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Unstable automation which causes randomness...(bad behaviour..) Issue Tools
issueid=1769 12-19-2009 11:51 PM
Human being with feelings
Unstable automation which causes randomness...(bad behaviour..)
unstable automation...

steps:
1. load a simple synth (with a stable cut off...)
2. insert midi item and create a single note. make a selections around that note and toggle repeat on...
3. create cut off automation env like you see in the pic.
4. press play and have a listen...


[img]http://img40.**************/img40/7222/randomautomation.png[/img]
Issue Details
Issue Type Feature Request
Project Deprecated REAPER issue tracker
Category Editing behavior
Status Suggested
Priority 1 - Highest
Suggested Version 3.15
Implemented Version (none)
Users who would use this feature 8
Users who would not use this feature 1
Assigned Users (none)
Tags (none)

12-19-2009 11:57 PM
Human being with feelings
 
EDIT 1: It doesn't have to be exactly at the same line...very close points cause unstable automation.

I'm making a short video, upload in few minutes..
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12-20-2009 12:10 AM
Human being with feelings
 
my recorder (camtasia) fucked up...can't make a video right now.

please test it yourself.
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12-20-2009 07:09 AM
Administrator
 
I don't think there is anything wrong with Reaper's handling of automation in this situation. I don't hear anything unusual, using a synth that I know has a sweepable filter (Olga).

What synth are you using? If the synth filter isn't sweepable (that is, if the plugin does not internally smooth automation within a buffer block), then the output could sound unpredictable, with audio glitches (because the filter state changes instantly and the plugin doesn't smooth the transition).

Also, although MIDI is sample-accurate*, a basic limit of plugin automation (in any DAW**) is that the plugin can only receive automation messages once per buffer block. If what you are hearing is slight differences in timing between the note start and the filter automation change occurring, the only fix is to lower your audio buffer size.

* More or less, depending on the the tempo, sample rate, and MIDI resolution, but greater resolution than once per buffer block, in any case.

** VST3 is supposed to help by providing a way for hosts to give sample-accurate automation information to plugins, but there are not many plugins that support VST3.
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12-20-2009 07:52 AM
Human being with feelings
 
In FL I get extremely stable results with the automation clips.

check out the 2 sound examples (1 from reaper, 1 from fl...) + attached image to show the automation I did to cause that.

same automation, same preset, same bmp etc...


File attached to the thread: FL_Reaper_Sytrus_automation_.zip


Maybe it is something with my settings in reaper..
my audio buffering settings:

[IMG]http://img709.**************/img709/4436/bsettings.th.png[/IMG]
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12-20-2009 08:01 AM
Administrator
 
Can you attach a Reaper project showing the issue (with a freely demo-able synth)?

The only audio setting that would affect this is the audio system buffer block size.
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12-20-2009 08:08 AM
Human being with feelings
 
check your inbox.
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12-20-2009 08:10 AM
Human being with feelings
 
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12-20-2009 08:18 AM
Administrator
 
Actually no need to attach a project. The issue is automation resolution (audio block size) versus MIDI resolution.

I can think of a couple of reasons why FLS might have different behavior than Reaper in this case.

1. Possibly there is communication between that that synth (an FLS product) and FLS that allows sample-accurate automation, either outside of the VST spec or using VST3. You can test this by using a different synth.

2. Different behavior aligning audio blocks with loop lengths. You can test this by, instead of looping over the same note, copying the note and automation (so you have many notes and automation points all in a row) In that case is the sound still consistent in FLS?
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12-20-2009 08:24 AM
Human being with feelings
 
Quote:
Originally Posted by schwa
1. Possibly there is communication between that that synth (an FLS product) and FLS that allows sample-accurate automation, either outside of the VST spec or using VST3. You can test this by using a different synth.
same results with Zebra 2.5

Quote:
Originally Posted by schwa
2. Different behavior aligning audio blocks with loop lengths. You can test this by, instead of looping over the same note, copying the note and automation (so you have many notes and automation points all in a row) In that case is the sound still consistent in FLS?
this is what I did in the audio examples, I didn't loop 1 note...I copy the note and the automation 8 times and rendered "offline". (yes, still consistent in FL)
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12-20-2009 08:58 AM
Administrator
 
Possibly FLS is forcing plugin automation points to align with the boundaries of the buffer blocks sent to plugins, I don't really know. That's something we can look at doing.

In any case, I'm going to move this to feature requests. Reaper currently interprets the automation curve in a sample-accurate way and updates the plugin parameter once per buffer block, which is the designed behavior. Forcing plugin automation points to fall on the buffer block boundaries would mean that the automation curve is no longer interpreted in a sample-accurate way, which may be a better solution (certainly it would be in your example), or may have some downsides.
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12-20-2009 12:06 PM
Administrator
 
FL is using arbitrary sized audio blocks so that it can provide precise automation positioning. This is something that causes a world of pain for plug-in compatibility, and it is something that we can look at adding for REAPER as well. It might be a bit, though.
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12-20-2009 03:30 PM
Human being with feelings
 
I don't have much (if any) compatibility problems with plug-ins in FL when it comes to automation...very smooth results.

*I use lots of plug-ins
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05-16-2010 02:33 AM
Human being with feelings
 
sry to bump but this is really unprofessional the way it is right now...I can't work with automation properly because of this unstable behaviour, it totally twists the sound.

it is like having a graphic program that can't give stable results for pixel size...

[img]http://img295.**************/img295/9770/36435817.png[/img]
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06-08-2010 03:21 PM
Human being with feelings
 
Idea:
Enable extra high envelope accuracry per track/project.

like in sytrus
[img]http://img130.**************/img130/8121/accuracy.png[/img]


PS- there is also option to enable it only for render, so you could save some resources while working.
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