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.
Related
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?
I'm making a simple SpriteKit game with two scenes, and I want the background music to loop unconditionally through both scenes. Right now, I'm using
if soundIsPlaying == false {
runAction(SKAction.repeatActionForever(backgroundMusicEffect), withKey: "backgroundMusic")
soundIsPlaying = true
}
in my menu scene where backgroundMusicEffect is a global variable
let backgroundMusicEffect = SKAction.playSoundFileNamed("content/divertimentoK131.mp3", waitForCompletion: true)
When I play my game, the music never loops. It always stops after one play. If I remove the if-else statement, the music plays over itself every time I reenter the menu.
Is there a better way to play background music? What am I doing wrong?
I believe that the way you are doing it, after the first time looping, every iteration after is "complete" since the sound is finished. You would need to create a new SKAction instance every time if you want to get this to loop.
This of course is a bad idea, since playSoundFileNamed is designed to only play a sound file once with as little over head as possible.
As #Alessandro Omano has commented, use SKAudioNode to get sound playing in a loop. This is my preferred way of doing in, but you limit yourself to >= iOS 9 users.
If you have to support iOS 8 users (At this point I would say why bother) then you need to look into the AVFoundation sections of the libs to get audio going, or use OpenAL.
I am working on a kids ABC learning app which will be somewhat like this app.
Petting Zoo
The user can do these gestures... Swipe UP, DOWN, LEFT , RIGHT and TOUCH and each gesture has a small animation clip (approx duration 1 -3 secs each ) linked to it like the character jumping on Swipe UP, etc. There will also be an IDLE loopable movie which will be playing continuously when there is no input from user.
So I am trying to use videos in MP4 and M4V format for these gestures but the problem is that the videos are lagging just before playing. Means they dont play instantly upon doing a gesture but take a time of say micro second to load and play.
I am looking for output like the video above. You can see that the animations are so responsive and do not hang even for little time.
My developer once achieved such smooth output with the MP4 video clips but those clips didnt have audio embedded in them and then when he used videos with audio embedded in them, they were lagging again.
Can audio be the issue for lag here ? Or anything else you experts will like to suggest.
Please help guys. Yours inputs will be very valuable for me.
You can use - (void)replaceCurrentItemWithPlayerItem:(AVPlayerItem *)item of AVPlayer.
This methods helps you to load the new item to an existing AVPlayer.
Here is the important reference for playing multiple videos using single AVPlayer.
I have some issue with avqueueplayer like app freezing for 2-3 seconds when each item ends in the queue. I am using queueplayer to play the records one after the other without gap. In order to achieve no gaps b/w player items, I need to load the assets for a player item in advance. I load assets for current playing player item and next player item so that there will be no gap at the end of 1st record. As the 1st record ends, I add 2nd player item to queueplayer to play and also load assets for 3rd player item.
In this way my playerqueue always contains a single player item but asset loading will be done for current playing item and next playing item. This will keep moving as the new records are added.
I found that a freeze of half a second is observed in new iOS devices and around 3-4 seconds in old iPod devices like iPod 4?
Can I know how we can achieve gapless and yet non freeze UI experience?
Thanks
Try lifting your requirement to only have a single player item in the queue.
An AVQueuePlayer will operate more effectively at item transitions if there is an item in its queue beyond what's currently playing.
"Loading" media can mean a few different things, and it's not clear what you're doing. Maybe you're downloading media outside of AVFoundation, building an AVAsset or building an AVPlayerItem. The work you're doing or deferring will vary depending on the kind of media (e.g an mp4 vs an HLS stream). Even if you "preload" everything (which is much more complicated for HLS media), AVFoundation still has more work to do that it won't start until the AVPlayerItem is put in a player. It has to set up a render pipeline specific to the media it needs to play back, and then start the rendering process. AVQueuePlayer can achieve gapless playback by starting some of that process before playback for that item needs to start. The queue player is also efficient about its use of resources in that it won't start loading items far down the queue until it needs to.
I am using AVPlayer to play videos. The lenght of them is short, 2-5 second. They are played in a random order. The problem is, when changing video, and a new video starts to play, the device lags for a very short time, but i wan't the change to be fluid. Is there a way to preload videos with AVPlayer?
Try using AVQueuePlayer. I am assuming that what you described as a lag, in fact is the pre buffering delay. This should be minimized or actually entirely be gotten rid of when using AVQueuePlayer as that baby will buffer the next AVPlayerItem while playing the current one.
From the AVFoundation documentation:
On iOS 4.1 and later, you can use an AVQueuePlayer object to play a
number of items in sequence (AVQueuePlayer is a subclass of AVPlayer).
Also see Mihai's answer on Pre-buffering-for-avqueueplayer.