Waveform

This application uses line detection to detect a soundwave through your phone's camera. Point your phone at a clear surface, and draw a soundwave on it. That soundwave will then be rendered in real audio, and played through your phone's speaker.

This app uses some open source code licensed under the Apache license version 2.

That open source code can be found here:

https://github.com/google/music-synthesizer-for-android

Here's the apache license:

https://github.com/google/music-synthesizer-for-android/blob/master/COPYING