Hi,

I heard about your project through the AGNULA news letter. It is very
interesting but what about laptops? I cannot fit a PCI card in there.

I have been interested in laptops for audio for quite some time and I
think that the most professional way to go is firewire. I know this might
complicate matters a bit. I am not an engineer so I cannot help in that
matter. It seems that the firewire cards available at the moment on the
market cannot be used with Linux distributions as the controlling
software is not compatible.

I would be interested to know if any plans for this are made in the
future.

Thank you,

Anthony Bonello.

Hi Anthony, Thank you very much for your supporting words. Your suggestion is very reasonable and expected. It is not impossible to make "patch" for this feature. We will discuss about this. One general problem for laptops is that any peripheral device will have some enclosure... yes, we will have more problems with mechanics and machining, and if interest exist... we will try to find some cheap box for this purpose. Also, in this case, we need external power supply (wall-cube) and small board for female pci connector... Note also that laptops and all their components is designed for small current consumption, and not for great performances... and some drawbacks will be appears... Anyway, suggestion is good, and thanks for it. Best regards, -boggy ----- Original Message ----- From: a.bonello at s...a.bonello at s...> To: Date: Sat May 8 12:35:44 CEST 2004 Subject: [oc] Audio DSP PCI Card for mobile studio

Hi (again) Anthony, Another problem is that FireWire cores is only in planning phase here. I don't know nothing about real status of three FireWire projects (seems to appear in project list). If maintainters of this projects read cores mailing list, it be very usefull to tell something about their plans. If that projects need some help, and if we can... no problem! In other case we will be pushed to find some FireWire dedicated chipset, even this will be (very) bad decision for open hardware project. Same thing is for AES3 and S/PDIF core... we have possibility to buy chips for this protocol, but it will be better to build a open core with RS422/485 transceiver... card will be cheaper, and more open and free. Best regards -boggy ----- Original Message ----- From: a.bonello at s...a.bonello at s...> To: Date: Sat May 8 12:35:44 CEST 2004 Subject: [oc] Audio DSP PCI Card for mobile studio

Hello,

I am maintaining one of these three projects: http://www.opencores.org/projects.cgi/web/llc1394/overview I am working on it slowly, perhaps too slowly. I have some pieces coded, but currently switched to designing schematics for a simple demo board, which in fact will have some audio in/out capability. As it looks now the board will be based on XC3S400 Spartan-3 FPGA and will have an off-the-shelf 1394a PHY chip. Besides that it will have some external memory (not decided yet whether it will be SRAM or SDRAM) and some audio I/O. I am planning to use Xilinx MicroBlaze core for implementing the 1394 stack. Unfortunately none of the open cores seems to be able to compete with the MicroBlaze in terms of footprint and performance. I also have a software guy who kind of joined this project informally but I am not sure of his commitments at the moment.

AES3/SPDIF receiver requires a PLL, in other words it is normally a mixed
signal circuit. I think there were attempts made to implement this
functionality digitally, but this is not so trivial, especially when you
consider low jitter requirements and the wide range of transmitters that
this receiver has to work with... Transmitter is much easier to do...


/Mikhail

Hello Mikhail, mikem at opencores.org wrote:

Ok, what FW phy chip you intend to use?

yes, I know, only receiver need PLL, but my plans _is_ to build an audio card with PLLs an low jitter please visit http://www.opencores.org/projects.cgi/web/fac2222m/overview -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums.cgi/cores/attachments/20040512/cf0ea92a/attachment.htm

The PHY chip will most likely be TSB41AB3 by TI.
I looked at the Audio DSP PCI card project you mentioned and have
several things to say:
1. It is not true that all nonFPGA digital audio implementations have
problems with latencies. The latency is usually a function of the OS and
bus used, and of the driver stack and has nothing to do with the FPGA
vs. DSP issue.
2. I don't want to start a flame here, but 200 kHz is a stupid overkill
driven by marketing departments. 96 kHz has plenty of margin. Well, I
understand modern ADCs and DACs are made this way, but that should
not be the reason to double processing requirements.
3. You are listing some very advanced DSP applications. Many of them
are certainly easier implemented in software...
4. XC2S200 is not likely to be enough to fit all that you want or even
half of that.

