Decoding file from Zoom M3 MicTrak

Audacity 3 Help Forum
1

Did some recordings and then stupidly formatted the SD card.

Doing a raw data dump from card contents to disk I can clearly see the old files.

The header starts as:
RIFFøS) WAVE

Hex:
52 49 46 46 F8 53 29 0C 57 41 56 45

The main issue I’m having is that while using audacity to open the raw data, I get an echo. It’s as if everything repeated 1 second after first coming into play.

Any idea on what may be causing that?

I’ve shared the files here.

220105_004_RAW.WAV - good file
[000011].wav - file with “echo”

Notice that you can’t play the file directly on browser (probably because it’s corrupted?) you have to import to audacity.

Many thanks,
Frankie

2

Frankie,
If you still have the SD card in its formatted state ie you haven’t re-used it, you could try recovering from it directly. If you are a Windows user (or have access to Windows) you could try QtPhotoRec which uses file carving to find certain file types. It’s free so you have nothing to lose. I’ve had good results with it. Make sure you use the GUI (QtPhotoRec) rather than PhotoRec which is a text-based program.
There are some other suggestions here: Free Data Recovery Software.
Good luck.
Mark B

3

Hi @evilmrb!

Thank you so much for your reply. Took me some time, but in the end I was able to get the files back.

As Zoom M3 MicTrak saves both a RAW and a WAV track simultaneously, it throws a curveball at data-recovery software.

I’ve developed a tool to extract these files (when they are still in the SD card):

I’ve also detailed the process, aside from the code, as it was a fun project and may eventually help someone.

Many thanks for your reply,
Frankie

1 Like
4

Frankie,
I’m very impressed by what you have done. Having figured out a solution, written a program to fix it, shared and documented it, you round the job off with a well-written story of the whole thing. You have my admiration. Maybe you should share your fix with Zoom or post something in their forum too, if they have one.
Mark B

1 Like
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