[xiph-commits] r13497 - websites/xiph.org/theora/faq
maikmerten at svn.xiph.org
maikmerten at svn.xiph.org
Thu Aug 9 09:17:58 PDT 2007
Author: maikmerten
Date: 2007-08-09 09:17:58 -0700 (Thu, 09 Aug 2007)
New Revision: 13497
Modified:
websites/xiph.org/theora/faq/index.shtml.en
Log:
sync FAQ on xiph.org/theora with the one on theora.org (both have a
high Google rank)
One day some decision has to be made to determine what should be kept
where.
Modified: websites/xiph.org/theora/faq/index.shtml.en
===================================================================
--- websites/xiph.org/theora/faq/index.shtml.en 2007-08-09 15:43:00 UTC (rev 13496)
+++ websites/xiph.org/theora/faq/index.shtml.en 2007-08-09 16:17:58 UTC (rev 13497)
@@ -26,9 +26,9 @@
<!--#include virtual="/ssi/pagetop.include" -->
<!-- All your page content goes here -->
-<h1>Theora FAQ</h1>
-
-<h2><a href="#what">What is Theora</a></h2>
+<h1 class="headline">Theora FAQ</h1>
+<a href="#what"><b>What is Theora</b></a>
+<br>
<ul>
<li><a href="#10">What is Theora?</a></li>
<li><a href="#11">Why use Theora?</a></li>
@@ -37,7 +37,7 @@
<li><a href="#14">What is the license for Theora?</a></li>
<li><a href="#15">Why the name 'Theora?'</a></li>
</ul>
-<h2><a href="#VP3">Theora and VP3</a></h2>
+<a href="#VP3"><b>Theora and VP3</b></a>
<ul>
<li><a href="#20">Is the Theora bitstream identical to VP3? </a></li>
<li><a href="#21">What can Theora do that VP3 couldn't do? </a></li>
@@ -46,131 +46,128 @@
<li><a href="#24">Isn't VP3 a patented technology? </a></li>
<li><a href="#25">What if Xiph.org and On2 decide to break off their agreement? </a></li>
</ul>
-<h2><a href="#development">Development</a></h2>
+<br>
+<a href="#development"><b>Development</b></a>
<ul>
<li><a href="#30">When will it all be finished? Can I use it right now?</a></li>
<li><a href="#31">What is an Alpha Release?</a></li>
<li><a href="#32">What is Tarkin? </a></li>
<li><a href="#33">How can I help with development?</a></li>
- <li><a href="#34">How will Ogg Theora interoperate with [insert your favorite media architecture]?</a></li>
+ <li><a href="#34"> How will Ogg Theora interoperate with [insert your favorite media architecture]?</a></li>
<li><a href="#35">How can I donate to these amazing projects?</a></li>
</ul>
-<h2><a href="#working"><b>Using Theora</b></a></h2>
+<br>
+<a href="#working"><b>Using Theora</b></a>
<ul>
<li><a href="#40">What players currently support Theora?</a></li>
<li><a href="#41">How can I encode videos to Theora?</a></li>
<li><a href="#42">Is there any way to use Theora on Microsoft Windows at this point?</a></li>
</ul>
-
+<br>
<a href="#misc"><b>Misc and Credits</b></a>
<ul>
<li><a href="#50">Who's in charge of Theora development?</a></li>
+ <li><a href="#51">Who designed this website? </a></li>
+ <li><a href="#52">Who is the webmaster of this site?</a></li>
<li><a href="#53">Who maintains The Glorious Theora FAQ?</a></li>
+ <li><a href="#54">When was this FAQ last updated?</a></li>
</ul>
-
-<p>Last update 2005 August 13 by Ralph Giles.</p>
-
-<h1><a name="what"></a>What is Theora</h1>
-
+<br>
+<a name="what"></a><b>What is Theora</b>
+<br>
+<br>
<a name="10"></a>
-<h2>Q. What is Theora?</h2>
-<div class="answer">
-<p>Theora is an <strong>open</strong> video codec being developed by the
-Xiph.org Foundation as part of their Ogg project (It is a project that aims to
+<b>Q. What is Theora?</b><br>
+<div class="txt">
+Theora is an <b>open</b> video codec being developed by the Xiph.org
+Foundation as part of their Ogg project (It is a project that aims to
integrate On2's <a href="http://en.wikipedia.org/wiki/VP3">VP3</a>
video codec, Ogg <a href="http://www.vorbis.com/">Vorbis</a> audio codec
and Ogg multimedia container formats into a multimedia solution that can
compete with <a href="http://en.wikipedia.org/wiki/MPEG-4">MPEG-4</a> format).
