Topic: salvaging a potentially damaged file???

[mikesalvo]

so let me preface this by saying I need to do a CF mod ASAP. I have the parts, just need to do it.

So, I taped 4 moe. shows this week, and all went fine with the transfers. Except when I got 2 set 2 from last night. the file is the size is should be. Just over a gig for one set. However, the iRiver wont play it, and when I drag it to my desktop, Quick time (mac os error -208), and Audacity ("Audacity recognizes the file type, but couldnt open the file") will both not open it. I have a feeling the drive is SHOT. Anyone have any simmilar experiences, and know how I could possibly salvage this set??? So far i have tried JFilerecovery.com and had no luck

thanks in advance,
~Mike

[rowjimmytour]

I never had to do it but I believe rename header is what you need to search for
http://taperssection.com/index.php/topic,111774.0.html

[mikesalvo]

I never had to do it but I believe rename header is what you need to search for
http://taperssection.com/index.php/topic,111774.0.html

good look. Ill get into that thread now. thanks!

[greenone]

Mike, if you have audacity, try File > Import and then import as raw, rather than trying to open or double-click the file. Just rescued a bad file of my own that way.

[mikesalvo]

I never had to do it but I believe rename header is what you need to search for
http://taperssection.com/index.php/topic,111774.0.html

tried everything suggested there, no dice

Mike, if you have audacity, try File > Import and then import as raw, rather than trying to open or double-click the file. Just rescued a bad file of my own that way.

just tried this as well. Also didnt work. this really blows

[Brian Skalinder]

What were the results of the scandisk / chkdsk?  Did you run it multiple times?  (I've sometimes had errors picked up on a 2nd run that didn't get caught on the first run.)

You tried CD Wave?  And what was the result?
I saw you tried Audacity...again, what was the result?

Did either app provide a message?  Did the file open but not look correct?  Did it open and look correct but not play?  Any information you're able to provide may help others help you.

If you have access to Audition/CEP, you might try it and again open as RAW.  I remember it having some additional user-specifiable parameters (sample offset, I think) that helped when I couldn't use other apps to open a WAV.

If WL is showing it as 16-bit / 0.0 kHz, the WAV header's probably screwy.  If using an app to open/save the fixed WAV header doesn't work, you might try editing the WAV header manually.

[pjdavep]

I would download the program called Winhex, and look at the file past all the header data (or in linux use "hexdump -c <filename>").  If you scan thru the file and all the hex digits are the same (ie all 'FF's), then most likely the file itself is hosed and beyond repair.  Since it's live music with constant crowd or sound, the characters should be all over the map.

If it does look like the file contents are valid, you may be able to manually repair the header file.   Here is the format:
http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html

Using Winhex to show a 16-bit wav file is shown here:
http://home.comcast.net/~pjdavep/wave_header.jpg

Keep in mind that the numbers are in reverse hex (little-endian) notation.  So the wave size (bits 4 thru are shown on the calculator.  If you switch that to decimal, it comes out to 15219828, which is the file size minus the 8 bit file format header.  I'll let you figure out the rest 

Later,
   pjdavep

[live2496]

We have utilities that can fixup the wave header without having to do the calculations yourself. I think Pigiron's utility can do this and also my Audiohack program.

Audiohack will read the input file off of the drive and create a new file. It sounds like this might be a good fit in this situation. It should work so long as it can scan to the data chunk and there is some info embedded in the RIFF header that indicates the sampling rate, # of channels, and bit depth. If that is missing then you can import as raw into Audacity, Wavelab, or Sampitude to fixup the file. 

Of course, all of this assumes that you can read/copy the data from the drive. If you ran chkdsk with the /f parameter hopefully all is well.

Here is some info on audiohack should you wish to try that.
http://live2496.com/phpBB/viewtopic.php?t=14

Gordon

[mikesalvo]

What were the results of the scandisk / chkdsk?  Did you run it multiple times?  (I've sometimes had errors picked up on a 2nd run that didn't get caught on the first run.)

You tried CD Wave?  And what was the result?
I saw you tried Audacity...again, what was the result?

