On Thu, 2014-09-04 at 22:05 +0100, Rui Nuno Capela wrote:
> On 09/04/2014 09:33 PM, Ralf Mardorf wrote:
> > -------- Forwarded Message --------From: Ralf Mardorf
> > <ralf.mardorf@rocketmail.com>
> > To: qtractor-devel@lists.sourceforge.net
> > Subject: Re: [Qtractor-devel] ; ) Was - Re: [LAU] Session management
> > with NSM
> > Date: Thu, 04 Sep 2014 22:31:15 +0200
> > Mailer: Evolution 3.12.5
> >
> > On Thu, 2014-09-04 at 21:27 +0100, Rui Nuno Capela wrote:
> >> On 09/04/2014 07:49 PM, Ralf Mardorf wrote:
> >>> Rui :)
> >>>
> >>> please consider to automatically add to
> >>>
> >>> File > Properties ... > Description
> >>>
> >>> the jackd "in" and "out" reported latency ;). Since the MIDI resolution
> >>> steps don't provide ms, frame information, a written note could help to
> >>> fix sync problems, without using a calculator.
> >>>
> >>> (I don't need it, perhaps you could add an option to the preferences, to
> >>> uncheck this feature ;)
> >>>
> >>
> >> jack_lsp -l does report latency of every port
> >>
> >> byee
> >
> > It doesn't report the latency a session was recoded 2 years ago.
> >
>
> and why would that be interesting?
>
> qtractor does its "recording/input latency compensation" of audio cľips
> *at the time* the audio material is captured, so that material gets
> aligned with the audio/MIDI content already in session and possibly
> being played back at the time of the recording. never again it gets
> adjusted no matter what jackd parameters change later, be that for worse
> or better. that's it.
>
> please understand that this is the only kind of latency compensation
> qtractor does and nothing else. nb. qtractor does NOT compensate for
> in-line output or plugin chain latency. never did and quite frankly it
> won't do so soon, i'm afraid.
>
> i really don't see how having distinct jackd i/o latency settings
> (buffer-size, periods, sample-rate) may lead to audio going out of sync
> to MIDI--if it does get out-of-sync anyway, it is probably because
> something else but latency compensation related, not to tell that
> session-management has nothing to do with either.
This year You record an audio track with an I+O latency of 10.7 ms.
Two year later you want to restore this session, but you don't remember
the jackd settings you used. Originally audio and MIDI tracks were in
sync, when you used 10.7 ms I+O latency. Within the years you got new
hardware, you don't remember what latency you once used and starts jackd
with a lower I+O latency. Nothing bad would happen for Ardour users, but
a Qtractor user would run into sync issues. Am I mistaken?
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
Received on Fri Sep 5 04:15:01 2014
This archive was generated by hypermail 2.1.8 : Fri Sep 05 2014 - 04:15:01 EEST