-Theora is derived directly
+<br> Theora is derived directly
from On2's VP3 codec; currently the two are nearly identical, varying
only in framing headers, but Theora will diverge and improve from
the main VP3 development lineage as time progresses.
-</p>
</div>
-
+<br>
+<br>
<a name="11"></a>
-<h2>Q. Why use Theora?</h2>
-<div class="answer">
-<p>
+<b>Q. Why use Theora?</b><br>
+<div class="txt">
It's open and free. Do you need more reasons?
-</p>
</div>
-
+<br>
+<br>
<a name="12"></a>
-<h2>Q. What other video formats will Theora compete with?</h2>
-<div class="answer">
-<p>
-Theora is targeted at competing with MPEG-4 (e.g., XviD and DivX),
+<b>Q. What other video formats will Theora compete with?</b><br>
+<div class="txt">
+ Theora is targeted at competing with MPEG-4 (e.g., XviD and DivX),
RealVideo, Windows Media Video, and similar lower-bitrate video
compression schemes.
-</p>
</div>
-
+<br>
+<br>
<a name="13"></a>
-<h2>Q. What is Ogg? What is Vorbis? What is Xiph.org?</h2>
-<div class="answer">
-<p><a href="http://www.vorbis.com/">Vorbis</a> is an audio codec,
+<b>Q. What is Ogg? What is Vorbis? What is xiph.org?</b><br>
+<div class="txt">
+ <a href="http://www.vorbis.com/">Vorbis</a> is an audio codec,
Theora is a video codec. Ogg is the transport layer that both are stored in,
so a video file will be Theora-encoded data inside an Ogg file, while audio
is normally Vorbis-encoded data inside an ogg file.
-</p><p>
+<br>
The <a href="http://www.xiph.org/">Xiph.org</a> Foundation is a
Delaware non-profit company devoted to producing, maintaining and
supporting an open multimedia platform.
-</p>
</div>
-
+<br>
+<br>
<a name="14"></a>
-<h2>Q. What is the license for Theora?</h2>
-<div class="answer">
-<p>
-The Theora reference implementation (like all codecs published by the
-Xiph.org Foundation) is distributed to the public under a
-BSD-style license. It is completely free for commercial or noncommercial
-use. That means that commercial developers may independently write
-Theora software which is compatible with the specification for no charge
-and without restrictions of any kind.
-<p>
+<b>Q. What is the license for Theora?</b><br>
+<div class="txt">
+Theora (and all associated technologies released by the Xiph.org
+Foundation) is released to the public via a BSD-style license. It is
+completely free for commercial or noncommercial use. That means that
+commercial developers may independently write Theora software which is
+compatible with the specification for no charge and without restrictions of
+any kind.
</div>
-
-
+<br>
+<br>
<a name="15"></a>
-<h2>Q. Why the name 'Theora?'</h2>
-<div class="answer">
-<p>
+<b>Q. Why the name 'Theora?'</b><br>
+<div class="txt">
Like other Xiph.org Foundation codec projects such as Vorbis or Tarkin,
Theora is named after a fictional character. Theora Jones was the name of
-Edison Carter's 'controller' on the television series
-<a href="http://imdb.com/title/tt0089568/" class="subtle">Max Headroom</a>.
-She was played by <a href="http://imdb.com/name/nm0005301/" class="subtle">Amanda Pays</a>.
-</p>
+Edison Carter's 'controller' on the television series Max Headroom. She was
+played by Amanda Pays.
