Skip to content

Playground

Jump to bottom
Jürgen Hock edited this page Oct 17, 2025 · 1 revision

Debugging

ADB

Use USB wire to install and run the app on your smartphone using Android Studio. Alternatively set up the Wi-Fi connection.

https://developer.android.com/tools/adb

Logcat

Use the Logcat compatible logger Log.h, which supports fmt based string formatting:

Log::d("2 + 2 = {0}", 4);

The logger should be already available in all .cpp source files. Otherwise include:

#include <voicesmith/Source.h>

In order to display only log entries produced by the logger, specify following filter string in the Logcat window:

voicesmith.java | voicesmith.cpp

https://developer.android.com/studio/debug/logcat

Audio Effect

An audio effect implements the following interface:

#include <voicesmith/fx/AudioEffect.h>

The reset callback is triggered once at startup. It provides the audio stream parameters in advance. Not all audio effects need to implement this event.

The apply callback is triggered on data block processing. The input and output buffers are of the same length and address the normalized mono samples.

Use the StereoChainEffect to combine multiple audio effects. It can handle both mono and stereo signal paths.

Audio Plugin

An audio plugin implements the following interface:

#include <voicesmith/fx/AudioPlugin.h>

and another one in the Kotlin domain:

AudioPlugin.kt

The purpose of the audio plugin is to manage the AudioSource, AudioSink, AudioPipeline, and [Stereo]ChainEffect instances.

It also must provide callbacks setup and set for parameter synchronization, as well as callbacks start and stop for state management.

On the Kotlin side the MainActivity.kt file provides the UI for the associated audio plugin, which is currently the TestAudioPlugin by default.

Currently the MainActivity.kt exposes three audio parameters:

  • delay in milliseconds
  • pitch in semitones
  • timbre in semitones

The parameter value range is also specified in the same .kt file. In default case, a change to any parameter triggers the TestAudioPlugin::set callback in the C++ domain. The parameter names and values are passed as a string.

The audio plugin preferences are managed by the Preferences.kt. The AudioFeatures.kt provides system defaults for samplesrate and blocksize.

Clone this wiki locally