Can someone please point me to a posting policy regarding this mailing list?
Personally I’d prefer not seeing html tags in the body of an email message
but that’s just me…
Also there is an unanswered question concerning audio under win32. When I
set a sample rate of 10,000 the playback frequency is much higher. When I
set a rate of 11,025 it works ok. Is there a bug, or is there a requirement
that the sampling rate be a factor of CD sampling rate? Works fine under
linux.
-Dave
Can someone please point me to a posting policy regarding this mailing list?
Personally I’d prefer not seeing html tags in the body of an email message
but that’s just me…
My mailer doesn’t understand HTML, so I would appreciate it if people not
post using HTML.
Also there is an unanswered question concerning audio under win32. When I
set a sample rate of 10,000 the playback frequency is much higher. When I
set a rate of 11,025 it works ok. Is there a bug, or is there a requirement
that the sampling rate be a factor of CD sampling rate? Works fine under
linux.
SDL doesn’t do rate conversion except with multiples of 11025 Hz.
I have an idea of how to fix this, but I haven’t implemented it yet.
-Sam Lantinga (slouken at devolution.com)
Lead Programmer, Loki Entertainment Software–
“Any sufficiently advanced bug is indistinguishable from a feature”
– Rich Kulawiec
“Dave Ashley (SDL list)” wrote:
Also there is an unanswered question concerning audio under win32. When I
set a sample rate of 10,000 the playback frequency is much higher. When I
set a rate of 11,025 it works ok. Is there a bug, or is there a requirement
that the sampling rate be a factor of CD sampling rate? Works fine under
Certainly not factor of CD s.r. … 44100, 88200, 132300… doesn’t make much
sense to me :-))
Maybe some hardware cannot support ‘strange’ rates (and 10000 is strange). It
would be safer to use 8192, 11025, 22050 or 44100 Hz. Or maybe (probable) the
problem is not in hw but in windows OS code? They (Microsoft) never use
anything but 11,22,44kHz (see WAV docs). On the other hand, DirectX has support
for it… at least in 3d sound api.
Vasek
set a rate of 11,025 it works ok. Is there a bug, or is there a requirement
that the sampling rate be a factor of CD sampling rate? Works fine underCertainly not factor of CD s.r. … 44100, 88200, 132300… doesn’t make much
sense to me :-))
…
Vasek
You’re listing multiples of 44100, not factors of 44100.
Anyway the code originated using a sample rate of 10,000 and direct
writes to the soundblaster hardware (msdos). Then I converted the sound
code to linux and kept the sampling rate the same and it worked. Then
going to SDL linux sound it worked fine. Just didn’t work right under
win32 SDL. So I switched to 11025 and lived with the higher pitches…
I doubt if 8192 would have worked now since Sam said the mixing only works
in factors of 44100.
-Dave
set a rate of 11,025 it works ok. Is there a bug, or is there a requirement
that the sampling rate be a factor of CD sampling rate? Works fine underCertainly not factor of CD s.r. … 44100, 88200, 132300… doesn’t make much
sense to me :-))
…
Vasek
You’re listing multiples of 44100, not factors of 44100.
Anyway the code originated using a sample rate of 10,000 and direct
writes to the soundblaster hardware (msdos). Then I converted the sound
code to linux and kept the sampling rate the same and it worked. Then
going to SDL linux sound it worked fine. Just didn’t work right under
win32 SDL. So I switched to 11025 and lived with the higher pitches…
I doubt if 8192 would have worked now since Sam said the mixing only works
in factors of 44100.
It’s actually rate conversion that only works with multiples of 11025
If the underlying hardware supports the requested rate, no problem.
-Sam Lantinga (slouken at devolution.com)
Lead Programmer, Loki Entertainment Software–
“Any sufficiently advanced bug is indistinguishable from a feature”
– Rich Kulawiec
It’s actually rate conversion that only works with multiples of 11025
If the underlying hardware supports the requested rate, no problem.
-Sam Lantinga (slouken at devolution.com)
Hmmm. I don’t know if I’m doing rate conversion. The code I’m speaking of
is sdlscavenger and it’s off of my web page
http://www.xdr.com/dash/linux.html
Follow the scavenger link.
