Advanced Porcupine Recording settings

[Nailik]

Add an option so users can choose whether porcupine also uses the advanced audio input settings.

This issue is a follow up to https://github.com/Nailik/rhasspy_mobile/issues/326

Use this function to process incoming data https://github.com/Picovoice/porcupine/blob/ec787ddcd69e54d6a54158125f0da5a4724e37d6/binding/android/Porcupine/porcupine/src/main/java/ai/picovoice/porcupine/Porcupine.java#L98

The only issue is, that it seems like they only support mono pcm audio with a special sample rate so it might be required to to record the audio and then process it depending on what the user has selected in the audio settings.

Here is an example how to convert stereo to audio: https://stackoverflow.com/questions/17363705/how-to-convert-audio-from-stereo-to-mono-in-android

Todos:

• When user selects Default or Stereo add the option if porcupine should use left, right or average mono (maybe remove default?)
• rename PCM_32BIT to PCM32Bit
• convert Stereo to Mono and send it to porcupine (don't use porcupine start function)
• check which sample rate porcupine uses max and convert from user selected sample rate down to whatever is necessary https://github.com/openimaj/openimaj/blob/master/audio/audio-processing/src/main/java/org/openimaj/audio/conversion/SampleRateConverter.java

[Nailik]

After a first test it seems that porcupine needs ShortArrays of exactly 512 shorts. They use 12000Hz, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT and those values also work when using the custom recorder but not when using anotherone.

Seems like some conversion is needed:

• Stereo to Mono
• Any Samplerate to 12000Hz
• PCM8BIT and PCM32BIT to PCM16BIT

[Nailik]

https://github.com/Nailik/AndroidResampler enables me to implement those changes.

However it does not support changing bit depth yet, which results in porcupine not working when setting other values than pcm16bit