SuperPAULA - if you have experinece in amiga music please give feedback

[biggun]

quote]
I totally agree with Piru, have a decent Paula emulation... and a nice modern audio chip with an AHI driver... Audio is a commodity now, technologically it's reached a plateau... you can't really do anything innovative (as is still possible to some degree in the GFX space). Great audio chips can be bought off the shelf for next to nothing.[/quote]

I know were you are coming from.
I think there is a very important point you are missing here. It might be my fault explaining it not good enough before.

The think is that:

-The Natami is fully Paula compatible already.
-The Natami can already switch to a new mode providing working 24bit Paula enhancements.
-And the Natami has working upsampling to 96kHz
-And the Natami has a very high quality DA converter.
The DA is of higher quality than the typical "next to nothing" sound card will have.

I fully agree with you that it makes no sense try to beat professional sound studio cards with the Natami.
If you need Studio feature the simplest solution is to buy such a card. And of course you can plug in any PCI soundcard into the Natami if you want.


But as the Natami sound device in on the board already
and as is able to produce good quality sound.
It makes good sense to think about how to get the most out of it without less effort.
Adding some extra features as panning, or 8 channels support
are only little firmware work for us now.
So if more channels is what people want, or if support for interleaved wave data is what would speed up AHI
then we can add this all "for free" now.


Please mind that adding an extra sound chip to the board is not a good idea. Putting another chip on the board would require that its DA-out gets mixed back with the Paula signal. This solution would consume a lot extra space on the board. As it would require extra wires from the FPG, we would not a more expensive FPGA to connect that extra chip.
And of course this would make the mainboard a lot more expensive as the board would need to be bigger. And this would require a new board layout.

The audio out of the Natami is quite good quality for a consumer device.
We have now the possibility to add some nice features to  the Natami audio for free.
We could as well add new features with a firmware update at a later time.

If you have input and sensible wishes now, fine
If not then this is okay for us too.


Cheers
Gunnar

[Krusher]

The thing I'd want is an AC3 multichannel output on eigther spdif or coax out so it can be hooked up to a modern Home theater system. Not shure about the rights for a Dolby Digital compatible stream though, although an open source project is available here.

[Hattig]

Well I ain't an audio expert, but I would mind seeing:

8 channels of sound.
Definable left/centre/right for each channel (or the four new channels). Preferably capable of a nice smooth pan.

Sure, a 68000 can software mix 8 channels of audio down into 4, but it's not doing much else at that time (which ain't too hot for a multitasking computer). Nice to have it all done in hardware, without having to end some notes early to play another one, etc.

Also it would be nice if the end spec was published, so, for example, MiniMig could implement that audio spec (on a hardware level at least, maybe the outputs wouldn't be the same quality) which would increase the market for that implementation, thus increasing the software that would support it.

[Karlos]

IMHO, as a musician, I'd like to see the following things per channel for an enhanced Paula:

1) 8/16-bit sample depth support
2) 8-bit volume register
3) 8-bit pan register (-127 full left, 127 full right)
4) Optional interpolation for playback of sample data below the hardware mixing frequency.

If you can do that per-channel, then I'd like to see at least 16 of them :-)

I use OctamedSS for pretty much all my composition, using it to drive MIDI kit as well as sample playback. Mix mode works well but these days I tend to render stuff to AIFF then do post-processing and mixing on the rendered output.

[biggun]

Also it would be nice if the end spec was published, so, for example, MiniMig could implement that audio spec (on a hardware level at least, maybe the outputs wouldn't be the same quality) which would increase the market for that implementation, thus increasing the software that would support it.

This is an excellent point!
Thanks for bringing this up.

I'm a big fan of open specification and fully agree with you that this is an important part.

You are absolutely right, that if the new Amigas will
share a common Paula audio enhancement this would be a good thing.
If the new Generation of Protracker Mods will play both on  MiniMig and Natami this would be really cool.

It think it will be real nice if we as Amiga community will manage to come up with a good spec for New Paula all together.

Cheers

[riftcon]

So I've had a look at the various AHI documents, the device interface in particular and some device source code.

As I suspected the AHI mixing routines output interleaved stereo sound in signed 16 (or 32) bit. So if the audio device doesn't support interleaved samples, the CPU will have to do some work. The Paula driver splits the stream itself.

Eight or more channels is supported (as is panning), but the mixing routines will obviously have to come into play if a program needs more.

EDIT: Having said that - if you're already spending time resampling and mixing, splitting the buffers is not going to add anything significant to the total...

While looking through the docs and the code, I thought of another addition to the wishlist. You've probably already thought of this, but the period registers need better precision, they're already a bit inadequate for the higher octaves - some higher notes are a bit off. When the samplerates go up, they will be next to useless for realtime playback as found in trackers.

[NorthWay]

I'm not the music guy you want, so you might want to ignore my ramblings:

8-bit volume on both left and right for each DMA channel. (You can do positional yourself with that.)
A small DSP for mixing. With DMA feed?
Instant DMA start as someone else said.

