JohnSwenson wrote: > This is an issue I am very interested in. Dirac is a very special room > correction suite, I think it is quite a bit better than the others and > would very much like to get it into the CSOS flow. > > Dirac is a software package (NOT free) which comprises two pieces, the > analysis part and the runtime part. The analysis takes the measurements > and figures out what the filter should look like, and the runtime > implements the filter in real time in your playback chain. Theoretically > these two could be on different OS's and machines. So you analyze the > room with your laptop and put the runtime on the wandboard. > > The dirac company has said that the runtime has been optimized to not > use very much processing horsepower so it should run on a wandboard. > They do have linux versions available which run on ARM processors. > > So the fun part is how this runtime gets integrated into the flow. Does > it get somehow attached to sqeezelite, or is it a plugin for LMS etc. > The off the shelf linux version creates a virtual ALSA device for your > application to send samples to, and it talks to the actual ALSA > hardware output device. This could easily be implemented in current > CSOS flow. There may be a problem though, we are using squeezelite to > implement a really good upsampling filter, if we keep this in place > dirac would then be given a 352.8 or 384 stream and I'm pretty sure that > is not going to work. > > I would prefer that dirac gets plugged in before the upsampling and I'm > not sure how to do that. > > I need to get some discussions going with the developers to find out > what they do about sample rates etc. If they can do the upsampling with > a custom upsampling filter that would make things much easier. > > John S.
As far as I can tell, their hardware isn't as powerful as a Wandboard (http://www.analog.com/en/processors-dsp/sharc/adsp-21369/products/product.html) A quote from their support forum: "devteam" post=13510 wrote: > > "djreflux" post=13464 wrote: > > I don't understand what the fuss is about. > > Dirac isn't revolutionary, by using IIR and FIR they can make the > > processing lighter on overheads making it perfect for hardware ports. It > > has a nice front end for end users thats simplified and great > > averaging/multiple measurement analysis. All they have done is port it > > to run on the Minidsp Sharc board. Most users would struggle to get as > > good a result as what this software can automate, but you can't do much > > else with the software. > > What hasn't been mentioned is.... Are the filters generated to send to > > the minidsp identical to the Native computer filters of Dirac Live. > > There is limited power on the hardware and I wouldn't be surprised if > > the filters have a few less taps/biquads. > > Deqx uses multiple sharc's to achieve its multichannel power remember. > > > > The end result is the sound though, and Dirac can sound great. > > > > It's up to the user. If you want to run on hardware DSP, minidsp give > > you whatever you need. > > Either a closed automated way for room correction or a more open > > professional route with your choice of more powerful Software filter > > generation such as Acourate (which can give you automated filters too). > > Both will cost the same amount and have the same hardware.> > > > @ DJreflux, > > Good question! what's the fuss all about? :-) Well, although IIR and > FIR are indeed filters that we've been having on miniDSP platforms for > a long time (and you'd find in other software/hardware platforms), the > hard work is down to how you "come up" the correct filters unless you > do have a PHD in acoustic and math modelling. (I know I don't... :-) > > 1) For one it starts with a measurement (in the case of Dirac, > multiple of them). What you do with all these measurements, analysis > and come up with the smart to make sure that a) you don't try to solve > something that you'll never be able to solve, b) you fix the problem > at its source (e..g impulse response) c) you make it easy to the > customer d)All together hoping you make it sounds good. Though there > are some very good software out there, that one step alone is really > not to be underestimated here. That's the smart behind Dirac's > solution and the many years of research, quite a few patents and > brainchild of few smart PHD's @ Dirac. > 2) You've got a very good point that fitting on a hardware that is low > power, doesn't require a GHz proc and runs passively is another > challenge. Coming up with huge FIR banks has been done for many years > now. There are some good implementations out there (e.g. DRC open > source) but once again, that's something with its limitations. Dirac > took a complete different path at solving the problem and that's how > we can make it happen. To you very good question: > " Are the filters generated to send to the minidsp identical to the > Native computer filters of Dirac Live?" > Yes, we indeed implemented a no compromise solution for this one, no > limitations. Without getting into details (under NDA), there are > different levels of implementation to allow for different hardware > resources. On the DDRC, we chose to really make push it to the highest > level so you all get the best experience. > 3) Finally, you do need to make this whole experience seamless. So our > team did work hard to make it such that you need limited hardware > (e.g. no need for external source for setup, embedded sweep), > plug&play experience, fitting all the goodness of High end Dirac > algorithms at its highest specs on our hardware. Of all the projects > we've done so far, it indeed was quite a fair amount of > brainstorming.. :-) > > So while on the outset, you're indeed wondering "what's the big deal > about FIR + IIR on miniDSP while we had that for the past 2 years", it > indeed did take us a lot of work (and partnership with the Dirac's > team) to make it happen.. :-) > > DevTeam Main System: Touch; Marantz SR-5004; TMA Premium 905; TMA Premium 901; BK Monolith+ FF; HDI Dune Smart D1; Pioneer PDP-LX5090H iPad 32GB Wifi + Squeezepad (local playback activated) Acer Iconia Tab A700 + Squeezeplayer Wandboard Duallite + CSOS, integrated LMS activated ------------------------------------------------------------------------ bakker_be's Profile: http://forums.slimdevices.com/member.php?userid=30369 View this thread: http://forums.slimdevices.com/showthread.php?t=97881 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
