Version bump

Signed-off-by: dimitris-c <d.chatzieleftheriou@gmail.com>

.github/workflows/swift.yml

@@ -14,10 +14,10 @@ jobs:
     name: Test iOS 
     runs-on: macOS-latest
     env: 
-      DEVELOPER_DIR: /Applications/Xcode_12.app/Contents/Developer
+       DEVELOPER_DIR: /Applications/Xcode.app/Contents/Developer
     strategy:
       matrix:
-        destination: ["OS=14.0,name=iPhone 11 Pro"] #, "OS=12.4,name=iPhone XS", "OS=11.4,name=iPhone X", "OS=10.3.1,name=iPhone SE"]
+        destination: ["OS=latest,name=iPhone 13 Pro"]
     steps:
       - uses: actions/checkout@v2
       - name: iOS - ${{ matrix.destination }}

AudioExample/AudioExample/AppCoordinator.swift

@@ -9,7 +9,6 @@
 import UIKit
 
 final class AppCoordinator {
-
     enum Route {
         case equalizer
     }
@@ -44,8 +43,8 @@ final class AppCoordinator {
 
     private func routeTo(_ route: AppCoordinator.Route) {
         switch route {
-            case .equalizer:
-                showEqualizerControls()
+        case .equalizer:
+            showEqualizerControls()
         }
     }
 

AudioExample/AudioExample/Controllers/EqualizerViewController.swift

@@ -9,7 +9,6 @@
 import UIKit
 
 class EqualizerViewController: UIViewController {
-
     private lazy var enableTextLabel = UILabel()
     private lazy var enableButton = UISwitch()
 
@@ -22,7 +21,8 @@ class EqualizerViewController: UIViewController {
         super.init(nibName: nil, bundle: nil)
     }
 
-    required init?(coder: NSCoder) {
+    @available(*, unavailable)
+    required init?(coder _: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
 
@@ -69,7 +69,7 @@ class EqualizerViewController: UIViewController {
                 stackView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
                 stackView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
                 stackView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
-                stackView.heightAnchor.constraint(equalTo: view.safeAreaLayoutGuide.heightAnchor, multiplier: 0.8)
+                stackView.heightAnchor.constraint(equalTo: view.safeAreaLayoutGuide.heightAnchor, multiplier: 0.8),
             ]
         )
     }
@@ -86,7 +86,7 @@ class EqualizerViewController: UIViewController {
 
     private func buildSliders() -> [UIView] {
         var sliders = [UIView]()
-        for index in 0..<viewModel.numberOfBands() {
+        for index in 0 ..< viewModel.numberOfBands() {
             guard let item = viewModel.band(at: index) else { continue }
             let slider = buildSlider(item: item, index: index)
             sliders.append(slider)

AudioExample/AudioExample/Controllers/EqualizerViewModel.swift

@@ -16,7 +16,6 @@ struct EQBand {
 }
 
 final class EqualzerViewModel {
-
     private var bands: [EQBand] = []
 
     private let equalizerService: EqualizerService
@@ -31,7 +30,7 @@ final class EqualzerViewModel {
         bands = equalizerService.bands.map { item in
             var measurement = item.frequency
             var frequency = String(Int(measurement))
-            if item.frequency >= 1_000 {
+            if item.frequency >= 1000 {
                 measurement = item.frequency / 1000
                 frequency = "\(String(Int(measurement)))K"
             }
@@ -43,7 +42,7 @@ final class EqualzerViewModel {
         if enable {
             equalizerService.activate()
         } else {
-            equalizerService.deactive()
+            equalizerService.deactivate()
         }
     }
 

AudioExample/AudioExample/Controllers/PlayerControlsViewModel.swift

@@ -153,7 +153,7 @@ extension PlayerControlsViewModel: AudioPlayerServiceDelegate {
         updateContent?(.updateMetadata(""))
     }
 
-    func errorOccured(error _: AudioPlayerError) {}
+    func errorOccurred(error _: AudioPlayerError) {}
 
     func metadataReceived(metadata: [String: String]) {
         guard !metadata.isEmpty else { return }

AudioExample/AudioExample/Controllers/PlayerViewController.swift

@@ -51,7 +51,7 @@ class PlayerViewController: UIViewController {
                                                            style: .plain,
                                                            target: self,
                                                            action: #selector(showEqualizer))
-        
+
         tableView.translatesAutoresizingMaskIntoConstraints = false
         tableView.delegate = self
         tableView.dataSource = self
@@ -92,12 +92,13 @@ class PlayerViewController: UIViewController {
 
     @objc private func addNowPlaylistItem() {
         let controller = UIAlertController(title: "Add new item", message: "", preferredStyle: .alert)
-        controller.addTextField { (textField) in
+        controller.addTextField { textField in
             textField.placeholder = "Insert url here"
         }
-        let saveAction = UIAlertAction(title: "Save", style: .default) { [viewModel] action in
+        let saveAction = UIAlertAction(title: "Save", style: .default) { [viewModel] _ in
             if let textfield = controller.textFields?.first,
-               let text = textfield.text {
+               let text = textfield.text
+            {
                 viewModel.add(urlString: text)
             }
         }
@@ -105,7 +106,7 @@ class PlayerViewController: UIViewController {
 
         controller.addAction(saveAction)
         controller.addAction(cancelAction)
-        self.present(controller, animated: true, completion: nil)
+        present(controller, animated: true, completion: nil)
     }
 }
 
@@ -149,14 +150,13 @@ extension PlayerViewController: UITableViewDelegate {
     }
 }
 
-
 final class PlaylistTableViewCell: UITableViewCell {
-    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
+    override init(style _: UITableViewCell.CellStyle, reuseIdentifier: String?) {
         super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)
     }
 
     @available(*, unavailable)
-    required init?(coder: NSCoder) {
+    required init?(coder _: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
 }

AudioExample/AudioExample/Controllers/PlayerViewModel.swift

@@ -18,14 +18,15 @@ final class PlayerViewModel {
     private let playerService: AudioPlayerService
     private let playlistItemsService: PlaylistItemsService
 
-    private let routeTo: ((AppCoordinator.Route) -> Void)
+    private let routeTo: (AppCoordinator.Route) -> Void
     private var currentPlayingItemIndex: Int?
 
     var reloadContent: ((ReloadAction) -> Void)?
 
     init(playlistItemsService: PlaylistItemsService,
          playerService: AudioPlayerService,
-         routeTo: @escaping (AppCoordinator.Route) -> Void) {
+         routeTo: @escaping (AppCoordinator.Route) -> Void)
+    {
         self.playlistItemsService = playlistItemsService
         self.playerService = playerService
         self.routeTo = routeTo
@@ -96,7 +97,7 @@ extension PlayerViewModel: AudioPlayerServiceDelegate {
         }
     }
 
-    func errorOccured(error _: AudioPlayerError) {
+    func errorOccurred(error _: AudioPlayerError) {
         currentPlayingItemIndex = nil
     }
 

