[Ardour-Dev] ardour3 + automation + fader-desk

[Robin Gareus]

On 09/23/2011 06:27 PM, Paul Davis wrote:
> On Fri, Sep 23, 2011 at 11:50 AM, Robin Gareus <robin at gareus.org> wrote:
> 
>> Does it make sense to file bug reports already? IIRC automation in A3
>> still has a major update coming up. So I may wait until after that.
> 
> indeed. we hope that ben will find some time (!) to port over the
> mostly-all-new automation data handling code from mixbus.
> 
>> Furthermore, sometimes a consecutive line of '-inf dB' gain points
>> results in NaN (on unsigned 16bit: 0) when exporting the soundtrack. I
>> have not tracked it down, but simply deleting all but the first and last
>> '-inf' gain points in row makes the clicks go away.. weird.
>>
>> Is that supposed to work already? If so I'll dig in the code.
> 
> it would be helpful but if you can't find a pointer to the problem
> very quickly i wouldn't put too much time into it.

It seems that re-editing some of the automation points caused this.

To reproduce:
 - create some fader automation (i used a BCF2000 with general midi)
 - Select a a couple of automation-points with the mouse in the editor
   timeline and then drag them down (decrease volume) so that some
   points will hit the bottom.

The GUI shows them as '-inf dB' aka 0.

Looking in the .session file they're actually negative values and
produce the "Ignoring illegal points on AutomationLine" warning message
when re-opening the session.
They're not ignored: those values are retained when saving the session
again.

These negative values also seem to be responsible for the clicks when
exporting the session; but that's just a guess..

Furthermore it is also possible to drag automation events to a
"fractional sample-number" as well as have duplicate values for the same
sample-number:

  - zoom in, drag some the automation points to left/right.


excerpt from the session file:
-----------
<events>
[...]
2122752 0.00590455858036876
2125824 0.00491013238206506
2128896 0.00402118265628815
2128990.3125 0.00402118265628815
2129084.625 0.00402118265628815
2129178.9375 0.00402118265628815
2131348.125 0.00402118265628815
2131442.4375 0.00402118265628815
2131536.75 0.00402118265628815
2131631.0625 0.00402118265628815
2131725.375 0.00402118265628815
2131819.6875 0.00402118265628815
2137135 0
2230272 -6.17613819914475e-06
2233344 -1.23522763982895e-05
2236416 -1.85284145974343e-05
2239488 -2.4704552796579e-05
2242560 -3.08806909957238e-05
[...]
</events>
-----------------