24 Oct
2008
24 Oct
'08
4:52 a.m.
Geeks, tuxians and audioslaves!
I need some help here. I got a bit freaked when I saw that
the libsndfile example files contained a program nearly 1000 lines long to
simply play
a file. But perhaps it's intended for a higher level of geekery. My needs
are very modest.
My task: I just want to load a few samples(wav) which are represented on a
GUI (using SDL) and when they knock about on the screen, sound (music)
is generated using some rules.I need them to mix, of course.
I was using SDL_mixer for this. But my problem was that I want to write to
file
(record) a whole session of the running program as a single wav. SDL_mixer
does not seem to have writing options.
Now is there a way I can do this in some reasonably efficient manner using
libsndfile?
I could load using libsndfile too, skipping SDL_mixer altogether. It's
already installed.
What to do? Any tips would be appreciated.
Thanks,
------- -.-
1/f ))) --.
------- ...
http://www.algomantra.com
24 Oct
24 Oct
5:18 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
AlgoMantra wrote:
Geeks, tuxians and audioslaves!
I need some help here. I got a bit freaked when I saw that
the libsndfile example files contained a program nearly 1000 lines long to
simply play a file. But perhaps it's intended for a higher level of
geekery.
That file contains code to play audio using :
Linux with ALSA
Linux with OSS
Apple using CoreAudio
Windows using the native Win32 API
Solaris using its' Solaris specific API.
My task: I just want to load a few samples(wav)
Sounds like a task for libsndfile.
which are represented on a
GUI (using SDL) and when they knock about on the screen, sound (music)
is generated using some rules.I need them to mix, of course.
I was using SDL_mixer for this. But my problem was that I want to write to
file (record) a whole session of the running program as a single wav. SDL_mixer
does not seem to have writing options.
So use libsndfile.
Now is there a way I can do this in some reasonably
efficient manner using
libsndfile?
libsndfile is for reading and writing sound files, not audio playback.
It reads/writes audio files as efficiently as possible,
I could load using libsndfile too, skipping SDL_mixer
altogether. It's
already installed.
You will still need something for audio I/O. libsndfile won't do that
for you.
For audio I/O there are at least three possibilities, from what is
probably easiest to hardest:
PortAudio
Jack
ALSA
Hope this helps,
Erik
PS: its probably not a good idea to address more than one mailing
list per email. One reason this is bad is that people may not be
subscribed to both lists and if they reply to all, they will get
their email bounced back from the list they are not subscibed to.
--
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
"Incompetence, like misery, seeks company." -- Erik Naggum
7:34 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
Dear List,
I've been suggested that arecord may be able to record direct from
PCM if I change the environment variables. Like:
SDL_AUDIODRIVER=alsa ./myprog
I'm quite scared of doing this, lest I lose audio altogether,
having seen how moody Ubuntu is regarding sound. I mean,
I still haven't been able to configure Audacity after months. It's
VERY confusing to say the least. I've used dev/dsp to spit sound
but people say its deprecated. I haven't even met Jack yet, and
Alsa, she behaves funny when I say hello. Sox and dev/dspworks for me
so far, smoothly.
libsndfile is probably going to be useful to a lesser extent than I
earlier supposed. It's useful but for a different project; currently I need
a
simpler solution because our actual C code is barely 200 lines. We
just need to record the audio session ( from a running SDL program).
sincerely,
------- -.-
1/f ))) --.
------- ...
http://www.algomantra.com
8:37 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
On Fri, 2008-10-24 at 17:04 +0530, AlgoMantra wrote:
Dear List,
I've been suggested that arecord may be able to record direct from
PCM if I change the environment variables. Like:
SDL_AUDIODRIVER=alsa ./myprog
I'm quite scared of doing this, lest I lose audio altogether,
having seen how moody Ubuntu is regarding sound. I mean,
Don't be afraid, it will only change the environment for this single
instance. Next time you run it, everything will be back to "normal".
Nothing evil will happen ...
8:46 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
I've been suggested that arecord may be able
to record direct from
PCM if I change the environment variables. Like:
SDL_AUDIODRIVER=alsa ./myprog
I'm quite scared of doing this, lest I lose audio altogether,
having seen how moody Ubuntu is regarding sound. I mean,
Don't be afraid, it will only change the environment for this single
instance. Next time you run it, everything will be back to "normal".
