OpenAL-Soft needs HRTF data for the extension to work. On Windows, by default OpenAL-Soft uses the %APPDATA% folder for this (download the binary distribution and see readme.txt for details). But you can easily override it with the ALSOFT_CONF environment variable:
- Download the
sample config file, rename it (say alsoft.conf), put it with your app.
- Download the
sample HRTFs, put them in a folder.
- Set the
hrtf-paths property in the config file to the folder where you put the HRTFs.
- Set the ALSOFT_CONF environment variable to the config file path.
If you now query ALC_NUM_HRTF_SPECIFIERS_SOFT, before creating the context, it should return 2. Querying ALC_HRTF_SPECIFIER_SOFT with alcGetStringiSOFT, using indices 0 and 1, should return the two HRTFs. If you get to that point, HRTF should be enabled when you create the context with ALC_HRTF_SOFT set to ALC_TRUE.