different starttime for host sequence and ticker bug!?

[Nubeat7]

i have a strange problem, i found out that the ruby ticker starts earlier to tick as the notesequences of cubase starts to play, to show this i built a small testschematic with a ticker which ticks from 0 to 3 in quaternotesteps and a note counter which counts note on events, all is done in ruby so all counts are shown accurate,

to test it export it as vst instrument load it in cubase and write a bar with 4 quater notes set the songposition to 0 and press play, note count and ticker should be in sync now but the ticker starts earlier (for about a 16th note here on my machine)!

the ticker is accurate and doesn't lose sync its just to early!

maybe soundcard latency?

does anyone have the same issue on other daw's?

[Nubeat7]

i also tried to delay the first tick with the soundcard latency, but its not that, this is really annoying because you cannot get accurate triggers on a beat like this or set some accurate delay after play has started in host...

i mean shouldn't the play primitive starts to play at the exactly same time as the host starts to play!?

would be great if anybody could confirm the issue or did i do something wrong in the schematic? if not i will report it as a bug.

[Exo]

I don't have Cubase, but I tested it in FL Studio and at first I thought it was in sync, but when I slowed the tempo right down I can see that your timer has a constant delay.

I will have a quick look at this now and report back if I discover anything.

[Exo]

Can you explain this code to me please?

Code: Select all

when 'state'
      if !@ticking && @state
          @ticking = true
          @count = -1          
          input 100,nil
      end
   when 100
      if @state
         @step = 0.001 if @step <= 0         
         input 100,nil,t+@step
      else
         @ticking = false
      end

I do not understand what this "100" is referring to and why.

[Nubeat7]

if state is set to on you set ticking to true and generate a trigger to input 100

so 'when 100' is the receiver of this trigger from above so to say 'when input 100'
then as long as state is active it keeps sending triggers to its own input 100

[Nubeat7]

the problem is that the first trigger when 'state' is set to true (host starts to play) it sends a trigger immediatly to input 100 and starts ticking in any given rate (every 4th note in my example) but the host starts to play later as the ticker starts ticking! in cubase you can see how it is counting with offset

[Exo]

I just tested again and it seems very much in sync. This is in FL Studio if you have that host to test.

I think the first time I tested I changed the tempo while playing and it messed the sync up.

[Nubeat7]

ok, also tested it in FL studio and Ableton live and also Renoise its fine over there but not in cubase...

[Nubeat7]

i tried to get the time difference between the ticks and the note on signals using the system time, it works in FS but not as exported vst, it seems that the system time isn't avaliable in vsts?

does anyone know another way to get the time difference between 2 ruby events?

[Exo]

Works in the VST here.

Often when it start is says 1 millisecond and then the next is often a lot shorter than the others, but the sync is definitely not stable there is often a few milliseconds difference, but some time the difference is quite a lot.

for instance at BPM 30 time in milliseconds averages 2010.000 milliseconds , occasionally it is 1900.000 milliseconds
and the first is usually 1899.000 or thereabouts. So not stable at all.