[LAD] Transport issue for Qtractor - has impact to the jitter issue

Ralf Mardorf ralf.mardorf at alice-dsl.net
Thu Jul 15 08:57:01 UTC 2010


Hi Rui :)

no, a misunderstanding, at -Rch -dalsa -dhw:0 -r96000 -p512 -n2 there's
an issue internal Qtractor, no JACK transport.

There's a MIDI track with FluidSynth DSSI and there's an audio track
with a recording of FluidSynth DSSI, done by Qtractor audio out directly
connected to audio in.

The recording is several bars. If I start somewhere within the bars
Qtractor might play the MIDI track and audio track in sync. If I stop
and start playing again, somewhere else, the same tracks are played with
delay. The delay can be around 1/16 note (this is around 125 ms @ 120
BPM, not measured, I'm able to here what a 1/16 note is ;).

It's a kick played at each beat. Sometimes when playing the MIDI and
audio kick are played in unison and after stopping and starting again,
there can be delay of around 1/16 note or sometimes less, but 1/16 note.

The MIDI and audio track aren't synced all the time after pushing play.

Cheers!

Ralf




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