[LAD] FOSS Ethernet Soundcard

Gene Heskett gene.heskett at verizon.net
Tue Nov 24 17:06:16 UTC 2009

On Tuesday 24 November 2009, Adrian Knoth wrote:
>On Tue, Nov 24, 2009 at 04:46:02PM +0100, Karl Hammar wrote:
>> Well, you have to start somewhere. I'm not in this to compete with
>> Behringer ADA8000, I'm in this to fiddle around with soldering.
>WTF? Soldering is what it takes to make the product. If soldering is the
>motivation for the project, I couldn't care less. ;)

Yes, but without those of us to whom a hot soldering iron is just as valuable 
a tool as the ubitiquous dual channel 100 mhz triggered, computerized scope 
is (I have both, and know well how to use them), all your ideas are just 
that, an abstraction that will wait for that hot soldering iron to bring it 
to life.  Only then will you know what it will take and can write the 

>OTOH, as Gene has pointed out, a completely open source protocol
>replacing ADAT is a valid motivation, so the HQ guys could still jump
>the band waggon once the protocol has settled.
>(given that it will ever make its way)

That is why the enthusiasm on my part. Barring under influence by the Apples 
and Microsofts extant, a truly royalty free, available from off the shelf 
parts, interface really should replace the rest of these wanna be bus's as 
soon as the old stuff's limitations begin to be an artistic limit.  That of 
course depends on the state of the individual studio, with some input from 
the tax and amortization schedules extant in that locale.

Given a level playing field, something we all know the Apples and M$'s of the 
world abhor with all their considerable bank accounts and lawyers, this could 
be a working reality in 5 years, and dominant in 10.  And the state of audio 
production would be considerably better off.

Of course I'm preaching to the choir, but one has to start someplace.  The 
more members the choir has, the louder they can sing. :)

>> One question tough. If you have ADAT, why go the longer way over an
>> ADAT-to-ethernet box than straight into your adat card in your computer?
>> What would one gain?

Don't have the ADAT, so I cannot begin to answer that in a sensible way.

>I could then place multiple ADAT converters on the net, combine their
>capacity without using MADI (64 channels over one cable), copy the
>signal at the FOH (front-of-house, mixing desk), feed every musician
>with his personal monitoring stream and record it.

At what cost in ADAT capable boxes?

>Today, RockNet does this, all audio distribution networks do this, but
>they are expensive. My impression was you want to provide this kind of
>functionality for less money.

Eggzactly. Lowest common denominator.

>If I could save the MADI card and just plug the network cable into my
>el-cheapo network card, I would have a gain.
>> uint48_t ethernet_addr;
>> uint32_t ip_addr = 192 << 24 | 168 << 16 | ethernet_addr & 0xffff;
>I'd probably slap you when come up with code like this. ;) This is
>lacking abstraction.
>For those who haven't heard, yet: An IP address isn't an uint32_t. This
>is the road to hell, leads to unportable code.

Thanks for pointing that out.

>But since I'm working for the networking chair at Jena University, let
>me tell you that the right structure for an IP address is
>   struct sockaddr_storage
>Nothing else. Don't even dare to shift bits in an uint32_t. Things like
>this might have been right in the 90ties, but we had RFC 3493 in
>February 2003 (and RFC 2553 in 1999). ;) (things might be different when
>we're talking kernel level)
>As mentioned in the original posting: if I could provide some input, I'd
>happily do this. It's probably a good idea to decide on the goals,
>first, but I might have missed that part of the discussion.

I think this might be the beginnings of _that_ discussion.


Cheers, Gene
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