Ambisonics to headphones + HRTF's

[CommonDirt]

this may be a silly question, but the Ai's of this world said something, so i thought i'd check

i'm running some old openal supporting games through Soft and wondered if the following settings achieve anything

channels = ambi*
stereo mode = headphones
hrtf's = full

as the game engines support openal natively, does that mean Soft has access to source positional data?

does this data then get encoded in to ambisonics, which then mixed down to an HRTF'd stereo signal?

does this combination of settings result is 3D spatial audio over headphones; and are there some caveats?

[kcat]

i'm running some old openal supporting games through Soft and wondered if the following settings achieve anything

channels = ambi*
stereo mode = headphones
hrtf's = full

Close, that should be:

channels = stereo
stereo-mode = headphones
hrtf-mode = full # or ambi1, ambi2, or ambi3 (or ambi4 with the latest Git version)

as the game engines support openal natively, does that mean Soft has access to source positional data?

Yes, it has the source position provided by the engine. This doesn't necessarily mean it has full 3D position info, but it knows what the engine told OpenAL.

does this data then get encoded in to ambisonics, which then mixed down to an HRTF'd stereo signal?

Using the ambi1, ambi2, ambi3, or ambi4 mode it does. Though with full it mixes sources with HRTF directly, skipping the ambisonic mix (an ambisonic mix is still used for effects processing, or sources that play an ambisonic buffer themselves, but the normal source's direct output goes through the specific HRTF for the given direction), which takes more CPU power with a sufficient number of sources.

does this combination of settings result is 3D spatial audio over headphones; and are there some caveats?

If the app provides 3D positioning info to OpenAL, and your headphones are properly configured as stereo headphones (not virtual 7.1 surround sound, for example), then using the settings I gave above should give you 3D spatial audio. Place the settings into an alsoft.ini file next to the executable, or alsoft.conf on non-Windows systems, and OpenAL Soft should detect it.

[CommonDirt]

when dropping Soft in to a game, i'm guessing i need alsoft.ini, openal32.dll and soft_oal.dll?

[kcat]

Yes. Either that, or alsoft.ini and rename soft_oal.dll to openal32.dll to put with it.

[CommonDirt]

thanks for you help