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<p class="MsoNormal"><span lang="EN-US">Hi all,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Playing with mod_opus came up with the following.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I am trying to recompile the codec with 8Khz and 40ms ptime. I am not familiar with the codec internals and not really sure what parameters should I change…<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">In mod_opus.c :<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Line 59:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL">int bitrate_bps = codec->implementation->bits_per_second;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"> int use_vbr = 1;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"> int complexity = 10;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"> int use_inbandfec = 1;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"> int use_dtx = 1;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"> int bandwidth = OPUS_BANDWIDTH_FULLBAND;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"> </span><span style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL">int err;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL">I suppose that the bandwidth must be changed to OPUS_BANDWIDTH_NARROWBAND and use_vbr=0 and I haven’t found yet whether the FEC parameter is passed
to opus encoder.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL">And in Line 184 , I think the following parameters must be changed<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"><o:p> </o:p></span></p>
<pre><span lang="EN-US"> </span><span class="hlidentifier"><span lang="EN-US">switch_codec_interface_t</span></span><span lang="EN-US"> *</span><span class="hlidentifier"><span lang="EN-US">codec_interface</span></span><span lang="EN-US">;<o:p></o:p></span></pre>
<pre><span lang="EN-US"> <span class="hlkeyword">int</span> </span><span class="hlidentifier"><span lang="EN-US">samples</span></span><span lang="EN-US"> = <span class="hlnumeric">480</span>;<o:p></o:p></span></pre>
<pre><span lang="EN-US"> <span class="hlkeyword">int</span> </span><span class="hlidentifier"><span lang="EN-US">bytes</span></span><span lang="EN-US"> = <span class="hlnumeric">960</span>;<o:p></o:p></span></pre>
<pre><span lang="EN-US"> <span class="hlkeyword">int</span> </span><span class="hlidentifier"><span lang="EN-US">mss</span></span><span lang="EN-US"> = <span class="hlnumeric">10000</span>;<o:p></o:p></span></pre>
<pre><span lang="EN-US"> <span class="hlkeyword">int</span> </span><span class="hlidentifier"><span lang="EN-US">x</span></span><span lang="EN-US"> = <span class="hlnumeric">0</span>;<o:p></o:p></span></pre>
<pre><span lang="EN-US"> <span class="hlkeyword">int</span> </span><span class="hlidentifier"><span lang="EN-US">rate</span></span><span lang="EN-US"> = <span class="hlnumeric">48000</span>;<o:p></o:p></span></pre>
<pre><span lang="EN-US"> <span class="hlkeyword">int</span> </span><span class="hlidentifier"><span lang="EN-US">bits</span></span><span lang="EN-US"> = <span class="hlnumeric">32000</span>;<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL">Can you propose any values about these parameters to achieve 8khz with 40ms packet time?
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EL"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks for any help,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Dimosthenis<o:p></o:p></span></p>
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