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<title>Asterisk Codecs Extension</title>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hi Alex, what if the codec I want to add is
for video? I noticed H263 is only available in asterisk/formats/. Does that
mean H263 is only being coded in client side and being passed-through by *?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>In that case, if I wanted to support the
pass-through of a video stream the only thing I would have to do would be
changing the SIP header to indicate the new codec name?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thank you,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Pedro<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Alex Volkov
[mailto:avolkov@bpvn.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> quarta-feira, 14 de Abril de
2004 8:20<br>
<b><span style='font-weight:bold'>To:</span></b> asterisk-dev@lists.digium.com<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Asterisk-Dev]
Asterisk Codecs Extension</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Pedro,</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Simply look at any codec code in asterisk/codecs/. I suggest
codec_ulaw.c or codec_alaw.c. The bulk of both of these is the necessary
interfacing code to make whatever-generic-codec work with asterisk, and the
actual conversions from xlaw to PCM and back are simple 2-liner loops. Once you
understand the basic structure of an * codec, look at codec_g723_1.c for an
example on how to handle a whatever-generic-codec that is an opaque
library.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Model your new * codec on those, as I think those
provide the best examples of an adaptation/abstraction layer.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Cheers!</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Alex.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>----- Original Message ----- <o:p></o:p></span></font></p>
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<p class=MsoNormal style='background:#E4E4E4'><b><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-weight:bold'>From:</span></font></b><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:est-p-bgoncalves@ptinovacao.pt"
title="est-p-bgoncalves@ptinovacao.pt">Pedro Bessa Goncalves</a> <o:p></o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>To:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:Asterisk-Dev@Lists.%20Digium.%20Com%20(asterisk-dev@lists.digium.com)"
title="asterisk-dev@lists.digium.com">Asterisk-Dev@Lists. Digium. Com
(asterisk-dev@lists.digium.com)</a> <o:p></o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Sent:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Tuesday, April 13,
2004 7:35 AM<o:p></o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Subject:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> [Asterisk-Dev]
Asterisk Codecs Extension<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p><font size=2 face="Times New Roman"><span style='font-size:10.0pt'>Hi, does
anyone know the required function headers for extending Asterisk codecs?</span></font>
<br>
<font size=2><span style='font-size:10.0pt'>Is there another way to import 3rd
party codecs?</span></font> <o:p></o:p></p>
<p><font size=2 face="Times New Roman"><span style='font-size:10.0pt'>Thank
you,</span></font> <br>
<font size=2><span style='font-size:10.0pt'>Pedro Goncalves</span></font> <o:p></o:p></p>
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