bug: Trim / Nudge Deleting Plug-In Snapshot Auto Breakpoints

[jeremiahmoore]

[update: pics posted]
http://www.flickr.com/photos/jaiapeo...379718/detail/

This one's been been a serious problem for me since sometime last fall. I don't know when it first appeared, but it's very dangerous as it could cause unexpected automation values in plug-ins at points on the track you thought you weren't affecting.

Today I took a few hours to figure it out - here's what I found:

Steps to reproduce:
- create a new session, import some audio, put a region on a track
- add a plug-in (I'm using EQ3 7-band)
- auto-enable some parameters on the plug-in
- cmd-/ write head and tail breakpoints for track (ahead of and behind your audio region)
- change one of your automated parameters and write using cmd-/ or opt-cmd-/
- view the automation playlist for the parameter in question. It has a normal square-corner, immediately returning to the default value for the track.
- use the trim tool to extend the tail region to the right - even a small edit will do.
- view the automation playlist for the parameter in question again. Now it ramps all the way to the tail-breakpoint.

This poses a serious problem if you have material on that track between the region you're trimming and the next breakpoint, as it will be processed by an unintended and ramping set of parameters.

Happens 100% of the time here. PT HD 7.4cs3 on G5, mac os 10.4.8


What's Actually Happening:
A close examination reveals the that PT is writing breakpoints for plug-in automation ONE SAMPLE AFTER THE TAIL of the selected area, whereas volume automation is written one sample INSIDE the tail. Thusly, when you trim the region the trailing breakpoint is removed, which causes a ramp of all automated values until the next written breakpoint.


Workaround:
- after writing any snapshot automation, nudge the tailmost region of the area you just wrote to (not just a fade - that won't work) to the right then back to the left. This "captures" the post-tail breakpoint inside the region, where it should be.


It appears Digi needs to adjust the code for Automation "Write to..." for plug-ins so that it writes the breakpoints one sample earlier.


-jeremiah

[Frank Kruse]

It sounds like it´s related to this:

http://duc.digidesign.com/showflat.p...part=1#1269376

[jeremiahmoore]

Frank-

The cause may be related - but the effect I'm experiencing is different. It results in long unintended glides of all automated parameters, created inadvertently by extending a region tail to the right.

About to post some pics to illustrate.

-jeremiah

[Matt Chan]

hey i started a thread about this a few years ago. i believe i was using a waves q10 and had the problem and digi said they couldn't recreate it. annoying eh? i'll try and dig up the thread.

the workaround is to write automation beyond the clip boundaries.

[Matt Chan]

here it is

[jeremiahmoore]

Yep Matt - looks like the same bug.

On my system it's doing it with volume automation too - not just plug-ins. (though yesterday I thought I did NOT see it with volume... I certainly am today. Perhaps I can look into some more when I'm not in the thick of work)

And yes - writing automation beyond the region edge is a workaround, but only if you don't extend your region out past that automation point... if you do, you wipe it out and it's the same problem.

I've also notified Digi directly.

-j

[Matt Chan]

yeah please let us know if you get a positive response. it's something that several people on here mentioned that slipped through the cracks.

thanks,
matt