Topic: help with corrupt file

[BJ]

Ok...so I was recording with my r-09.  The sd card filled up, and the fiel that was being recorded too is now corrupt.  I am guessing it couldnt finish writing the needed information.  I read through some old threads about headers, but couldnt get anything to work.  Wondering if anyone has ideas.

Here is apic of my .wav file in UltraEdit.  comments, suggestions..whatever 

[live2496]

Assuming that you can read the entire file with no problems...

Take a known good file recorded using the same settings. Open up both files in ultraedit.
Type into the bad file the first 44 bytes of the good file.
Zero out bytes 5,6,7,8 and 45,46,47,48.

Run it through Audiohack to correct the counters.

Gordon

<edit>
P.S. You could also import as raw into an audio application.
</edit>

[BJ]

Hard to suggest anything unless we know more. What have you tried?  Is the file length as it should be?  Have you tried various alignment offsets when importing?  How's the waveform look?

You might need to use something like photorec to recover all the data...

i havent tried anything.  I looked at the file to see if i could alter the header information like was suggested in other threads.  However, I couldn't match up the header, b/c I didn't see the things in the file that they mentioned.  I am totallyl lost, as this is the first time i have ever had problems.

as for the waveform, I can't open it with audacity or cdwave b/c it says its not a valid wav file.  I will google photorec to see what that is.

Assuming that you can read the entire file with no problems...

Take a known good file recorded using the same settings. Open up both files in ultraedit.
Type into the bad file the first 44 bytes of the good file.
Zero out bytes 5,6,7,8 and 45,46,47,48.

Run it through Audiohack to correct the counters.

Gordon

<edit>
P.S. You could also import as raw into an audio application.
</edit>

im in Madison WI on business right now, as soon as I return back to fayetteville, I will give this a try.



thanx guys.

bj

[pigiron]

i think you nailed it... there's no WAVE header in the file.

the utility i wrote should make it work, but you'll lose the first 44 bytes of first song... and like the thread says, try it on a backup copy.

http://taperssection.com/index.php/topic,72936.0.html

thinking about enhancing the utility to append a header on a file like this.

[BJ]

Assuming that you can read the entire file with no problems...

Take a known good file recorded using the same settings. Open up both files in ultraedit.
Type into the bad file the first 44 bytes of the good file.
Zero out bytes 5,6,7,8 and 45,46,47,48.

Run it through Audiohack to correct the counters.

Gordon

<edit>
P.S. You could also import as raw into an audio application.
</edit>

i tried this, but i get nothing...i get a message saying

INPUT  FILENAME    [.WAV] ==>test
OUTPUT FILENAME #1 [.WAV] ==>part1
OUTPUT FILENAME #2 [.WAV] ==>part2
. writing header info
. input file has no data chunk!

I looked at it..and the ....data is byte 5  are you sure im supposed to zero them out?

i think you nailed it... there's no WAVE header in the file.

the utility i wrote should make it work, but you'll lose the first 44 bytes of first song... and like the thread says, try it on a backup copy.

http://taperssection.com/index.php/topic,72936.0.html

thinking about enhancing the utility to append a header on a file like this.

i tried this, and the whole file was just hiss.


I'm beginning to think the file is a gonner 

[pigiron]

I have hope... the music's there, you're just getting bad advice    at least from me...

Probably the best way to fix this thing is to import a copy of the original bad file as a "raw" file into an audio editor (as mentioned by live2496).

I just tried it with the free Audacity editor and it works...

I took a perfectly good WAVE file and deleted the 44 byte header (http://ccrma.stanford.edu/CCRMA/Courses/422/projects/WaveFormat/)... read it into Audacity (Project -> Import Raw Data)... filled in the dialog describing the audio format... then saved it as a WAV file (File -> Export as WAV).

Give it a shot, as the hex dump you provided looks like perfectly good audio data without a header... and I'm guessing 24 bits.

[Nicola Fankhauser]

hi

importing as raw is definitely the way to go. if that does not yield something usable (but still resembling audio), you'd have to correct offsets by hand, 24bits stereo should be 3x8 bits for the first channel, then 3x8 bits for the second channel. so if your file begins in the middle of this sequence, you need to re-align it by inserting one to five (meaning 8 - 40 bits) bogus characters at the beginning of the file.

if however the file allocation table (FAT) has gone awry, you'd have to resort to proper data rescue software.

regards
nicola

[BJ]

well...i got it imported..but BLEH!  it looks like my levels were way to hot (stealth job so i couldnt check - and a borrowed pre taboot!)

damn...oh well.  Thanx guys..I appreciate the help.

[live2496]

Does it sound ok? Sometimes the alignment of frames is off and this can cause diginoise or swapped channels.

Samplitude has a handy feature that I think we should put into wav file repair utilities. You can specify a start offset where your data begins in your input file.

If you are missing an wav header in any file, I would use my previous suggestion to open up both files in Ultraedit. The good file contains a good header, so copy the first 44 bytes from that file onto your file which you wish to fix. Yes, this will lose 44 bytes of data, but what is 44 bytes compared to how many bytes per second that are recorded? Maybe you could have presssed record a second  later and missed a lot more.

P.S. If any tapers are in Little Rock bring your files by and I will fix them for free. Just PM me or email.