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Un-corrupt WAV files with Audacity


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Files weren't copied off the Zoom H6 and the owner had already managed to format the unit.

Fortunately as it turns out the owner's not too tech savvy so he used disk utility to format the 8gb lexar (premium series) SD card, and hadn't recorded anything on it. 

I have the card, I did some recovery and managed to recover the Wav files. Problem is, the files are broken.

I watched and read through mutliple tutorials and I couldn't manage to un-corrupt the files but I was left with the impression that it could be done. 

I would love to know definitely if these files are 100% recoverable, then I'd know how to proceed with the client. 

 

I uploaded the files here: https://www.dropbox.com/sh/plmswwn3c7ilghg/AAB_EOqDHHk2-jZ3SJnY4Hu6a?dl=0 there are two folders. Working contains  4 copies of files that were recovered and work fine (the last 6 recodings) and 4 copies of the corrupted files (38 total). 

Are there files un-corruptable / recoverable?

Thank you very much in advance for your help. 

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Maybe recoverable, usually in that scenario, the metadata header is not written, change the extension to <.raw> and try. Unfortunately, not many apps can open a RAW audio file. AFAIK, Sound Forge Pro and some versions of PTs will. Not sure about Adobe Audition (Cool Edit Pro) or the free Audacity.

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Adobe Audition and Audacity can open RAW audio files. I've had success recovering production sound using Audacity though and not Audition. And as mentioned, it's a hit and miss situation. 

I can try to recover and see on my end, but I need to know what bit depth and sample rate the audio files were recorded at. 

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  • 2 weeks later...

Sort of on the same topic.  Yesterday my producer started copying my Nomad card to three hard drives via a program called Hedge.  When the process started the card showed up as normal and started the copying process.  After a few minutes the copying was aborted and after that the card was deemed unreadable by the computer.  We tried other card readers and different computers, all with the same result.  I had this happen one other time with Shot Put Pro.  So the card was somehow corrupted so the computer couldn't read the card.  Any ideas as to how this happens?  I've already converted the files from the MARF card and sent them to him so nothing was lost except for time.  Would like to avoid this in the future if possible.  Our DP did a scan with a program called Rescue File Pro by Sandisk and the files were there, just couldn't be seen by the computers.

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27 minutes ago, Philip Perkins said:

Did you try the Audacity "RAW" trick?

I didn't Philip!  I'm going to make sure all the files match up from using Zaxconvert (I had multiple projects that I hadn't back up yet) and then I'll try the Audacity procedure.  I'll come back and let you know how it goes.  

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I've had amazing results with software from Tom Erbe: http://www.soundhack.com/

...not only turning raw into readable with headers, but also turning text and graphics files into audio...

...and a lot of sound design tools, like one of the best phase vocoders around. [Don't let the name food you. It's not a sound-effect-into-voice vocoder, but a way to do extreme time expansion on speech without audible splices or changing the pitch.]

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The hash is probably caused by not having the decoding software (Audacity?) set to the proper Bit Depth, Sample Rate or Track Count.

Don't know if Audacity will automatically look for the data chunk in the wav file but if not, the offset of the other chunks in the file header can screw up the interleave alignment and create the hash.  Raw PCM data is stored in a single chunk that is organized 2 or 3 bytes per sample (2 for 16bit 3 for 24bit), then next 3 bytes is channel 2 sample 1 then channel 3, sample 1, channel 4, sample 1,  etc.  then next sample for each channel in succession.  So any mis-alignment of the start byte of the data chunk or incompatible decoding settings cause the samples to be interpreted incorrectly as the interleave doesn't line up.

 

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