[LAU] Audio and Midi Synchronization

[Rui Nuno Capela]

On Wed, 28 Oct 2009 01:57:09 -0700 (PDT), Oliver Jaun <olijaun at yahoo.com>
wrote:
> Hi
> 
> I'm trying to switch from Mac to Linux. I'm using
> UbuntuStudio. I'm happy with Ardour for audio recording and Hydrogen
> for Drums. I managed to synchronize Ardour and Hydrogen without any
> problems.
> 
> Now I have a drum beat with Hydrogen and a Bass
> recorded with Ardour and I would like to record a MIDI Track with
> Qtractor along with the drums and the bass. When I do that then MIDI is
> recorded, but when I play a note on beat 1 then and I look at it in the
> piano roll editor then this note is actually on beat 1.5 (more or
> less).

what do you mean exactly with "beat 1.5" ? is it a beat-and-half ? what
tempo (bpm)? how much is that half-beat delay in (mili)seconds? (a
screenshot would be worth a thousand words)

it might seem that your playing is just human and seldom matches the rigor
of the metronome ;)

if what you're after is quantization _while_ recording, please check
View/Options.../MIDI/Capture/Quantize global setting. 

however, i would recommend you do all quantization _after_ recording, via
Tools/Quantize... from the midi clip editor menu (aka piano-roll widget).


> When I listen to it then it seems to be in sync but of course this makes
> editing in Qtractor useless because everything is displayed delayed.
> The same happens with rosegraden so it doesn't seem to be a Qtractor
bug.
>

again, how much is the delay?

 
> I'm using a MidiSport 2x2 Midi-Interface but I don't think the delay
> comes from there because when connect my keyboard directly with e.g.
> LinuxSampler then I can play very nicely (short latency)
> 

what it seems might not be precise enough. maybe you can run and compare
to benchmarks with this gem:
  http://github.com/koppi/alsa-midi-latency-test


byee
-- 
rncbc aka Rui Nuno Capela
rncbc at rncbc.org