How to play audio files by overlapping some area between 2 adjacent audio files?

Question

I have 5 audio files with each having length 5 seconds. I wanted to play each sound file one by one but the condition is if an audio file playing next file should play after 4 seconds ie adjacent audio file sounds should overlap for 1 second. How can I implement it? Which is the best audio player you can suggest?

Answer 1

The amount of specific work you can do with audio playback on the Java side is pretty limited on android.

It sounds like you will need to mix your sounds at some point during their playback to overlap.

The best way to do this in my head is through a C++ library called Oboe (I am currently working with this). This is a library created by Google for audio playback. Now hold on now, let me explain! I know implementing C++ (especially if your only on the Java stack right now) can add a bit of time to your project.

The reason this came to mind is because in this way of playing audio (through Oboe/C++), you physically move individual bits of the audio sample through a buffer stream. The C++ libraries also actually have a Mixer class that you can put 2 different audio samples (up to 100 actually) into to mix, and then eventually render through the buffer stream.

Using this methodology, you can add specific logic to manage when your audio starts playing (after 4 seconds if adjacent). At which point you can mix the first second of the next clip with the current playing clip.

Now the exciting bit, is you may be able to replicate this process in Java! I found this post which may be of help to you:

Android: How to mix 2 audio files and reproduce them with soundPool

Now I do warn you, rendering audio in this way (through buffer streams) is a complicated process, and some extra research may be needed to fully understand the process. I can't say I know all of the functionality of the Java audio libraries, but I'm willing to bet they don't have much support for mixing sound in the way that you need. So most likely you will have to mix it yourself, or your last resort might be to use the NDK (C++).

Hopefully this answer helps. The best wishes in your research! Hopefully you will find a simple way that works. (If you do, don't forget to share your findings on this question!)