Editing Voice while calling - Android

Question

I am newbie in android developing, I have searched for this question but i didn't find my answer.

I want to know is there any ability to edit the sound calls in android?

I mean i want to add noise or change sounds of caller, Is it possible to change the sound in calls or adding a new sound to it?

Answer 1

TL DR : The answer is not yet.

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And it's not like we've been waiting. The first entry i can find is from July 31 of 2009, the issue #3434 and, as of today (May 13 of 2015) it's still has not been assigned.

It's really hard to actually work on low-latency project, audio recording and of course, voices changers when you can't do low latency.

Not to say there's hasn't been any workarounds, you could emulate yourself the call, and add the voice effect sure (build your own dialer, and work with that), but let me warn you : you probably won't have any good perfs when it comes to real-time appliucations. No low-latency means no efficiency when it comes to audio recording.

You'll have to wait then.

Answer 2

Your question can be resolved partially depending your using model. the premises are :

1. you just want to eject some noise into your outgoing audio stream, not into the incoming audio stream.
2. you may use a third-party VoIP application to make the phone call.

or simply say, you just want the peer to hear some modified voice. it is feasible.

Normal a native phone application on Android platform uses "Android audio system module" in the framework, the vendor provided audio libraries and Linux ALSA audio libraries to transmit/receive the audio data. These .so and .a files are under the read-only mode normally and could not be overwritten by user, so you can not inject data into this data chain.

But you have more capability to manipulate the data if you use a VoIP application to make the phone call, some VoIP applications can give a real phone number, like Fongo, you can receive a phone call to that number, the caller does not know you are using a VoIP application to speak.

So if I was assigned to do this project, here are my steps:

1. find a usable and open sourced VoIP client on Android.
2. find the code to sample the audio data from microphone ,add the code to manipulate the raw PCM data and send the result to audio encoder.
3. build and run it on Android
4. register or apply a phone number for this VoIP client.
5. done.

Hope it help