Summarizing, an FPGA based card can be a great audio I/O card, but
serious processing is better left to a DSP chip if it is really required,
since the trend in the industry to do all the processing on the host CPU
anyway...

The card I am doing is very similar to what you are planning, the main
difference being that it has Firewire instead of PCI and that I am
planning to use a Spartan-3 FPGA. I was going to have PCI as well but
then dropped this idea since making golden fingers increases PCB
manufacturing cost by quite a bit...


/Mikhail

mikem at opencores.org wrote:
If audio stream don't circulate throughout PCI-driver-OS we don't have
problem with long and _unpredictable_ interrupt latencies.


Correct, i don't try to say this. But FPGA will do faster some dsp
functions than specialised DSP processors. And yes, this
will be harder job for programmer... for audio applications we don't
need this


I don't think so. Some people hear differences, probably therefore
antialiasing brickwall filter at half of sample frequency have
smaller impact to phase characteristic in high frequencies. But I don't
hear any diference :)


This is not hard work for fpga, and 192kHz is one of the number of
sampling frequencies... will we disable it? If yes, why?


Yes, you are right, but we don't have usable software tools for DSP
chips freely available. This is main reason for choosing FPGA.


This is an list of possible applications, not all in FPGA in same time.
I think that fac2222m will be cheap as possible, without
drawbacks in audio quality


through PCI, interrupts, OS and drivers... ok, we have this in any shop :)


Great! We can cooperate :)


this is not big problem :)

mikem at opencores.org wrote:
Sorry, I forget to say you thanks for informations about FireWire PHY.

Best regards.

-boggy

Perhaps we should take it offline...



That's right, but this still has nothing to do with the FPGA vs. DSP
thing. Besides, if we are talking about latency during monitoring then
you don't need most of those DSP algorithms for this purpose.



Don't need what?


overkill

I don't think so. Some people hear differences, probably therefore
antialiasing brickwall filter at half of sample frequency have
smaller impact to phase characteristic in high frequencies. But I
don't hear any diference :)

Dear Mikhail, ----- Original Message ----- From: mikem at o...mikem at o...> To: Date: Thu May 13 04:38:43 CEST 2004 Subject: FireWire + Re: [oc] Audio DSP PCI Card for mobile studio > Perhaps we should take it offline... I do not want to quarrel with you in any way whether privately or on a discussion list. We are colleagues before all. We may differ in our opininons, that is our right and that's it. > > > If audio stream don't circulate throughout PCI-driver-OS we > don't > > have problem with long and _unpredictable_ interrupt > latencies. > That's right, but this still has nothing to do with the FPGA vs. > DSP > thing. Besides, if we are talking about latency during monitoring > then > you don't need most of those DSP algorithms for this purpose. Purpose of fac2222m open hardware card is developing such applications, research, learning VHDL/Verilog, learning DSP technology, etc. Audio is not only music, IMHO. This will be audible frequencies, but not only for human being. > > But FPGA will do faster some dsp > > functions than specialised DSP processors. And yes, this > > will be harder job for programmer... for audio applications we > > don't need this > Don't need what? FPGA will not be used in fac2222m audio card, because it will runs some dsp functions faster than DSP chip. > > >2. I don't want to start a flame here, but 200 kHz is a > stupid > > overkill > > >driven by marketing departments. 96 kHz has plenty of > margin. > > > > > I don't think so. Some people hear differences, probably > therefore > > antialiasing brickwall filter at half of sample frequency have > > smaller impact to phase characteristic in high frequencies. > But I > > don't hear any diference :) > This is a fact. If you don't beleive me try to find archives of the > pro > audio mailing list. This issue has been beaten to death there. > Those who > hear either think they hear or hear different effects. I don't think that "pro audio mailing lists" is great place to learn any thing about proffesional audio, even if you try to find answers for your questions about music appliance of professional audio. > > This is not hard work for fpga, and 192kHz is one of the > number of > > sampling frequencies... will we disable it? If yes, why? > Of course 192 kHz in itself is not a hard work, but processing at > this > rate is, especially processing of multiple channels. Basically, at > this > point I don't really care whether it will be enabled or disabled. I > am > simply saying that it doesn't make sense, especially for a free > product. Why? Is it some common principle to make free hardware projects minor than wery expensive closed hardware/software projects? I don't know that this principle exist. > Those market driven are looking for big numbers for their ads to > make > people buy new hardware and make it look like whatever they have is > obsolete. Some market driven things is against some other market driven things... Not only users will be enemy in this "war". 96kHz is standard recommanded sample rate for broadcast, and 192kHz isn't forbiden. > > Yes, you are right, but we don't have usable software tools > for DSP > > chips freely available. This is main reason for choosing FPGA. > I am afraid this is a bad reason. FPGAs are good for fixed > processing, > but not well suited for developing complex and flexible DSP > algorithms. Sorry, I don't think so. > In fact, you can get alternative tools for SHARCs quite cheaply... ...but _not_ free like free beer :) > > through PCI, interrupts, OS and drivers... ok, we have this in > any > > shop :) > Well, I am afraid to disappoint you, but an FPGA solution exists > too: > http://www.rme-audio.com/english/hammer/d9636.htm This is not only one FPGA based and non free audio card available on the market, but I don't thik that here, at opencores mailing list, is good practice to promote non free hardware, IMHO. > And I am not sure I understand how you are going to avoid OS, > drivers, > interrupts, etc.? fac2222m have MIDI I/O. > > > I was going to have PCI as well but > > >then dropped this idea since making golden fingers > increases > > PCB manufacturing cost by quite a bit... > > > > > this is not big problem :) > What do you mean? You don't need PCI anymore? Golden fingers is expensive and this is not big problem. Please do not forget that there are kinds of music besides commercial and that some other kinds of music require really precise handling of spectrum and phase. Best regards, -boggy > /Mikhail > >

