We're currently using Linphone library to make VOIP calls and they have their own solution for audio playback. However, we would like to display a visualizer for the audio that Linphone is outputting from within our own app. Is there a way that we can intercept this data (maybe through sample buffering) in order to draw up audio waves/volume meter in the user interface?
AVAudioPlayer or AVPlayer is out of the question since we do not have access to those objects. Is there a solution in place for AVAudioSession or in CoreAudio?
Only if the audio output app is exporting the audio data using Inter-App-audio or Audiobus. Otherwise the iOS security sandbox will hide that audio output from your app.
Related
I want to get my OWN app audio output (for example currently playing video in UIWebView) and save it to file. How to create a AudioKit Node for this purpose?
Just because your app has audio doesn't really mean you have control of the audio if you're just using web views for instance. Another example is using the speech synthesizer in iOS - the app utters the speech, but you can't direct that audio anywhere except to the user's speaker.
I'm aiming to create an audio-visualisation app for iOS. I need to somehow tap into the current audio output from another app (such as Apple's music app, or Spotify) and get the amplitude of the signal for each sample of the music. I will then perform an FFT algorithm on the data to convert it to the frequency-domain and display the data visually.
Is it possible to read this data from the audio output of other apps? If so, what do I need to use to extract this data?
No. The iOS security sandbox will prevent the reading of any audio samples from other apps via any public API (unless the playing app was coded to explicitly export audio data via inter-app audio or other similar interface).
I am looking at the feasibility of getting the current raw audio stream playing and do stuff with it such as stream it over Bluetooth or equalize it, etc. Is there any way to do this in iOS 8?
For example: apps such as Pandora/Spotify are playing music and I want to access the audio they are playing.
To process audio from another app, that app needs to participate in Inter-App Audio.
I don't know if your example apps do that.
I'm in the process of building an app that uses the IPod Library Access API, so that I can play songs from iTunes in the app. However I also need to access the audio data of whatever song is playing, like how a music visualizer would.
So far, looking through the Audio Session documentation and the Core Audio documentation, I haven't found any officially supported means of achieving this. As I understand it, it would require accessing audio data from another audio session, as in the iPod access api, technically iTunes is playing in the background as I understand it and thus has a different audio session.
So basically how can you access audio data from another audio session? Specifically getting the audio data of songs played through the iPod Access API?
See the AudioTapProcessor iOS Sample sample app in Apple's iOS Developer Library (sign on required), for the use of the AVFoundation MTAudioProcessingTap API.
I want to process the stereo output from iOS devices, no matter what application causes them and visualize it in real-time.
Is it possible to use the generic output device (or anything else) to get at the audio data which are currently being played? Maybe as an input to a remoteIO unit?
In other words: I want to do what aurioTouch2 does (FFT only) but instead of using the microphone as input source, I want to process everything which is coming out of the speakers at a given time.
Kind regards
If your own app is playing using the RemoteIO Audio Unit, you can capture that content. You can not capture audio your app is playing using many of the other audio APIs. The iOS security sandbox will prevent your app from capturing audio that any other app is playing (unless that app explicitly exports audio via the Inter-App Audio API or equivalent).