AudioExample/AudioExample/Services/AudioPlayerService.swift

@@ -13,7 +13,7 @@ protocol AudioPlayerServiceDelegate: AnyObject {
     func didStartPlaying()
     func didStopPlaying()
     func statusChanged(status: AudioPlayerState)
-    func errorOccured(error: AudioPlayerError)
+    func errorOccurred(error: AudioPlayerError)
     func metadataReceived(metadata: [String: String])
 }
 
@@ -168,7 +168,7 @@ extension AudioPlayerService: AudioPlayerDelegate {
     }
 
     func audioPlayerUnexpectedError(player _: AudioPlayer, error: AudioPlayerError) {
-        delegate.invoke(invocation: { $0.errorOccured(error: error) })
+        delegate.invoke(invocation: { $0.errorOccurred(error: error) })
     }
 
     func audioPlayerDidCancel(player _: AudioPlayer, queuedItems _: [AudioEntryId]) {}

AudioExample/AudioExample/Services/EqualizerService.swift

@@ -10,7 +10,7 @@ import AVFoundation
 
 final class EqualizerService {
     private let playerService: AudioPlayerService
-    private let _freqs = [32, 64, 128, 250, 500, 1_000, 2_000, 4_000, 8_000, 16_000]
+    private let _freqs = [32, 64, 128, 250, 500, 1000, 2000, 4000, 8000, 16000]
     private let eqUnit: AVAudioUnitEQ
 
     var bands: [AVAudioUnitEQFilterParameters] {
@@ -23,7 +23,7 @@ final class EqualizerService {
         self.playerService = playerService
 
         eqUnit = AVAudioUnitEQ(numberOfBands: _freqs.count)
-        for i in 0..<_freqs.count {
+        for i in 0 ..< _freqs.count {
             eqUnit.bands[i].bypass = false
             eqUnit.bands[i].filterType = .parametric
             eqUnit.bands[i].frequency = Float(_freqs[i])
@@ -45,7 +45,7 @@ final class EqualizerService {
         playerService.add(eqUnit)
     }
 
-    func deactive() {
+    func deactivate() {
         isActivated = false
         playerService.remove(eqUnit)
     }

AudioExample/AudioExample/Services/NowPlayingCenter.swift

@@ -9,10 +9,9 @@
 import MediaPlayer
 
 final class NowPlayingCenter {
-
     private let infoCenter: MPNowPlayingInfoCenter
 
-    init(infoCenter: MPNowPlayingInfoCenter = .default()){
+    init(infoCenter: MPNowPlayingInfoCenter = .default()) {
         self.infoCenter = infoCenter
     }
 

AudioExample/AudioExample/Services/PlaylistItemsService.swift

@@ -80,7 +80,7 @@ final class PlaylistItemsService {
 func provideInitialPlaylistItems() -> [PlaylistItem] {
     let allCases = AudioContent.allCases
     let casesForQueueing: [AudioContent] = [.piano, .local, .khruangbin]
-    let allItems = allCases.map { PlaylistItem.init(content: $0 , queues: false) }
-    let casesForQueuingItems = casesForQueueing.map { PlaylistItem.init(content: $0 , queues: true) }
+    let allItems = allCases.map { PlaylistItem(content: $0, queues: false) }
+    let casesForQueuingItems = casesForQueueing.map { PlaylistItem(content: $0, queues: true) }
     return allItems + casesForQueuingItems
 }

AudioStreaming.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name = 'AudioStreaming'
-  s.version = '0.5.0'
+  s.version = '0.9.0'
   s.license = 'MIT'
   s.summary = 'An AudioPlayer/Streaming library for iOS written in Swift using AVAudioEngine.'
   s.homepage = 'https://github.com/dimitris-c/AudioStreaming'

AudioStreaming.xcodeproj/project.pbxproj

@@ -52,6 +52,7 @@
 		B59DF1A32493E90C0043C498 /* AudioFileStream+Helpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = B59DF1A22493E90C0043C498 /* AudioFileStream+Helpers.swift */; };
 		B5AEDBB824744153007D8101 /* AudioStreaming.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B5AEDBAE24744153007D8101 /* AudioStreaming.framework */; };
 		B5AEDBBF24744153007D8101 /* AudioStreaming.h in Headers */ = {isa = PBXBuildFile; fileRef = B5AEDBB124744153007D8101 /* AudioStreaming.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		B5B36E432655A32200DC96F5 /* FrameFilterProcessor.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5B36E422655A32200DC96F5 /* FrameFilterProcessor.swift */; };
 		B5B3B7CC248647ED00656828 /* AudioPlayerState.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5B3B7CB248647ED00656828 /* AudioPlayerState.swift */; };
 		B5D4A40925D9321400E1450C /* IcycastHeaderParser.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5D4A40825D9321400E1450C /* IcycastHeaderParser.swift */; };
 		B5D4A41025D948EF00E1450C /* IcycastHeadersProcessor.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5D4A40B25D9445600E1450C /* IcycastHeadersProcessor.swift */; };
@@ -144,6 +145,7 @@
 		B5AEDBB224744153007D8101 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		B5AEDBB724744153007D8101 /* AudioStreamingTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = AudioStreamingTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		B5AEDBBE24744153007D8101 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		B5B36E422655A32200DC96F5 /* FrameFilterProcessor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FrameFilterProcessor.swift; sourceTree = "<group>"; };
 		B5B3B7CB248647ED00656828 /* AudioPlayerState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AudioPlayerState.swift; sourceTree = "<group>"; };
 		B5D4A40825D9321400E1450C /* IcycastHeaderParser.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IcycastHeaderParser.swift; sourceTree = "<group>"; };
 		B5D4A40B25D9445600E1450C /* IcycastHeadersProcessor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IcycastHeadersProcessor.swift; sourceTree = "<group>"; };
@@ -259,6 +261,7 @@
 		B55CEAC024855AA20001C498 /* Processors */ = {
 			isa = PBXGroup;
 			children = (
+				B5B36E422655A32200DC96F5 /* FrameFilterProcessor.swift */,
 				B5667A8F2499018D00D93F85 /* AudioFileStreamProcessor.swift */,
 				B5667B3D249BC43000D93F85 /* AudioPlayerRenderProcessor.swift */,
 				B55CE97024810DE20001C498 /* MetadataStreamProcessor.swift */,
@@ -615,6 +618,7 @@
 				B5667A902499018D00D93F85 /* AudioFileStreamProcessor.swift in Sources */,
 				B59D0B6F255C904900D6CCE5 /* FileAudioSource.swift in Sources */,
 				B5EF9555247E9393003E8FF8 /* AudioEntry.swift in Sources */,
+				B5B36E432655A32200DC96F5 /* FrameFilterProcessor.swift in Sources */,
 				B51FE0C02488F67C00F2A4D2 /* Queue.swift in Sources */,
 				B5667A922499063D00D93F85 /* AudioPlayerContext.swift in Sources */,
 				B55CE97124810DE20001C498 /* MetadataStreamProcessor.swift in Sources */,
@@ -794,6 +798,7 @@
 			buildSettings = {
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 2;
 				DEFINES_MODULE = YES;
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
@@ -806,7 +811,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 0.5.0;
+				MARKETING_VERSION = 0.9.0;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_BUNDLE_IDENTIFIER = com.decimal.AudioStreaming;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
@@ -824,6 +829,7 @@
 			buildSettings = {
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 2;
 				DEFINES_MODULE = YES;
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
@@ -836,7 +842,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 0.5.0;
+				MARKETING_VERSION = 0.9.0;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_BUNDLE_IDENTIFIER = com.decimal.AudioStreaming;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";