Did either app provide a message?  Did the file open but not look correct?  Did it open and look correct but not play?  Any information you're able to provide may help others help you.

If you have access to Audition/CEP, you might try it and again open as RAW.  I remember it having some additional user-specifiable parameters (sample offset, I think) that helped when I couldn't use other apps to open a WAV.

If WL is showing it as 16-bit / 0.0 kHz, the WAV header's probably screwy.  If using an app to open/save the fixed WAV header doesn't work, you might try editing the WAV header manually.

let me preface by saying that the iRiver is playing back all files but this one. When i flip to it on the iRiver, it just skips right over it. However it is still 1 GB long (just under to be exact).

-ran check disc. on my iRiver twice. No problems found.

-second attempt to import raw file into Audacity=fail

-im gonna give CD wave a shot shortly.

- i dont have access to Audition (this is a pay program correct???)

-file will not open AT ALL. See OP for error messages.

-I will try Audio hack and Winhex soon also.

Thanks VERY much to everyone who has made suggestions thus far. Should I post a megaupload of the file???

[live2496]

Can you copy the file from the iRiver to another disc? If so, do you get all 1GB ?

[mikesalvo]

Can you copy the file from the iRiver to another disc? If so, do you get all 1GB ?

busy day, so I didnt get to mes with it al all. Yes, the full file transfers. Full size.

[live2496]

Ok. Then there is a good chance that the file can totally be recovered.

Here is one way how to proceed. Open up the file with the suggested utility WinHex. Also open up a known good file that has the same sampling rate recorded on the same recorder. Edit the first 44 bytes of the bad file to ensure that both headers are identical.

At that point you should be able to use Pigiron's utility to fixup the counters or run the file through Audiohack to fix it.

Importing as raw is also a way to fix it, but you have to know where the PCM samples start. Otherwise you might get white noise. So at that point you would have to experiment with importing with differing offsets. Using the utilities is quite a bit easier.

[mikesalvo]

Ok. Then there is a good chance that the file can totally be recovered.

Here is one way how to proceed. Open up the file with the suggested utility WinHex. Also open up a known good file that has the same sampling rate recorded on the same recorder. Edit the first 44 bytes of the bad file to ensure that both headers are identical.

At that point you should be able to use Pigiron's utility to fixup the counters or run the file through Audiohack to fix it.

Importing as raw is also a way to fix it, but you have to know where the PCM samples start. Otherwise you might get white noise. So at that point you would have to experiment with importing with differing offsets. Using the utilities is quite a bit easier.

Good to hear its probably salvageable. Unfortunately, your last (and very in depth and helpful post, is very foreign to me. What exactly is a header?

[live2496]

Sorry about that. By header I was referring to the top part of the file. This typicially has data in it to identify the file as a wave file and various attributes such as sampling rate, # of channels, bit depth.

To elaborate... the first part of a wave file contains the literal bytes "RIFF" followed by a counter. Then what follows are a series of "chunks". The "fmt " chunk has the sampling rate info. There are optional chunks, but the pcm samples are in what is called a "data" chunk. The data chunk contains a count of the number of bytes in that chunk. Each aforementioned chunk contains a count. This is how application software skips through the file to locate information. You don't need to know all of this to fix a wave file (necessarily), but it should provide some insight.

You might refer to this link which was posted by pjdavep earlier:
http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html

Also, I don't know if you have any computer courses in your backbround, but hexadecimal is a notation whereby computer bytes are displayed in a base16 format. The symbols used to represent numbers are 0-9, and A-F (16 characters). However, most hexadecimal capable editors also display the bytes as ascii text. So should see literal values "RIFF", "fmt", "data" as you view the top part of the file.

[Kush]

Mike, if you can't eventually get it I could send you a copy of my second set. It's not way FOB like you were that night but it's directly FOB and dead center, even used the AKG 393s as well. You should have come back to say hello. I wasn't coming near that mob scene up front.

It will probably take me a few more days to get my copy finished, I'm a turtle when it comes to uploading.

I saw two stands that night way FOB, who else was up there with you? Not many tapers that night. I also saw two stands dead center of the balcony, Dr. Stan's I presume?