14hour recording crashed before saving...


This is my first post in over 3 years. I use Audacity 1.3.6 to record continuous performances that last more than 14-hours. On Saturday May 26th, 2012 I used Audacity to record one of these extreme temporal performance at the Santa Cruz Museum of Modern Art and History MAH. Audacity was a champ; my 2.5 GHz Intel Core Duo w/ 4 GB 667 MHz DDR2 SDRAM computer was able to handle my 8-channel 24/44.1 Audacity Project and SuperCollider patch that employed granular synthesis… Amazing!

But, at exactly 14 hours, Audacity crashed and I am embarrassed to say that I had not saved the project since first creating it!!! I know I know…

Ok, because the performance was not yet finished, I panicked… I first checked my external HD that had over 50 gigs used since the project began, which made me happy! I then reopened Audacity and I did not take a screen shot of the message but it had to do with recovering the project I probably hit “ok”. The first 4 channels appeared while channels 5-8 where blank and the project was slow to zoom out so that I could confirm all 14 hours of the 4 visible channels were present. I decided to save the project as it was and start a new project to record the remaining hour or so of the concert.

After saving the crashed project, the amount of space taken up in my HD was significantly lower around 18GB which does not add up to the amount required for 8 mono 24/44.1 14-hour files.

Now when I try and open the crashed project, it begins to inspect project the file and 3 seconds in, Audacity stops responding and I can only Force Quit.

The project does have a DATA Folder that is 18.38 Gigs. How can I recover the available data?

The last attempt involved downloading Audacity 2.0 and I get a few new messages

I am attaching 4 images

Looking forward and thank you for your patience!
ZachalyAudacityCrashPics.zip (591 KB)

I believe your chances of recovery go way up if you use Audacity 2.0 for both recording and recovery. Great Strides have been made on the recovery front and there have been some very strong discussions about what Audacity should do under emergency conditions. Keeping in mind, of course, that emergency conditions can vary widely between the computer platforms.



my 2.5 GHz Intel Core Duo w/ 4 GB 667 MHz DDR2 SDRAM computer

And which computer is this exactly? I’m typing on a Mac Mini.

Just curious, after you successfully complete your enormous capture session and you press stop, then what? You’re very near the limit of file sizes for many major file formats – if not over. Another point, why did it crash? There are some very practical limits to the length of an Audacity show. Audacity is not an open-ended surveillance recorder.

How did you get eight channels of sound in and visible/Audacity-aware? This is a very common problem in Audacity Land. Koz

Here is my take. Given you see the “Faulty Sequence Tags” error in 2.0.0 and you are not now using “Automatic Crash Recovery” but are trying to open a probably faulty project, you could end up making more of the data inaccessible if you use 2.0.0.

It probably would have crashed even if you had saved a project. 1.3.6 is an obsolete Beta version and more than 13.5 hours at 44100 Hz is in excess of 2^31 samples (the 32-bit storage limit).

As I pointed out on feedback@, even Audacity 2.0.0 cannot yet save projects from more than 13.5 hours of audio at 44100 Hz. The best you could do, even if the recording had completed, would be to export WAV files from the recording up to 2 GB in size (to ensure compatibility with all players). If you had wanted to save a project, you would have to cut and paste the audio to new project windows until you had no more than 13.5 hours on the Timeline in each project before you saved any projects.

Crash recovery in 1.3.6 was notably inferior to that in 2.0.0. But if you save the project and close it with empty tracks, that is how it will be saved and data relating to tracks that “should” have data will be deleted.

The best thing to do if the project recovers incorrectly is usually to force quit Audacity. This preserves the autosave (temporary project) file which may or may not help, but more importantly it also preserves the full data.

Note that saving a project with some data is better than quitting Audacity after recovery and saying “No” to the “Save Changes?” question. That would delete the autosave file and all the recorded data, leaving you with nothing.

From where you are now it sounds as if the project could be corrupted, but are you waiting long enough?

What happened when in 2.0.0 you clicked OK on the “Faulty Sequence Tags” dialogue? I would have expected Audacity to “orphan” the data concerned. This will not delete it, but make it inaccessible to the project. It could “fix” the project in the sense of making it usable, but you could lose access to even more of the data. I would have expected the log to list the small .au block files it was intending to “orphan”. Since it doesn’t do so, I would be suspicious. If you haven’t yet force quit 2.0.0, I would choose “Close project immediately” which will mean no further changes will be made to the data.