AudioStreaming/Core/Extensions/AVAudioFormat+Convenience.swift

@@ -5,7 +5,7 @@
 
 import AVFoundation
 
-extension AVAudioFormat {
+public extension AVAudioFormat {
     /// The underlying audio stream description.
     ///
     /// This exposes the `pointee` value of the `UsafePointer<AudioStreamBasicDescription>`

AudioStreaming/Core/Helpers/Logger.swift

@@ -31,7 +31,7 @@ internal enum Logger {
     }
 
     static func error(_ message: StaticString, category: Category, args: CVarArg...) {
-        proccess(message, category: category, type: .error, args: args)
+        process(message, category: category, type: .error, args: args)
     }
 
     static func error(_ message: StaticString, category: Category) {
@@ -39,14 +39,14 @@ internal enum Logger {
     }
 
     static func debug(_ message: StaticString, category: Category, args: CVarArg...) {
-        proccess(message, category: category, type: .debug, args: args)
+        process(message, category: category, type: .debug, args: args)
     }
 
     static func debug(_ message: StaticString, category: Category) {
         debug(message, category: category, args: [])
     }
 
-    private static func proccess(_ message: StaticString, category: Category, type: OSLogType, args: CVarArg...) {
+    private static func process(_ message: StaticString, category: Category, type: OSLogType, args: CVarArg...) {
         guard isEnabled else { return }
         os_log(message, log: category.toOSLog(), type: type, args)
     }

AudioStreaming/Core/Helpers/Retrier.swift

@@ -13,7 +13,7 @@ final class Retrier {
     private let maxInterval: Int
     private let timeoutTimer: DispatchTimerSource
 
-    /// Initiliazes a new object with the given parameters
+    /// Initializes a new object with the given parameters
     /// - Parameters:
     ///   - interval: The Mach absolute time at which to execute the dispatch source's event handler.
     ///   - maxInterval: The maximum interval in which the internal timer will retry the callback.
@@ -38,6 +38,7 @@ final class Retrier {
 
     /// Cancels retrying
     func cancel() {
+        interval = .seconds(1)
         timeoutTimer.removeHandler()
         timeoutTimer.suspend()
     }

AudioStreaming/Core/Network/NetStatusService.swift

@@ -9,12 +9,14 @@ import Network
 enum NetConnectionType: Equatable {
     case cellular(connected: Bool)
     case wifi(connected: Bool)
+    case other(connected: Bool)
     case undetermined
 
     var isConnected: Bool {
         switch self {
         case let .cellular(connected),
-             let .wifi(connected):
+             let .wifi(connected),
+             let .other(connected):
             return connected
         default:
             return false
@@ -39,15 +41,13 @@ final class NetStatusService: NetStatusProvider {
         network.currentPath.toNetConnectionType()
     }
 
-    private var currentConnectionType: NetConnectionType = .undetermined
-
     private let network: NWPathMonitor
 
     private let monitorQueue: DispatchQueue
 
     init(network: NWPathMonitor) {
         self.network = network
-        monitorQueue = DispatchQueue(label: "net.path.queue", qos: .background)
+        monitorQueue = DispatchQueue(label: "net.path.queue", qos: .utility)
     }
 
     deinit {
@@ -59,20 +59,15 @@ final class NetStatusService: NetStatusProvider {
     /// - parameter connectionChange: A callback block to listen to changes of the network type, this skips duplicates.
     /// - Note:  The callback will be executed on the main thread.
     func start(connectionChange: @escaping (NetConnectionType) -> Void) {
-        network.pathUpdateHandler = { [weak self] path in
-            guard let self = self else { return }
-            let connecionType = path.toNetConnectionType()
-            if self.currentConnectionType != connecionType {
-                connectionChange(self.connectionType)
-                self.currentConnectionType = self.connectionType
-            }
+        network.pathUpdateHandler = { path in
+            let connectionType = path.toNetConnectionType()
+            connectionChange(connectionType)
         }
         startIfNeeded()
     }
 
     func stop() {
         network.cancel()
-        network.pathUpdateHandler = nil
     }
 
     func startIfNeeded() {
@@ -85,12 +80,17 @@ extension NWPath {
     func toNetConnectionType() -> NetConnectionType {
         let isCellular = usesInterfaceType(.cellular)
         let isWifi = usesInterfaceType(.wifi)
+        let isOther = usesInterfaceType(.loopback)
+            || usesInterfaceType(.other)
+            || usesInterfaceType(.wiredEthernet)
         let isConnected = status == .satisfied
 
         if isCellular {
             return .cellular(connected: isConnected)
         } else if isWifi {
             return .wifi(connected: isConnected)
+        } else if isOther {
+            return .other(connected: isConnected)
         }
 
         return .undetermined

AudioStreaming/Core/Network/NetworkingClient.swift

@@ -13,12 +13,15 @@ enum DataStreamError: Error {
 public enum NetworkError: Error, Equatable {
     case failure(Error)
     case serverError
+    case missingData
     public static func == (lhs: NetworkError, rhs: NetworkError) -> Bool {
         switch (lhs, rhs) {
         case (.failure, failure):
             return true
         case (.serverError, .serverError):
             return true
+        case (.missingData, .missingData):
+            return true
         default:
             return false
         }
@@ -82,7 +85,7 @@ internal final class NetworkingClient {
 
     // MARK: Private
 
-    /// Schedules the given `NetworkDataStream` to be performed immediatelly
+    /// Schedules the given `NetworkDataStream` to be performed immediately
     /// - parameter stream: The `NetworkDataStream` object to be performed
     /// - parameter request: The `URLRequest` for the `stream`
     private func setupRequest(_ stream: NetworkDataStream, request: URLRequest) {

AudioStreaming/Core/Structures/BiMap.swift

@@ -5,7 +5,7 @@
 
 import Foundation
 
-/// A convenient type that holds tasks in a two-way manner, such as `URLSessionTask` to `NetworkDataStream` and reverved
+/// A convenient type that holds tasks in a two-way manner, such as `URLSessionTask` to `NetworkDataStream` and reversed
 struct BiMap<Left, Right> where Left: Hashable, Right: Hashable {
     private var leftToRight: [Left: Right] = [:]
     private var rightToLeft: [Right: Left] = [:]

AudioStreaming/Streaming/Audio Entry/AudioEntry.swift

@@ -53,7 +53,7 @@ internal class AudioEntry {
         return Double(audioStreamFormat.mFramesPerPacket) / Double(sampleRate)
     }
 