Oh, and I hope you have blitterlists (like copperlists) for the new blitter.

[ChrisH]

I'm not a music guy either, but it seems to me you should Keep It Simple Stupid (KISS) :  Don't bother with fancy panning modes, when you can achieve the same with two audio channels.  Better to just have as many h/w channels as you can easily accomodate (8 at least, 16 would be cool, but 32 might be overkill), and then let the CPU handle any complex effects.

IMHO the "Amiga way" was to have flexible/semi-programmable hardware, rather than to hard-code specific effects into the hardware.  So any semi-general functionality which would allow you to reduce the CPU load (say some clever DMA modes) for certain effects would be great (and maybe programmers can find ways to use such functionality in ways not imagined).

[amigaksi]

>>    If mixing is not noticable in today computers, it sure >>will be with a slow 060

>What you say is non true at all!
>
>Even with a stock 68000 you can mix 8 channels.
>For a 68060 mixing 8 extra channels takes no time

Better to keep as much in hardware as possible.  Even in the B&W Mac days, they thought the 68000 was so powerful that they put so much in software that nowadays that Mac is pretty much obsolete since all that software functionality can be done better on a PC.  If something time-critical was being done and music/samples were playing in the back-ground, at least the hardware can be exactly measured rather than relying on a software module to mix tracks.  

Also, today's PCs also seem to have a mixer of analog signals as well since the CDROM-audio can be mixed with the wave audio at various volume levels.  I'm not a musician but I sample lots of stuff from cassettes into compressed digitized audio and I find that some parts of the music is very low in volume and has to be normalized by hand.  I don't know if there's a music term for that but a dynamic normalization mode could help there (perhaps playing lower bits as if they were higher bits in a 24-bit/8-bit mode).

[Piru]

nowadays that Mac is pretty much obsolete since all that software functionality can be done better on a PC.

Macs use exact the same common audio components as PCs.

Also, today's PCs also seem to have a mixer of analog signals as well since the CDROM-audio can be mixed with the wave audio at various volume levels.

I don't know which decade you're living on, cd-rom audio hasn't been analog for years (the analog audio cable isn't even connected).

[bloodline]

Piru wrote:

nowadays that Mac is pretty much obsolete since all that software functionality can be done better on a PC.

Macs use exact the same common audio components as PCs.

I think he's taking about the old Macs (of the 80s)

Also, today's PCs also seem to have a mixer of analog signals as well since the CDROM-audio can be mixed with the wave audio at various volume levels.

I don't know which decade you're living on, cd-rom audio hasn't been analog for years (the analog audio cable isn't even connected).

Very true! I think the last time I connected a CD ROM audio cable was 1999...

[amigaksi]

Yes, the Macs before they switched identities and still used the same name.

>>
>>        Also, today's PCs also seem to have a mixer of >>analog signals as well since the CDROM-audio can be mixed >>with the wave audio at various volume levels.


>    I don't know which decade you're living on, cd-rom audio >hasn't been analog for years (the analog audio cable isn't >even connected).

>Very true! I think the last time I connected a CD ROM audio >cable was 1999...

On my PC the audio cable is connected to the motherboard (it's a 1Ghz Dell running Windows 3.11).   It saves on the bandwidth to have it mix the analog audio rather than run it through some Media Player that reads the digital data off the CD and plays it like a WAVE which prevents using applications at the same time that use the WAVE output.  The old Thinkpads had some sort of module that let you play multiple wave files simultaneously-- may be it was their MWAVE DSP that did that.  

Anyway, I guess any analog mixing would be external to the Paula chip if this is going to be a plug-in replacement or backward compatible on the hardware level.

[Piru]

it's a 1Ghz Dell running Windows 3.11

Ouch. This is not "today's PC".

Regardless, even 1GHz system (running proper OS) can mix at least 128 simultanous audio sources together without any trouble. You're most certainly not limited to a single wave.

[FrenchShark]

Hello Biggun,

I am also working on a AAA FPGA Amiga but my pace is a lot slower (because of work, family, ...).

Anyway, I thought about the same compatibility issues in my design. Here is what I came up with :
- 16 16-bit channels.
- 2 volume control registers (one for left, one for right).
- Better precision for the period register. I guess your SuperPaula clock will be 28 MHz at least. Even at 28 MHz, you need to have a "fractional" part for the period register so you can generate 32 kHz, 44.1 kHz or 48 kHz sampling rate.
- The 4 standard Paula channels are mapped on channels 10 - 13 (because of the address decoding :-D )
- Have one or two DSPs that can access the chip registers and the chip RAM (or the DMA FIFOs ?) and have their own instruction memory (32KB or 64KB per DSP).

Regards,

Frederic

[AeroMan]

I just would like to know Natami's complete specs. Do you have this in a document, or do you intend to let this public?

I believe many people here would like to help you in this project someway. I'm the first one to raise my hand :-)

[persia]

And thus you have it, you can't possibly beat today's PC or Mac but you can come close to a 1999 PC without destroying compatibility.  Given that this is retro-computing some might complain that that's not retro enough!