If 2.0.0 doesn’t list any files that it is going to orphan (or lists hundreds of them) then 1.3.6 may have the best chance of opening at least the four tracks it initially recovered. If 1.3.6 still hangs despite waiting at least 20 minutes, then you could attach the .aup file, but there is only a slim chance we could see something we could correct.

The only other choice is to sort the .au files in the _data folders into timestamp order, rename them while so sorted into a consistent alphanumeric sequence, then use the 1.2 Recovery Utility to make WAV files. You will need to make folders containing the .au files that are no more than 1 GB in size and recover each folder separately.

Even then, you will expect that some .au files will be in the wrong tracks because their timestamps will be identical and the renaming won’t be able to distinguish them. It may not be worth the effort, but if you want to try, please see Missing features - Audacity Support .


Thank you Koz and Gale for your valuable insight.

I am using a MacBook Pro and my sound card is a MOTU Traveler.

This is the 3rd time I have used Audacity to record long performances using 1.3.6 and in the past I was able to save a 13 1/2 to 14 hour continuous project recording at 24/44.1. Of course, in order to bounce the mono tracks to .wav files, I have to save each mono file in 2 GB increments and import them into another DAW line them up in time, mix and then bounce the newly created stereo mixes. As you can imagine, this process takes forever!!! But I have been successful on 2 occasions!
The aforementioned recordings are available as streaming MP3s on pennsound (http://writing.upenn.edu/pennsound/x/Ratcliffe.php)

  1. human/nature, recorded at UC Davis, June 6, 2008
  2. Remarks on Color / Sound, Marin Headlands Center for the Arts, May 16, 2010

Ok, I will try and wait 20 minutes or more in version 1.3.6 before force quitting.

I will let you know what happens.
Thank you

That might be safer than doing it in Audacity 1.3.6, but I would hope 2.0.0 could cope with mixing to MP3 as long as you don’t try and save an Audacity project. You wouldn’t see a very rapid response though with tracks of that length.


I waited almost an hour while audacity employed the psychedelic beach ball to no avail.

I am attaching the project .aup file in this response.

I appreciate all of your help
Temporality_05-26-12.aup.zip (525 KB)

It appears you have hit the 2^31 samples limit with that project. Each track has numsamples=“2147483648” which is exactly 2^31.

A 14-hour recording would have 2222640000 samples per track - too much.
A 13.5 hour recording would have 2143260000 samples per track - OK

You hit the 2^31 limit at 13 hours, 31 minutes 36 seconds.

You might be able to do major surgery on the AUP file and get it to open. It appears to contain 7 mono tracks, the last 5 or which are empty.

– Bill

Thank you Bill!

I would love to salvage any remaining material. When I immediately reopened this project after it crashed on Saturday, I was able to view 4 of the 8 tracks and I then chose to save the project. As “we” know, I have not been able to successfully open the project since saving it.

I appreciate everyone’s help knowing that this issue is outside of this forums purview since it is not a “bug” per se.

I am not a programmer and do not have experience with fixing .aup files. I humbly ask for any suggestions/leads/contacts etc…

Thank you,

What Bill may be suggesting is breaking the project down into chunks. Try opening “Temporality_05-26-12-track-1-only.aup” or “Temporality_05-26-12-track-1-first-half-only.aup” in the attached, which are the first track or the first half only of the first track.

Try the complete first track to begin with. If it opens, export it as WAV files (maximum 2 GB each). If not, try the half track. It is OK to have the .aup file named differently to the project_data folder (Temporality_05-26-12_data) as long as you don’t save the project. If you prefer, you can make a copy of the .aup and rename the copy to Temporality_05-26-12.aup for each attempt.

If 1.3.6 lists project errors, you will get many errors about “orphan block files” when opening these .aup files. The orphans are the remainder of the audio data that is not now referred to in the much shorter .aup file. You can ignore those errors.

I don’t see any obvious reason in the original project file why it should not open, unless 1.3.6 cannot cope with the tracks at the maximum storage limit.

If 1.3.6 does not open the shorter projects then you could try 2.0.0 again. I do not see any block files in the original project that are longer than they should be, which would cause the “Faulty Sequence Tags” error in 2.0.0. I suggest you click OK when you get the Sequence Tags error then look in the log to see the changes it has made. Post the log here then choose “Close project immediately” in the dialog that you see. This way, none of the changes you see in the log will be carried out.