-    private var avaragePacketByteSize: Double {
+    private var averagePacketByteSize: Double {
         let packets = processedPacketsState
         guard !packets.isEmpty else { return 0 }
         return Double(packets.sizeTotal / packets.count)
@@ -109,7 +109,7 @@ internal class AudioEntry {
             if packetsCount > estimationMinPacketsPreferred ||
                 (audioStreamFormat.mBytesPerFrame == 0 && packetsCount > estimationMinPackets)
             {
-                return avaragePacketByteSize / packetDuration * 8
+                return averagePacketByteSize / packetDuration * 8
             }
         }
         return (Double(audioStreamFormat.mBytesPerFrame) * audioStreamFormat.mSampleRate) * 8
@@ -151,12 +151,12 @@ extension AudioEntry: AudioStreamSourceDelegate {
         delegate?.dataAvailable(source: source, data: data)
     }
 
-    func errorOccured(source: CoreAudioStreamSource, error: Error) {
-        delegate?.errorOccured(source: source, error: error)
+    func errorOccurred(source: CoreAudioStreamSource, error: Error) {
+        delegate?.errorOccurred(source: source, error: error)
     }
 
-    func endOfFileOccured(source: CoreAudioStreamSource) {
-        delegate?.endOfFileOccured(source: source)
+    func endOfFileOccurred(source: CoreAudioStreamSource) {
+        delegate?.endOfFileOccurred(source: source)
     }
 
     func metadataReceived(data: [String: String]) {

AudioStreaming/Streaming/Audio Source/AudioStreamSource.swift

@@ -10,9 +10,9 @@ protocol AudioStreamSourceDelegate: AnyObject {
     /// Indicates that there's data available
     func dataAvailable(source: CoreAudioStreamSource, data: Data)
     /// Indicates an error occurred
-    func errorOccured(source: CoreAudioStreamSource, error: Error)
+    func errorOccurred(source: CoreAudioStreamSource, error: Error)
     /// Indicates end of file has occurred
-    func endOfFileOccured(source: CoreAudioStreamSource)
+    func endOfFileOccurred(source: CoreAudioStreamSource)
     /// Indicates metadata read from stream
     func metadataReceived(data: [String: String])
 }

AudioStreaming/Streaming/Audio Source/FileAudioSource.swift

@@ -74,7 +74,7 @@ final class FileAudioSource: NSObject, CoreAudioStreamSource {
         do {
             try performOpen(seek: offset)
         } catch {
-            delegate?.errorOccured(source: self, error: error)
+            delegate?.errorOccurred(source: self, error: error)
         }
     }
 
@@ -139,11 +139,11 @@ extension FileAudioSource: StreamDelegate {
         case .hasBytesAvailable:
             dataAvailable()
         case .endEncountered:
-            delegate?.endOfFileOccured(source: self)
+            delegate?.endOfFileOccurred(source: self)
         case .errorOccurred:
-            delegate?.errorOccured(source: self, error: AudioPlayerError.codecError)
+            delegate?.errorOccurred(source: self, error: AudioPlayerError.codecError)
         case .endEncountered:
-            delegate?.endOfFileOccured(source: self)
+            delegate?.endOfFileOccurred(source: self)
         default:
             break
         }

AudioStreaming/Streaming/Audio Source/RemoteAudioSource.swift

@@ -86,12 +86,12 @@ public class RemoteAudioSource: AudioStreamSource {
         let metadataProcessor = MetadataStreamProcessor(parser: metadataParser.eraseToAnyParser())
         let netStatusProvider = NetStatusService(network: NWPathMonitor())
         let icyheaderProcessor = IcycastHeadersProcessor()
-        let retrierTimout = Retrier(interval: .seconds(1), maxInterval: 5, underlyingQueue: nil)
+        let retrierTimeout = Retrier(interval: .seconds(1), maxInterval: 5, underlyingQueue: nil)
         self.init(networking: networking,
                   metadataStreamSource: metadataProcessor,
                   icycastHeadersProcessor: icyheaderProcessor,
                   netStatusProvider: netStatusProvider,
-                  retrier: retrierTimout,
+                  retrier: retrierTimeout,
                   url: url,
                   underlyingQueue: underlyingQueue,
                   httpHeaders: httpHeaders)
@@ -109,8 +109,7 @@ public class RemoteAudioSource: AudioStreamSource {
 
     func close() {
         retrierTimeout.cancel()
-        netStatusService.stop()
-        streamOperationQueue.isSuspended = true
+        streamOperationQueue.isSuspended = false
         streamOperationQueue.cancelAllOperations()
         if let streamTask = streamRequest {
             streamTask.cancel()
@@ -138,12 +137,10 @@ public class RemoteAudioSource: AudioStreamSource {
     }
 
     func suspend() {
-        streamRequest?.suspend()
         streamOperationQueue.isSuspended = true
     }
 
     func resume() {
-        streamRequest?.resume()
         streamOperationQueue.isSuspended = false
     }
 
@@ -154,8 +151,8 @@ public class RemoteAudioSource: AudioStreamSource {
             guard let self = self else { return }
             guard connection.isConnected else { return }
             if self.waitingForNetwork {
+                self.seek(at: self.supportsSeek ? self.position : 0)
                 self.waitingForNetwork = false
-                self.seek(at: self.position)
             }
         }
     }
@@ -163,14 +160,13 @@ public class RemoteAudioSource: AudioStreamSource {
     private func performOpen(seek seekOffset: Int) {
         let urlRequest = buildUrlRequest(with: url, seekIfNeeded: seekOffset)
 
-        let request = networkingClient.stream(request: urlRequest)
+        streamRequest = networkingClient.stream(request: urlRequest)
             .responseStream { [weak self] event in
                 guard let self = self else { return }
                 self.handleResponse(event: event)
             }
             .resume()
 
-        streamRequest = request
         metadataStreamProcessor.delegate = self
     }
 
@@ -181,65 +177,67 @@ public class RemoteAudioSource: AudioStreamSource {
         case let .response(urlResponse):
             parseResponseHeader(response: urlResponse)
             streamOperationQueue.isSuspended = false
-        case let .stream(event):
-            handleStreamEvent(event: event)
+        case let .stream(.success(response)):
+            handleSuccessfulStreamEvent(response: response)
+        case let .stream(.failure(error)):
+            handleFailedStreamEvent(error: error)
         case let .complete(event):
             if let error = event.error {
-                delegate?.errorOccured(source: self, error: error)
+                delegate?.errorOccurred(source: self, error: error)
             } else {
                 addCompletionOperation { [weak self] in
                     guard let self = self else { return }
-                    self.delegate?.endOfFileOccured(source: self)
+                    self.delegate?.endOfFileOccurred(source: self)
                 }
             }
         }
     }
 