</div>
-
-
+<br>
+<br>
<a name="VP3"></a>
-<h1>Theora and VP3</h1>
-
+<b>Theora and VP3 </b>
+<br>
+<br>
<a name="20"></a>
-<h2>Q. Is the Theora bitstream identical to VP3?</h2>
-<div class="answer">
-<p>
-Yes and No. Theora is a superset of VP3, so VP3 streams (with minor
+<b>Q. Is the Theora bitstream identical to VP3?</b><br>
+<div class="txt">
+ Yes and No. Theora is a superset of VP3, so VP3 streams (with minor
syntactic modifications) can be made into Theora streams without
recompression (but not vice versa).
-</p><p>
-Theora is based upon the VP3 codec designed by On2.
-However, in addition to the new featuers, some redundancy was removed
-from the bitstream, so even for VP3-compatible Theora streams, the
-binary packet formats are not identical.
-</p>
+<br>
+ Theora will be almost entirely based upon the VP3 codec designed by On2.
+However, Theora video data will be delivered inside of the Ogg container
+format (with Vorbis for audio), so Ogg Theora files will not be the same as
+VP3 files. There also may be quite a few performance advantages to using
+Theora when 1.0 is complete; While our focus is integration, there will
+certainly be a lot of optimization involved, as well.
</div>
-
-
+<br>
+<br>
<a name="21"></a>
-<h2>Q. What can Theora do that VP3 couldn't do?</h2>
-<div class="answer">
-<p>
-The major change from VP3 to Theora is architectural. VP3, like most
+<b>Q. What can Theora do that VP3 couldn't do?</b><br>
+<div class="txt">
+ The major change from VP3 to Theora is architectural. VP3, like most
codecs of today, makes certain assumptions about the nature of the material
it compresses. These assumptions take the form of fixed sets of numeric
values, such as quantization matrices, which control how different
@@ -180,35 +177,30 @@
to allow the encoder to modify these values appropriately for the material.
This simple, powerful approach has already been proven effective in Vorbis,
and will allow for a longer cycle of encoder optimization without requiring
-client-side updates.
-</p>
+client-side updates.
</div>
-
-
+<br>
+<br>
<a name="22"></a>
-<h2>Q. How will I transition my old VP3 files to the new format?</h2>
-<div class="answer">
-<p>
-Because Theora is a 'superset' of VP3, tools can easily be created that
+<b>Q. How will I transition my old VP3 files to the new format?</b><br>
+<div class="txt">
+ Because Theora is a 'superset' of VP3, tools can easily be created that
will allow VP3 files to be losslessly transcoded into Ogg Theora format
-with no loss in quality. An example tool is included with the reference
-implementation.
-</p>
+with no loss in quality.
</div>
-
-
+<br>
+<br>
<a name="23"></a>
-<h2>Q. Can I convert Ogg Theora files into VP3?</h2>
-<div class="answer">
-<p>Why would you want to do something like that? Are you nuts?</p>
+<b>Q. Can I convert Ogg Theora files into VP3?</b><br>
+<div class="txt">
+ Why would you want to do something like that? Are you nuts?
</div>
-
-
+<br>
+<br>
<a name="24"></a>
-<h2>Q. Isn't VP3 a patented technology?</h2>
-<div class="answer">
-<p>
-Yes, some portions of the VP3 codec are covered by patents. However, the
+<b>Q. Isn't VP3 a patented technology?</b><br>
+<div class="txt">
+ Yes, some portions of the VP3 codec are covered by patents. However, the
Xiph.org Foundation has negotiated an irrevocable free license to the VP3
codec for any purpose imaginable on behalf of the public. It is legal to
use VP3 in any way you see fit (unless, of course, you're doing something
@@ -217,137 +209,116 @@
it in a free product, make changes to the source and distribute those
changes, or print the source code out and wallpaper your spare room with
it.
-</p><p>
-For more information, check the VP3 Legal Terms on the SVN page.
