Upload Android APK to GitHub (pre)release

[ThreeDeeJay]

We'll be able to download the Android app from the repo's GitHub releases like this: https://github.com/ThreeDeeJay/sview/releases/tag/latest

The reason for this is that HRTF is broken in the current Android app, apparently because of 2 reasons:

• The library is too old, but updating solved part of the problem, just like on Windows "OpenAL HRTF mixing: Unsupported format" - Fixed in OpenAL Soft #115. There's some relevant discussion, where someone built libopenal.so (32 and 64 bits) Compiling OpenAL 1.23.0 for Android. kcat/openal-soft#824 (comment)
• The MHR (HRTF) file can't be found because even though it exists in openal-soft-1.17.2-arm7.tar.bz2, it doesn't seem to be copied anywhere, so OpenAL Soft falls back to non-HRTF stereo. So I think a solution would be embedding Default HRTF.mhr and also allowing custom MHRs loaded from public data locations like: sdcard/Android/data/com.sview/, or somewhere easier to access like sdcard/OpenAL/HRTF

I figured this out because since my phone happened to be rooted, I was able to replace the .so library in /data/app/.../<sview lib folder>/ and also create a alsoftrc.config in /etc/openal/ where I specified an existing path to load the MHR from (According to the log, it attempts to load MHRs from /usr/local/share/openal/hrtf, /usr/share/openal/hrtf and ./, which seem like Linux paths that aren't present/accessible by non-root apps on Android). After this, HRTF worked in surround/ambisonics files even without having to turn it on in the settings.

Anyhow, I submitted gkv311/sview-deps-android#1 to fix one part of the issue, till we figure out how to embed/load custom MHRs externally. 👀👌

[ThreeDeeJay]

@gkv311 Good news: Turns out there was a bug in OpenAL Soft that caused the Android library to crash when attempting to load the embedded HRTF, but it was just fixed earlier in kcat/openal-soft#1010 (comment)

Also, the pre-built library can now be downloaded from GitHub Actions artifacts https://github.com/kcat/openal-soft/actions/runs/10230657183, which I included in my sview-deps-android fork

So long story short, merging this PR and gkv311/sview-deps-android#1 should fix HRTF👏
Just gotta enable it in the settings. No more need for root, config file or external HRTFs.

[gkv311]

Also, the pre-built library can now be downloaded from GitHub Actions artifacts

It's nice to see OpenAL soft have automated builds for Android now!

[ThreeDeeJay]

It's nice to see OpenAL soft have automated builds for Android now!

Absolutely.

By the way, would you happen to know how to get the AudioDeviceInfo type and getExternalFilesDirs (e.g. storage/emulated/0/Android/data/com.sview/) via C++ instead of Java?
We're hoping that'd allow OpenAL Soft to detect headphones to auto-enable HRTF, and to load user config/HRTF, respectively.

Otherwise, perhaps sView could add the external app data folder as a path to load alsoft.conf and MHR (HRTF) files on its end 🤔

The app would set the ALSOFT_LOCAL_PATH env var with setenv to the path it provides for the user to add mhr files (where it will look in the given path directly, no subdirs). Or append a path to XDG_DATA_DIRS where OpenAL Soft will then look in <path>/openal/hrtf/ for more mhr files.

Similarly, it can prepend a path to XDG_CONFIG_DIRS where it will look for <path>/alsoft.conf. This needs to be done before making any OpenAL calls, since OpenAL Soft will initialize and load the config settings on certain calls, and won't reload the configs afterward.