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IDProjectCategoryView StatusLast Update
0002569ardourbugspublic2012-05-23 15:09
Reportersletz Assigned Topaul  
Status assignedResolutionopen 
Product Version3.0-beta1 
Target Version3.0 
Summary0002569: Transport management in JACK1 (latest SVN) and JACK2 (latest SVN)
DescriptionA bug report concerning Transport management in JACK2 here:

The thing is that when "time master" in on in Ardour, changing the position cause the timebase callback to be called with a new_pos = true. The timebase callback takes a jack_position_t *pos parameter containing the *new* pos (in the "frame" field) but for some reason Ardour timebase callback set it back to the *current* pos. Then JACK2 takes this pos in account and the final position *does not* change...

JACK1 seems not to take this changed pos value in account, and so the final position *does* change...

The documentation says here :

"The timebase master may not use its pos argument to set pos->frame. To change position, use jack_transport_reposition() or jack_transport_locate(). These functions are realtime-safe, the timebase_callback can call them directly."

This is not so clear for me, so who is right?

- JACK1 and Ardour (changing the pos in the timebase callback) are both right?

- or JACK1 and Ardour (changing the pos in the timebase callback) both have bugs that cancel each other?

- or Ardour has a bug (changing the pos in the timebase callback) but JACK2 is correct and the resulting behaviour is incorrect...

Thanks for any clarification!
TagsNo tags attached.


has duplicate 0002856 confirmed jackdmp (jack2) & Timemaster issue 



2010-08-31 14:44

administrator   ~0008968

i think its a bug in ardour. working a fix now.


2011-11-21 00:12

administrator   ~0012145

Did this get fixed?


2011-11-21 01:03

administrator   ~0012147

i did some work on it, but need to check it. will do so along with a general test of jack 1.9.6, which now appears "too old" to support 2.8.12 and 3.

Issue History

Date Modified Username Field Change
2009-02-24 17:24 sletz New Issue
2010-04-24 10:28 cth103 Category bugs => bugs2
2010-04-24 10:31 cth103 Category bugs2 => bugs
2010-06-07 18:21 paul Status new => assigned
2010-06-07 18:21 paul Assigned To => paul
2010-08-06 18:01 paul Relationship added has duplicate 0002856
2010-08-31 14:31 paul cost => 0.00
2010-08-31 14:31 paul Product Version 2.7.1 => 3.0-beta1
2010-08-31 14:44 paul Note Added: 0008968
2010-09-02 02:58 cth103 Target Version => 3.0-beta1
2011-11-15 17:27 cth103 Target Version 3.0-beta1 => 3.0-beta2
2011-11-21 00:12 cth103 Note Added: 0012145
2011-11-21 01:03 paul Note Added: 0012147
2012-01-10 20:46 cth103 Target Version 3.0-beta2 => 3.0-beta3
2012-02-14 17:20 paul Target Version 3.0-beta3 => 3.0 beta4
2012-05-23 15:09 cth103 Target Version 3.0 beta4 => 3.0