216 lines
8.3 KiB
HTML
216 lines
8.3 KiB
HTML
<!DOCTYPE doctype PUBLIC "-//w3c//dtd html 4.0 transitional//en"><html><head>
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<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
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<meta name="GENERATOR" content="Mozilla/4.78 [fr] (X11; U; Linux 2.4.17 i686) [Netscape]">
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<meta name="Author" content="Jean-Marc Valin">
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<title>The Speex Speech Codec</title>
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</head>
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<body text="#000000" bgcolor="#ffffff" link="#0000ef" vlink="#59188e" alink="#ff0000">
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<center>
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<img src="speex.png" alt="Speex">
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</center>
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<br>
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<br>
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<a href="http://sourceforge.net/projects/speex">The Speex project</a>
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aims to build an open-source (LGPL) <A href="patents.html">patent-free</A> voice codec. Unlike
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other codecs like MP3 and <a href="http://www.vorbis.org/">Ogg Vorbis</a>,
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Speex is specially designed for compressing voice at low bit-rates in the
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8-32 kbps/channel range. Possible applications include Voice over IP (VoIP),
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Internet audio streaming, archiving of speech data (e.g. voice mail), and
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audio books. In some sense, it is meant to be complementary to the
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Ogg Vorbis codec.
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<p>If you are interested in participating to the project, contact us at <a href="mailto:speex-devel@lists.sourceforge.net">
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speex-devel@lists.sourceforge.net</a> or <a href="http://lists.sourceforge.net/lists/listinfo/speex-devel">
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join our mailing list</a>. Right now, we are mostly looking for
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developers with signal processing and speech coding knowledge, as well
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as people with knowledge about patents in that field. See the
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<A href="http://sourceforge.net/pm/task.php?group_project_id=19556&group_id=46651&func=browse">task list</A> for more details about what's left to do in Speex<br>
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</p>
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<h2>Download</h2>
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You can download Speex from <a href="http://sourceforge.net/project/showfiles.php?group_id=46651">
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here</a>.<br>
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<h2>Documentation</h2>
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This Speex manual includes information about the
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algorithms used in Speex, the bit-stream, the API and more.
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<br>
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<A href="manual.pdf">Speex manual (PDF)</A>
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<br>
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<A href="manual.ps">Speex manual (Postscript)</A>
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<br>
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<A href="manual/">Speex manual (HTML online)</A>
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<br>
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<A href="manual.tar.gz">Speex manual (HTML tarball)</A>
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<br><br>
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There is also some API documentation generated by Doxygen directly from the header files
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<br>
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<A href="refman.pdf">Speex API (PDF)</A>
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<h2>Samples</h2>
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You can listen to samples encoded with Speex <A href="/audio/samples/">here</A>
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<h2>Who uses Speex</h2>
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<A href="http://www.linphone.org">LinPhone</a>: A SIP-based VoIP phone written for GNOME
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<br>
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<A href="http://jzb.rapanden.dk/speex/">Speex XMMS plugin</a> written by <a href="mailto:jzb@rapanden.dk">Jens Burkal</a>
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<br>
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<A href="http://www.openh323.org">OpenH323</a>: An open-source H.323 stack
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<br>
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<A href="http://www.gnomemeeting.org">GnomeMeeting</A>: A H323 Video Conferencing Program
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<br><br>
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In development:
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<br>
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<A href="http://www.asteriskpbx.org">Asterisk</a>: An open-source PBX
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<h2>News</h2>
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<h3>2002/09/04</h3>
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Speex 0.8.1 released. This release fixes a bug in the new 0.8 API (function
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speex_mode_query). For those using only speexenc/speexdec, no need to upgrade
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but those using libspeex (directly or through another application) should.
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<h3>2002/08/24</h3>
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Speex 0.8.0 released. The speex_decode() function no longer uses the
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'lost' parameter. Applications will need
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to be updated.
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<h3>2002/08/09</h3>
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Speex 0.7.0 released. The format of the bit stream has changed once again
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and the bandwidth required has been
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reduced slightly.
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<h3>2002/08/01</h3>
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Speex 0.6.0 has been released. This is a major release that contains many improvements and lots of bug-fixing. The post-filter that was causing problems throughout 0.5.x was replaced with a new perceptual enhancement system, which sounds better and consume much less CPU. Also many changes to Ogg encoder/decoder, including possibility to see the bit-rate being played/encoded. There is also a discontinuous transmission (DTX) mode. Last but not least, 0.6.0 now reports no error when being run with the valgrind memory debugger.
