improve androidaudioplugin-samples-host-engine and androidaudioplugin-ui-compose

[atsushieno]

There have been couple of attempts to improve the plugin's MainActivity i.e. androidaudioplugin-ui-compose. Its feature set is limited to what androidaudioplugin-samples-host-engine provides.

Technically, it is just an example use case, but since it is being widely used, I would rather like to have something better.

Namely:

• user can pick up arbitrary audio sample to apply effects.
• ~user can determine some MIDI sequence, either an SMF and/or UMP sequence picker, to apply.~ We leave it to resident-midi-keyboard. Playing SMF etc. is overkill for a preview app. It also adds extraneous state management burden.
• ~static or dynamic application example.~ Static plugin application has quite different paradigm, so we would focus on dynamic plugin application and keep things only instant.
• host parameter controls that responds to Web and native UI inputs i.e. resembles what typical DAWs do.

[atsushieno]

There has been plugin-manager-ui-vnext branch which should become the new main (to be merged). Not really working with audio I/O yet though.

[atsushieno]

the plugin-manager-ui-vnext branch almost caught up with what samples-host-engine provides now:

• pros:
  • it can play arbitrary audio file in theory (needs UI support), and we now use short (uint16_t) based ogg vorbis for the default audio file (embedded resource is way smaller).
  • the embedded keyboard can send MIDI2 notes, pitch bend, etc.
  • native UI can control plugin parameters.
• cons:
  • some audio noise occurs when PluginPlayer is active, and the final audio output to Oboe sounds weird (on both audio playing and synth output via MIDI2)
  • ~controlling parameters via knobs on the generic UI causes crash~ fixed (2903db93)

[atsushieno]

It seems the weird audio output problem ^ is exactly the same as #92.

[atsushieno]

The last remaining issue is fixed and plugin-manager-ui-vnext is now merged into main.

I would close this issue once we finished the replacement work.