Give priority to background music ( itunes ) over avfoundation player node - ios

Question

I'm using AVFoundation framework. Whenever the player plays the buffer, my background music gets stopped so I used below code to allow it to continue playing irrespective of the AVFoundation player.
try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, with: [.mixWithOthers,.allowBluetooth])
try audioSession.setMode(AVAudioSessionModeDefault)
try audioSession.setActive(true)
It does work but the problem is the quality of the background music gets dramatically affected. The music don't have the bass effects anymore whenever the AVPlayer plays the buffer.
I want the background music uninterrupted while using AVPlayer. Is it possible?
update : I added full code if anyone wants to check. Can feel the difference in background itune music as soon as the app is opened or the session is activated when using this code.
class ViewCosdfntroller: UIViewController {
var engine = AVAudioEngine()
let audioSession = AVAudioSession.sharedInstance()
let player = AVAudioPlayerNode()
let mixer = AVAudioMixerNode()
override func viewDidLoad() {
super.viewDidLoad()
do {
try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, with: [.mixWithOthers,.allowBluetooth])
try audioSession.setMode(AVAudioSessionModeDefault)
try audioSession.setActive(true)
} catch {
}
let input = engine.inputNode
let bus = 0
let inputFormat = input.outputFormat(forBus: bus)
let recordingFormat = AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: 11025.0, channels: 1, interleaved: false)
engine.attach(player)
engine.attach(mixer)
engine.connect(input, to: mixer, format: input.outputFormat(forBus: 0))
engine.connect(player, to: engine.mainMixerNode, format: recordingFormat)
mixer.installTap(onBus: bus, bufferSize: AVAudioFrameCount(inputFormat.sampleRate * 0.4), format: inputFormat, block: { (buffer: AVAudioPCMBuffer!, time: AVAudioTime!) -> Void in
let Converter:AVAudioConverter = AVAudioConverter.init(from: inputFormat, to: recordingFormat!)!
let newbuffer = AVAudioPCMBuffer(pcmFormat: recordingFormat!,frameCapacity: AVAudioFrameCount((recordingFormat?.sampleRate)! * 0.4))
let inputBlock : AVAudioConverterInputBlock = { (inNumPackets, outStatus) -> AVAudioBuffer? in
outStatus.pointee = AVAudioConverterInputStatus.haveData
let audioBuffer : AVAudioBuffer = buffer
return audioBuffer
}
var error : NSError?
Converter.convert(to: newbuffer!, error: &error, withInputFrom: inputBlock)
self.player.scheduleBuffer(newbuffer!)
})
do {
try! engine.start()
player.play()
} catch {
print(error)
}
}
}

Answer 1

Unless this is some weird mixing quirk, the quality change you report may just be that recording categories change the default audio output device to the tiny, tinny receiver (because telephones, don't ask). Override this behaviour by adding .defaultToSpeaker to your setCategory() call:
try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, with: [.mixWithOthers,.allowBluetooth, .defaultToSpeaker])

Answer 2

I think you need this one:
try audioSession.setCategory(AVAudioSessionCategoryAmbient)
Documentation:
https://developer.apple.com/documentation/avfoundation/avaudiosessioncategoryambient
When you use this category, audio from other apps mixes with your audio