[sdiy] Sblive AUD_EXT

[mikko.a.helin at nokia.com]

Forgot to mention, SB Live! digital output (S/PDIF) is resampled, it's not bit-accurate. You need and want an S/PDIF output which will not alter the data.

The GP outputs AFAIK just set some switches on/off (like connect the optical TOSLINK receiver to S/PDIF input or connect the coaxial input to S/PDIF input in Live platinum external box). For you they are as usefull as lets say RS232 control/status lines (yet some people use them for communications with external devices instead of the data lines). Digital means just they have discrete values "0" or "1", they are no data streams. Also even though there seems to be multiple SPDIF outputs they can't be used with Windows drivers. MIDI output is the only useful output signal from EMU10K.

-Mikko

> -----Original Message-----
> From: ext Linium [mailto:intent at club-internet.fr]
> Sent: 30. September 2002 16:53
> To: Helin Mikko.A (NET/Tampere)
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Sblive AUD_EXT
> 
> 
> Le Lundi 30 Septembre 2002 14:06, vous avez écrit :
> > I think the GP outs are GP (general purpose) outs, you set 
> a bit in a
> > register and read value 5V or 0V in this pin (assuming TTL level).
> >
> > Anyway, I have also been thinking the same with S/PDIF. It 
> would be ideal
> > if you could write a VST plugin and do the MIDI -> CV/gate 
> conversion
> > there. Unfortunately only floating point data is used with 
> VST, though you
> > maybe could access the sound card with the S/PDIF from the 
> plugin via
> > DirectSound and use integer format. Maybe the code could be 
> in another
> > process and your plugin just sends the changed data there 
> some other way
> > (shared memory, MIDI, IPC, RPC, Corba, COM name it).
> >
> > -Mikko
> 
> Yes there are said as "general purpose" outs, i forgot to 
> mention that in my 
> previous post. On the other hand it doesn't bring any extra 
> clarity, at 
> least for me ;), so may be that's why i didn't add this precision.
> But it seems that "general purpose" outs are meaning 
> something for you.
> It is a start :) The sblive has several pins on this 
> connector and despite i 
> have the name of them it's not clear in what format binary 
> datas are sent.
> I know there are several spdif outs and several I2s outs and 
> theses famous GP 
> outs. There are various clocks and frame signals too.
> 
> Here is the details:
> 
> http://w1.910.telia.com/~u91003452/live/images/PinoutDrawings.gif
> 
> As you see spdif/I2s and GP outs are labelled simillary so we 
> can think that 
> the same audio channels are "outed" in different formats.
> 
> I have a little AVR MCU i could use to figure out how datas 
> are organized.
> But i don't know yet what clock to use, and it will take a 
> little time.
> 
> Concerning the idea of a VST plugin i have no peculiar insight. 
> All depends what you want really. As far as i am concerned i 
> use PureData 
> which is a free (source code and usage) program that can 
> handle midi and 
> audio. It runs on windoz and linux. It is very easy to 
> connect a sequencer 
> using the Hubi's midi loopback tool to PD which run in back ground.
> Each note received can trigger some software modulators of 
> your own. (it is 
> very easy to learn and program).
> And you have all latitude to send the corresponding audio 
> signals you want to 
> the soundcard.
> In our case the audio signals sent go to one of the digital 
> stereo outs of 
> the SBlive and a MCU is there to spread the info to DACs or a 
> multiplexed DAC.
> 
> But you could use theorically any softsynthesizer you want. 
> It just has to 
> allow you to multiplex the outed signals ( if not you have 
> only 2 outs).
> 
> Thx for reading,
> 
> Linium
> 
> 
> 
> 
>  
> 
> 
>