Re: MIDI Output Buffer Size and MIDI Output Delay preference (Re: [Jsynthlib-devel] Signal Errors on Mac OSX)

[Jeff W. <jww...@ya...>]

--- Joe Emenaker <jo...@em...> wrote:
> Jeff, how were you testing for errors? We you using
> the loopback test, 
> or something else? If the loopback test can catch
> these signaling 
> errors, then it could be integrated into an
> "auto-tuning" wizard which 
> would keep increasing the buffer sizes and delay
> times until the 
> loopback test succeeds.

I didn't try the loopback test because I'm lazy and
didn't want to reroute cables. I just noticed the
frequency of signal errors increased dramatically when
I started sending FCB1010 patches a couple weeks ago.
Since that device has a 6010 byte patch, it led me to
suspect there might be a correlation between the size
of the patch and the frequency of signal errors.
That's when I tweaked the buffer size and added the
timeout on my local copy of MidiUtil.java.

Since then, I've been running with a 256 byte buffer
and a 100 msec timeout and while it hasn't eliminated
the signal errors entirely, it has dramatically cut
down on the frequency. I just downloaded the most
recent change (with the buffer and timeout settings in
the preferences) and I'm going to try a 128 bytes/100
msec for a while and see how that goes.

Using the loopback test for detecting signal errors
might be worth a try. But I think you would probably
want to have it send a longer message. Right now it
only sends 11 bytes. Even sending multiple short
messages might skew the results because woudn't be
much different than setting the buffer size to 11
bytes and sending a long message.



	
		
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