-</p>
+<br>
+For more information, check the VP3 Legal Terms on the SVN page
</div>
-
-
+<br>
+<br>
<a name="25"></a>
-<h2>Q. What if Xiph.org and On2 decide to break off their agreement?</h2>
-<div class="answer">
-<p>
-Because Theora is an Open Source project, the source code will continue to
+<b>Q. What if Xiph.org and On2 decide to break off their agreement?</b><br>
+<div class="txt">
+ Because Theora is an Open Source project, the source code will continue to
be available and development will continue. Users will still be protected
from the On2 patents.
-</p>
</div>
-
-
+<br>
+<br>
<a name="development"></a>
-<h1>Development </h1>
-
+<b>Development </b>
+<br>
+<br>
<a name="30"></a>
-<h2>Q. When will it all be finished? Can I use it right now?</h2>
-<div class="answer">
-<p>
-Theora alpha 4 is out and bitstream format was frozen in 2004. So, files
-produced by the alpha 3 and later reference encoder will be supported by
-all future decoders. It's completely ready to use today.
-</p>
+<b>Q. When will it all be finished? Can I use it right now?</b><br>
+<div class="txt">
+The bitstream format is frozen since the release of Theora alpha 3. So, files produced by
+the alpha 3 reference encoder will be supported by all future decoders. This means
+you can safely use Theora to encode your content right now.
</div>
-
-
+<br>
+<br>
<a name="31"></a>
-<h2>Q. What is an Alpha Release?</h2>
-<div class="answer">
-<p>
-Typically when software is created at a software company, it goes
-through a number of stages before it's released out to the world. You've
-probably heard of 'beta-testing' before. That's when people take code
-that has been deemed 'not quite ready' and are testing it out so that
+<b>Q. What is an Alpha Release?</b><br>
+<div class="txt">
+Typically when software is created at a software company, it goes through a number of stages
+before it's released out to the world. You've probably heard of 'beta-testing' before. That's
+when people take code that has been deemed 'not quite ready' and are testing it out so that
the authors can fix bugs where necessary.
-</p><p>
-'Alpha' code is strictly for internal development only, which is to
-say, 'No one sees this code, it's not even close to being done yet.' At
-the Xiph.org Foundation, we release everything we do so that people can
-help us move the codebase forward by reporting bugs and submitting patches.
-So, even 'Alpha' code needs to get out to the world.
-</p><p>
-And like many open source projects, our 'alpha' code has in fact been
-very stable since the alpha 3 release and is ready for real use. We're
-still calling it alpha more to indicate that it's not feature complete,
-and that we reserve the right to change some things, not that it's
-buggy.
-</p><p>
+<br>
+'Alpha' code usually is strictly for internal development only, which is to say, 'No one sees this code,
+it's not even close to being done yet.' At the Xiph.org Foundation, we release everything we do
+so that people can help us move the codebase forward by reporting bugs and submitting patches.
+<br>
We encourage and depend on the open-source developer community to get
-involved early. We release Alpha builds to give these hearty souls a chance
+involved early. We release Alpha builds to give people a chance
to see what's cooking, and perhaps to add some ingredients of their own. If
you think you have the right stuff, please join the party at
<a href="http://www.Theora.org/lists">www.Theora.org/lists</a>.
+<br><br>
+While Theora is labelled alpha/beta it has been in production use in many systems for over 3 years and is completely safe to adopt.
</div>
-
-
+<br>
+<br>
<a name="32"></a>
-<h2>Q. What is Tarkin?</h2>
-<div class="answer">
-<p>
-Tarkin was essentially a proof-of-concept wavelet-based codec. Its
+<b>Q. What is Tarkin?</b><br>
+<div class="txt">
+Tarkin is essentially a proof-of-concept wavelet-based codec. Its
experimental nature means it will not be ready for general use for some
time. VP3 is a high-quality codec that can meet today's video needs now, so
-we are focusing our efforts on Theora for the moment.
-<p>
+Xiph.org will be focusing its efforts on Theora for the near future.
</div>
-
-
+<br>
+<br>
<a name="33"></a>
-<h2>Q. How can I help with development?</h2>
-<div class="answer">
-<p>
+<b>Q. How can I help with development?</b><br>
+<div class="txt">
Head on over to the <a href="http://www.Theora.org/svn.html">SVN</a>
page to grab the codebase, and hack away! Post your contributions online,
and tell us about it on the <a href="http://www.Theora.org/lists.html">Theora-dev
</a> mailing list.
