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Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 8:57 pm
by superbatone

I have had the distressing, heart attack-inducing experience of opening a previously saved Audacity document only to find that it somehow has self-destructed, in the time between my saving it and opening it again. Huge gaps in the waveforms suddenly appear, and unless I've backed it up elsewhere (which I ususally do), THERE'S NO GETTING IT BACK!
I will illustrate. A document which formerly looked like this:
IIIiiiIiiiiIiiiIiiIIIIiiIiiIiiIi
with nice continuous waveforms,
Suddenly turns into this:
IIIi--IiiiiI----iiIII----ii-i
--with permanent loss of data! This occurs randomly, without warning. It has happened after I've successfully opened, edited, and saved the same document many times.
(I usually export the document to .aiff format, and then re-open it in Audacity.)
I am using the latest version of Audacity (1.3.12-beta) on my brand new iMac (iMac11,3). It's a beautiful program, except for this -- ! (Other than that, Mrs. Lincoln, how did you enjoy the play??)
So: HELP! Has anyone had this problem? How do you deal with it?
Re: Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 9:25 pm
by billw58
What is the setting in Preferences > Import/Export > When importing audio files? Is it "Read uncompressed audio files directly from the original (faster)"?
superbatone wrote:(I usually export the document to .aiff format, and then re-open it in Audacity.)
If you deleted that AIF that you imported, Audacity would lose the audio, except in the places where you have made edits.
See:
http://manual.audacityteam.org/man/Impo ... references
Change the preference to "Make a copy of uncompressed audio files before editing (safer)" and this should not happen again.
-- Bill
Re: Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 9:28 pm
by kozikowski
Audacity doesn't pull music inside itself for editing. Instead, Audacity goes out to each music file on your computer as it's needed and plays it. The music files never move.
If you do something to the music files -- like clean up, rename, or delete them, that's the end of your show.
You can get your show back by moving the music files back where they were.
If you have trouble remembering where everything was, you can open up the AUP file in a text editor and read it.
You can set Audacity so it does pull music inside itself for editing, but the program slows down if you do that.
Koz
Re: Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 10:56 pm
by steve
superbatone wrote:Has anyone had this problem? How do you deal with it?
See here:
http://manual.audacityteam.org/man/Audacity_Projects
Re: Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 11:08 pm
by superbatone
Hi Steve.
The manual isn't much help here.
My usual procedure is to keep an audio (.aiff) document intact in its own file, open it in Audacity for editing, then export it back to that file as audio (.aiff) again. I never delete music files, only revise them.
I will use this same procedure again and again without mishap; then I'll do it again, as usual, and suddenly get a shredded document! This seems completely random and unpredictable.
I've now taken to saving the Audacity file AS an Audacity file, bypassing the exporting until it's time to finally transfer to CD. Will that keep it intact?
Thanks for the help,
Superbatone
Re: Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 11:11 pm
by billw58
kozikowski wrote:
You can set Audacity so it does pull music inside itself for editing, but the program slows down if you do that.
In my tests on Mac, Audacity is actually faster when copying in files before editing.
http://wiki.audacityteam.org/wiki/Propo ... nd_copy-in
-- Bill
Re: Audacity Documents that SELF DESTRUCT!
Posted: Tue Feb 01, 2011 11:52 pm
by kozikowski
In my tests on Mac, Audacity is actually faster when copying in files before editing.
I did that to a two-hour show editing session once and trust me, it did
not speed up.
Sudden, unexplained computer insanity can be caused by your hard drive filling up. Go > Utilities > Disk Utilities > Select your system drive. Mine is Macintosh HD. At the bottom of the frame, it should tell you the size of the disk and the amount you have used. Edit systems need at least 10% free space to work right. Some people claim more. If you're tight on space, you
really need to fix that before you do anything else. Fuller than the 90% full point, the MacOS may start to act funny.
While you're in there, you can Verify Disk and Repair Permissions if everything else is OK.
Another, pretty serious thing that can cause show insanity is Audacity. Audacity 1.2 is not fully supported on modern Macs. You're fine until Something Happens and then there may be troubles until you upgrade.
The current version for all Macs is Audacity 1.3.12 from here...
http://audacityteam.org/download/
If you use lame to get MP3 or FFMpeg to get other formats, make sure and get both of them from the same place. they're not all the same and you can't use the older versions.
As a compulsive engineer, I'm horrified you overwrite files as you go, but I'm pleased you keep masters and originals isolated and safe. We have posters who insist on editing and overwriting
capture originals and that's just begging for trouble.
You can certainly Save an Audacity Project and that's fine as long as you understand what the rules are. It's not "A File." Audacity saves Projects which are collections of sometimes hundreds of files that make up your show. You can't easily move projects and they're brittle and easily damaged.
Audacity 1.3 will open Audacity 1.2 projects.
Koz
Re: Audacity Documents that SELF DESTRUCT!
Posted: Wed Feb 02, 2011 12:21 am
by steve
superbatone wrote:The manual isn't much help here.
My usual procedure is to keep an audio (.aiff) document intact in its own file, open it in Audacity for editing, then export it back to that file as audio (.aiff) again.
The manual is highly relevant if the file that you are overwriting is a "dependency".
As others have already said, Audacity does not necessarily copy the data from AIFF files when you import them as Audacity is able to read the data directly from the file.
Let's say that you import a file that has three sections: A, B and C
and you have Audacity set to read uncompressed files directly (faster).
Let's say that you now use a filter on section B - Audacity will read the data from the file, process it and write it to its "temp" file as lots of little ".AU" data fragments.
Let's say that you then delete section A. Audacity does not need to write any new data. Note that at this stage, section C has not been copied by Audacity and is being read directly from the original AIFF file.
You now "Export" the project and overwrite the original AIFF file.
Suddenly there is a problem.
The new version of the AIFF file has a modified version of section B in the place where section A used to be and section C is written over the place where section B used to be.
Then when you try and use the Audacity Project again, Audacity can read section B because that data was copied into the project, but when it tries to retrieve the data for section C, it looks at the end of the AIFF file and it's no longer there !
There's a longer article in the Audacity wiki that may explain the subject of file management more clearly:
http://wiki.audacityteam.org/wiki/File_Management_Tips
Re: Audacity Documents that SELF DESTRUCT!
Posted: Wed Feb 02, 2011 2:05 am
by kozikowski
The short version is stop overwriting your work as you go, or at least don't step directly on imported files.
Many editors like to Save a Project with a new name as they go. If it's important enough, I Export a new sound file periodically and save a Project. I never step on old work.
The powerful Hollywood Producer comes around the corner and says, "Can we hear the edit from about three versions ago?"
"Sure, when did we do that, about 3pm or so?" [Flipping through files] "Here it is."
Koz