Mark Knecht wrote: >On Fri, 19 Nov 2004 02:24:59 +0100, Florian Schmidt <mista.tapas@xxxxxxx> wrote: > > >>>rom my POV a more interesting idea would be to do an external sound >>>device, probably 1394 based since that will work for more people. >>>Please remember that a PCI card is almost useless for laptop users >>>unless we're trying to put this into a cardbus formal also. That adds >>>money. >>> >>>If it was 1394 based then you can put a 1394 adapter in your PC for >>>$20 and then everyone uses the same audio unit. We control how it >>>works, so we can follow specs or do it in our own standard. You get >>>the advantage of probably more channels and better SNR, but you do >>>have to package the unit in a box or some type to be of general use. >>> >>>Anyway, those are some ideas for you to chew on. Hope I haven't poked >>>a balloon with a pin here... >>> >>> >>No, i find the alternative of a 1394 device completely acceptable, too. But >>how much cheaper would it be? I suppose the logic for talking to the 1394 bus >>[?? i don't know anything about firewire, except for 1. serial, 2. faster >>than USB] can be put into a FPGA again, right? >> >>For the sake of an example, let's choose a stereo full duplex device with >>48khz only samplerate, and with medium to good quality AD/DA's. So we got >>like 15-30 bucks for the DA/AD's. What's the rest? How expensive is the FPGA >>to control all this? What else is needed? Ok, a case mustn't be pretty, so i >>suppose anything will do -> 2-3$ :) >> >>Flo >> >> >Well, I guess my thought is that with a 1394 device we can just buy >standard links and Phys and sort of wire things together without going >to a full-fledged bus structure like PCI. I may be wrong about that. >The most common Link devices are 1394 OCHI and they are generally PCI >based so that puts us back into all of this stuff. > >Think about this from another direction though. The 2-channel cards >are always going to be cheap since that's what most of the world wants >and that's where the big companies provide value. I don't think we can >do anything at that number of channels that makes a lot of financial >sense. > >However, what about a much bigger devices, competing more or less with >an RME HDSP 9652 or a DigiFace? If we went that direction then there >isn't all that much incremental cost to add the channels (we can talk >about this later) but we get another degree of flexibility. Think of >this like a Digiface, or a MultiFace, or a Delta-1010 class device, >but most importantly with built-in reprogrammable DSP capability. >wouldn't that be cool? How about the ability to run LADSPA plugins in >hardware. To me that sound exciting, and would open up a really >interesting new way to use all the programming talent we have around >these forums. > >If we could come up with a process to take a ladspa plugin and map it >to gates in an FPGA then Linux audio would suddenly jump up to the >level of product like the higher end Creemware machines and start >approaching some of the lower-end pro versions of Pro Tools. > >Instead of a $400 2 channel PCI card we might end up with a $600 >16-in/16-out device with hardware signal processing on board. To me >this is probably a better place to go. If we do all this work ten we >want to start working towards an architecture that will last. > > Taking ladspa and mapping it to FPGA: how? and how would you do this efficiently, if you could do it? A C function to VHDL function convertor? (it's been a long time since I've worked with FPGAs. I'm sure there are advances) It might be more cost effective to use DSPs -- that is: more cost effective in the long run for everybody -- mostly the end user. brad
