[hpsdr] Step 1 Question

[Graham / KE9H]

Phil:

This is what VAC is all about.

FLdigi expects to hook to a sound card and receive 16 bit audio from
the jack that that sound card is hooked to.  It puts out 16 bit audio
to be given to a sound card for transmission to a radio input.

PowerSDR puts out 16 bit audio for output through a sound card equivalent.
Also accepts digital audio.

VAC takes the 16 bits from PowerSDR, and hands it to FLDigi, so that
FLdigi thinks it is talking to a sound card.  The fun begins if PowerSDR 
and
FLdigi are running in two different time domains, so VAC also has the
ability to resample the audio in both directions and cross time domains
if necessary.

So either build VAC functionality into the new software, or have an
interface that looks like a soundcard.  Could be at the GUI, or
at the signal processing server.

Or, define a "plug-in" interface so a PSK-31 modem module can
plug directly into the GUI, or the signal processing server, so that you
get to recreate/re-write every kind of digital modem software in the 
world, too.

Many ways to skin this cat, architecturally.  Suggest that openHPSDR
stick to the radio signal processing until things are under control there.

--- Graham / KE9H

==

Phil Harman wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> All,
>
> Just received this interesting and thought provoking question from the
> dttsp-linux reflector regarding our digital data plans.
>
> Comments and suggestions welcome.
>
> 73's Phil...VK6APH
>
>
> Phil
>
> Interesting - as a data mode ham, I have a couple of questions:
>
> "All DSP on the server" - now how does this split work for say PSK-31? On
> my current
> setup I take raw I/Q audio via jack from the softrock, dttsp does the hard
> work of
> selecting an chunk of spectrum, and this reappears (again in jack) as an
> audio
> signal. FLdigi is connected to this, and does not know it wasn't connected
> to the
> headphone socket of a 'real' radio.
>
> Would your design export the intermediate audio (realtime across the
> network), or
> would you split fldigi to run its modem(s) on the server, and export
> decoded text
> (plus non-realtime waterfall data) to the client?
>
> One other detail - is this work GPL v3 or GPL v2?
>
> 73
>
> --David G8SQH
>
>
> ___


 1281361353.0