See http://theora.org/ for more information.

== Features ==

Features available in the Theora format (and a comparison to VP3 and MPEG-4 ASP):

* block-based motion compensation
* 8x8 Type-II Discrete Cosine Transform
* free-form variable bit rates (VBR)
* adaptive in-loop deblocking applied to the edges of the coded blocks (not existing in MPEG-4 ASP)
* block sizes down to 8x8 (MPEG-4 ASP supports 8x8 only with 4MV)
* 384 8x8 custom quantization matrices: intra/inter, luma/chroma and even each quant (more than VP3 and MPEG-4 ASP/AVC)
* flexible entropy encoding (Theora supports 80 VLC tables selectable per-frame, MPEG-4 ASP has just one)
* 4:2:0, 4:2:2, and 4:4:4 chroma subsampling formats (VP3 and MPEG-4 ASP only support 4:2:0)
* 8 bits per pixel per color channel
* multiple reference frames (not possible in MPEG-4 ASP)
* pixel aspect ratio (eg for anamorphic signalling/playback)
* non-multiple of 16 picture sizes (as possible in ASP, but not in VP3)
* non-linear scaling of quants values (as done in MPEG-4 AVC)
* adaptive quantisation down to the block level (as possible in MPEG-4 ASP/AVC, but not in VP3)
* intra frames (I-Frames in MPEG), inter frames (P-Frames), but no B-Frames (as supported in MPEG-4 ASP/AVC)
* HalfPixel Motion Search Precision (MPEG-4 ASP/AVC supports HalfPixel or QuarterPixel)
* technologies used already in Vorbis (decoder setup configuration, bitstream headers...) not available in VP3

Note that not all of these features are already implemented in the reference encoder/decoder.

== Status ==
* Beta 2 is the latest stable release (2007-Okt-12).
* The bitstream format was frozen in Theora alpha 3: every file created with this encoder (and, of course, later encoders) will be playable by any compliant Theora decoder.

== Development ==

* [[TheoraTodo|Todo list for development]]

== More information ==
{{Template:Theora}}

== External links ==

* [http://www.theora.org/ Theora homepage]
* [http://www.annodex.net/software/theora/ Theora documentation daily builds]
* [[Wikipedia: Theora]]
* [http://www.vp3.com VP3 homepage]: The homepage of the codec Theora is based on
* [http://www.on2.com On2 Technologies]: The authors of VP3
* [http://forum.doom9.org/showthread.php?s=&threadid=77314 Ogg Theora Information on Doom9 Forum]
* [http://www.parrishtech.com/content/view/16/1/ HOWTO: Rip DVD to Theora using Linux]
* [http://www.doom9.org/index.html?/codecs-quali-105-1.htm Codec shoot-out 2005] Comparison of many video codecs, including Theora

IceS

2007-12-29T16:26:27Z

Zdzdzd:

''' [http://free-music-download-0.blogspot.com/ Free Music Downloads] MP3 Music, Music Videos, Lyrics and Music cd '''

== Stable Releases ==
[http://www.icecast.org/ices.php Ices Website]

Ices comes in two flavors,
* 0.x flavor which supports sending an MP3 stream to an icecast server
* 2.x flavor which supports sending an Ogg Vorbis stream to an icecast server.

== Development ==

=== ices0 ===
for the latest version of ices0 hav a look in the svn repository at http://svn.xiph.org/icecast/trunk/ices0/

=== ices2 ===
development of ices2 is split up into two branches right now.

* http://svn.xiph.org/icecast/trunk/ices here you find the latest version of the ices2.0 release
* http://svn.xiph.org/icecast/branches/kh/ices the kh branche of ices2 as several new features and depends on a [[http://svn.xiph.org/icecast/branches/kh/libshout modified version of libshout]].

one of the new features in ices2-kh is a new input plugin for [http://jackit.sf.net jack]. this way you can send a live ogg vorbis stream from any jack capable audio application.

[http://ices.reboot.fm/ some notes on using ices2 with jack]

MonthlyMeeting200609

2007-12-29T16:25:35Z

Zdzdzd:

''' [http://free-music-download-0.blogspot.com/ Free Music Downloads] MP3 Music, Music Videos, Lyrics and Music cd '''

== 2006 September MonthlyMeeting ==

Will there be a meeting?

== Agenda ==

* Google [[Summer of Code]] students that "vanished"
* Can we find some webmasters?
* Should we go forward with [[OggPCM]]?
* There are over 50 tickets marked as PATCH in the [http://trac.xiph.org/report/18 trac]. Many of these are fix for old and known problems, and some are already fixed (sometimes in different ways) into Linux distributions (notably Debian) with custom patches, while others add new features. Would be nice if someone takes up some time reviewing and applying/rejecting the trac and distribution patches, so even other distributions/who build from source get the benefits.
* Seems that it is no more possible to add/modify tickets in the trac without an account; can users reporting bugs get such account (best would be reuse the accounts of wiki.xiph.org)?