<html><body bgcolor="#FFFFFF"><div>Hi Alberto,</div><div><br></div><div>I think most of us are Reading the data from USB and after processing a buffer putting either every result sample into the queue for sending to the USB or ever 2nd or 4th depending on the sample rate of 48, 96 or 192. When that queue has the number of samples needed then they are written to the USB.</div><div><br></div><div>My first test was to loopback audio from Penelope mic input to Mercury using this algorithm.</div><div><br></div><div>Regards,</div><div><br></div><div>John g0orx/n6lyt<br><br>Sent from my iPhone</div><div><br>On 30 Jul 2009, at 13:27, Alberto I2PHD <<a href="mailto:i2phd@weaksignals.com">i2phd@weaksignals.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div><span>***** High Performance Software Defined Radio Discussion List *****</span><br><span></span><br></div></blockquote><blockquote type="cite"><div>
Phil Harman wrote:
<blockquote cite="mid:6D43F2B5E8C94F968BF5EEAAA272A46E@phil" type="cite">
<style></style>
<blockquote style="border-left: 2px solid rgb(0, 0, 0); padding-left: 5px; padding-right: 0px; margin-left: 5px; margin-right: 0px;"><font size="-1"><font face="Tahoma">
<div><big>2) If 1) is true, how should I behave when e.g. the
input data have a sampling frequency of 96 kHz ? Should I send<br>
an output frame every two input frames, or should I send the output
frames at the same rates of the input ones,<br>
repeating the data if need be ?</big></div>
<big> </big>
<div><big> </big></div>
<big> </big>
<div><big><font color="#000000" face="Arial" size="2">Always send
the data at 48kHz, just discard data at higher rates. </font><br>
</big></div>
</font></font></blockquote>
</blockquote>
Hi Phil,<br>
<br>
<br>
thanks for the answer.<br>
<br>
Just to check whether I am getting it right.... suppose I set Mercury
for a final downsampling frequency of 192 kHz.<br>
For this my initial test I don't need the input data, I use the input
stream just as a clock.<br>
Does this mean that I count 4 input frames, and I send one output frame
every 4 of them ? This seems to me the<br>
only way to obtain the needed 48 kHz, as if the data which I want to
playback are coming from a WAV file, they do not have an implicit <br>
arrival rate. Of course they were originally sampled at 48 kHz, but the
rate at which I can read a WAV file is of course much<br>
higher, so I need a way to pace my sending.<br>
<br>
Thanks for your patience<br>
<br>
73 Alberto I2PHD<br>
<br>
</div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>HPSDR Discussion List</span><br><span>To post msg: <a href="mailto:hpsdr@openhpsdr.org"><a href="mailto:hpsdr@openhpsdr.org">hpsdr@openhpsdr.org</a></a></span><br><span>Subscription help: <a href="http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org"><a href="http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org">http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org</a></a></span><br><span>HPSDR web page: <a href="http://openhpsdr.org"><a href="http://openhpsdr.org">http://openhpsdr.org</a></a></span><br><span>Archives: <a href="http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/"><a href="http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/">http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/</a></a></span><br></div></blockquote></body></html>