trying to get the setup property kAudioSessionProperty_OverrideCategoryMixWithOthers to work with MediaPlayback category in AudioQueue. Ultimately I need the app to mix with other audio and play in background mode which is what the MediaPlayback category and OverrideCategoryMixWithOthers will accomplish. However, when setting the mixWithOthers property, app crashes. Any suggestions?
Mick
Related
When playing an audio file in watchOS (using SpriteKit):
run(SKAction.playSoundFileNamed("ready.wav", waitForCompletion:false))
It will works until you background the app (says face the watch outwards) and back, then the audio file cannot be played anymore.
I have tried many workarounds, including setting UIBackgroundModes to audio, but the sound will always stop working after the app is background and back. Any solution?
PS: I think I might have found the answer: use AVAudioPlayer instead of SKAction.
You need to start HKWorkoutSession and in info.plist enable workout background processing. Don't need the audio to play in background, just continue to play once it comes back from background.
Use AVAudioPlayer instead of SKAction. This works.
Only SKAction.playSoundFileNamed has this issue.
Currently I am designing an iOS application that will connect to a music stream through a network and play the audio to the user.
I have a simple setup with a button the enables the stream to start, and a UIwebview that connects to the stream. When I run the app (on an iPhone, NOT a simulator), the button works fine and launches the Quicktime player to begin playback for the audio. Pausing and playing from this screen works like a charm as well.
However I want my user to be able to start up the stream, turn the phone off (sleep the display) and continue to listen to the stream. However sleeping the display will fade out the audio until it stops playback.
I have tried to go into the app's PList file like a few others have told me to do online and added the field "Required background modes" and added App plays audio or streams audio/video using Airplay to the 0 array field and App downloads content from the network to the 1 array field.
("App plays audio" was not offered through auto-complete even though that was the phrase told to make the stream work. Instead I left it as "App plays audio or streams audio/video using Airplay" before trying it the other way to little more luck)
However neither of these are allowing the audio to continue to play when the display has been put to sleep. Can anyone offer up a suggestion as to how to make it work?
In Xcode 5.1, there's another place aside from the Plist that this needs to be set, Target -> Capabilities -> Background Modes... this seems to do more than just affect the plist, though I'm not absolutely sure of this.
Look here an sample code https://github.com/jsagorin/iOSBackgroundAudio
and here .. some explanations (how to Set UIBackgroundModes key in app-info.plist file, Set Audio Session Category , etc) http://www.sagorin.org/ios-playing-audio-in-background-audio/
Just make an entry in plist
Application does not require background mode and set its value to 'NO'
And add background Mode to VOIP
I'm working on a radio alarm clock, and i have some issues.
I am using local notifications for the alarms, so it has a gentle fallback if the app is not running.
I am well aware of the limitations of the device, and i know what i can and cannot do when the device has gone into background.
But my question is this:
I have seen other apps starting an audio streamer when i've locked the device. How is this possible? May this be inside an execution-timeframe?
How is the best way to implement this? Is it any way i can activate a streaming session when the device is locked?
Edit
To clarify: I know how i make audio play in the background. But the issue is triggering the audio-playback when an local notification or some other event fires.
One app that seems to do this, is Radio Alarm Clock. I haven't tried it for long period of times yet. But it seems to do this. A video demo of the app: http://www.youtube.com/watch?v=KJQiFOcdBWk
Have you already declared your background task?
Support for some types of background execution must be declared in advance by the app that uses them. An app declares support for a service using its Info.plist file. Add the UIBackgroundModes key to your Info.plist file and set its value to an array containing one or more of the following strings:
audio — The app plays audible content to the user while in the background. (This content includes streaming audio or video content using AirPlay.)
iOS App Programming Guide - Implementing Long Running Background Tasks
You can add this by clicking on your main project icon, then under the Info tab you can add "Required Background Modes" to the "Custom iOS Target Properties" section. "App Plays Audio" will be one of the three default values.
