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Author Topic: Homegrown WAVE header repair utility  (Read 104168 times)

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Offline zebweber

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Re: Homegrown WAVE header repair utility
« Reply #90 on: June 01, 2011, 07:52:12 PM »
I have the 4GB CF card sitting here with the original corrupted files on it, wishing it could be rid of this troublesome file and be recorded on again...

"So as long as you preserve the media, you haven't lost anything."

Yes, but, if all I can get is 93 minutes of annoying static, I haven't gained anything either...

This has been a crash course for me on wave files and their quirks - I really think I'm close to being able to completely salvage this file...can I be, please??

Offline Emile

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Re: Homegrown WAVE header repair utility
« Reply #91 on: June 10, 2011, 06:03:19 AM »
Recorded a show on my Zoom H2 the other day and I dropped the zoom while it was saving the recording. The result was a wav file that wouldn't play, but definitely had data in it.

Wanted to share that this fixed the problem and that I was able to recover the file. Thank you so much

Emileh
« Last Edit: June 13, 2011, 09:05:20 AM by Emile »
SP-CMC-2 (AT831s) > SP-SPSB-1 > SP-XLRM-MINI-2 > Edirol UA-5 bm2p+ (Toslink out) > (Optical in) iRiver iHP-120 (CF Mod 16 GB / Rockbox 3.13)
Recordings on LMA: http://archive.org/bookmarks/emileh

Offline GroundHog420

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Re: Homegrown WAVE header repair utility
« Reply #92 on: June 21, 2011, 06:53:00 AM »
I'm revisiting this thread again, in the hopes that someone might be able to help me resurrect a 0 byte file. I spent a good deal of time with it last year, but things got busy, and haven't settled down much since.

This was a killer set by Portland's own Jackie-O Motherf*cker, from the 2010 PDX Pop Now! Festival; maybe it still is, I don't know.
I had an Edirol R-04 running for this set, and we hadn't got the cables together yet for a SBD feed, so only two channels were used, for two mics at center stage lip.
I was stage manager for the event, and was handling the changeover after their set, instead of running back to the oar to shut off the Edirol - I figured I would get to that while the next band was running through a quick soundcheck.
Unfortunately, when the band that went on next plugged in, they immediately blew out a power bank that included the strip the Edirol - still recording -  was plugged into.
That left me with a "0 byte file".

I pored through these threads, and any place on the internet that related to this issue, but this looks like the most solid thread anywhere to be found on the subject - the only problem is, I can't get my head around what is being described here.


If anyone wants to have a look at this mess, I've uploaded a .zip file to my iDisk server:
https://public.me.com/j.free.pdx
(There is a bunch of other stuff there, mostly a bunch of Feelies shows - feel free to download whatever looks good, but let me know if you do, so I can keep track of the mileage on that server, okay?)

The file name I'm trying to repair is in this:
jomf_ppn.zip

Inside are two copies of the file that was damaged (the original file is still on the Edirol drive) - they both suggest that there might be 44MB of data, which I would assume is the header.
The trouble is, I can't actually look at the contents of the file itself, either on a Mac (using Audacity) or a PC (using CD Wav or SoundForge).

Trying my best to follow pigiron's instructions for the PC (running XP), I never even got to the part where the program would ask questions, so i could plug in answers - the window just blinked and disappeared, every time, just as Nick Graham had mentioned earlier. I did follow pigiron's instructions after that, as best as I can understand them, but I don't seem to be getting it.
[THIS: click "Start" then click "Run" and then enter "cmd.exe", it will open up a DOS box... then "cd" to the directory that contains "fixwav" and enter "fixwav your_file_path"... where "your_file_path" is the BACKUP copy of the audio file.  Example:  fixwav C:\foo\bad.wav]

I also tried Jason Sobel's advice (creating the .bat file, etc), but then I get an error/prompt that tells me "fixwave is not a valid command".

I tried Wayne's Mac version (On a G5/OSX), but that opens up a Flash decompiler.

I don't usually feel too stupid with computers, but this is tough for me to understand, for some reason.

Any helpful advice is welcome, and if anyone wants to look at the file, feel free.

Thanks in advance to anyone who can help me see the light here.
Hey man, that common sense shit won't fly around here, we're from Portland, we're edgy & different or something  ???
she kept playing with the balls for around 2 years after i thought i had seen it all from them.

Offline it-goes-to-eleven

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Re: Homegrown WAVE header repair utility
« Reply #93 on: June 21, 2011, 10:11:29 AM »
The file on see on the server is only 1K in length.

It sounds like you have not yet run pigiron's utility.  It runs under dos, in a command window.  So clicking on it, etc, will not work.

Approximately how many minutes long is the audio you hope to recover?  What was the original sample rate and bit depth?  How large is the file on disk?

The header portion of a wave file is only 44 bytes in length.

Pigiron's utility works in cases where the file itself is complete but the header is not correct.  It will not work in cases where the file on disk is smaller than it should be.  That will require a different approach.