-    private func handleStreamEvent(event: NetworkDataStream.StreamResult) {
-        switch event {
-        case let .success(value):
-            if let audioData = value.data {
-                addStreamOperation { [weak self] in
-                    guard let self = self else { return }
-                    if self.shouldTryParsingIcycastHeaders {
-                        let (header, extractedAudio) = self.icycastHeadersProcessor.proccess(data: audioData)
-                        if let header = header {
-                            self.shouldTryParsingIcycastHeaders = false
-                            let parser = IcycastHeaderParser()
-                            self.parsedHeaderOutput = parser.parse(input: header)
-                            if let metadataStep = self.parsedHeaderOutput?.metadataStep {
-                                self.metadataStreamProcessor.metadataAvailable(step: metadataStep)
-                            }
-
-                            let audioCount = self.processAudio(data: extractedAudio)
-                            self.relativePosition += audioCount
-                            return
-                        }
+    private func handleSuccessfulStreamEvent(response: NetworkDataStream.Response) {
+        guard let audioData = response.data else {
+            self.delegate?.errorOccurred(source: self, error: NetworkError.missingData)
+            return
+        }
+        addStreamOperation { [weak self] in
+            guard let self = self else { return }
+            if self.shouldTryParsingIcycastHeaders {
+                let (header, extractedAudio) = self.icycastHeadersProcessor.process(data: audioData)
+                if let header = header {
+                    self.shouldTryParsingIcycastHeaders = false
+                    let parser = IcycastHeaderParser()
+                    self.parsedHeaderOutput = parser.parse(input: header)
+                    if let metadataStep = self.parsedHeaderOutput?.metadataStep {
+                        self.metadataStreamProcessor.metadataAvailable(step: metadataStep)
                     }
-                    let audioCount = self.processAudio(data: audioData)
-                    self.relativePosition += audioCount
                 }
-            }
-        case .failure:
-            if !netStatusService.isConnected {
-                waitingForNetwork = true
+                let audioCount = self.processAudio(data: extractedAudio)
+                self.relativePosition += audioCount
                 return
             }
-            waitingForNetwork = false
-            retryOnError()
+            let audioCount = self.processAudio(data: audioData)
+            self.relativePosition += audioCount
         }
     }
 
+    private func handleFailedStreamEvent(error: Error) {
+        if !netStatusService.isConnected {
+            waitingForNetwork = true
+            return
+        }
+        waitingForNetwork = false
+        retryOnError()
+    }
+
     /// Processing audio data, extracting metadata if needed.
     /// - Parameter data: The audio to be processed
     /// - Returns: An `Int` value representing the amount of audio data bytes.
     private func processAudio(data: Data) -> Int {
-        if self.metadataStreamProcessor.canProccessMetadata {
-            let extractedAudioData = self.metadataStreamProcessor.proccessMetadata(data: data)
-            self.delegate?.dataAvailable(source: self, data: extractedAudioData)
+        if metadataStreamProcessor.canProcessMetadata {
+            let extractedAudioData = metadataStreamProcessor.processMetadata(data: data)
+            delegate?.dataAvailable(source: self, data: extractedAudioData)
             return extractedAudioData.count
         } else {
-            self.delegate?.dataAvailable(source: self, data: data)
+            delegate?.dataAvailable(source: self, data: data)
             return data.count
         }
     }
@@ -260,7 +258,7 @@ public class RemoteAudioSource: AudioStreamSource {
             supportsSeek = acceptRanges != "none"
         }
 
-        // check to see if we have metadata to proccess
+        // check to see if we have metadata to process
         if let metadataStep = parsedHeaderOutput?.metadataStep {
             metadataStreamProcessor.metadataAvailable(step: metadataStep)
         }
@@ -271,9 +269,12 @@ public class RemoteAudioSource: AudioStreamSource {
         // check for error
         if statusCode == 416 { // range not satisfied error
             if length >= 0 { seekOffset = length }
-            delegate?.endOfFileOccured(source: self)
+            delegate?.endOfFileOccurred(source: self)
         } else if statusCode >= 300 {
-            delegate?.errorOccured(source: self, error: NetworkError.serverError)
+            delegate?.errorOccurred(
+                source: self,
+                error: NetworkError.serverError
+            )
         }
     }
 
@@ -290,7 +291,7 @@ public class RemoteAudioSource: AudioStreamSource {
         urlRequest.addValue("1", forHTTPHeaderField: "Icy-MetaData")
         urlRequest.addValue("identity", forHTTPHeaderField: "Accept-Encoding")
 
-        if supportsSeek && seekOffset > 0 {
+        if supportsSeek, seekOffset > 0 {
             urlRequest.addValue("bytes=\(seekOffset)-", forHTTPHeaderField: "Range")
         }
         return urlRequest
@@ -299,7 +300,7 @@ public class RemoteAudioSource: AudioStreamSource {
     private func retryOnError() {
         retrierTimeout.retry { [weak self] in
             guard let self = self else { return }
-            self.seek(at: self.position)
+            self.seek(at: self.supportsSeek ? self.position : 0)
         }
     }
 

AudioStreaming/Streaming/AudioPlayer/AudioPlayer.swift

@@ -6,7 +6,7 @@
 import AVFoundation
 import CoreAudio
 
-public final class AudioPlayer {
+open class AudioPlayer {
     public weak var delegate: AudioPlayerDelegate?
 
     public var muted: Bool {
@@ -86,6 +86,19 @@ public final class AudioPlayer {
     /// The current configuration of the player.
     public let configuration: AudioPlayerConfiguration
 
+    /// A Boolean value that indicates whether the audio engine is running.
+    /// `true` if the engine is running, otherwise, `false`
+    public var isEngineRunning: Bool { audioEngine.isRunning }
+
+    /// The `AVAudioMixerNode` as created by the underlying audio engine
+    public var mainMixerNode: AVAudioMixerNode {
+        audioEngine.mainMixerNode
+    }
+
+    public var frameFiltering: FrameFiltering {
+        frameFilterProcessor
+    }
+
     /// An `AVAudioFormat` object for the canonical audio stream
     private var outputAudioFormat: AVAudioFormat = {
         AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: 44100.0, channels: 2, interleaved: true)!
@@ -95,27 +108,23 @@ public final class AudioPlayer {
     private var stateBeforePaused: InternalState = .initial
 
     /// The underlying `AVAudioEngine` object
-    let audioEngine = AVAudioEngine()
+    private let audioEngine = AVAudioEngine()
     /// An `AVAudioUnit` object that represents the audio player
     private(set) var player = AVAudioUnit()
     /// An `AVAudioUnitTimePitch` that controls the playback rate of the audio engine
-    let rateNode = AVAudioUnitTimePitch()
-
-    /// A Boolean value that indicates whether the audio engine is running.
-    /// `true` if the engine is running, otherwise, `false`
-    var isEngineRunning: Bool { audioEngine.isRunning }
+    private let rateNode = AVAudioUnitTimePitch()
 
     /// An object representing the context of the audio render.
     /// Holds the audio buffer and in/out lists as required by the audio rendering
-    let rendererContext: AudioRendererContext
+    private let rendererContext: AudioRendererContext
     /// An object representing the context of the player.
     /// Holds the player's state, current playing and reading entries.
-    let playerContext: AudioPlayerContext
+    private let playerContext: AudioPlayerContext
 