As far as I know it is just trying to output a sample. If rate conversion
is involved I’m not explicitly requesting it. I’m not even familiar with
that term as regards SDL…
-Dave
It’s actually rate conversion that only works with multiples of 11025
If the underlying hardware supports the requested rate, no problem.
-Sam Lantinga (slouken at devolution.com)
Hmmm. I don’t know if I’m doing rate conversion. The code I’m speaking of
is sdlscavenger and it’s off of my web page
http://www.xdr.com/dash/linux.html
Follow the scavenger link.
As far as I know it is just trying to output a sample. If rate conversion
is involved I’m not explicitly requesting it. I’m not even familiar with
that term as regards SDL…
If the underlying hardware does not support the requested rate, and you
pass NULL as the second argument to SDL_OpenAudio(), then SDL will try to
do rate conversion for you.
-Sam Lantinga (slouken at devolution.com)
Lead Programmer, Loki Entertainment Software–
“Any sufficiently advanced bug is indistinguishable from a feature”
– Rich Kulawiec
“Dave Ashley (SDL list)” wrote:
Certainly not factor of CD s.r. … 44100, 88200, 132300… doesn’t make much
sense to me :-))
…
VasekYou’re listing multiples of 44100, not factors of 44100.
Oops. I should rather shut up if I don’t know the language… ;-(
Anyway the code originated using a sample rate of 10,000 and direct
writes to the soundblaster hardware (msdos). Then I converted the sound
code to linux and kept the sampling rate the same and it worked. Then
going to SDL linux sound it worked fine. Just didn’t work right under
win32 SDL. So I switched to 11025 and lived with the higher pitches…
I doubt if 8192 would have worked now since Sam said the mixing only works
in factors of 44100.
I see. But it works under SDL/Linux so the problem MUST be either in win32 or
SDL-dx5 (if you don’t use DIB version). I think I do remember some problems with
DirectX and arbitrary frequencies, but I can’t say I’m 100% sure.
Wouldn’t the easiest solution really be to convert your samples to 11025? You
could use SOX to convert it…
Vasek
Anyway the code originated using a sample rate of 10,000 and direct
writes to the soundblaster hardware (msdos). Then I converted the sound
code to linux and kept the sampling rate the same and it worked. Then
going to SDL linux sound it worked fine. Just didn’t work right under
win32 SDL. So I switched to 11025 and lived with the higher pitches…
I doubt if 8192 would have worked now since Sam said the mixing only works
in factors of 44100.
I think the Win32 sound API limits you to the standard 8192 Hz (which is
the Sun Audio sampling rate, also close enough to digital telephony
rates), 11025 (one-quarter the CD sampling rate), 22050 (half the CD
sampling rate), and 44100 (the full CD sampling rate). Oddball rates like
10 kHz are allowed by almost all sound cards; it’s just that the Win32 API
doesn’t have facilities to allow us to use them. I believe that the OSS
API under Linux has no such limitations, and so 10 kHz works fine.
BTW, you could easily perform rate conversion with minimal degradation
using Sox or some other sound file format conversion utility under Linux.
Since we are all stuck to using the sampling rates Win32 allows if we
want our programs to be cross-platform portable, we might as well
resample stuff at the standard rates; after all 11K is not all that much
more than 10K.On Thu, 26 Aug 1999, Dave Ashley wrote:
| Rafael R. Sevilla @Rafael_R_Sevilla_94 |
| Instrumentation, Robotics, and Control Laboratory |
| College of Engineering, University of the Philippines, Diliman |
|---|
Being the official people we are on this list, it’s something along the lines
of “be nice” 
If you don’t know what that means, it means no HTML, no large attachments, no
useless flaming, and plenty of idea sharing 
Oh, and can somebody shoot the authors of Cc: mail? ;-)On Wed, Aug 25, 1999 at 09:26:42PM -0700, Dave Ashley wrote:
Can someone please point me to a posting policy regarding this mailing list?
–
– Michael Samuel