Offline live2496

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Re: Homegrown WAVE header repair utility
« Reply #94 on: June 21, 2011, 12:55:43 PM »
It sounds then like you have two problems. The first of which is to run a file recovery tool to get back all of the sectors associated with your recording. Does not Edirol have a utility for that? Or am I thinking of something else.

Once the data is recovered you can look into fixing up the header which Pigiron's utility deals with.

In windows I would use chkdsk with the /f option, but you will need to find something equivalent. Hopefully the media is not overwritten yet?
« Last Edit: June 21, 2011, 12:58:05 PM by live2496 »
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Offline it-goes-to-eleven

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Re: Homegrown WAVE header repair utility
« Reply #95 on: June 21, 2011, 01:36:04 PM »
In windows I would use chkdsk with the /f option, but you will need to find something equivalent. Hopefully the media is not overwritten yet?

Rule 1 of data recovery is that you don't alter the original.  You work on a copy.  What you suggest alters the original.

Offline live2496

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Re: Homegrown WAVE header repair utility
« Reply #96 on: June 21, 2011, 02:22:02 PM »
It corrects the file allocation table. He can't get his data without that. Once that table is reconstructed I would copy the file to the hard drive and work on that.
AEA R88MKII > SPL Crimson 3 > Tascam DA-3000

Offline it-goes-to-eleven

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Re: Homegrown WAVE header repair utility
« Reply #97 on: June 21, 2011, 03:20:51 PM »
It corrects the file allocation table. He can't get his data without that. Once that table is reconstructed I would copy the file to the hard drive and work on that.

Absolutely false.  You do not need to modify the file allocation table to recover the file.

The windows tools are far too clumsy and prone to failure to risk using them on the original source.  But, really, the industry standard is that no tool should be trusted to modify the compromised original when you don't have a backup.

He may get lucky and chkdsk may work.  But he really wants to recover the show, so I don't see that it is worth the risk.  I am conservative in these situations, and never, ever want to explain to someone how their data was lost when a bit more care could have prevented the loss.

Also, situations like this are why you really want to never delete files from your recorder.  It is much better to let it fill and then format it.  The benefit is the blocks of the WAV files will be sequential.  That makes brute force recovery methods fairly easy.

Photorec is probably the best way to recover this right now.  It does not write to the disk, so it is far safer.  Since your disk isn't experiencing a hardware failure, it is okay to use it directly with the disk.  If your disk's hardware was compromised, I'd suggest making a copy of it and working on that.  There are threads here on using photorec.  I'd suggest de-selecting all of the file types except the type you are recovering.  That will prevent false recoveries.  The downside is you will lose your filenames and recover old audio.

The other alternative is to image copy the drive under linux and repair the copy.

Once you have the file, you will still need to repair the header (or even add a header).

Offline GroundHog420

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Re: Homegrown WAVE header repair utility
« Reply #98 on: June 21, 2011, 03:22:44 PM »
Thanks to those of you who have already taken some time to look at this, and offer your suggestions.

The original "file", whatever it consists of, is still on the Edirol drive. It was/is a 24-bit, 48kHz 2-channel recording. I copied it to a PC, and also to a Mac, to try a few options I had seen discussed in this thread.

It's correct that I can't run pigiron's utility - I was attempting to run it from a command window, but that did not work, in this case - that's why I also tried the alterante method which involved creating the .bat file, and clicking on that, which also was unsuccessful in this case.

It was on the Mac that the fixwave program kept opening up a flash decompiler, and for the life of me, I don't get that at all.
Hey man, that common sense shit won't fly around here, we're from Portland, we're edgy & different or something  ???
she kept playing with the balls for around 2 years after i thought i had seen it all from them.

Offline it-goes-to-eleven

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Re: Homegrown WAVE header repair utility
« Reply #99 on: June 21, 2011, 03:31:03 PM »
Again, how large is the file and how long did you expect the recording to be?

Did you check the download zip size - it only reported 1K?

It is critical that you *not* write or record anything to the edirol.


Offline live2496

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Re: Homegrown WAVE header repair utility
« Reply #100 on: June 21, 2011, 04:43:29 PM »
If you've got tools on the mac that can scan the disc that is preferred.
AEA R88MKII > SPL Crimson 3 > Tascam DA-3000

Offline GroundHog420

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Re: Homegrown WAVE header repair utility
« Reply #101 on: June 21, 2011, 06:29:29 PM »
The set should have been approximately 30 minutes - 24-bit, 48kHz sample rate.
I don't know that I can not record anything else to the Edirol, we've got another 2-day Festival coming up this weekend.

Yes, the file appears to 0 bytes - 1K is probably the folder.

Again, how large is the file and how long did you expect the recording to be?

Did you check the download zip size - it only reported 1K?

It is critical that you *not* write or record anything to the edirol.
Hey man, that common sense shit won't fly around here, we're from Portland, we're edgy & different or something  ???
she kept playing with the balls for around 2 years after i thought i had seen it all from them.

Offline it-goes-to-eleven

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Re: Homegrown WAVE header repair utility
« Reply #102 on: June 22, 2011, 10:46:51 AM »
The set should have been approximately 30 minutes - 24-bit, 48kHz sample rate.
[quote/]

So at two channels, you need to recover about 518MB in order to have 30 mins.

