I'm having an issue with playing sequences of different kinds of items in a background.
In an app I'm working on we've introduced playlists which contain both content provided by the app and Apple Music content.
For that use AVPlayer and MPMusicPlayerController respectively. We observe one player or the other (depending what content is now playing) and if the other kind of content comes next, we release the old player (if we can - MPMusicPlayerController is a singleton, so best we can do is stop it) and load item to another player.
The problem starts when the app leaves foreground. Once MPMusicPlayerController takes over it doesn't want to give up control, so if any AVPlayer content comes after MPMusicPlayerController content, the music stops.
One workaround that I've tried is playing with .mixWithOthers options when I set the category on AVAudioSession, however this creates new category of problems - I'm loosing lockscreen controls, therefore I'm also loosing airplay. One dirty trick that I've tried was setting .mixWithOthers 3 seconds before MPMediaItem ends, and then disabling it back once AVPlayer starts. Beside the fact that there're probably many different things that can go wrong here, MPMediaPlayerController still doesn't want to give me back the control over lockscreen controls.
Is there any way this could ever work on iOS 13?
Related
I found myself in a situation where I need to simulate audio playback to trick OS controls and MPNowPlayingInfoCenter into thinking that an audio is being played. This is because I am building a player that plays multiple audio tracks, with pauses in-between creating one, continuous "audio" track. I have already everything setup inside the app itself, and the lock screen controls are working correctly but the only problem I am facing is while the actual audio stops and a pause is being "played", the lock screen info center stops the timer, and it only continues with showing correct time and overall state once another audio track starts playing.
Here is the example of my audio track built from audio files and pause items:
let items: [AudioItem] = [
.audio("part-1.mp3"),
.pause(duration: 5), // value of type: TimeInterval
.audio("part-2.mp3"),
.pause(duration: 3),
... // the list goes on
]
then in my custom player, once AVAudioPlayer finishes its job with current item, I get the next one from the array and play either a .pause with a scheduled Timer or another .audio with AVAudioPlayer.
extension Player: AVAudioPlayerDelegate {
func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
playNextItem()
}
}
And here lies the problem, once the AVAudioPlayer stops, the Now Playing info center automatically stops too, even tho I keep feeding it fresh nowPlayingInfo. Then when it hits another .audio item, it resumes correctly and shows current time, etc.
And here lies the question
how do I trick the MPNowPlayingInfoCenter into thinking that audio is being played while I "play" my .pause item?
I realise that it may still not be clear, what I am trying to achieve but I am happy to share more insight if needed. Thanks!
Some solutions I am currently thinking about:
A. Keeping 1s long empty audio track that would play on loop for as long as the pause is needed to play.
B. Creating programatically empty audio track with appropriate lenght and playing it instead of using Timer for keeping track of pause duration/progress and relying completely on AVAudioPlayer for both .audio and .pause items. Not sure this is possible though.
C. Maybe there is a way to tell the MPNowPlayingInfoCenter that the audio keeps playing without the need of using AVAudioPlayer but some API I am not familiar with?
AVAudioPlayer is probably the wrong tool here. You want AVAudioPlayerNode, which is slightly lower-level. Create an AVAudioEngine, and attach an AVAudioPlayerNode. You can then call scheduleFile(_:at:completionHandler:) to play the audio at the times you want.
Much of the Apple documentation on AVAudioEngine appears broken right this moment, but the links hopefully will be available again shortly in the links for Audio Engine Building Blocks. (If it stays down and you have trouble finding docs, leave a comment and I'll hunt down the WWDC videos and other tutorials on using AVAudioEngine. It's not particularly difficult for simple problems.)
If you know in advance how you want to compose these items (and it looks like you may), see also AVMutableComposition, which lets you glue together assets very efficiently, including adding empty segments of silence. See Media Composition and Editing for the various tools in that space.
I have an app that uses AVPlayer (or AVQueuePLayer) to play local files that were recorded by the App. All works great. But I also want this to work on iPhone when a call is in progress (the videos are event recordings). What I found is that during a phone call, the video feed to avplayerLayer goes blank, AVPlayer rate change to 0 (STOP), and all attempts to change rate to non-zero (PLAY) are ignored (rate stays at 0). There does not appear to be any documentation on this, and the only way to detect this condition in the player, is that player is STOPPED and will not start PLAYBACK. Of course, I also check for audio interruptions, and call center calls in progress.
Obviously, in this case the interruption is caused by a call, so there is always a inactive/resume or a intactive/background/foreground/resume transition. As well as audio route notification, audio interruption. So indirectly I know the condition is probably occurring.
So questions are:
(1) Is there any direct method (specific to AVPlayer,AVPlayerLayer) to be notified that AVPlayer is in this non-playing mode. I now use "avplayer.rate failed to change rate from 0 to non-zero", but this seems hacky (and too much "crossing the streams"!) I want to Notify user that video temporarily can not be played or previewed, so they do not think the App is broken. And also inform them or automatically continue Playback when iPhone call ends. (Without a looping process that keeps trying to start playback every 500ms!)
(2) Can AVPlayer play anything while a iPhone call (Green Bar) is in progress? or is this just the way apple designed the AVPlayer SDK? (If so there is no documentation on this) Obviously, other apps can play video during an iPhone call, but I suspect they are using a lower level SDK and not AVPlayer.