Nothing evil will happen ...
9:15 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
On Friday 24 October 2008 07:34:53 am AlgoMantra wrote:
I've used dev/dsp to spit sound but people say its
deprecated.
Don't be afraid of OSS. While it's not perfect for every application (*no*
audio API is), it is still very effective for some. It has the great benefit
of simplicity -- open a device, set a couple of ioctls, write data, and
you're done. For simple cases, the whole business can be done in a about a
dozen lines. See:
http://manuals.opensound.com/developer/
Cheers!
|-------------------------------------------------------------------------|
| Frederick F. Gleason, Jr. | Chief Developer |
| | Paravel Systems |
|-------------------------------------------------------------------------|
| The nice thing about standards is that there are so many of them to |
| choose from. |
| -- Andrew S. Tanenbaum |
|-------------------------------------------------------------------------|
9:41 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
Hi Algomantra, Hi LAD list,
There is some code for using libsndfile for similar tasks.
http://trac.assembla.com/audioexperiments/browser/Sndobject
actually, this are some friendly shortcuts for using libsndfile:
http://trac.assembla.com/audioexperiments/browser/Sndobject/sndobj.cpp
and this file has some testing/examples of usage:
http://trac.assembla.com/audioexperiments/browser/Sndobject/test.cpp
you can get that code with:
svn co http://svn.assembla.com/svn/audioexperiments/Sndobject
For playback, i like portaudio for it is the only one i have used in c++.
its easy and seems to play with what is available (jack/alsa okay as far as
i went). Take a look on its demo code (that comes when you co its
repository), i found some straight line reusable code there.
cheers,
2008/10/24 Fred Gleason <fredg(a)paravelsystems.com>
On Friday 24 October 2008 07:34:53 am AlgoMantra
wrote:
I've used dev/dsp to spit sound but people
say its deprecated.
Don't be afraid of OSS. While it's not perfect for every application (*no*
audio API is), it is still very effective for some. It has the great
benefit
of simplicity -- open a device, set a couple of ioctls, write data, and
you're done. For simple cases, the whole business can be done in a about a
dozen lines. See:
http://manuals.opensound.com/developer/
Cheers!
|-------------------------------------------------------------------------|
| Frederick F. Gleason, Jr. | Chief Developer |
| | Paravel Systems |
|-------------------------------------------------------------------------|
| The nice thing about standards is that there are so many of them to |
| choose from. |
| -- Andrew S. Tanenbaum |
|-------------------------------------------------------------------------|
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Linux-audio-dev(a)lists.linuxaudio.org
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6:40 p.m.
New subject: [libsndfile-users] help with libsndfile/etc
Don't be afraid of OSS. While it's not perfect for every application (*no*
audio API is), it is still very effective for some. It has the great
benefit
of simplicity -- open a device, set a couple of ioctls, write data, and
you're done. For simple cases, the whole business can be done in a about a
dozen lines. See:
http://manuals.opensound.com/developer/
Thanks, Fred....I have been playing a lot with examples provided here on the
list
a few months ago, doing simple additive synthesis, and it's been fun. This
document
is very helpful....they have some nice sample code too.
------- -.-
1/f ))) --.
------- ...
http://www.algomantra.com
11:28 a.m.
New subject: [libsndfile-users] help with libsndfile/etc
For audio I/O there are at least three possibilities,
from what is
probably easiest to hardest:
PortAudio
Jack
ALSA
Don't forget RtAudio:
http://www.music.mcgill.ca/~gary/rtaudio/
Particularly in combination with STK's RtWvOut object, using it is
nice and simple:
------------
#include "RtWvOut.h"
#include <math.h>
int main()
{
RtWvOut dac;
int i=1;
while (i++)
dac.tick(sin(i*6.28*440/44100));
}
------------
Steve
5667
days inactive
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days old
linux-audio-dev@lists.linuxaudio.org
8 comments
6 participants
participants (6)
-
AlgoMantra -
Erik de Castro Lopo -
Fred Gleason -
Jens M Andreasen -
Renato Fabbri -
Stephen Sinclair