Quote
I don't know that I can not record anything else to the Edirol, we've got another 2-day Festival coming up this weekend.

Well then... you must resolve this before you write to the drive!

You could try photorec, use chkdsk, or try one of the many linux tutorials on recovery.    The tutorials will be somewhat complicated.  You might just want to try the chkdsk and see if that recovers the 500MB file (and then we can worry about fixing the header).  If not, then it is on to photorec.  Just don't write anything to the drive.

Quote
Yes, the file appears to 0 bytes - 1K is probably the folder.

Checked it again, and your zip file only shows as 1K.  The other files in the directory show as hundreds of MB, or GB.  Though this does not matter unless you have the full 500MB in the zip.



Offline EarlyMorningRain

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Re: Homegrown WAVE header repair utility
« Reply #103 on: June 22, 2011, 12:47:37 PM »

The set should have been approximately 30 minutes - 24-bit, 48kHz sample rate.

Checked it again, and your zip file only shows as 1K.  The other files in the directory show as hundreds of MB, or GB.  Though this does not matter unless you have the full 500MB in the zip.

I was kinda thinking the same thing, that the file size to start with should be what he is expecting it to be. However a chkdsk /f and/or a chkdsk /r couldn't hurt any.
« Last Edit: June 22, 2011, 12:49:13 PM by EarlyMorningRain »

Offline GroundHog420

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Re: Homegrown WAVE header repair utility
« Reply #104 on: August 18, 2011, 09:50:04 PM »
I gave up on the last file rescue attempt; I appreciate the efforts some folks made to try and help out with that, but after a year and the fact that it sounded like a lost cause, I needed the machine for other projects. It just wasn't practical to tie up a machine all that time for a file that didn't seem to have much of a chance anyway, but it was a festival set, and I did have a video of the set, so that's better than nothing, I think.


Back into the present, I had an even weirder experience just last night, and this one has got me freaking out a bit. I've been recording a performer in a weekly Wednesday residency at a local venue, in the hopes of culling enough varied material that we might be able to construct a nice compilation or something along those lines. Weeks 1 & 2 went off without a hitch, and yesterday the 1st set seems to have ended up being nothing but white noise, despite the fact that I was monitoring the entire set at the time, and it seemed to be recording just fine, and reporting a correct time length, etc.

The unit being used for this series of performances is a Zoom R24, due to the fact that the line-up changes each week, and we never really know who is in the band each week until right before show time. One week had a 4-piece band, the next week no drums; last night it ended up being a stripped-down duo. I ended up only using 3 channels - 2 miked guitar amps, and a vocal line from the house PA. At the very start of my recording, there is about a minute of soundcheck for a banjo - then I paused the unit until they started playing, a few minutes later. The red record lights were on. The timer ticked away the seconds and minutes. I made minor level adjustments throughout the set, just as always, and listened through a headset; again - everything seemed normal.

This morning, I transferred a copy of the file from the 8GB SDHC card that I used for last night's sets. The second set sounds great - pretty much the kind of quality I expected, based on the previous weeks for the same series of shows. The first set, however, had a weird anamoly - the first minute of soundcheck is clear as a bell, and then the set itself is all white noise - type static, and the .wav file appears to be what a lot of digital tapers call "brickwalled". I can't think of a single reason this could have happened - the sole difference between how I recorded the 1st and 2nd sets is just the fact that I paused the unit after soundcheck, then re-engaged it for the set itself. I've done this many times in the past, and there is no reason that should have caused nearly an hour of music to turn into static, but that does seem to be the result. The "save" process at the end of set 1 appeared normal as well.

Since the media itself is independent, I can refrain from using that card - however, based on some of the discussion regarding my last situation, I'm concerned that since I wrote the 2nd set to the same card, there may be nothing I can do to try and save it; although I would certainly like to be proven wrong in this situation. I had a devil of a time trying to get my head around the rescue processes previously discussed, and now it looks like I will need to wrestle with it all again, and I could definitely use a bit of hand-holding here, if anyone feels up for it. The major difference with my last incident and this one, is that in the previous situation, the file had never been saved before the power was cut - in this case, however, the file saved normally (or so it seemed anyway). It would be a huge understatement to say that any helpful advice would be more than just a bit appreciated.

Here is a link to one of the three .wav files, copied from the SD card:
https://files.me.com/j.free.pdx/7665pi
This is the guitar track for the entire 1st set.

Here is what information I do have:

PC sees this:
3 files -
478MB each (1152kbps)
total folder size: 1.40GB

CDWave reports this:
"File is truncated"

Traders Little Helper analysis:
Length: 58:05.790
"Wave header is not canonical"
also
"Wave header is inconsistent about data size and/or file size"

The Zoom R24 reports this:
1436.6MB
58:05
24bit/48kHz
« Last Edit: August 19, 2011, 04:37:41 PM by GroundHog420 »
Hey man, that common sense shit won't fly around here, we're from Portland, we're edgy & different or something  ???
she kept playing with the balls for around 2 years after i thought i had seen it all from them.

 

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