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<div class="moz-cite-prefix">On 12/13/2012 11:57 PM, John Marvin
wrote:<br>
<br>
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<blockquote class=" cite" id="mid_50CA5D49_6000401_themarvins_org"
cite="mid:50CA5D49.6000401@themarvins.org" type="cite">
<pre wrap=""><i>But I wonder if there isn't another way of doing this. Perhaps a new
extio that understands the metis/hermes UDP protocol combined with using
VAC would allow development of an extio that doesn't need support within
the program itself. The VAC part wouldn't be necessary if you were
happy with using the computer sound for the audio output. But if you
wanted the sound to go back to the Mercury/Hermes you could set Winrad
to output to VAC and the extio would have an option to listen on the
other side of the VAC and send that audio back to Mercury/Hermes via the
network interface. Just a simple weekend project as Phil likes to say </i><i><span class="moz-smiley-s1" title=":)"><span>:)</span></span></i><i>.</i></pre>
</blockquote>
<br>
John,<br>
<br>
I thought at this possibility when developing the ExtIO DLL for
HPSDR, but then I dismissed<br>
it because it negated the main advantage of using the on-board DAC
of Mercury... latency...<br>
If you pass through VAC you have about the same latency of a real
sound card.<br>
<br>
The reduction in latency is directly perceivable if you enable both
the sound card output and<br>
the DAC output in the DLL... a few tens of a second... that's why I
took the way to modify <br>
Winrad to send the demodulated audio through the reverse USB channel
to Mercury for playback.<br>
I would have preferred to keep the main program hardware-agnostic,
relegating all the HW<br>
specific functions to the ExtIO DLL, but in this case I had no
choice.<br>
<br>
BTW, while we are talking of this, I switched on my HPSDR combo
after more than year that<br>
it was on hold on a shelf (I needed the table space for other
tasks), and noticed that the<br>
DLL has some problems with the latest firmware V3.3 for Mercury. I
am modifying it (almost done)<br>
and will upload it to the SVN when ready.<br>
<br>
<div class="moz-signature">-- <br>
<i><b>73 Alberto I2PHD</b></i>
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