3D mono playback chirps when listener turns rapidly

Frank Black <[email protected]> Fri, 26 Apr 2013 07:31:03 +0300
Newsgroups gmane.comp.lib.openal
Message-ID <CALgHfE-G858qFnSNhA+KO3-KQLXhD1PJmUb_TogZhxJH2Uyy9Q@mail.gmail.com>
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Hi All,

I have downloaded SDK and been playing around with precompiled tool
EFX10ShowWin32 for a while. Created a source with a smooth looped sample at
2,0,0 and placed the listener at 0,0,0.
Opening the graphical aid (menu/windows/position window) and by dragging
the listener direction knob around in circles i hear chirping sounds when
the angle changes rapidly.

The sample i used is a smooth string, 16bit MONO 22k rate and loops nicely
when listener is left without turning.

I have quickly integrated OpenAL to the game i contribute to at
mage-online.com, and i experience similar chirping noises now.

The openal device is created by using defaults (NULL), i skipped
enumeration. I have tested it on win98, win7 systems and getting similar
noises.

The noise gets worst when the source is moving rapidly from left to right
(using earphones).

Is there any way to raise the priority level of the audio library? Could
that be the problem?

Next, i tried using 16bit Stereo sample and calculating myself the distance
and gain factors. This way the chirping goes away (but of course this is
not 3D anymore).

Thanks,
Frank

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<div dir=3D"ltr"><div><div><div>Hi All,<br><br></div>I have downloaded SDK =
and been playing around with precompiled tool EFX10ShowWin32 for a while. C=
reated a source with a smooth looped sample at 2,0,0 and placed the listene=
r at 0,0,0.<br>
</div>Opening the graphical aid (menu/windows/position window) and by dragg=
ing the listener direction knob around in circles i hear chirping sounds wh=
en the angle changes rapidly.<br><br></div><div>The sample i used is a smoo=
th string, 16bit MONO 22k rate and loops nicely when listener is left witho=
ut turning.<br>
<br></div><div>I have quickly integrated OpenAL to the game i contribute to=
 at <a href=3D"http://mage-online.com">mage-online.com</a>, and i experienc=
e similar chirping noises now.<br><br></div><div>The openal device is creat=
ed by using defaults (NULL), i skipped enumeration. I have tested it on win=
98, win7 systems and getting similar noises.<br>
<br></div><div>The noise gets worst when the source is moving rapidly from =
left to right (using earphones).<br><br></div><div>Is there any way to rais=
e the priority level of the audio library? Could that be the problem?<br>
<br></div><div>Next, i tried using 16bit Stereo sample and calculating myse=
lf the distance and gain factors. This way the chirping goes away (but of c=
ourse this is not 3D anymore).<br></div><div><br></div><div>Thanks,<br>
</div><div>Frank<br></div></div>

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