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Hi Robin :)
On Wed, 2010-07-14 at 15:44 +0200, Robin Gareus wrote:

quoted text
> On 07/14/2010 03:23 PM, Ralf Mardorf wrote:

> > [..]

> > AND IT'S AUDIBLE THAT THERE IS MUCH MORE JITTER BUT 1.1 ms.

> >

> > Any hints how to solve this are welcome.

>

> Did you try to start jackd with -p64 instead of -p1024

A good argument, because when I made tests in the past for the USB MIDI,

things become better at  >= -p256 (when I had this Windows test install

latency for the EWX 24/96 audio was less high than for Linux). The

problem here is, that I need at least -p512 and even than I'm not safe

regarding to issues for JACK audio, that's why I used -p1024 instead of

-p512. For a test -p64 should work, but when recording music I would

need to increase it step by step until a minimum of -p512.
IIRC when I did tests for the USB MIDI with -p64 or even -p125 (I'm not

sure) it theoretically did work, but this isn't a solution, because at

some point JACK audio will fail.
> using JACK-midi, I've encountered a similar issue with fluidsynth always

quoted text
> synchronizing note-start/ends to jack cycles.

>

> Simply lowering the frames-per-period got me playing again so I did not

> check if it's related to JACK-midi or FluidSynth 1.1.1 in general.

At least FluidSynth DSSI (host is Qtractor) is able to play in unison

with any DSSI or virtual ALSA MIDI and JACK MIDI (-Xseq) synth on my

machine. Just 'in unison' for virtual synth to hw synth there sometimes

is more delay, but just an early reflection like effect.
Note! It was hard to groove when I connected the master keyboard to ALSA

hw MIDI in --> DIRECTLY TO --> ALSA hw MIDI out and this to a 100% ok

drum module. Directly connecting the master keyboard to the drum module

there were no issues.
I need to do something else now, but I take time off. From Friday

(perhaps earlier) until next Sunday noon I could spend the whole days

for this MIDI issue only.
Resume:
I assume that -p64 would solve this 'looooooong early reflection like

effect/async', but then hard disk recording will become impossible.
The target is, that Linux at least replace the Atari ST as sequencer +

an analog 4-Track machine synced by SMPTE. With -p64 4-track recoding

would become impossible.
'Read you later' today or at the latest on Friday.
Cheers!
Ralf
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