-</p>
</div>
-
-
+<br>
+<br>
<a name="34"></a>
-<h2>Q. How will Ogg Theora interoperate with [insert your favorite media architecture]?</h2>
-<div class="answer">
-<p>
-As the Ogg Vorbis format has gained acceptance, components have become
+<b>Q. How will Ogg Theora interoperate with [insert your favorite media architecture]?</b><br>
+<div class="txt">
+ As the Ogg Vorbis format has gained acceptance, components have become
available to play Ogg files on practically all of the major media players.
We expect a similar if not superior level of support for Ogg Theora.
Developers wanted! (if you're interested, sign up for the
-Theora-codecs at xiph.org mailing list).
-</p>
+Theora-codecs at xiph.org mailing list).
</div>
-
-
+<br>
+<br>
<a name="35"></a>
-<h2>Q. How can I donate to these amazing projects?</h2>
-<div class="answer">
-<p>
-Wow, thanks! You can find more information on donating to the Xiph.org
-Foundation by following <a href="http://www.xiph.org/donate">
+<b>Q. How can I donate to these amazing projects?</b><br>
+<div class="txt">
+ Wow, thanks! You can find more information on donating to the Xiph.org
+Foundation by following <a href="http://www.xiph.org/donate/">
this link</a>! Thanks in advance!
-</p>
</div>
-
-
+<br>
+<br>
<a name="working"></a>
-<h1>Using Theora</h1>
-
+<b>Using Theora </b>
+<br>
+<br>
<a name="40"></a>
-<h2>Q. What players currently support Theora?</h2>
-<div class="answer">
-<p>
+<b>Q. What players currently support Theora?</b><br>
+<div class="txt">
Major players like <a href="http://www.mplayerhq.hu/">mplayer</a>,
<a href="http://www.xinehq.de/">xine</a>, <a
href="http://www.helixcommunity.org">helix player</a> and <a
href="http://www.videolan.org/">VideoLAN</a> supports Theora.
Directshow <a href="http://www.illiminable.com/ogg/">filters</a>
are also available for use on Windows platform.
-</p>
</div>
-
-
+<br>
+<br>
<a name="41"></a>
-<h2>Q. How can I encode videos to Theora?</h2>
-<div class="answer">
+<b>Q. How can I encode videos to Theora?</b><br>
+<div class="txt">
<p>Have a look at <a
-href="http://www.dogphilosophy.net/SECTION-Technical_Stuff/ogg-theora-microhowto.html">
+href="http://people.xiph.org/~j/ogg-theora-microhowto.html">
ogg-theora-microhowto</a> and <a href="http://www.annodex.net/anx_theora.html">transcode
</a>quicktime mov files to Theora files under Linux.
You can use libogg, to wrap theora video with vorbis audio in Ogg
@@ -357,68 +328,82 @@
with ffmpeg2theora. It can be found at: <a href="http://www.v2v.cc/~j/ffmpeg2theora/">
http://www.v2v.cc/~j/ffmpeg2theora/</a>
</p>
-<p>The <a href="http://www.pitivi.org/">PiTiVi</a> video editor is
-another nice way to make Ogg Theora videos. Just drag your source
-into the timeline and export.</p>
-<p>A way to both stream and encode theora format video is with videolan (VLC).
+<p>A way to both stream and encode theora format video is with videolan (VLC). <br>
Example for streaming the video4linux device in ogg theora/vorbis:
</p>
-<p><code>vlc v4l:/dev/video:input=3:norm=pal:size=384x288 --sout \
-'#transcode{vcodec=theora,vb=300,acodec=vorb,ab=96}:std{access=http,mux=ogg,url=server.example.org:8000}'</code>
+<p>vlc v4l:/dev/video:input=3:norm=pal:size=384x288 --sout \ <br>
+'#transcode{vcodec=theora,vb=300,acodec=vorb,ab=96}:std{access=http,mux=ogg,url=server.example.org:8000}'
</p>
-<p>Or, replace <code>v4l:/dev/video:input=3:norm=pal:size=384x288</code>
-with a filename if you want to transcode.
