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IDProjectCategoryView StatusLast Update
0009230ardourbugspublic2023-02-19 22:53
Reporterlorenzosu Assigned Tox42  
PrioritynormalSeverityminorReproducibilityalways
Status resolvedResolutionfixed 
PlatformGNUOSLinuxOS Version(any)
Product Version7.2 
Summary0009230: MIDI Import intrprets midi pitch-bend rest position incorrectly as automation lines
DescriptionImporting a MIDI files Ardour always tries to 'interpolate' (i.e. create a line) between different pitch bend values, including if the value is 8191.

8191 should be considered the 'rest' or 'central' position of a pitch bend (wheel) and therefore a netural value not to be automated towards the next value unless explicitly requested. Some software expose to the user values of -8191 to +8191 and 0 (zero) as the central position which is more similar to how the actual pitch bend wheel works on many keyboards.
The problem is that typically sequencers interpret this value as a rest position and therefore won't automate to the next value, unless a series of controllers is explicitly required.

Overall this poses the more general issue of how to interpret 'automation' in midi, especially when importing and when control or pitch-bend changes are written in the MIDI file and some have a certain interpretation (e.g. CC 64 pedal, or other on/off controllers don't really make sense to be automated continuously).

Attached is a simple 1-track midi file which shows the problem.
Also attached screenshots of how Ardour imports it and how it is interpreted and used in other two MIDI sequencer software

Steps To Reproduce- Import a MIDI file with pitch bends which include explicit values of 8191 (like the attached)
- Ardour interprets as automation lines changes from the last 8191 to the next different value
TagsMidi, midi import, pitch bend

Activities

lorenzosu

2023-02-08 15:27

reporter  

qtractor_pitch_bend.png (15,064 bytes)   
qtractor_pitch_bend.png (15,064 bytes)   
rosegarden_pitch_bend.png (9,119 bytes)   
rosegarden_pitch_bend.png (9,119 bytes)   

x42

2023-02-08 15:35

administrator   ~0027327

Is this still the case? I believe this was already fixed in 7.2-7-g75c9927d75

lorenzosu

2023-02-19 20:04

reporter   ~0027397

I can confirm that with a freshly built version (rev 7.3-22-gcf0b119b45) this now works as expected and is indeed fixed. Thanks!

Issue History

Date Modified Username Field Change
2023-02-08 15:27 lorenzosu New Issue
2023-02-08 15:27 lorenzosu File Added: bend_test.mid
2023-02-08 15:27 lorenzosu File Added: ardour_pitch_bend_automation.png
2023-02-08 15:27 lorenzosu File Added: qtractor_pitch_bend.png
2023-02-08 15:27 lorenzosu File Added: rosegarden_pitch_bend.png
2023-02-08 15:27 lorenzosu Tag Attached: Midi
2023-02-08 15:27 lorenzosu Tag Attached: pitch bend
2023-02-08 15:27 lorenzosu Tag Attached: midi import
2023-02-08 15:35 x42 Note Added: 0027327
2023-02-19 20:04 lorenzosu Note Added: 0027397
2023-02-19 22:53 x42 Assigned To => x42
2023-02-19 22:53 x42 Status new => resolved
2023-02-19 22:53 x42 Resolution open => fixed