-    let fileStreamProcessor: AudioFileStreamProcessor
-    let playerRenderProcessor: AudioPlayerRenderProcessor
+    private let fileStreamProcessor: AudioFileStreamProcessor
+    private let playerRenderProcessor: AudioPlayerRenderProcessor
+    private let frameFilterProcessor: FrameFilterProcessor
 
-    private let audioReadSource: DispatchTimerSource
     private let serializationQueue: DispatchQueue
     private let sourceQueue: DispatchQueue
 
@@ -132,7 +141,6 @@ public final class AudioPlayer {
 
         serializationQueue = DispatchQueue(label: "streaming.core.queue", qos: .userInitiated)
         sourceQueue = DispatchQueue(label: "source.queue", qos: .userInitiated)
-        audioReadSource = DispatchTimerSource(interval: .milliseconds(200), queue: sourceQueue)
 
         entryProvider = AudioEntryProvider(networkingClient: NetworkingClient(),
                                            underlyingQueue: sourceQueue,
@@ -142,6 +150,8 @@ public final class AudioPlayer {
                                                        rendererContext: rendererContext,
                                                        outputAudioFormat: outputAudioFormat.basicStreamDescription)
 
+        frameFilterProcessor = FrameFilterProcessor(mixerNode: audioEngine.mainMixerNode)
+
         playerRenderProcessor = AudioPlayerRenderProcessor(playerContext: playerContext,
                                                            rendererContext: rendererContext,
                                                            outputAudioFormat: outputAudioFormat.basicStreamDescription)
@@ -154,7 +164,6 @@ public final class AudioPlayer {
     deinit {
         playerContext.audioPlayingEntry?.close()
         clearQueue()
-        stopReadProccessFromSource()
         rendererContext.clean()
     }
 
@@ -183,14 +192,13 @@ public final class AudioPlayer {
             do {
                 try self.startEngineIfNeeded()
             } catch {
-                self.raiseUnxpected(error: .audioSystemError(.engineFailure))
+                self.raiseUnexpected(error: .audioSystemError(.engineFailure))
             }
         }
 
         sourceQueue.async { [weak self] in
             guard let self = self else { return }
             self.processSource()
-            self.startReadProcessFromSourceIfNeeded()
         }
     }
 
@@ -246,7 +254,6 @@ public final class AudioPlayer {
     public func stop() {
         guard playerContext.internalState != .stopped else { return }
 
-        stopReadProccessFromSource()
         serializationQueue.sync {
             stopEngine(reason: .userAction)
         }
@@ -277,7 +284,6 @@ public final class AudioPlayer {
             serializationQueue.sync {
                 pauseEngine()
             }
-            stopReadProccessFromSource()
             playerContext.audioPlayingEntry?.suspend()
             sourceQueue.async { [weak self] in
                 self?.processSource()
@@ -303,9 +309,10 @@ public final class AudioPlayer {
             }
             startPlayer(resetBuffers: false)
         }
-        startReadProcessFromSourceIfNeeded()
     }
 
+    /// Seeks the audio to the specified time.
+    /// - Parameter time: A `Double` value specifying the time of the requested seek in seconds
     public func seek(to time: Double) {
         guard let playingEntry = playerContext.audioPlayingEntry else {
             return
@@ -328,10 +335,16 @@ public final class AudioPlayer {
         }
     }
 
+    /// Attaches the given `AVAudioNode` to the engine
+    /// - Note: The node will be added after the default rate node
+    /// - Parameter node: An instance of `AVAudioNode`
     public func attach(node: AVAudioNode) {
         attach(nodes: [node])
     }
 
+    /// Attaches the given `AVAudioNode`s to the engine
+    /// - Note: The nodes will be added after the default rate node
+    /// - Parameter node: An array of `AVAudioNode` instances
     public func attach(nodes: [AVAudioNode]) {
         nodes.forEach { node in
             customAttachedNodes.append(node)
@@ -341,6 +354,8 @@ public final class AudioPlayer {
         reattachCustomNodes()
     }
 
+    /// Detaches the given `AVAudioNode` from the engine
+    /// - Parameter node: An instance of `AVAudioNode`
     public func detach(node: AVAudioNode) {
         guard customAttachedNodes.contains(node) else {
             return
@@ -350,6 +365,8 @@ public final class AudioPlayer {
         reattachCustomNodes()
     }
 
+    /// Detaches the given `AVAudioNode`s from the engine
+    /// - Parameter node: An array of `AVAudioNode` instances
     public func detachCustomAttachedNodes() {
         customAttachedNodes.forEach { node in
             audioEngine.detach(node)
@@ -385,7 +402,7 @@ public final class AudioPlayer {
             audioEngine.prepare()
             try audioEngine.start()
         } catch {
-            Logger.error("⚠️ error setuping audio engine: %@", category: .generic, args: error.localizedDescription)
+            Logger.error("⚠️ error setting up audio engine: %@", category: .generic, args: error.localizedDescription)
         }
     }
 
@@ -400,7 +417,7 @@ public final class AudioPlayer {
                 self.playerRenderProcessor.attachCallback(on: unit, audioFormat: self.outputAudioFormat)
             case let .failure(error):
                 assertionFailure("couldn't create player unit: \(error)")
-                self.raiseUnxpected(error: .audioSystemError(.playerNotFound))
+                self.raiseUnexpected(error: .audioSystemError(.playerNotFound))
             }
         }
     }
@@ -428,12 +445,12 @@ public final class AudioPlayer {
         fileStreamProcessor.fileStreamCallback = { [weak self] effect in
             guard let self = self else { return }
             switch effect {
-            case .proccessSource:
+            case .processSource:
                 self.sourceQueue.async {
                     self.processSource()
                 }
             case let .raiseError(error):
-                self.raiseUnxpected(error: error)
+                self.raiseUnexpected(error: error)
             }
         }
     }
@@ -453,7 +470,7 @@ public final class AudioPlayer {
             if let first = customAttachedNodes.first {
                 audioEngine.connect(rateNode, to: first, format: nil)
             }
-            for index in 0..<customAttachedNodes.count - 1 {
+            for index in 0 ..< customAttachedNodes.count - 1 {
                 let current = customAttachedNodes[index]
                 let next = customAttachedNodes[index + 1]
                 let format = current.inputFormat(forBus: 0)
@@ -506,24 +523,7 @@ public final class AudioPlayer {
         Logger.debug("engine stopped 🛑", category: .generic)
     }
 
