[PlanetCCRMA] crackling sound on F7 - using Csound in realtime

[Hector Centeno]

Well, I found what the problem was. There was an option checked inside
the envy24control for resetting the sample rate and for some reason
with Csound causes a conflict. After unchecking that everything seems
fine.

Thanks!

Hector


On 6/13/07, Hector Centeno <hcengar@gmail.com> wrote:
> ok, now this is getting strange.. changing the PCI latency timer
> didn't really make a difference, as soon as I increase the buffers in
> Jack (i.e. something higher than 256x2 like for example 512x2 and also
> setting the -B -b flags in Csound accordingly) I start getting
> crackling on the right channel... but I found that if at the same
> time, while Csound is running in realtime (and crackling like crazy),
> I start another sound application that uses jack (like Ardour or
> Aqualung player) the crackling disappears immediately! If I quit that
> jack application without stopping Csound then the sound remains clean.
> If I restart Csound (without any other app. running) the crackling
> comes back, but if I restart Csound without closing the other jack
> app. then Csound is clean! It's like the presence of another jack app.
> at the same time makes Csound to enter in sync with jack properly...
> or something like that.
>
>
> Hector
>
> p.d. I'm forwarding this to the Csound list
>
> On 6/12/07, Fernando Lopez-Lezcano <nando@ccrma.stanford.edu> wrote:
> > On Tue, 2007-06-12 at 20:17 -0400, Hector Centeno wrote:
> > > I found this guide:
> > > http://www.ibm.com/developerworks/library/l-hw2.html#N10093 (Linux
> > > hardware stability guide, Part 2) and followed the advice about
> > > setting the latency. It seems to be working better now but still have
> > > to test a little bit more. I don't know if the settings discussed in
> > > that article are still valid for a modern system (well, the article is
> > > from 2001 but technology changes so fast...). So basically I set the
> > > latency of all devices to 176 and my sound card to the maximum (248),
> > > so it can send longer bursts of data without interruptions...
> >
> > Yes, that's correct (and that articles is still valid, I think I have a
> > link somewhere in the Planet CCRMA pages).
> >
> > > also I set the priority of Csound to 55.
> >
> > Hmmm, so you are using csound in realtime? Is it using Jack?
> > -- Fernando
> >
> >
> > > On 6/12/07, Fernando Lopez-Lezcano <nando@ccrma.stanford.edu> wrote:
> > > > On Tue, 2007-06-12 at 19:30 -0400, Hector Centeno wrote:
> > > > > Hi Fernando,
> > > > >
> > > > > Thank you for your advice. It says the Audiophile has a latency of 64
> > > > > which is what it's set at in the BIOS. Should I reduce this?
> > > >
> > > > The latency in this context is how many pci cycles can the card use
> > > > before it has to give up the bus.
> > > >
> > > > The point would be to see if there is another card that has that value
> > > > set very high and then can hog the pci bus itself and starve the
> > > > soundcard (64 sounds right for a default).
> > > >
> > > > -- Fernando
> > > >
> > > >
> > > > > On 6/12/07, Fernando Lopez-Lezcano <nando@ccrma.stanford.edu> wrote:
> > > > > > On Tue, 2007-06-12 at 16:56 -0400, Hector Centeno wrote:
> > > > > > > Hi,
> > > > > > >
> > > > > > > I'm having problems with my new motherboard (Asus P5B-VM with an Intel
> > > > > > > Core 2 Duo) and a M-Audio Audiphile PCI audio interface. My problem is
> > > > > > > mainly with Csound and getting crackling sound on one channel. If I
> > > > > > > set jack buffers to anything higher than 512x2 the crackling gets
> > > > > > > worse. I tried switching the card to the other PCI slot (it has only
> > > > > > > two) and the problem got even worse as I would get crackling audio
> > > > > > > always. I noticed that both PCI slots are sharing IRQ with other 3
> > > > > > > devices (usb, video card, libata). In the motherboards manual it says:
> > > > > > >
> > > > > > > 1.8.2 Configuring an expansion card
> > > > > > > After installing the expansion card, configure it by adjusting the
> > > > > > > software settings.
> > > > > > > 1. Turn on the system and change the necessary BIOS settings, if any. See
> > > > > > > Chapter 4 for information on BIOS setup.
> > > > > > > 2. Assign an IRQ to the card. Refer to the tables on the next page.
> > > > > > > 3. Install the software drivers for the expansion card.
> > > > > > >
> > > > > > > There is no more details about how to perform step 2, Chapter 4 only
> > > > > > > talks about reserving IRQ for ISA interfaces and in the bios there is
> > > > > > > no way to manually assign IRQs and it looks like it's something you
> > > > > > > are supposed to do va software, so I was wondering if anyone knows how
> > > > > > > to do IRQ assignment in Linux using the CCRMA kernel. With my older
> > > > > > > motherboard and FC6 it was possible to get the Audiophile to have it's
> > > > > > > own IRQ and I never had any problems with the audio (until the hard
> > > > > > > drive controllers in the mobo started to fail and had to replace it).
> > > > > >
> > > > > > I would check the pci latency settings just in case that's the problem.
> > > > > >
> > > > > > Do a "/sbin/lspci -v" and see what numbers you have for the latency
> > > > > > parameter for the cards installed (included the video card).
> > > > > >
> > > > > > -- Fernando
> >
> >
> >
>
>
> --
> ===============================
> http://www.hcenteno.net
>


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