How can I crossfade 2 tracks using the Spotify ios-streaming-sdk? - ios

I'd like to implement a crossfade feature for an iOS app where one track gradually fades out as the next track fades in to create a smooth transition.
Spotify does not allow the streaming of multiple tracks at once with the ios-streaming-sdk.
There should be a way to access the last 10 seconds of a track before it finishes playing, store it in a separate buffer, and mix it with the next track played.
Any guidance would be very appreciated.

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iOS audio background mode for short one time sounds

I want to create a feature in my app the makes a sound every 5 seconds. The sound file is short and in order to play it every 5 seconds i use a timer.
The issue is i want to play it even if the app is in the background for a maximum time of 30 min and could also be different bpm for each user. I have used background audio mode to do it but i could find in the documentation how does playing sounds is threated by the system i dont want my app to be suspended. I only saw referance to playing music songs in the background with a player.
How can i be certain i will receive the background time needed just for playing small sounds every few seconds and not playing continues music? I was thinking about empty sound wave file but afraid apple would reject my app.
Thanks for any help i can get.

FSAudioController music transitions

I'm using FSAudioController to play mp3's from my service. I have a URL list and I'm playing songs by shuffling the list.
What I want to do is, 5 seconds before the current song ends, next song will start playing and there will be a soft transition between songs. But I couldn't find anything about how to play 2 songs at the same time.
I thought about using 2 different FSAudioController objects, but I wanted to ask if there is smarter way to do it first.
Thanks in advance!
Unfortunately FSAudioController does not support crossfade option so you will have to use 2 different FSAudioController objects.

Playing interactive videos with finger gestures in iOS

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.

Transitioning to background, AVPlayer Video has small audio gap

I have followed the many helpful previous questions to get my AVPlayer successfully streaming video when my app goes to the background. There are two methods described on Apple's QA1668 and they both work for my stream urls.
The problem is that there is a noticeable audio gap during the transition that is identical for both methods. On my iPhone 6 in release mode I would say the gap is less than 0.5 seconds, which may not seem terrible but if I'm playing something like a music video this is very distracting.
After more testing it looks like this gap actually occurs when I remove the AVPlayerLayer (or, if I am using the other method, when I disable the AVMediaCharacteristicVisual tracks) as I have determined it will still happen if I hook those actions up to a button rather than the backgrounding state.
My guess is that is has something to do with the audio re-syncing to the new video state of the AVPlayer but really I have no clue. Any help would be greatly appreciated!

Gapless and non freeze playing of player items using AVQueuePlayer

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.

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