https://wiki.xiph.org/api.php?action=feedcontributions&user=Snicolai&feedformat=atomXiphWiki - User contributions [en]2024-03-28T09:25:20ZUser contributionsMediaWiki 1.40.1https://wiki.xiph.org/index.php?title=Bounties&diff=1262Bounties2005-02-08T04:05:38Z<p>Snicolai: /* Xiph Quicktime Plugin */</p>
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<div>These are proposed bounty projects, similar to http://gnome.org/bounties/ <br />
or the [http://ghostscript.com/article/58.html Ghostscript bug bounty] program.<br />
We don't have the same level of funding but could start a pot with $10-$100 and<br />
let people contribute to specific bounties through paypal.<br />
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=== OggVorbis 5.1 ===<br />
5.1 Sound encoding in Ogg Vorbis.<br />
<br />
There are two steps here. Simple coupling and lowpass for the .1 channel, and a full set of tuned modes.<br />
They should be separate bounties.<br />
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=== Xiph Quicktime Plugin ===<br />
You have to write a Quicktime Plugin for the Ogg container and the Xiph Codec Family.<br />
[http://qtcomponents.sf.net qtcomponents] provides support for Ogg Vorbis and MNG. This could be used as start.<br />
Xiph Quicktime Plugin has to support encoding/decoding for:<br />
* Ogg Media container<br />
**[http://qtcomponents.sf.net qtcomponents] ''has an operational pluggable API for import, it needs some work to be long term supportable. It does not have a pluggable API for exporting at this time.''<br />
* Support for Chained Ogg Streams<br />
**[http://qtcomponents.sf.net qtcomponents] ''imports chained files as multiple tracks in QuickTime. It does not create chained files during export.''<br />
* Support for Icecast Streams (sending is optional)<br />
**[http://qtcomponents.sf.net qtcomponents] ''implements nothing towards this item. First up is a reverse-engineering effort, as the specifications for a streaming media handler have not been published.''<br />
* Support for Xiph Codec Family: Vorbis, Theora, FLAC, Speex, Writ<br />
**[http://qtcomponents.sf.net qtcomponents] ''has code for Vorbis and Speex (not working at the moment) and there is code at [http://damien.drix.free.fr/qtflac/ Damien Drix's site] for FLAC (decode only).''<br />
It must also be possible to use the Xiph codecs in .mov files in combination with other quicktime codecs.<br />
*[http://qtcomponents.sf.net qtcomponents] ''supports embedding media encoded with Xiph codes into .mov files.''<br />
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=== Aggressive low-bitrate libvorbis encoding improvements for Vorbis I ===<br />
<p>libvorbis has a lot of room for improvement in all quality/bitrate departments, particularly at the lower quality levels / bitrates. There are many directions to approach this problem from.</p><br />
To claim this bounty, the following criteria would have to be met:<br />
* A 25%-or-better reduction in bitrate for quality levels -1, 0, 1 on a reasonable testsuite while maintaining qualitative equivilence (or improvement) in community testing.<br />
* No overall qualitative/bitrate regressions in quality levels 2 upwards<br />
* Output ogg files compatible with Vorbis I spec<br />
* Changes under suitable license for re-integration with Xiph.Org libvorbis<br />
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=== iPod playback support ===<br />
The [http://ipodlinux.sourceforge.net/ Linux on iPod] project has vorbis decode working (with alternate firmware) at a good fraction of realtime. It should be a small matter of optimization to get it working<br />
for useful playback.<br />
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=== FLAC support in libfishsound ===<br />
[http://annodex.net/software/libfishsound/ libfishsound] currently only supports Ogg Vorbis and Ogg Speex. It should be extended to support FLAC to complete the set of Xiph audio codecs.<br />
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=== Ogg Vorbis Bitrate Peeling ===<br />
<p>Ogg Vorbis bitrate peeling has been a topic brought up time and again to combat MP3 enthusiasts. But this feature does not actually exist, only the mere possibility abounds. This bounty is set to change that.</p><br />
The peeler must meet the following criteria:<br />
* Any (optionally transcoded) Vorbis stream can be losslessly re-encoded to a lower quality setting<br />
* Resulting streams would be identical or nearly identical to a stream generated by encoding the original source to the selected quality<br />
* This process is reasonably fast (that is, signifigantly faster than re-encoding from source)<br />
The following must also be accomplished to claim this bounty:<br />
* The encoding libraries must be updated to create <em>peelable</em> Vorbis streams natively<br />
* Old Vorbis streams must be <em>peelable</em> already, or convertable with a utility in order to be made <em>peelable</em><br />
* If older streams are not natively <em>peelable</em>, old <em>unpeelable</em> Vorbis streams must be identifiable and discernable from <em>peelable</em> streams in such a way as to facilitate transcoding streams from the old format<br />
* All work submitted must be licenced under the GPL or compatible licence (excepting circumstances where other licences conflict) ''[Note: In the GPL-alike case the contribution couldn't be re-integrated with the reference Vorbis encoder/decoder... do we need to stipulate a libvorbis-compatible license like the BSD/X11?]''</div>Snicolai