18 Apr
2010
18 Apr
'10
7:15 p.m.
Try using sndfile-convert (in the sndfile-programs
package in
Debian/Ubuntu) to conver the file to a format which allows
files larger than 4G. Try:
sndfile-convert large-file.wav large-file.w64
Let me know if that doesn't work.
Erik
--
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/
Nope, unfortunately it didn't work.
Here's the output of sndfile-info on the wav and the resultant w64
http://pastebin.com/YzPdxrNg
The resultant w64 length is only 20 minutes, just the same as the one
that is able to be read from the wave file.
What happens if a wav file has a size larger than 4G? Does it stop
writing any audio data? Or the audio data is there,
but can not be read because of the header length is insufficient? But
why is the error start after only 20 minutes of audio,
shouldn't it worked for the first 4G?
I saved the recordings as wavex because I thought wavex support file
size more than 4GiB.
Speaking of file formats, do you have any recommendations for file
format for recording?
My choice is between w64, caf, or sun/next au. I heard au is more
primitive, but is chunk-less,
and that gives it some advantage over the others, though i don't
understand what kind of advantage it has.
w64 has more support in the windows world, which is what my friends
using, but I can always bounce to a different format later.
I'm not sure what caf has to offer though, I don't understand the
technical terms.
Here's a blog where I read it about
http://blog.bjornroche.com/2009/11/wave64-vs-rf64-vs-caf.html
18 Apr
18 Apr
8:36 p.m.
New subject: Need help salvaging a recording
Shani Hadiyanto Pribadi wrote:
Nope, unfortunately it didn't work.
Here's the output of sndfile-info on the wav and the resultant w64
http://pastebin.com/YzPdxrNg
The resultant w64 length is only 20 minutes, just the same as the one
that is able to be read from the wave file.
What happens if a wav file has a size larger than 4G? Does it stop
writing any audio data?
It doesn't stop writing data, it stops reading. Basically you have
a file which contains > 4Gig of audio data, but the file header
says its only 20 minutes (60001717 frames).
Or the audio data is there,
but can not be read because of the header length is insufficient?
The audio data is there, but the file header says it isn't.
But
why is the error start after only 20 minutes of audio,
shouldn't it worked for the first 4G?
sndfile-info says this:
Length : 4774981144
Warning : filelength > 0xffffffff. This is bad!!!!
The length of the audio data is kept in th0x11c9c6e18e file header as an unsigned
32 bit integer and the largest number that can be store in that header
field is 0xffffffff or 4294967295. Sine your file is 4774981144 bytes
long (0x11c9c6e18 in hex), when you store something like 0x11c9c6e18
in a 32 bit unsigned integer you get 0x1c9c6e18 == 480013848.
I saved the recordings as wavex because I thought
wavex support file
size more than 4GiB.
It doesn't. WAVEX is just as bad as WAV.
Speaking of file formats, do you have any
recommendations for file
format for recording?
My choice is between w64, caf, or sun/next au. I heard au is more
primitive, but is chunk-less,
Any of W64, RF64 and CAF (all supported by libsndfile) would be fine.
I would not recommend sun/next au; it main disadvantage is that it
has no way of storing meta data.
w64 has more support in the windows world, which is
what my friends
using, but I can always bounce to a different format later.
I'm not sure what caf has to offer though, I don't understand the
technical terms.
Here's a blog where I read it about
http://blog.bjornroche.com/2009/11/wave64-vs-rf64-vs-caf.html
All three formats have their various flaws, and all three are fine
for most purposes.
As for salvaging this file, give me a day or two and I'll write a
utility to drag your data out of the file.
Erik
--
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/
19 Apr
19 Apr
12:15 a.m.
New subject: Need help salvaging a recording
On Mon, 19 Apr 2010, Erik de Castro Lopo wrote:
Any of W64, RF64 and CAF (all supported by libsndfile)
would be fine.
I would not recommend sun/next au; it main disadvantage is that it
has no way of storing meta data.
That's not a bug, it's a feature! (In this case, anyway)
Use a simple utility(dd comes to mind) to strip the header off the .wav
file, and write the rest to .au .
Then use another utility (sox?) to read the .au file, which will read the
entire file since it doesn't have any bogus header data to convince it
otherwise, and write out a .w64 file.
--
Rick Green
"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."
-Benjamin Franklin
"As for our common defense, we reject as false the choice between our
safety and our ideals."
-President Barack Obama 20 Jan 2009
20 Apr
20 Apr
3:14 p.m.
New subject: Need help salvaging a recording
Erik de Castro Lopo wrote:
As for salvaging this file, give me a day or two and
I'll write a
utility to drag your data out of the file.
New program called sndfile-salvage here:
http://www.mega-nerd.com/tmp/sndfile-salvage.c
which can be compiled using:
gcc -Wall `pkg-config --cflags --libs sndfile` sndfile-salvage.c -o sndfile-salvage
If you're on 32 a 32 bit system you should add:
-D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE=1
just after gcc in the command line above.
The program is run as:
sndfile-salvage very-large.wav very-large.w64
and very-large.wav will remain untouched.
This program hasn't had a lot of testing but should work for your
case. Let me know how it goes.
Cheers,
Erik
--
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/
31 May
31 May
3:57 p.m.
New subject: Need help salvaging a recording
Excerpts from Erik de Castro Lopo's message of 2010-04-20 13:10:54 +0200:
Erik de Castro Lopo wrote:
Hi Erik.
I just want to let you know that sndfile-salvage was very useful to me.
I had a recording running all night and forgot about the 4GB limit, so I
ended up with a 4.4GB wav file showing 40 minutes length...
sndfile-salvage seems to have solved the problem for me.
Thanks a lot!
--
Regards,
Philipp
--
"Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen
offen." Bertolt Brecht, Der gute Mensch von Sezuan
As for salvaging this file, give me a day or two
and I'll write a
utility to drag your data out of the file.
New program called sndfile-salvage here:
http://www.mega-nerd.com/tmp/sndfile-salvage.c
which can be compiled using:
gcc -Wall `pkg-config --cflags --libs sndfile` sndfile-salvage.c -o sndfile-salvage
If you're on 32 a 32 bit system you should add:
-D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE=1
just after gcc in the command line above.
The program is run as:
sndfile-salvage very-large.wav very-large.w64
and very-large.wav will remain untouched.
This program hasn't had a lot of testing but should work for your
case. Let me know how it goes.
Cheers,
Erik
5291
days inactive
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days old
linux-audio-user@lists.linuxaudio.org
4 comments
4 participants
participants (4)
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Erik de Castro Lopo -
Philipp Überbacher -
Rick Green -
Shani Hadiyanto Pribadi