Temporality-track-1.zip (207 KB)

By the way I forgot to adjust the “h” value (the starting position of the waveform) in the half-track project. With it set at 433 seconds (12 hours or so) it will now be after the end of the audio. I suggest opening the .aup file in TextEdit then changing the “h” value near the top to:


to make the waveform start at the start of the track.


Thank you!

This gets a tight tricky to explain because I am alternating between Audacity V1.3.6 and V2.0.

Temporality_05-26-12-track-1-only.aup file does not open in either version, instead Audacity immediately freezes just like when opening the original file.
I am attaching the Log Notes provided by version 2.0

Temporality_05-26-12-track-1-first-half-only.aup freezes both versions, EXCEPT that in version 1.3.6 I do see the tracks correct Acoustic Envelope and ending at exactly half way through the recording approx. 6 hours 45 minutes.

Bare with me… but from my own limited deduction skills, I imagine that if I were to open an .aup file that segmented the file into even smaller divisions it would work in 1.3.6?

Looking forward and deep thank you!
logTrack1Only.txt (1.69 KB)

In addition, I experienced the same results as the last posted test round using a Mac Pro:
3.07 GHz Intel Core i7
12 GB 1333 MNz DDR

Gale, I successfully replaced the “h” value in the Audacity1.3.6_track-1-first-half-only .aup. The project continues to crash immediately.

Just for clarity, is the a .cfg file the same as the .aup? Either way, I opened and edited the .aup file in TextEdit.


Yes sorry, the “.cfg” was my mistake, which I’ve corrected now in my post. The .aup file is what you wanted to edit. The .cfg file controls Audacity’s preferences settings ( Index of /man ).


There seems a difference between the two first-half-only images for 1.3.6 at about an hour and at the end. Are there supposed to be long silences either side of the hour mark?

Did you press OK when you saw “Faulty Sequence Tags” in 2.0.0? If so, it’s odd the log has no more details.

You can make a smaller .aup file referencing fewer block files yourself if you wish, but I’m not convinced it will help because I don’t know why it is not responding. If you look near the top of the original .aup you will see:

  <sequence maxsamples="262144" sampleformat="262145" numsamples="2147483648">

What you have to do is make the numsamples in that line match with the total number of samples in however many waveblocks you have listed underneath. Each waveblock is 262144 samples, so if you have included ten waveblocks, “numsamples” in the line above has to be “2621440”.

So at the top of your shortened .aup you want:

<?xml version="1.0" standalone="no" ?>
<!DOCTYPE project PUBLIC "-//audacityproject-1.3.0//DTD//EN" "http://audacityteam.org/xml/audacityproject-1.3.0.dtd" >
<project xmlns="http://audacityteam.org/xml/" projname="Temporality_05-26-12_data" version="1.3.0" audacityversion="1.3.6" sel0="0.0000000000" sel1="0.0000000000" vpos="240" h="0.0000000000" zoom="0.1788139343" rate="44100">
		<tag name="id3v2" value="1"/>
	<wavetrack name="Audio Track" channel="2" linked="0" offset="0.00000000" rate="44100" gain="1" pan="0">
		<waveclip offset="0.00000000">
			<sequence maxsamples="262144" sampleformat="262145" numsamples="2147483648">

(with “numsamples” in the last line of the above changed to show the total number of samples in the waveblocks).

Then you want series of waveblocks like this as copied from the project:

<waveblock start="0">
<simpleblockfile filename="e00008c1.au" len="262144" min="-0.004022" max="0.36529" rms="0.002519"/>

then finally after the final you want the following to end the .aup file:

<envelope numpoints="0"/>

Of course you can just find and drag the .au files from the _data folder (in the order they are listed in the project file) into a new project, but that will take a pretty while because each .au file imports to a new track. The difficulty with automating any such piecing together is that the .au file names as stored in the .aup are random. You would need to try time sorting then renaming the .au files using the 1.2 recovery tools I already mentioned ( http://wiki.audacityteam.org/wiki/Crash_Recovery#Automatic_recovery_tools ).

I also looked at Steve’s Append Import plug-in ( https://forum.audacityteam.org/t/append-import/20421/1). You might be able to use it if you edited the .aup down to just the “simpleblockfile filenames” listed in the .aup and then gave that list of names to Append Import as a “filelist.txt” file. See https://forum.audacityteam.org/t/append-import/20421/10 for instructions. This has the benefit that the files “would” then be imported end-to-end in the correct order, which they may not be using 1.2 Recovery tools.


everyone is getting so smart!

time to roll up my sleeves!