-    /// Starts the timer of `audioReadSource` for proccesing the source read stream
-    ///
-    /// This calls `processSource` method every `500 ms`
-    private func startReadProcessFromSourceIfNeeded() {
-        guard audioReadSource.state != .activated else { return }
-        audioReadSource.add { [weak self] in
-            self?.processSource()
-        }
-        audioReadSource.activate()
-    }
-
-    /// Stops and removes the handler from the timer, @see `audioReadSource`
-    private func stopReadProccessFromSource() {
-        audioReadSource.suspend()
-        audioReadSource.removeHandler()
-    }
-
-    /// Starts the audio player, reseting the buffers if requested
+    /// Starts the audio player, resetting the buffers if requested
     ///
     /// - parameter resetBuffers: A `Bool` value indicating if the buffers should be reset, prior starting the player.
     private func startPlayer(resetBuffers: Bool) {
@@ -536,7 +536,7 @@ public final class AudioPlayer {
             try player.auAudioUnit.startHardware()
         } catch {
             stopEngine(reason: .error)
-            raiseUnxpected(error: .audioSystemError(.playerStartError))
+            raiseUnexpected(error: .audioSystemError(.playerStartError))
         }
     }
 
@@ -544,7 +544,6 @@ public final class AudioPlayer {
     private func processSource() {
         dispatchPrecondition(condition: .onQueue(sourceQueue))
 
-        guard !playerContext.disposedRequested else { return }
         guard playerContext.internalState != .paused else { return }
 
         if playerContext.internalState == .pendingNext {
@@ -581,7 +580,6 @@ public final class AudioPlayer {
                 setCurrentReading(entry: entry, startPlaying: shouldStartPlaying, shouldClearQueue: false)
             } else if playerContext.audioPlayingEntry == nil {
                 if playerContext.internalState != .stopped {
-                    stopReadProccessFromSource()
                     stopEngine(reason: .eof)
                 }
             }
@@ -597,7 +595,7 @@ public final class AudioPlayer {
             playingEntry.seekRequest.lock.unlock()
 
             if originalSeekToTimeRequested, playerContext.audioReadingEntry === playingEntry {
-                proccessSeekTime()
+                processSeekTime()
 
                 let version = playingEntry.seekRequest.version.value
                 if currSeekVersion == version {
@@ -609,7 +607,7 @@ public final class AudioPlayer {
         }
     }
 
-    private func proccessSeekTime() {
+    private func processSeekTime() {
         assert(playerContext.audioReadingEntry === playerContext.audioPlayingEntry,
                "reading and playing entry must be the same")
         fileStreamProcessor.processSeek()
@@ -724,7 +722,7 @@ public final class AudioPlayer {
         }
     }
 
-    private func raiseUnxpected(error: AudioPlayerError) {
+    private func raiseUnexpected(error: AudioPlayerError) {
         playerContext.setInternalState(to: .error)
         // todo raise on main thread from playback thread
         asyncOnMain { [weak self] in
@@ -745,7 +743,7 @@ extension AudioPlayer: AudioStreamSourceDelegate {
             let openFileStreamStatus = fileStreamProcessor.openFileStream(with: source.audioFileHint)
             guard openFileStreamStatus == noErr else {
                 let streamError = AudioFileStreamError(status: openFileStreamStatus)
-                raiseUnxpected(error: .audioSystemError(.fileStreamError(streamError)))
+                raiseUnexpected(error: .audioSystemError(.fileStreamError(streamError)))
                 return
             }
         }
@@ -755,7 +753,7 @@ extension AudioPlayer: AudioStreamSourceDelegate {
             guard streamBytesStatus == noErr else {
                 if let playingEntry = playerContext.audioPlayingEntry, playingEntry.has(same: source) {
                     let streamBytesError = AudioFileStreamError(status: streamBytesStatus)
-                    raiseUnxpected(error: .streamParseBytesFailure(streamBytesError))
+                    raiseUnexpected(error: .streamParseBytesFailure(streamBytesError))
                 }
                 return
             }
@@ -766,12 +764,12 @@ extension AudioPlayer: AudioStreamSourceDelegate {
         }
     }
 
-    func errorOccured(source: CoreAudioStreamSource, error: Error) {
+    func errorOccurred(source: CoreAudioStreamSource, error: Error) {
         guard let entry = playerContext.audioReadingEntry, entry.has(same: source) else { return }
-        raiseUnxpected(error: .networkError(.failure(error)))
+        raiseUnexpected(error: .networkError(.failure(error)))
     }
 
-    func endOfFileOccured(source: CoreAudioStreamSource) {
+    func endOfFileOccurred(source: CoreAudioStreamSource) {
         let hasSameSource = playerContext.audioReadingEntry?.has(same: source) ?? false
         guard playerContext.audioReadingEntry == nil || hasSameSource else {
             source.delegate = nil
@@ -802,7 +800,10 @@ extension AudioPlayer: AudioStreamSourceDelegate {
         playerContext.audioReadingEntry = nil
         playerContext.entriesLock.unlock()
 
-        processSource()
+        sourceQueue.async { [weak self] in
+            guard let self = self else { return }
+            self.processSource()
+        }
     }
 
     func metadataReceived(data: [String: String]) {

AudioStreaming/Streaming/AudioPlayer/AudioPlayerConfiguration.swift

@@ -13,11 +13,11 @@ public struct AudioPlayerConfiguration: Equatable {
     /// Number of seconds of audio required to before playback first starts.
     /// - note: Must be larger that `bufferSizeInSeconds`
     let secondsRequiredToStartPlaying: Double
-    /// Number of seconds of audio required after seek occcurs.
+    /// Number of seconds of audio required after seek occurs.
     let gracePeriodAfterSeekInSeconds: Double
-    /// Number of seconds of audio required to before playback resumes after a buffer underun
+    /// Number of seconds of audio required to before playback resumes after a buffer underrun
     /// - note: Must be larger that `bufferSizeInSeconds`
-    let secondsRequiredToStartPlayingAfterBufferUnderun: Int
+    let secondsRequiredToStartPlayingAfterBufferUnderrun: Int
 
     /// Enables the internal logs
     let enableLogs: Bool
@@ -26,7 +26,7 @@ public struct AudioPlayerConfiguration: Equatable {
                                                            bufferSizeInSeconds: 10,
                                                            secondsRequiredToStartPlaying: 1,
                                                            gracePeriodAfterSeekInSeconds: 0.5,
-                                                           secondsRequiredToStartPlayingAfterBufferUnderun: 1,
+                                                           secondsRequiredToStartPlayingAfterBufferUnderrun: 1,
                                                            enableLogs: false)
     /// Initializes the configuration for the `AudioPlayer`
     ///
@@ -35,22 +35,22 @@ public struct AudioPlayerConfiguration: Equatable {
     /// - parameter flushQueueOnSeek: All pending items will be flushed when seeking a track if this is set to `true`
     /// - parameter bufferSizeInSeconds: The size of the decompressed buffer.
     /// - parameter secondsRequiredToStartPlaying: Number of seconds of audio required to before playback first starts.
-    /// - parameter gracePeriodAfterSeekInSeconds: Number of seconds of audio required after seek occcurs.
-    /// - parameter secondsRequiredToStartPlayingAfterBufferUnderun: Number of seconds of audio required to before playback resumes after a buffer underun
+    /// - parameter gracePeriodAfterSeekInSeconds: Number of seconds of audio required after seek occurs.
+    /// - parameter secondsRequiredToStartPlayingAfterBufferUnderrun: Number of seconds of audio required to before playback resumes after a buffer underrun
     /// - parameter enableLogs: Enables the internal logs
     ///
     public init(flushQueueOnSeek: Bool = true,
                 bufferSizeInSeconds: Double = 10,
                 secondsRequiredToStartPlaying: Double = 1,
                 gracePeriodAfterSeekInSeconds: Double = 0.5,
-                secondsRequiredToStartPlayingAfterBufferUnderun: Int = 1,
+                secondsRequiredToStartPlayingAfterBufferUnderrun: Int = 1,
                 enableLogs: Bool = false)
     {
         self.flushQueueOnSeek = flushQueueOnSeek
         self.bufferSizeInSeconds = bufferSizeInSeconds
         self.secondsRequiredToStartPlaying = secondsRequiredToStartPlaying
         self.gracePeriodAfterSeekInSeconds = gracePeriodAfterSeekInSeconds
-        self.secondsRequiredToStartPlayingAfterBufferUnderun = secondsRequiredToStartPlayingAfterBufferUnderun
+        self.secondsRequiredToStartPlayingAfterBufferUnderrun = secondsRequiredToStartPlayingAfterBufferUnderrun
         self.enableLogs = enableLogs
     }
 