Big Edit With New Answer:
If everything else is already in order, you can keep your app running in the background using the UIApplication method
- (UIBackgroundTaskIdentifier)beginBackgroundTaskWithExpirationHandler:(void (^)(void))handler
detailed here: UIApplication Class Reference
with an example here: Hour 21: Building Background-Aware Applications
This allows you to run an instance of NSTimer which triggers your music player. The difference between this approach and UILocalNotifications is that this method never lets the app fully enter the background mode, the music player exists the entire time which subverts the need to create it from the background, which looks to be impossible.
There may be limitations to how long of a timer you can set, I haven't tested this past 14 minutes out.
we can easily capture a view(screenshot) programmatically in iPhone.
But i am trying to capture screen automatically after every 5 seconds.that also, can be done.
But my main objective is , to capture screen, even if the app is closed, i.e in background.
Apple doesn't allow to background process to run for a long time, but can we do it for 5-10 min in background.
Capturing screen,even if the app is closed.Ofcourse user can close this function, within the app.
Apple might reject this, but is this possible ?
Regards
This is possible but it's not easy. You can register you app (via a .plist setting) as being a media app, this will allow it to run in the background. This is normally to allow media apps to continue playing music when the app is sent to the background. However if you are careful you can get it to do other thing in there too.
In your plist under "Required Background Modes" add a key "Item 0" and set it to "App plays Audio". This will mean you can do it.
You will then have to using AVAudioPlayer, play a silent sound that is say 5mins long, and then register one of your controllers for the AVPlayerItemDidPlayToEndTimeNotification notification. Then when this calls back, you can have your bit of code that, first takes a screenshot, and then starts the sound again.
This is the general concept, look somewhere like :
http://mobile.tutsplus.com/tutorials/iphone/ios-sdk_background-audio/
for how to set up the audio playing.
Just a note: APPLE WILL REJECT THIS!
If you are making an app for personal use only, this is fine, but will never make it to the app store.
Hoep this sheds some light on your situation! :)
I'm developing an interactive storybook type application for the iPhone and I've recently encountered a frustrating bug concerning audio mixing on the device.
Firstly, I setup an audio session. I set the category to AVAudioSessionCategoryAmbient and then init and play my AVAudioPlayer instance. Now, in the background whilst the audio is playing I'm pre-loading a video to play using an MPMoviePlayerController followed by a call to prepareToPlay. The reason I pre-load the video this way is because I need it to play instantly later on cue with fairly strict timing.
In this configuration, the audio/movie works fine and they mix and do not interrupt each other. However, this particular audio session category does not permit audio to continue playing while the device is locked, a feature I really need. As a result I'm forced to consider a different category: AVAudioSessionCategoryPlayback.
By default this category does not permit mixing with other audio, according to the Apple docs. To enable mixing with other audio I am overriding the relevant category:
OSStatus propertySetError = 0;
UInt32 setProperty = 1;
propertySetError = AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(setProperty), &setProperty);
assert(propertySetError == 0);
Unfortunately, this solves my playing whilst locked issue but introduces another issue: the AVAudioPlayer audio is interrupted briefly as the video loads with a minor stutter. The stutter is small, perhaps less than a second but is enough to disrupt the user experience. I've read this related post which enabled me to pre-load the video with the AVAudioSessionCategoryAmbient, but unfortunately the same approach doesn't seem to work with the new category.
The audio session category is applied successfully, according to the return code. Does anyone know why enabling audio mixing with this category is not the same as the mixing facility provided by ambient category?
The best way I've found working a similar problem is to use the newer AVPlayer (+1 #adam) and set your app to enable background audio and receive remote control notifications. I was tipped off to this by #MarquelV following How can you play music from the iPod app while still receiving remote control events in your app?
If you can get backgrounding working properly, that should enable you to continue playing while the device is locked. Oh, and don't forget to add keys to info.plist, its easy to do and then have no idea why it isn't working.