I was having issues with a lack of doppler when using the current
version of OpenAL (head of cvs source tree) on Mac OS X until I noticed
that it defaults to a doppler factor of 0 while our code assumed that
it defaulted to 1 as the specification outlines.
Thank for the following note in the implementation document... not sure
how I missed it on my first of reading it.
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Notable areas that still need to be addressed;
- Doppler: The 3DMixer actually has doppler support built in, but
I have left it off for now as I think to make
this feature useful, an application has to have it
avilable during development so the behavior
and speed of the OALSources actually produces the
desired effect for the listener. I don't believe
Ryan has any doppler support in UT2003, do any
implmentations make use of this part of the
specification?
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Not a big deal for us to correct by setting doppler in our code. Given
the above comment I want to let any Apple folks listening that at least
one game (World War ][ Online, wwiionline.com) is using doppler and has
its sound field designed/tuned to work with it (at least for some
definition of tuned).
We are still having unusual minor pops, crackles, etc. when using the
latest (again built from head of cvs source) OpenAL for Mac OS X,
quirks we didn't have (or at least hear) with a prior version (pre 3D
mixer IIRC). Also some folks are complaining about the general sound
quality of the 3D sound field (even with the
ALC_SPATIAL_RENDERING_QUALITY_HIGH set). I personally have found in
testing that sounds seem to walk across the sound field in steps not as
smoothly as they did with prior versions (could be an artifact of how
we set and update sound locations and velocities. So it may be helpful
if I can hook up with some Apple folks working on OpenAL and Core Audio
for a little listening, testing, consulting, and gaming fun even. I
know the 3D mixer can do some neat and good quality sounding stuff so
it likely is an issue of tuning out inputs to OpenAL a little better.
I should also report that I found an issue with customers that have
sound output set to a rate other then 44KHz. If say set to 48KHz when
they try to play the game the quickly get a very loud and persistent
hiss in the right channel and crackling in the left channel (and other
speakers in a multi-channel system). So something may be wrong in the
resampling that I believe the implementation/read me implies should be
happening automatically. Our sounds are loaded out of wav buffers
sampled at 44KHz. Note sure how to report the issue officially....
-Shawn
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Shawn Carl Erickson
FreeTime Software
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