Hello Boggy,


I do not want to quarrel with you in any way whether privately or
on a discussion list.

Dear colleague, I found some your remarks as thought provoking in positive terms. However, phase distortion, jitter, wander and some other effcts are important when considering audio field. It is our idea to make those phenome controllabel with FPGA design as it is proved by some designs that are already in use. Thus, we prefer FPGA. However, if someone wants to use DSPs that is fine too. Best wishes, Vedran Vucic ----- Original Message ----- From: mikem at o...mikem at o...> To: Date: Thu May 13 15:26:36 CEST 2004 Subject: FireWire + Re: [oc] Audio DSP PCI Card for mobile studio
or

That's not what I meant. I just wanted to say that this discussion
is
probably off-topic for the list.

great

answers for

And why is that? The list I am talking about has some top-notch
professionals on it, who designed some of the best pro audio
equipment
in the world, some of them I know personally.

projects

know

No, that's not the point. The point is that when you are not
worried
about profits you shouldn't be worried about satisfying every
market
driven reqirement either, especially when you know that the
requirement
has no other base besides achieving higher profits.

fixed

DSP

> Sorry, I don't think so.

Vedran,



What to use is of course your choice. However I have a feeling that you
don't fully understand what you are embarking on. I do perfectly
understand the importance of phase, jitter, etc. in the audio field, but
how does it relate to choosing FPGA vs. DSP? What do you mean when
you are saying "to make this phenomenas controllable with FPGA"? What
exactly has been proved by the exisiting designs that you are referring
to? You have to be more specific and technical...

Dear colleague, It is hard to be more technical in this way of cmmunication. It will tajke a lot of space and time. However, my approach is that waht is controllable is better. Best wishes, Vedran Vucic ----- Original Message ----- From: mikem at o...mikem at o...> To: Date: Fri May 14 16:11:55 CEST 2004 Subject: FireWire + Re: [oc] Audio DSP PCI Card for mobile studio
when

I am sorry but you either don't know what you are doing or you simply don't want to disclose details of your project, which is really strange since you published it on the opencores site. Unfortunately, we don't have a different way of communication. Yes, typing takes more time than talking, but it also gives you a chance to think more about what to say. Anyways, good luck in your project, whatever it is. /Mikhail ----- Original Message ----- From: vvucic at e...vvucic at e...> To: Date: Sat May 15 13:29:17 CEST 2004 Subject: FireWire + Re: [oc] Audio DSP PCI Card for mobile studio