Zoom Gear & Home Recording Forum

I am in dire need of some help here - I was recording in 4CH mode for about 30min, when the battery died. When I checked the card, I had two empty (0kb) .wav files, one for the inputs and one for the mic, of course. The data must be physically written on the SD card somewhere, but no utility I've been able to find has been able to recover the lost recordings. These were incredibly important for a paid project I'm working on. Is there any utility used by Zoom staff or users that has proven effective in recovering 'lost' data? Every recovery program I've used just comes up with the empty files, with no sound data inside.

What should I do??? Any and every piece of advice is helpful!

I'm sure if you look through the pages of topics in the forum, you'll find essentially duplicates of your post.

Most applications are reporting empty files because the WAV HEADER was not written; the header contains the length/format of the data that follows. Since the header is empty, regardless of the physical size of the file, players will see "size 0" and go "nothing to play".

http://audacity.sourceforge.net/about/features
Claims to have an "open raw" (no header) file -- you may then have to cut off the first few milliseconds of data which would be the unwritten header, and resave (as a different name in case you need to go back to the original data)...

It's been my experience that Audacity can't import from the files that the file system (not just the header) thinks are 0 KB, so you need to fix that first. I've been able to recover the data from 0 KB files after an H4n battery failure by using PC Inspector File Recovery, which is freeware. It's the only one I know of that does this properly.

http://www.pcinspector.de/Default.htm?language=1

After recovering the files, they still won't be playable because the file headers weren't properly updated, but they can be imported into Audacity as Wulfraed says.
When you import, you need to set the sample frequency and bit-depth of the original files, and if you aren't sure what you have set in the H4n, it's shown in the menu REC -> REC FORMAT display. (I believe the default is 48/24 for 4CH mode.) Enter a file offset of 910. After importing, you can save it as a .wav file.

ETA: Actually, thinking back, I've seen several different things happen if the batteries run down or if the power is turned off without stopping the recording first. The 0 KB thing is one case but I've also seen files with a valid name and non-0 size that couldn't be opened by any program, and it may have been that case that Audacity couldn't import, rather than the 0 KB files. So, try Audacity directly first. Also, someone mentioned that sometimes the files can be recovered by the Windows "Check for errors" function in the disk Properties -> Tools tab, so you can also give that a try to get the file back, but you would still need to import into Audacity to make them playable.

Sorry to hijack your post .... but,

I also have this problem and although I have read through the previous postings on this issue I can't seem to fix it myself.

If anyone out there is confident in retrieving data from these 0kb files I will happily pay a fee for this to be done. I have saved images of the SD cards that the files were on and could provide these. Please message me if interested.
Cheers

I encountered this problem recently when an SD card was pulled out of an H4N whilst it had been left paused on a recording. The Zoom had created a 0KB file but not attached the recorded data to it. After no luck with data recovery tools I hit upon this solution-

1. Do a raw copy of the entire SD card, including "empty space"- this should generate a file as large as the disk
(e.g. HDDGURU: HDD Raw Copy Tool)

2. Open this file as Raw data in a wave editor (I used Adobe Audition) and ensure you set the sample rate, bit depth and channel count correctly (in Audition I also had to play with the byte offset and the type of PCM encoding to get a perfect interpretation).

Then, if you're as lucky as I was, somewhere in this long file should be the recording you're looking for. Mine came out perfectly continuous without any artefacts.

Best of luck!

I have tried most of the ideas (except the most recent one which is next on my list) and have had no luck. My H2 batteries died while I was in the middle of a 2 hour recording. The real bummer is I just assumed the file was there, and I then replaced the batteries and continued recording for another hour and a half. It was only then that I discovered the empty file for the first recording. I will try aumeta's idea but I'm afraid I may have overwritten the lost file...so far, none of the data recovery programs have been any help and I wasn't able to get audacity to read the empty file.

Emphasis mine...



At this point, you can probably forget about recovery.

When it "died" it meant that the FAT (directory) identifying allocated blocks were not updated to reflect the data written. If the directory entry is wrong, the card would show an available capacity corresponding to the space taken by the "missing" recording.

From Wikipedia

If the cluster chain (the table entries for a single file) were not written, then the FAT likely contained "unused" markers in that chain, so when the second recording was started and the system looked for a free cluster, it would find the ones that were supposed to be the first recording.

Well that's not good news...but not entirely unexpected. Too bad. The recording was of an 84 year old who I only get to see once a year, and it will be another year before I can record him again.

Time for a telephone<>recorder interface cable, and a long-distance phone call?