debugging strange usb audio behaviour.

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Hi,
I'm getting some strange behaviour between LinuxSampler, JACK and the
USB audio driver and I'm not quite sure where to look to narrow it down
further.

What *appears* to be happening is that when LinuxSampler is being output
to JACK and JACK is using a usb audio device (with or without an
intervening client) then there is a weird "arpeggiation" of the notes
being played which sounds like something is messing with the events in
the ALSA sequencer, the additional notes are the fifth and octave of the
original note it sounds like though I haven't tried it right across the
keyboard, ( this happens whether the MIDI input is from e.g. a USB
keyboard or aplaymidi.) Other clients (e.g. AlsaModularSynth ) in
exactly the same configuration play fine as well as does ardour and so
forth. LinuxSampler outputting to JACK when using the internal
(hda-intel) audio does not exhibit this behaviour. LinuxSampler
outputting directly to the usb-audio doesn't do it either.

Examining the sequencer input by hooking up both the MIDI input of
LinuxSampler and aseqdump to the MIDI pass-through port and pointing
aplaymidi at that doesn't show anything untoward which makes me doubt my
original theory, but what I would like to be able to do is peek inside
the sequencer and see all the events rather than just the ones on the
port I am listening on - is this infact at all possible?

Can anyone suggest a way to narrow this down and determine exactly where
the bug is?

I'll confess right now that I don't have the most up to date alsa
drivers (or JACK) which leads to an additional question or two as I'm
sure the first advice will be to get the 1.0.15rc1 ALSA drivers - I've
stuck with the 1.0.13 that came with the Mandriva 2007.0 because I'm on
X86-64 but would like to keep the 32bit alsa-libraries *as well* so I
can get sound from flash player (32bit only ) with nspluginwrapper (and
lets face it youtube is pretty crap without the sound :-), so my
question is if I was to update the drivers will the older libraries
still work (albeit with any bugs which might be there,) or can I also
upgrade the libraries (64bit) and expect the older 32bit ones to carry
on working? Secondary to this when I try to compile JACK it tries to
link against the 32bit libraries in /usr/lib rather than the proper ones
in /usr/lib64 - does anyone know a workaround or shall I just hack
something and report a bug against JACK?

Thanks

/J\
-- 
This signature kills fascists

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