<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Bob,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The RTCM utilizes local loop back of the audio in hardware if you configure it for 'Mode 3" operation so it not a problem.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Mark - K7IZA<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> arm-allstar-bounces@hamvoip.org [mailto:arm-allstar-bounces@hamvoip.org] <b>On Behalf Of </b>kk6ecm<br><b>Sent:</b> Tuesday, September 01, 2015 7:31 PM<br><b>To:</b> ARM Allstar<br><b>Subject:</b> Re: [arm-allstar] software update status<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Is this an issue with usbradio on ACID (higher throughput burden) as well?<br><br>Thanks,<o:p></o:p></p><div><p class=MsoNormal>Bob<o:p></o:p></p></div><div><p class=MsoNormal>kk6ecm<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Sent from iPad<o:p></o:p></p><div><div><p class=MsoNormal><o:p> </o:p></p></div></div></div></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><br>On Sep 1, 2015, at 1:01 PM, Tim Sawyer <<a href="mailto:tisawyer@gmail.com">tisawyer@gmail.com</a>> wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal>David,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Sounds like you've found the root cause of this and have a fix is the works.<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Excellent!<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I think this same problem is happening with RTCM's as well. I does seem less frequent or harder to detect by ear. That may have more to do with using ACID on Intel Atom hardware than it does with RTCM's, don't know. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Is your fix only to simpleUSB, or is there a chance it will help RTCM's as well? <o:p></o:p></p></div></div></div><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Mon, Aug 31, 2015 at 11:24 PM, David McGough <<a href="mailto:kb4fxc@inttek.net" target="_blank">kb4fxc@inttek.net</a>> wrote:<o:p></o:p></p><p class=MsoNormal><br>Hi Bob,<br><br>The variable audio delay issue is occasionally seen on PC-computer<br>platforms, too, particularly with the simpleusb driver. This is NOT the<br>audio delay that is unavoidable due to buffering as the audio samples pass<br>through Asterisk. Nor is this issue related to the Asterisk jitter buffer,<br>etc.<br><br>Basically stated, the problem is that the input sample rate -dynamically-<br>varies from the output sample rate. Depending on various factors, you may<br>have too many samples, or too few, at any given moment. With the current<br>code, the main issue seen is that too many output sound frames get queued,<br>causing a frequently increasing in length input to output audio<br>delay--sometimes with delays of maybe as much as one second (really<br>annoying!). If there is an output buffer under-run, you hear a pop/click<br>due to running out of samples.<br><br>Initially, I suspected some kind of subtle bug in the simpleusb sound<br>code. But, after experimentation, I've been able to easily duplicate this<br>issue using my native ALSA stand-alone test software or even ALSA<br>applications like arecord and aplay, etc.<br><br>One solution to this problem is to use a dynamic buffer that effectively<br>re-samples the audio, gently up-sampling or down-sampling, depending on<br>the current trends for overrun or under-run. I've got working software<br>that accomplishes this now. And, it runs full-duplex beautifully for 24+<br>hours with no change in audio delay and no logged clicks or pops.<br><br>Hopefully, I'll get a few days time when I'm rested to focus on completing<br>the integration of this code into simpleusb. So far, I've had no time at<br>all to complete this.<br><br>But, hopefully soon.<br><br>73, David KB4FXC<o:p></o:p></p><div><div><p class=MsoNormal><br><br><br>On Mon, 31 Aug 2015, kk6ecm wrote:<br><br>> Couple of questions:<br>><br>> 1) Is this audio delay the same as experienced with ACID?<br>><br>> 2) What is the nature of the fix that reduces the delay?<br>><br>> Thanks,<br>> Bob<br>> kk6ecm<br>><br>> Sent from iPad<br>><br>><br>> > On Aug 27, 2015, at 9:33 AM, David McGough <<a href="mailto:kb4fxc@inttek.net">kb4fxc@inttek.net</a>> wrote:<br>> ><br>> ><br>> > Hi LaRoy,<br>> ><br>> > Progress has been slow in recent weeks, due primarily to family<br>> > commitments that I've got. At this point, the update is waiting on me.<br>> ><br>> > I am hopeful to minimally have a bug-fix interim release soon. The big<br>> > item on the list being resolution for the variable audio delay.<br>> ><br>> > I hope to have more details soon.<br>> ><br>> ><br>> > 73, David KB4FXC<br>> ><br>> ><br>> ><br>> >> On Thu, 27 Aug 2015, LaRoy McCann wrote:<br>> >><br>> >> Doug,<br>> >> Just curious on how things are progressing with a new software update<br>> >> for the PI2?<br>> >><br>> >> Thanks,<br>> >><br>> >> LaRoy McCann, K5TW<br>> >><br>> >><br>> >><br>> >><br>> >> ---<br>> >> This email has been checked for viruses by Avast antivirus software.<br>> >> <a href="https://www.avast.com/antivirus" target="_blank">https://www.avast.com/antivirus</a><br>> >><br>> >> _______________________________________________<br>> >><br>> >> arm-allstar mailing list<br>> >> <a href="mailto:arm-allstar@hamvoip.org">arm-allstar@hamvoip.org</a><br>> >> <a href="http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar" target="_blank">http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar</a><br>> >><br>> >> Visit the BBB and RPi2 web page - <a href="http://hamvoip.org" target="_blank">http://hamvoip.org</a><br>> ><br>> > _______________________________________________<br>> ><br>> > arm-allstar mailing list<br>> > <a href="mailto:arm-allstar@hamvoip.org">arm-allstar@hamvoip.org</a><br>> > <a href="http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar" target="_blank">http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar</a><br>> ><br>> > Visit the BBB and RPi2 web page - <a href="http://hamvoip.org" target="_blank">http://hamvoip.org</a><br>> _______________________________________________<br>><br>> arm-allstar mailing list<br>> <a href="mailto:arm-allstar@hamvoip.org">arm-allstar@hamvoip.org</a><br>> <a href="http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar" target="_blank">http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar</a><br>><br>> Visit the BBB and RPi2 web page - <a href="http://hamvoip.org" target="_blank">http://hamvoip.org</a><br>><br><br>_______________________________________________<br><br>arm-allstar mailing list<br><a href="mailto:arm-allstar@hamvoip.org">arm-allstar@hamvoip.org</a><br><a href="http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar" target="_blank">http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar</a><br><br>Visit the BBB and RPi2 web page - <a href="http://hamvoip.org" target="_blank">http://hamvoip.org</a><o:p></o:p></p></div></div></div><p class=MsoNormal><br><br clear=all><o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <o:p></o:p></p><div><div><div><div><div><p class=MsoNormal>--<o:p></o:p></p></div><div><p class=MsoNormal>Tim<o:p></o:p></p></div></div></div></div></div></div></div></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>_______________________________________________<br><br>arm-allstar mailing list<br><a href="mailto:arm-allstar@hamvoip.org">arm-allstar@hamvoip.org</a><br><a href="http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar">http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar</a><br><br>Visit the BBB and RPi2 web page - <a href="http://hamvoip.org">http://hamvoip.org</a><o:p></o:p></p></div></blockquote></div></body></html>