----- Original Message -----

From: James

To: csound@lists.bath.ac.uk

Sent: Thursday, August 27, 2009 11:15 PM

Subject: [Csnd] Csound and Jack in Linux

I'm having trouble getting real-time playback working with Csound 5.

My orchestra header is as follows:

sr = 48000
kr = 4800
ksmps = 10
nchnls = 2

The error I get at runtime is:
rtjack: period size (-b) must be an integer multiple of ksmps

If I change -b to a multiple of 10 it tells me -B is too small.
Eventually I adjust my arguments to csound -b 400 -B 1600, it runs but I get no audio. No errors in the qjack listener. It just says:
18:12:02.781 JACK connection graph change.
18:12:02.881 JACK connection change.

..presumably when the program starts and stops.


Any help would be appreciated,
James

----- Original Message -----

From: James

To: csound@lists.bath.ac.uk

Sent: Thursday, August 27, 2009 11:15 PM

Subject: [Csnd] Csound and Jack in Linux

I'm having trouble getting real-time playback working with Csound 5.

My orchestra header is as follows:

sr = 48000
kr = 4800
ksmps = 10
nchnls = 2

The error I get at runtime is:
rtjack: period size (-b) must be an integer multiple of ksmps

If I change -b to a multiple of 10 it tells me -B is too small.
Eventually I adjust my arguments to csound -b 400 -B 1600, it runs but I get no audio. No errors in the qjack listener. It just says:
18:12:02.781 JACK connection graph change.
18:12:02.881 JACK connection change.

..presumably when the program starts and stops.


Any help would be appreciated,
James

----- Original Message -----

From: James

To: csound@lists.bath.ac.uk

Sent: Saturday, August 29, 2009 5:15 PM

Subject: [Csnd] Re: Re: Csound and Jack in Linux

Thanks Victor. I had to increase the buffer size to 1024 to get Csound to run. Csound produces no errors but I get no audio. It seems to be a problem with jack itself because the same thing happens with jack.play. I posted to the jack-devel list but no one has got back to me. In the meantime if I just write -odac I can play audio in realtime.

As an incidental question, when I use these settings I have to omit kr becuase it gives me this error: "inconsistent sr, kr, ksmps"
-+rtaudio=jack -b 128 -B 1048 -iadc -odac
sr = 48000 , ksmps = 32 , nchnls = 2

What happens when I leave kr blank. Does it default to some value or does it calculate it based on sr and ksmps? What would I have to set kr to avoid the above error.

James

On Thu, Aug 27, 2009 at 6:32 PM, victor <Victor.Lazzarini@nuim.ie> wrote:

Also make sure you connect Csound to the output.

 

Victor

----- Original Message -----

From: James

To: csound@lists.bath.ac.uk

Sent: Thursday, August 27, 2009 11:15 PM

Subject: [Csnd] Csound and Jack in Linux

I'm having trouble getting real-time playback working with Csound 5.

My orchestra header is as follows:

sr = 48000
kr = 4800
ksmps = 10
nchnls = 2

The error I get at runtime is:
rtjack: period size (-b) must be an integer multiple of ksmps

If I change -b to a multiple of 10 it tells me -B is too small.
Eventually I adjust my arguments to csound -b 400 -B 1600, it runs but I get no audio. No errors in the qjack listener. It just says:
18:12:02.781 JACK connection graph change.
18:12:02.881 JACK connection change.

..presumably when the program starts and stops.


Any help would be appreciated,
James

kr doesn't have to be an integer. I never set it, because I always use
sr=44100 and almost always ksmps=16; sometimes I try other values, but
at any rate I don't much care what kr works out to.
I'm running jack with this command:
jackd -R -P 70 -dalsa -P -p128 -n3 -r44100
I'm not sure how the -p and -n of jackd do or don't relate to -b or -B
of Csound, but I also never set those when using Jack.

Incidentally, I've added this to /etc/security/limits.conf:
@audio - rtprio 100
@audio - nice -10
@audio - memlock 400000

The first line there, the rtprio one, allows me to run jackd with high
priority, which is the -P 70 argument to jackd. In case you didn't
know. If you don't need all that, you can leave out that argument.

-Chuckk

On Sat, Aug 29, 2009 at 7:15 PM, James wrote:
> Thanks Victor. I had to increase the buffer size to 1024 to get Csound to
> run. Csound produces no errors but I get no audio. It seems to be a problem
> with jack itself because the same thing happens with jack.play. I posted to
> the jack-devel list but no one has got back to me. In the meantime if I just
> write -odac I can play audio in realtime.
>
> As an incidental question, when I use these settings I have to omit kr
> becuase it gives me this error: "inconsistent sr, kr, ksmps"
> -+rtaudio=jack -b 128 -B 1048 -iadc -odac
> sr = 48000 , ksmps = 32 , nchnls = 2
>
> What happens when I leave kr blank. Does it default to some value or does it
> calculate it based on sr and ksmps? What would I have to set kr to avoid the
> above error.
>
> James
>
> On Thu, Aug 27, 2009 at 6:32 PM, victor  wrote:
>>
>> Also make sure you connect Csound to the output.
>>
>> Victor
>>
>> ----- Original Message -----
>> From: James
>> To: csound@lists.bath.ac.uk
>> Sent: Thursday, August 27, 2009 11:15 PM
>> Subject: [Csnd] Csound and Jack in Linux
>> I'm having trouble getting real-time playback working with Csound 5.
>>
>> My orchestra header is as follows:
>>
>> sr = 48000
>> kr = 4800
>> ksmps = 10
>> nchnls = 2
>>
>> The error I get at runtime is:
>> rtjack: period size (-b) must be an integer multiple of ksmps
>>
>> If I change -b to a multiple of 10 it tells me -B is too small.
>> Eventually I adjust my arguments to csound -b 400 -B 1600, it runs but I
>> get no audio. No errors in the qjack listener. It just says:
>> 18:12:02.781 JACK connection graph change.
>> 18:12:02.881 JACK connection change.
>>
>> ..presumably when the program starts and stops.
>>
>>
>> Any help would be appreciated,
>> James
>
>