I'm writing a music player for iOS that needs to have all the features of the built-in Music app. My app needs to continue running in the background so I have to use the AVPlayer class.
Are there any open source implementations out there that I can use instead of writing the whole thing myself?
Just found this. It works great:
https://github.com/gangverk/GVMusicPlayerController
If you want to play tracks from your iTunes music library, and don't want to use the MPMusicPlayerController class, your best bet is to use AVPlayer or AVQueuePlayer (subclass of AVPlayer). You must establish the appropriate audio session and register to receive remote control events for the app to continue playing music in the background.
There are downsides to this method; you won't be able to play DRM-protected tracks and audiobooks purchased from the iTunes store. There's no way to instantiate an iTunes Match download with the AVPlayer class. Furthermore, you'll have a bit of work on your hands if you want to add gapless playback and equaliser settings (The closest you'll get to gapless playback is with the AVQueuePlayer subclass, though in theory, you could overlap AVPlayers with an NSTimer).
You'll also need to change 'Required Background Modes' in your Info.plist to 'App plays audio'
As for the rest of your app, I suggest you read up on UITabBarControllers and UITableViewControllers along with MPMediaQuerys.
See this solution for the audio part.
I have a video composition which I'd like to play over Airplay (without mirroring). The app works as expected when using normal Airplay mirroring, but I'd like to get the speed, reliability, and resolution bump you get from using Airplay video instead.
The problem is that when I set
player.usesAirPlayVideoWhileAirPlayScreenIsActive = YES;
...the player goes blank.
Notes:
Since I don't create separate windows for each display, they are both trying to use the same AVPlayer.
My AVVideoComposition contains different files and adds opacity ramps between them.
This unanswered question suggests that the problem is more likely due to the fact that I'm playing an AVComposition than the use of a shared player: AVComposition doesn't play via Airplay Video
Two questions:
Do I have to get rid of the player on the iPad?
Can an AVVideoComposition ever be played over AirPlay?
I can't make comments so I had to post this as an answer although it might not fully respond to the questions.
I had similar issue and at the end I found out that when AVPlayer plays AVComposition it simply doesn't display anything on the external display. That's why I had to do it myself by listening to UIScreen connection notifications.
I have to say that all worked pretty perfect. I'm checking first if there are more than one screen and if there are I simply move the AVPlayer on that screen while displaying a simple message on the device's screen that content is played on... plus the name of AirPlay device. This way I can put whatever I want on the external display and is not very complicated. Same thing is when I receive UIScreenDidConnectNotification.
That was fine until I noticed that the composition plays really choppy on the the external display. Even if it consists of only one video without any complex edits or overlays. Same video plays perfectly if I save it to the Camera Roll or if I use MPMoviePlayerController.
I've tried many things like lowering resolutions, lowering renderScale and so on but with no success.
One thing bothers me more is how actually Apple do this in iMovie - if you have AirPlay enabled and you play a project (note it's still not rendered so it must use a composition in order to display it) right after tapping play button it opens a player that plays content really smoothly on the external monitor. If you however activate AirPlay from the player it closes and start rendering the project. After that it plays it I thing by using MPMoviePlayerController.
I'm still trying to find a solution and will post back if I have any success.
So for the two questions:
I don't see why you have to get rid.
Yes it can be played but with different technique and obviously issues.
in the app .plist create a new item called:
required background modes
add a new array element called:
App plays audio or streams audio/video using AirPlay
Not sure if you have already tried this, but you don't mention it in your post.
Cheers!
I have a bit of a strange problem. I have a music app that uses the [MPMusicPlayerController iPodMusicPlayer]. Everything is fine, notifications are fired for track changes and changes in playback state.
I have one screen where the user needs to review one single song, I don't want him to go on to the next song in his queue. Since there is no delegate method for when a track WILL change (only DID change), to prevent the music player from continuing to the next track I use a new [MPMusicPlayerController applicationMusicPlayer], give it iPodMusicPlayer's currently playing song and all is well. No new tracks to continue to, and I'm not touching the original iPodMusicPlayer queue so in theory, when I close this screen and use the iPodMusicPlayer again, all should be perfectly fine.
However, when the user is done on this screen and closes it, iPodMusicPlayer is now suddenly broken, notifications are not called and when I put the app to the background, music stops playing, causing me to believe that iPodMusicPlayer is now actually applicationMusicPlayer.
Okay so my question is basically: I need a way to prevent the music player to continue on to the next track in the queue. Switching to applicationMusicPlayer with one track seems to break stuff, as explained above. What's the best solution?
EDIT: because this might be a bit difficult to understand, I created a small project to show the problem: https://github.com/kevinrenskers/MPMusicPlayerControllerTest. Open the app while music is playing, see that the play button behaves correctly. Now open the popup, close it again and the play button is broken.
I found a solution to my problem: set the repeatMode to MPMusicRepeatModeOne and then catch the MPMusicPlayerControllerNowPlayingItemDidChangeNotification notification. You can stop the playback and you never continue to the next track. Once I'm done with the second screen I reset the repeatMode to the original value.