+<p>Or, replace "v4l:/dev/video:input=3:norm=pal:size=384x288" with a filename if
+you want to transcode.
</p>
-For more on the vlc syntax, see:
+For more on the vlc syntax, see: <br>
<a href="http://videolan.org/doc/videolan-howto/en/ch09.html">http://videolan.org/doc/videolan-howto/en/ch09.html</a>
-</p>
</div>
-
-
+<br>
+<br>
<a name="42"></a>
-<h2>Q. Is there any way to use Theora on Microsoft Windows at this point?</h2>
-<div class="answer">
-<p>
+<b>Q. Is there any way to use Theora on Microsoft Windows at this point?</b><br>
+<div class="txt">
Yes, you can use your Theora files on windows using <a
href="http://www.illiminable.com/ogg/">Directshow filters</a>. <a
href="http://ffdshow.sourceforge.net/">FFdshow</a> also has support for Theora. You
can also try <a href="http://www.videolan.org/">vlc</a>, realplayer <a
href="https://helixcommunity.org/project/showfiles.php?group_id=7">
Theora plugins</a> or <a href="http://www.mplayerhq.hu/">mplayer for windows</a>.
-</p>
</div>
-
-
+<br>
+<br>
<a name="misc"></a>
-<h1>Misc and Credits </h1>
-
+<b>Misc and Credits </b>
+<br>
+<br>
<a name="50"></a>
-<h2>Q. Who's in charge of Theora development?</h2>
-<div class="answer">
-<p>
-The Xiph.org Foundation is the primary developer of Theora, but this
-just means a group of volunteers; the process is open to anyone with
-good ideas who whats to contribute.
-</p><p>
-The VP3 codec that served as the base of
-Theora was written by a company called <a href="http://www.on2.com">On2 Technologies</a>.
-Who donated the source code to the Xiph.org Foundation in 2002.
-</p>
+<b>Q. Who's in charge of Theora development?</b><br>
+<div class="txt">
+The Xiph.org Foundation is the primary developer of Theora, but this is
+mainly an integration issue. The VP3 codec that serves as the base of
+Theora was written by a company called <a href="http://www.on2.com">On2 Technologies</a>. Xiph.org will be
+responsible for all aspects of the development. On2 will provide both
+monetary and technical support to Xiph.org throughout the project. On2 is
+also providing the source code of their implementation of the VP3 codec as
+well as some of their video tools.
</div>
-
-
+<br>
+<br>
+<a name="51"></a>
+<b>Q. Who designed this website?</b><br>
+<div class="txt">
+This website is based on a design called 'Nutrition,' available for public
+download from <a href="http://www.oswd.org/">Open Source Web Design</a>.
+The original author is known by the nickname of 'BrAInDeD-'.
+</div>
+<br>
+<br>
+<a name="52"></a>
+<b>Q. Who is the webmaster of this site?</b><br>
+<div class="txt">
+ That would be <a href="mailto:manuel at xiph.org">Manuel Lora</a>, the greatest webmaster
+on the face of the planet.
+</div>
+<br>
+<br>
<a name="53"></a>
-<h2>Q. Who maintains The Glorious Theora FAQ?</h2>
-<div class="answer">
-<p>
-No one person at the moment. Send changes to the list if it needs them. It
+<b>Q. Who maintains The Glorious Theora FAQ?</b><br>
+<div class="txt">
+ No one person at the moment. Send changes to the list if it needs them. It
was originally written by Emmett Plant and Dan Miller. his FAQ wouldn't be
here at all without the work of Slammin' Stan Seibert, to whom we are
-eternally grateful. It has since been updated by a number of people.
-</p>
+eternally grateful.
</div>
+<br>
+<br>
+<a name="54"></a>
+<b>Q. When was this FAQ last updated?</b><br>
+ August 6th, 2007 by Maik Merten.
+<br>
+<br>
-
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