Old Analog Guy wrote:
I've recorded an air check that's behaving oddly. It's recorded in
Cool Edit 2000 and the problem., as best I can describe it, is that
the audio isn't in sequence. It goes along normally for a few seconds
and then I hear some audio that's sort of "from the future," after a
couple of more seconds of ordinary audio I get a gap, which is where
the "audio from the future" came from.
It's as if a gremlin has edited random sections and placed them a few
seconds earlier in the file. If you're listening to it it sounds like,
"And now we {Texas} go to Joe Blow in {} for that story." Where the
part in curly braces is placed in an earlier part of the file. This
happens hundreds or thousands of times in a 5 hour air check.
5 hours ... hmm, did you try to record more than 4 gigabytes of audio?
Now the computer crashed during the air check. But the crash happened
at the end of the recording. And the problem starts at the very
beginning of the recording, hours before the crash.
If so, then it is because new audio was dumped at the start of the file
once the block addressing started to wrap around because
offset-adressing becomes a modulo function due to numeric overflow.
As a consequence
of the crash the file was never saved. I know that Cool Edit 2000
records a temporary file in something like "raw" format and I've been
trying to recover from that, but I always get this odd time warp
stuff.
Until disproven I assume that the file is larger than 4 gigabytes.
What I did was go in after the crash and rename the big temp file that
Cool Edit 2000 had made. Then I've been trying to open this file.
Does anyone know any arcane tricks for recovering the raw temp files
from Cool Edit 2000?
IF you can find some way of splitting it then perhaps you can use it IF
it is just written sequentially and the apparant chaos in the file is
just that: apparent, i.e. happens on read and didn't happen on write.
Is my problem that I'm just not recovering the
file in the correct format or is this likely just how the audio is
now? Will a computer crash always cause something like this, even when
the beginning of the file should have been all right? Or is this
strange time warp stuff not even related to the crash?
Cool Edit will stop working correctly if the file size exceeds 4 GB's as
will the OS it was written for and certainly the FAT32 file system. NTFS
is capable of 64 Terabytes rather than 4 gigabytes, but that doesn't
change the internal limitations of the math in the software in question.
Airchecking on Scullys was never like this!
Finding some way of splitting the file may remedy it or at least salvage
the first 4 GB's. But you are up against a basic limitation of file
system, OS and software. I can't recall just when behaviour was modified
so that a new time file would be written well ahead of reaching 4 GB's
..... i.e. at 4000 megabytes. IF the temp file is less than 4 GB, then it
is a simple "open as" however it was you recorded it, and there will be
another tempfile with the rest of the recording.
That said, last time I managed to exceed 4 GB's the file was obviously
lost and I didn't try bothering with the temp-files, it was just the
nights classical FM and not an unbearable loss.
Thanks for any advice
You could try the open as menu, there you can specify how a file should
be assumed to be. Press F1 for help .... O;-)
An Old Analog Guy (slowly adapting)
32 kHz sampling frequency is your friend for long recordings .... O;-)
Kind regards
Peter Larsen
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