Corrupt audio files from Tascam DR60

Try this, put the machine into record (with internal batteries fitted) but running on external powering, now remove the external powering.... Does the machine stop or flash or do anything different?
What happens if recording and the external power is removed and then plugged back in and out a few times, what do the files then look like?
 
Rick R said:
I used a Tascam DR-680 for a film (64 shooting days). If the 680's external batteries die or the PS gets pulled, it automatically switches to the internal batteries. That actually saved my ass on a take. I think the new F8 is redundant as well.
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Ohhh! That is good to hear. As I'm thinking to buy the DR-680 mk2 once I get some more regular paid sound work.
 
OldCorpse said:
Since he did have internal batteries, he's right that it cannot be lack of power or some kind of interruption of external power.

So, no, that's not the answer.
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The problem wasn't caused by power; that I'm sure of.

The fool operating the recorder is where I'd put my money!


I'm going to try and recreate the issue this weekend.
 
I've had an SD card with very important audio corrupted by windows (7) and possibly my own fumbling (was too eager to hear audio, forgot I hadn't copied it over yet from card, dragged files into Premiere, *poof* gone). Used the windows disk repair program -> *poof*, gone even further. Since the audio was very important and the camera sound unusable, I had to go the route of data recovery. Some info: I used a Tascam DR-40, a freshly formatted card and dual channel WAV recording of a mono signal. Data recovery is much easier if it isn't a dual channel recording, much harder if the card is not freshly formatted or the recording uncompressed.

First I too tried data recovery software, but it recovered files that were unplayable. I tried opening one of these files in a hexeditor and copying in a valid wav header and that helped, but the audio was still unusable, as I had dual track recording on and so I got : 3 sec normal level - 3 sec lower level echo - 3 sec normal level.

In the end, what saved me was: using linux to get a full image of the sd cards content, taking that to a programmer friend who wrote a python program to separate the audio information, because there was some weird stuff going on (if i recall correctly, the recorder wrote the information out in symmetric X - X - X byte chunks but when it reached maybe the 8MB border, it had a situation where it could not write stuff out in the usual chunk size and we had to reverse engineer how it handled the border)

If your recording is one channel, the trick will be to find the position of the recording you want in the image file of the card, calculate the approximate length (this should be easy once you've located the recording WAV header in the image), and copy the content from the start of your WAV header until the next WAV header. Look up WAV header specs online.

What you need is thumbdrive bootable linux, a hex editor and some python knowledge and patience, or a friend with these.
 
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That is really complicated, glad it worked for you but it's not where I would recommend people start start. There are data recovery apps that often do a good job at recovering files. In your case it sounds like the header info you pasted was for a mono file and you had an interlaced two track file. You probably could have used the RAW file import talked about above and plugged the proper settings in and gotten usable audio, but? I would try that before reinventing the wheel with programing.
 
I agree Scott, it is probably overkill for most people. The issue in my case was that the interlacing was not something inside of one file, but rather the recorder was writing two files concurrently and the file interlacing information was inside the file allocation table, which was the first thing out the window when the card failed. I think this was the reason that the data recovery apps I tried did not yield usable sound either.
 
The thing with data recovery is that everyone is "right". I have been down this path a few times and what works once is a god place to start but YMMV is an understatement.

I wasn't saying your route is not a solution just that it's not the first thing I would try. I don't personally know programers that could write scripts to my specific needs so I probably would have given up before I got to your solution. But you never know? I'm glad you posted because it's one more possibility when you are up against the wall. If I absolutely need to get that file back then well you do whatever it takes.
 
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