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The Sound Server FAQ  

UPDATE Feb 21, 2004
The current sound server uses WAVE files ".wav" rather than NDS files.  The following is old information of general use, but the file type is now .wav
Please see MMS Script Template for current information.  updated by Ben Shedd

  1. What kind of sound files does the sound server want?

It wants NDS sound files (or own invention, we have a reason, maybe?. They are 22050Hz sampling rate and 16 bit and may contain any number of channels.

  1. How do I create NDS sound files?

First you have to make sure, that your files use 22050 Hz sampling rate and 16 bit. Many sound files you’ll find out there in the world-wild spaghetti bowl will be something else. So you need to make sure, that you convert the format first. A good program to do this is Goldwave (http://www.goldwave.com).

  1. But how do I use that Goldwave then?

Well, first load the sound file you want to convert. Then make sure, that the sample rate is 22050. For that you should click on menu "Effects/Resample? and change it to 22050. Then "Save as? and select "Save as type:" to be "Sun (*.au)" and "File attributes:" to be "16-bit, mono, signed, byte-swapped" and save it. Goldwave can do a lot more for you, like trimming and manipulating your sounds. (Check out all those fun toys in "Effects".

  1. Is that all? Where does that NDS format come into play?

Then you need to convert your file to NDS format. Run the command-line program snd2nds on your file. Should look like this:

snd2nds yourfilename.au yourfilename.nds

  1. Where do I put my sound files?

The default place, the sound server looks for files is a directory on the server machine, but you’re probably shouldn’t save your files there. Instead you should just put them into:

"S:\DisplayWall\Sounds\cs495\"

where S:\ is hopefully mapped to \\newfs\shrimpNT. There are already a few sound examples in "S:\DisplayWall\Sounds\cs495\examples".

  1. How do I listen to my sound file?

Try:

playsound S:\DisplayWall\Sounds\cs495\mysound.nds

playsound will play your sound file on the sound server. If the file is stereo, the left channel is mapped to all the left speakers and the right channel to all the right. Both channels go into the sub-woofers. Of the sound file is something else (mono or more than 2 channels) the first channel will be played in all speakers.

  1. How do I play more sound files at once and how do I put them into specific speakers?

This is more tricky. You’ll have to create a sound-table file (just a simple text file) that contains the following line for each sound file you want to play:

mysoundfile.nds <volume> <map1> <map2> ?/P>

Where <volume> is a number between 0.0 and 1.0 (silence to loud).

And <mapN> maps this sound file into the speaker with this mapping number.

You can play the sound table by using:

playsoundtable S:\DisplayWall\Sounds\mysoundtable.txt

  1. But how do I know the mapping numbers of the speakers?

Grab them from this picture:

(This picture was adapted from a picture by Perry Cook.)

  1. How do I (insert your favorite fancy idea)?  

Well, you might look into S:\DisplayWall\Sounds\sources\. There is example programs in there which use the NDSoundServerStub-interface to the sound server. If you have some C or C++, you might just be able to do (your favorite fancy idea). You can also bug me (gessl@cs.princeton.edu).

Where do I get a more technical background?

Just read on?/P>

What if I don’t want that background?

Stop reading here!

(Continue on webpage: displayw.html#SoundServer)

 

last edited 04/28/2008