[PD] PD 0.33 test 6 works with alsa 0.9B3 but not 0.9B4

Karl MacMillan karlmac at peabody.jhu.edu
Tue Jun 12 16:34:34 CEST 2001

On Mon, 11 Jun 2001, Winfried Ritsch wrote:

> Hello,
>  >
>  > I've just been entertaining myself with trying to get Pd to run with Alsa
>  > 0.9Beta 4.  I had to upgrade to RedHat 7.1 because 0.9Beta4 seems not to work
>  > with 2.2 kernels.  And now I find that Pd 0.33test6 (the latest) doesn't work
>  > at all with Alsa except in OSS emulation.  OSS emulation seems to work OK
>  > at least.
>  >
>  > If any of you have tried test versions of Pd 0.33 with Alsa 0.9B4 and founf
>  > out how to get it to work I'd sure like to know how you do it.  In the
>  > meantime I'll continue trying to find out what my problems are.
>  >
> If got PD to work with ALSA 0.9Beta4 and 2.4.5 (but not 2.4.4 some
> socket open troubles)  and the snd-card-rme96 (RME96/8 PST) Soundcard
> and MIDI with PCI128 (snd-card-ens1370) and snd-seq-oss. But I failed
> with rme9652, since all the anounced features (which are actually
> drawbacks in performance) like dev "plug:x,x", "share:x,x" or
> "multi:x,x" I cant get to work, even hacking on pd code (doing my own
> testing programm).

I have had similar problems and haven't had time to really look into
things in depth.

> I got it to work with the onboard CMIPCI-Card, but using MIDI of this
> Card frezzes the computer, so I think some of the drivers have MIDI
> broken and I worked a little better (only MIDI-out) if I turn the
> APIC (and IO-APIC)-feature in kernel Config on (not SMP).
> Also the philosophy in ALSA is that using "mmap -interface" feature
> turns out that you have to use a mmap-pointer update routine which in
> facts makes a copy of sounddata to the real mmap-memory, which in fact
> undermines the idea of mmap and doing the data-conversion (flot to
> int32) ourselves. So there I see no point to use mmap in ALSA, since it
> does the same: coping sound-data to the device ;-(. So I think best is
> using Guenthers driver for Hammerfall (which also provides an stereo
> device for eg. snd Soundeditor and so on).

My understanding is that the mmap-pointer update routine only does a copy
when the card can't do mmap for some reason (that is, it fakes mmap).  The
'advertisement' for alsa mmap is that it is real mmap.  If you are certain
about this, then it yet another reason alsa is a bigger pain in the butt
than it is worth.  I think I am going to try Guenter's driver . . .


> mfg winfried

| Karl W. MacMillan                                 |
| Computer Music Department                         |
| Peabody Institute of the Johns Hopkins University |
| karlmac at peabody.jhu.edu                           |
| mambo.peabody.jhu.edu/~karlmac                    |

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