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<h3>2002/07/26</h3>
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Speex 0.5.2 is out and brings a number of improvements and bug fixes. First,
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the search has been improved and it is now possible to choose the right
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quality/encoding time tradeoff (--comp option). Is is also possible to pack
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more that one frame in an Ogg packet (--nframes), reducing the overhead for
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low bit-rates. Last but not least: there is now some documentation about
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Speex!
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<h3>2002/07/17</h3>
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Version 0.5.1 is released. This release brings quality improvements at very
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low bit-rate (5.7 kbps) and a new post-filter. VBR should also be a bit
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better though there's still a lot to do. Most of the modes are bit-rate
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compatible with 0.5.0, with the exception of the very low bit-rate (which is
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sometimes used in VBR, so expect some glitches). The source (and probably
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binary) compatibility with 0.5.0 is maintained.
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<h3>2002/07/08</h3>
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Speex 0.5.0 is out. The most important new feature is Varible Bit-Rate
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(VBR). It can be enabled by using the --vbr option to speexenc. When
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encoding in VBR, the --quality option can still be used. Note VBR
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implementation in this release is experimental and still requires lots of
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tuning.
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<h3>2002/06/23</h3>
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Speex 0.4.0 is here, adding many more bit-rates to both narrowband and wideband, as
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well as the ability to change bit-rate dynamically from frame to frame. The
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narrowband modes now range from 8 kbps to 18 kbps, while wideband range from
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10 kbps to 28 kbps. There is also a "noise coding" mode at 2 kbps for
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narrowband and 3 kbps for wideband. All this will lead to real Variable
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Bit-Rate (VBR) in the future. Also, worth mentioning the codec latency has
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been reduced from 40 ms to 30 ms (20 ms frames + 10 ms lookahead).
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<h3>2002/06/12</h3>
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Speex 0.3.0 has been released. There is now a new "low bit-rate" narrowband
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mode for coding speech at 8 kbps. There's also support for big-endian
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machines (untested, please report bugs). Speex files now have real header
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containing information like bit-stream version (revents from playing an
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incompatible bit-stream), sampling rate, bit-rate and user comments. On the
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quality side, the post-filter has been improved and there has been more
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codebook optimization. Note that this release breaks bit-stream
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compatibility with previous releases.
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<h3>2002/06/07</h3>
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Speex 0.2.0 is out. This is a major release with lots of improvements and
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bugfixes. First, the encoder and decoder can work directly from wav files
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(mono only for now) and the decoder can play directly to soundcard. Also,
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most of the codebooks have been re-trained in order to improve quality (but
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this also breaks format compatibility with previous versions), while
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slightly decreasing complexity. Speex is now able to encode both DTMF and
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music (not as good as Vorbis of course) after bugs were fixed in the pitch
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prediction and LSP quantization. Last but not the least, the perceptual
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post-filter has been improved.
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<h3>2002/06/04</h3>
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Speex 0.1.2 is out. This adds a perceptual post-filter at the decoder to
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(hopefully) increase quality. It can be enabled with the --pf option to
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speexdec. The Speex format remains the same for both narrowband
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and wideband.
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<h3>2002/05/15</h3>
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Speex 0.1.0 has been released. Speex now uses the Ogg bitstream (using
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libogg). That means that there is now (limited) bitstream error
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recovery. Also, the narrowband bit-rate has been reduced from 15.7 kbps to
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15.1 kbps and the wideband bit-rate has been reduced from 31.3 kbps to 27.7
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kbps. The quality remains roughly the same for both narrowband and
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wideband. Once again, this breaks compatibility with previous versions.
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<hr width="100%" size="2">
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<div align="right"><a href="http://uk.eurorights.org/issues/cd/quick/"><img
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border="0" width="160" height="40" src="badcd002.png"
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alt="Say NO to corrupt audio discs" /></a>
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<br>
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<img src="http://sourceforge.net/sflogo.php?group_id=46651&amp;type=5" alt="SourceForge Logo">
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<br>
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<a href="mailto:jean-marc.valin@hermes.usherb.ca">Jean-Mrc Valin</a> <br>
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$Date: 2002/09/16 00:59:10 $</div>
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</body></html>
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