15 Jan
2013
15 Jan
'13
4:10 a.m.
I want to write a simple application that can open a .wav file
(stereo or mono), grab the header, and then read and dump
the sample values from a portion of the .wav file to an ascii data
file (I want to plot minute portions of the sound file with
application such as gnuplot).
I am most comfortable working in C, though I would
consider working in C++.
What library or libraries do people suggest I work with?
Thanks.
P.S. Or maybe someone can suggest a command line utility
that already does this.
15 Jan
15 Jan
4:12 a.m.
On Mon, Jan 14, 2013 at 10:09 PM, Ivan K <ivan_521521(a)yahoo.com> wrote:
I want to write a simple application that can open a .wav file
(stereo or mono), grab the header, and then read and dump
the sample values from a portion of the .wav file to an ascii data
file (I want to plot minute portions of the sound file with
application such as gnuplot).
How about squishyio?
http://svn.xiph.org/trunk/squishyio
the header file probably tells you everything you need to know. I use
it for quick simple things.
(It's the file loader/writer from the Squishyball tool separated out
into a standalone lib)
Monty
9:21 a.m.
On Mon, Jan 14, 2013 at 07:09:56PM -0800, Ivan K wrote:
I want to write a simple application that can open a
.wav file
(stereo or mono), grab the header, and then read and dump
the sample values from a portion of the .wav file to an ascii data
file (I want to plot minute portions of the sound file with
application such as gnuplot).
I am most comfortable working in C, though I would
consider working in C++.
All you need is libsndfile and the standard C or C++ libraries.
Note that gnuplot will just plot the sample values, not the
analog waveform represented by them. If the signal contains
significant energy at high frequencies (say FS / 10) just
plotting the samples will provide a poor idea of the waveform.
One solution in that case is to upsample first.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
8:07 p.m.
Fons Adriaensen <fons(a)linuxaudio.org> writes:
On Mon, Jan 14, 2013 at 07:09:56PM -0800, Ivan K wrote:
Thanks; I do want to go with whatever is standard or most
commonly used.
I want to write a simple application that can
open a .wav file
(stereo or mono), grab the header, and then read and dump
the sample values from a portion of the .wav file to an ascii data
[...]
All you need is libsndfile and the standard C or C++ libraries. Note that gnuplot will just plot the sample values,
not the
analog waveform represented by them. If the signal contains
significant energy at high frequencies (say FS / 10) just
plotting the samples will provide a poor idea of the waveform.
One solution in that case is to upsample first.
Again, thank you for the advice!
10:29 a.m.
Hi Ivan,
Here's a commandline utility approach:
On 01/15/2013 04:09 AM, Ivan K wrote:
I want to write a simple application that can open a
.wav file
(stereo or mono), grab the header,
sndfile-info <filename>
and then read and dump
the sample values from a portion of the .wav file to an ascii data
file
sox infile.wav outfile.dat
(I want to plot minute portions of the sound file with
application such as gnuplot).
There's sndfile-waveform
I am most comfortable working in C, though I would
consider working in C++.
What library or libraries do people suggest I work
with?
libsndfile in general.
Thanks.
P.S. Or maybe someone can suggest a command line utility
that already does this.
8:13 p.m.
Robin Gareus <robin(a)gareus.org> writes:
Here's a commandline utility approach:
[...]
sox infile.wav outfile.dat
This is totally what I was looking for! Is there anything
sox cannot do?
The plots with gnuplot with sox's data dumps are
exactly what I was after, too!
(I want to plot minute portions of the sound file
with
Again, thanks!
application such as gnuplot).
There's sndfile-waveform 
16 Jan
16 Jan
3:01 a.m.
Ivan K <ivan_521521@...> writes:
I want to write a simple application that can open a
.wav file
(stereo or mono), grab the header, and then read and dump
the sample values from a portion of the .wav file to an ascii data
file (I want to plot minute portions of the sound file with
application such as gnuplot).
FWIW, this task is incredibly easy in SuperCollider:
// Open an existing sound file
// Automatically parses the header
f = SoundFile.openRead(Platform.resourceDir +/+ "sounds/a11wlk01.wav");
// Jump ahead to a given "sample frame"
// f.sampleRate "frames" always corresponds to 1 sec,
// no matter how many channels
f.seek(4410); // 0.1 seconds in
// Allocate space for the samples, and get them
// Channels are interleaved
d = FloatArray.newClear(50);
f.readData(d);
f.close;
// Push them out to a text file
o = File("~/samples.txt", "w");
d.do { |sample| o << sample << Char.nl };
o.close;
It's also possible to rework this (fairly minor adjustments) to run it from the
commandline. No time to do it at the moment -- maybe later, if anyone is
curious.
hjh
4358
days inactive
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6 comments
5 participants
participants (5)
-
Fons Adriaensen -
Ivan K -
James Harkins -
Monty Montgomery -
Robin Gareus