DirectSound 3 Readme File


1. New Features in DirectSound 3
================================

- DirectSound3D is finally available!  This implementation includes
  the ability to position and move sounds in 3D space, complete with Doppler
  shifting, attenation due to distance, and a sound cone feature which
  allows you to create sounds which are louder when pointing straight at
  you than when they are pointing away.  DirectSound3D has a flexible
  coordinate system which allows you to use your internal game coordinates
  and still get the effects you want.  To learn more, check out the help
  files, or look at the following samples:

        \dxsdk\sdk\samples\ds3dview
        \dxsdk\sdk\samples\dsshow3d
        \dxsdk\rockem

- Global Sounds.  Many developers wanted to make sounds even when their
  application is not the foreground application.  Now you can!  Just create
  your sound sound buffer with the DSBCAPS_GLOBALFOCUS flag specified and
  the sound buffer will be audible regardless of sound focus.  However,
  please note the following caveats:

        a) Global sounds will not be audible if the sound focus application
           has the DSSCL_EXCLUSIVE level set.  That application has requested
           that it not be interrupted, so we respect that request.

        b) You can't create a global sound on a DirectSound object that has
           DSSCL_WRITEPRIMARY.


2. New Sound Driver Support
===========================

This release contains support for the ESS 1788 card and new versions of
the ESS 1688 and SoundBlaster AWE 32 cards, in addition to the drivers
supported  in DirectX 1 and 2.  This brings our total sound card coverage
to the following:

- Sound Blaster:  8-bit cards, 16-bit cards, and the AWE32.
- ESS: 488, 688, 1488, 1688, 1788.
- MediaVision: PAS 16, PAS Studio, PAS Plus, Pro 3D, and Blue Lite Special.
- Aztech: Nova 16, Washington 16, Rocky 2.
- Microsoft: Windows Sound System.

Sound cards which do not have DirectSound drivers can still be accessed
through DirectSound.  If no driver is available, DirectSound will use its
emulation layer to communicate with the device through the standard Wave
driver interface.  This provides full DirectSound functionality, but
increases latency significantly and prevents access to hardware
acceleration.

We have also encountered faults in certain situations on the Roland
Rap 10 and the Gravis UltraSound MAX.


3. Known Problems with this release
===================================

- DirectSound3D consumes more CPU than ordinary mixing.  Our measurements
  indicate that it consumes about 6% of a P90 per sound.  If you ask
  DirectSound to play more 3D sounds than the processor is capable of, we
  will do our best to satisfy your demand.  In practice, this will mean
  that the CPU will be overloaded and will be unable to spend any cycles
  on ordinary things like updating your display or reading your keyboard.
  So be sure to test your application to make sure that it runs on your
  low-end target platform.


Thanks!
The DirectSound Team.


