"Tremolo" is (simplifying a little) a fast native library to read OggVorbis on Android. See http://wss.co.uk/pinknoise/tremolo/ for the details.

This repository allows to easily recompile Tremolo and copy the result over the Castle Game Engine sources. It assumes:

• You have installed Android NDK, and ndk-build is on $PATH.

• The source code of Castle Game Engine is in $CASTLE_ENGINE_PATH.

Then just run make build .

It will recompile the library for the appropriate Android versions and architectures used by Castle Game Engine:

• 32-bit ARM
• 64-bit ARM (aka Aarch64)
• 32-bit X86
• 64-bit X86 (x86_64)

Right now, assumes using NDK 25, to have 16 KB ELF alignment.

It is possible to alternatively use a low-precision version of Tremolo. Instead of libtremolo.so, you would take libtremolo-low-precision.so. The low precision version may be faster, although the quality is very bad in my tests.

You can use these libraries with Castle Game Engine "ogg_vorbis" component (see https://github.com/castle-engine/castle-engine/blob/master/tools/build-tool/data/android/integrated-services/ogg_vorbis/README.adoc ).

The source code here is taken from Tremolo 0.08 release, http://wss.co.uk/pinknoise/tremolo/Tremolo008.zip . The idea to arrange it like this, to easily compile using NDK, is from http://repo.or.cz/openal-soft/android.git . Michalis only did some tiny changes to Android.mk to easily compile both shared libraries.