I'm just beginning my research into this question and simply because the need for a fast turn around I thought I would post the question here while I continue research on my own.
The first question I have is, is it possible to detect the device's outgoing audio signal(s) - from any source - using CoreAudio or any of the audio frameworks (or combination of) listed in the dev library?
My instinct tells me this is locked down.
Has anyone any experience with this?
I guess you can only detect if its playing or not with using
[[AVAudioSession sharedInstance] secondaryAudioShouldBeSilencedHint]
Will be true when another application with a non-mixable audio session
is playing audio
Related
I understand that this question might get a bad rating, but I've been looking at questions which ask how to reroute audio output to the loud speaker on iOS devices.
Every question I looked at the user talked about using your AVAudioSession to reroute it.. However, I'm not using AVAudioSession, I'm using an AVAudioEngine.
So basically my question is, even though I'm using an AVAudioEngine, should I still have an AVAudioSession?
If so, what is the relationship between these two objects? Or is there a way to connect an AVAudioEngine to an AVAudioSession?
If this is not the case, and there is no relation between an AVAudioEngine and an AVAudioSession, than how do you reroute audio so that it plays out of the main speakers on an iOS device rather than the earpiece.
Thank you!
AVAudioSession is specific to iOS and coordinates audio playback between apps, so that, for example, audio is stopped when a call comes in, or music playback stops when the user starts a movie. This API is needed to make sure an app behaves correctly in response to such events
AVAudioEngine is a modern Objective-C API for playback and recording. It provides a level of control for which you previously had to drop down to the C APIs of the Audio Toolbox framework (for example, with real-time audio tasks). The audio engine APIs are built to interface well with lower-level APIs, so you can still drop down to Audio Toolbox if you have to.
The basic concept of this API is to build up a graph of audio nodes, ranging from source nodes (players and microphones) and overprocessing nodes (mixers and effects) to destination nodes (hardware outputs). Each node has a certain number of input and output busses with well-defined data formats. This architecture makes it very flexible and powerful. And it even integrates with audio units.
so there is no inclusive relation between this .
Source Link : https://www.objc.io/issues/24-audio/audio-api-overview/
Yes it is not clearly commented , however, I found this comment from ios developer documentation.
AVFoundation playback and recording classes automatically activate your audio session.
Document Link : https://developer.apple.com/library/content/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/ConfiguringanAudioSession/ConfiguringanAudioSession.html
I hope this may help you.
I'm making an app where I gotta record sound through microphone, change its pitch, save it in Documents Directory and play it.
I have accomplished the recording and playing part successfully via AVRecorder and AVAudioPlayer. But I'm unable to change the pitch of the recorder sound :(
Searched a lot all over StackOverlow and Google, but all methods aren't working. DIRAC is not available now I guess, SoundTouch integration is going over my head, other solutions are in Objectice-C++ which I don't understand.
Also tried OpenAL, but it only allows to play the changed pitch sound, not save it.
Please tell me if it's possible using Objective-C, or any other example/tutorial.
Thank you.
I'm having some trouble working with the iOS Audio frameworks to create a simple app. I would like to record audio through the Microphone and play it back to the user while recording.
I have tried each of the audio framework layers(AVFoundation, Audio Queue API, and RemoteIO), but have only found old documentation and broken examples.It seems like a simple request that AVFoundation should handle, but I have explored the following other SO questions and still find myself circling for hours to get the hang of this. Here is what I have reviewed:
iOS: Sample code for simultaneous record and playback (Other SO Users also state the accepted answer is not concrete and difficult to implement even with a delay of ~70ms.)
Record and play audio Simultaneously (From 2010 and very high level, I have downloaded the sample code and can't find a working example that does simultaneous playback and recording).
Adjust the length of an AudioUnit Buffer (RemoteIO is so confusing to me right now, is this really required?)
I have also downloaded and reviewed both the SpeakHere and AurioTouch sample projects from Apple. I promise I wouldn't post up without hours of googling and struggling. You can see "record audio and playback iOS simultaneously" returns many dated and non-working examples.I know myself and the community could really benefit from some updated documentation and examples in the audio section. RemoteIO seems to be too advanced for such a simple task. Thanks again for your help and consideration.
The appropriate way to do this is via AudioUnit APIs, even though it seems like a common scenario which should be handled by higher level APIs.
I wrote a small demo app using AudioUnit. You're free to try it our and modify it for suiting your purpose. The demo app does record audio and play it simultaneously, but it's recommended to use a ear phone to see the effect.
The RemoteIO Audio Unit is the only way to play back what is being recorded with low latency. RemoteIO is low latency because it runs audio callbacks in a separate dedicated real-time thread which is why it is fast, but also why it is a bit more complex to code. All the other iOS audio APIs are built on top of RemoteIO and thus add latency.
You will also need to configure the app's Audio Session APIs to request low latency with the appropriate audio session type. The foreground app can request and get audio input and output latencies as low as 5.6 milliseconds on most iOS devices most of the time.
I'm building an app in which I need to steam multiple tracks of audio that make up a song. They all need to be synchronized so the song plays back naturally.
I've been able to play back local multitrack audio very well with the solution on this thread: multi track mp3 playback for iOS application, but it looks like AVAudioPlayer isn't able to stream.
I've been looking into working with DOUAudioStreamer because I've read that it's the best solution for streaming audio on iOS without going pretty low-level, but it seems to lack the equivalent of a -playAtTime: method, which is how the tracks were synced up using `AVAudioPlayer.
Does anyone know a workaround for this using DOUAudioStreamer, or have any advice on another way I should approach this? Thanks.
I am using UIImagePickerController for recording video in one of my application. i have successfully Recorded video. But now i want to mute mic (video without audio) while recording video.
i have searched Alot but not a single clue about it.
please help me about this issue.
is it possible or not. if possible than how.
thanks in advance.
If you want your app to be in app store , then there is no apple approved method to actually mute whole iPhone.There are certain libraries but they are not approved.
Apple's documentation on Audio Session
According to the documentation you can only ask the user to have the phone silenced physically and you can respond to certain audio changes such as other sounds,phone calls, email sounds but you cannot mute programmatically.
Also See this Documentation on Programming in iPhone See the part 3.3 for Audio.(Events that can be accessed and performed in iOS).
You can use AVFoundation framework to record a video without the sound, check at this :
AVFoundation Programming Guide