[openal] Not Find DirecSound on Windows

[Chris Robinson]

On 12/31/2014 12:30 PM, William Wolff wrote:
> Hi!
>
> I download OpenAL Soft on my Windows machine and cmake it properly
> and everything was fine, but cmake not find the DSOUND Backend and
> not properly create the Project to support it.
> This is strange because DirectX are not being distributed anymore,
> but are coming natively with the S.O.

You need the dsound.lib and dsound.h to build applications and libraries 
that use dsound. The dsound.dll that comes with the system isn't enough.

The lib and header files are part of the DirectX SDK, as far as I know. 
Do you have those anywhere on your system?