Re: [Qtractor-devel] Should it be true?

[Frank N. <bea...@we...>]

Hi Rui and others,
I wrote:

> > re. audio parts not being played back after copy&paste: is that new or
> > old as well?
> 
> Honestly, I can't say for sure. All my experiments with audio loops so far
> were pretty short due to the crashy behaviour so that I didn't ever try to
> check any further. However, I'd want to believe this is also a somehwat
> older problem.
> 
> I'll try to come up with some test material to (hopefully) reproduce this
> easily.

Ok, I have now put together a tiny test pattern which you might want to
try on your own; still, it's not directly reproducible, but requires some
effort (oh, and this is not about muted audio but rather about audio patterns
coming out of sync, but I think the problems might be related):

* wget http://www.linuxaudio.de/drumtest.tar.gz
* Unpack it in /tmp
* Open qtractor with it (audio ports might not get autoconnected on your
  system, so wire them as needed to hear them)
* Ignore the first 3 (MIDI) tracks, I just left them in for reference
* Play back the pattern, which is just 2 bars with the same content.
* As playback is playing and looping, press the "Mute" button on any of the
  3 audio tracks ("Kick Audio", "Snare Audio", "Hihat Audio") at will,
  wildly, for a while - preferably just before the playhead restarts from
  the beginning.

What I have observed is that after a while, the sample from the 2nd bar is
getting out of sync. Whenever the loop restarts, things are ok (during
the first bar), but as the playhead moves on to the second bar, it will reproduce the faulty behaviour. Stopping and restarting playback fixes this,
though. Something seems wrong here about playback pointers pointing to the
wrong position.

If interested, I can provide an audio example of that artifact, but I think
you should be able to reproduce this, too. It typically takes me less than
30 seconds to create the issue.

Greetings,
Frank

PS: Rui: I know that part of your answer will be "wildly pressing the Mute
button? qtractor is not designed to handle that.", but...please be merciful :)