[jsyn] FW: jsyn and jack or soundflower

[jsyn at music.columbia.edu]

Oh,

Supposedly, in Java 1.7, the gc is revamped. I somehow got it to compile on
my mac, but have yet get it to run an app. (though it can tell itself what
it is wish java -version).

Anyway, just seems (by reading various threads) like these troubles will get
better with improvements to the jvm.

Best,

Mike


------ Forwarded Message
From: Michael Winter <mwinter at unboundedpress.org>
Date: Thu, 28 Jan 2010 00:20:35 -0800
To: "jsyn at music.columbia.edu" <jsyn at music.columbia.edu>, Larry Polansky
<Larry.Polansky at Dartmouth.EDU>
Subject: Re: [jsyn] jsyn and jack or soundflower

Hi Phil,

So I tweaked around a bunch and am not sure if I have improved anything. I
have implemented some jvm arguments from some online streaming media product
and jacked the max heap size way up:

-Xmx8192M  -Djava.net.preferIPv4Stack=true -XX:+UseConcMarkSweepGC
-XX:+CMSIncrementalMode -XX:NewSize=1024m -verbose:gc

I also tried setting the min and max heap size to the same value to better
control gc, but just cant tell if I am getting better results. As a I am
debugging the garbage collector, it seems that many of the clicks are not
always from the the gc (though when the gc goes into action, it definitely
interrupts everything).

I might be hallucinating, but increasing the number of frames to the
PolynomialTableData object seemed to help. That and increasing the durations
as to limit the number of grains. Finally, I also increased the latency;
seems like between 200 and 400 ms is a good middle ground for my purposes.

I am on snow leopard so will have to take what I can get. I am attaching
Larry to the email so he knows what we are up against. Also, I need to find
a multichannel sound card to test whether this whole interapplication web
with jackosx that I want to implement will work.

Best,

Mike


On 1/27/10 11:02 AM, "jsyn at music.columbia.edu" <jsyn at music.columbia.edu>
wrote:

> Hi Mike,
> 
> 
>> I actually got jackosx to work.
> 
> That's good to know. Thanks.
> 
> 
>> By the way, I am actually hacking the code for freeHorn
> 
> Did you get that from Larry?
> 
>> The only problem now is that I am getting what
>> sounds like some dropped samples with the pure java jsyn
>> (regardless of the jackosx implementation). Any thoughts on that?
> 
> I have also heard these tiny clicks. Try increasing the suggested
> latency in JSyn.
> 
> Also we can try tuning the JVM:
> 
> http://docs.sun.com/source/817-2180-10/pt_chap5.html
> 
> Try tweaking the garbage collector. Also try increasing the heap space
> for Java by passing -Xms512m or -Xms1024m. You can pass these as JVM
> arguments using Eclipse or on the command line.
> 
> Please let us know any results you find.
> 
> Phil
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------ End of Forwarded Message