@@ -70,15 +70,15 @@ public struct AudioPlayerConfiguration: Equatable {
             ? defaults.gracePeriodAfterSeekInSeconds
             : self.gracePeriodAfterSeekInSeconds
 
-        let secondsRequiredToStartPlayingAfterBufferUnderun = self.secondsRequiredToStartPlayingAfterBufferUnderun == 0
-            ? defaults.secondsRequiredToStartPlayingAfterBufferUnderun
-            : self.secondsRequiredToStartPlayingAfterBufferUnderun
+        let secondsRequiredToStartPlayingAfterBufferUnderrun = self.secondsRequiredToStartPlayingAfterBufferUnderrun == 0
+            ? defaults.secondsRequiredToStartPlayingAfterBufferUnderrun
+            : self.secondsRequiredToStartPlayingAfterBufferUnderrun
 
         return AudioPlayerConfiguration(flushQueueOnSeek: flushQueueOnSeek,
                                         bufferSizeInSeconds: bufferSizeInSeconds,
                                         secondsRequiredToStartPlaying: secondsRequiredToStartPlaying,
                                         gracePeriodAfterSeekInSeconds: gracePeriodAfterSeekInSeconds,
-                                        secondsRequiredToStartPlayingAfterBufferUnderun: secondsRequiredToStartPlayingAfterBufferUnderun,
+                                        secondsRequiredToStartPlayingAfterBufferUnderrun: secondsRequiredToStartPlayingAfterBufferUnderrun,
                                         enableLogs: enableLogs)
     }
 }

AudioStreaming/Streaming/AudioPlayer/AudioPlayerContext.swift

@@ -6,30 +6,31 @@
 import Foundation
 
 internal final class AudioPlayerContext {
-    var stopReason = Protected<AudioPlayerStopReason>(.none)
+    var stopReason: Protected<AudioPlayerStopReason>
 
-    var state = Protected<AudioPlayerState>(.ready)
+    var state: Protected<AudioPlayerState>
     var stateChanged: ((_ oldState: AudioPlayerState, _ newState: AudioPlayerState) -> Void)?
 
-    var muted = Protected<Bool>(false)
+    var muted: Protected<Bool>
 
     var internalState: AudioPlayer.InternalState {
         playerInternalState.value
     }
 
-    let entriesLock = UnfairLock()
+    let entriesLock: UnfairLock
     var audioReadingEntry: AudioEntry?
     var audioPlayingEntry: AudioEntry?
 
-    var disposedRequested: Bool
-
     /// This is the player's internal state to use
     /// - NOTE: Do not use directly instead use the `internalState` to set and get the property
     /// or the `setInternalState(to:when:)`method
     private var playerInternalState = Protected<AudioPlayer.InternalState>(.initial)
 
     init() {
-        disposedRequested = false
+        stopReason = Protected<AudioPlayerStopReason>(.none)
+        state = Protected<AudioPlayerState>(.ready)
+        muted = Protected<Bool>(false)
+        entriesLock = UnfairLock()
     }
 
     /// Sets the internal state if given the `inState` will be evaluated before assignment occurs.

AudioStreaming/Streaming/AudioPlayer/AudioPlayerDelegate.swift

@@ -22,7 +22,7 @@ public protocol AudioPlayerDelegate: AnyObject {
                                      stopReason: AudioPlayerStopReason,
                                      progress: Double,
                                      duration: Double)
-    /// Tells the delegate when an unexpected error occured.
+    /// Tells the delegate when an unexpected error occurred.
     /// - note: Probably a good time to recreate the player when this occurs
     func audioPlayerUnexpectedError(player: AudioPlayer, error: AudioPlayerError)
 

AudioStreaming/Streaming/AudioPlayer/AudioRendererContext.swift

@@ -20,8 +20,6 @@ final class AudioRendererContext {
 
     let packetsSemaphore = DispatchSemaphore(value: 0)
 
-    var discontinuous: Bool = false
-
     let framesRequiredToStartPlaying: UInt32
     let framesRequiredAfterRebuffering: UInt32
     let framesRequiredForDataAfterSeekPlaying: UInt32
@@ -36,7 +34,7 @@ final class AudioRendererContext {
         let canonicalStream = outputAudioFormat.basicStreamDescription
 
         framesRequiredToStartPlaying = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.secondsRequiredToStartPlaying)
-        framesRequiredAfterRebuffering = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.secondsRequiredToStartPlayingAfterBufferUnderun)
+        framesRequiredAfterRebuffering = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.secondsRequiredToStartPlayingAfterBufferUnderrun)
         framesRequiredForDataAfterSeekPlaying = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.gracePeriodAfterSeekInSeconds)
 
         let dataByteSize = Int(canonicalStream.mSampleRate * configuration.bufferSizeInSeconds) * Int(canonicalStream.mBytesPerFrame)
@@ -77,8 +75,8 @@ private func allocateBufferList(dataByteSize: Int) -> UnsafeMutablePointer<Audio
     let _bufferList = AudioBufferList.allocate(maximumBuffers: 1)
 
     _bufferList[0].mDataByteSize = UInt32(dataByteSize)
-    let alingment = MemoryLayout<UInt8>.alignment
-    let mData = UnsafeMutableRawPointer.allocate(byteCount: dataByteSize, alignment: alingment)
+    let alignment = MemoryLayout<UInt8>.alignment
+    let mData = UnsafeMutableRawPointer.allocate(byteCount: dataByteSize, alignment: alignment)
     _bufferList[0].mData = mData
     _bufferList[0].mNumberChannels = 2
 

AudioStreaming/Streaming/AudioPlayer/Processors/AudioFileStreamProcessor.swift

@@ -9,7 +9,7 @@ import AVFoundation
 
 enum AudioConvertStatus: Int32 {
     case done = 100
-    case proccessed = 0
+    case processed = 0
 }
 
 struct AudioConvertInfo {
@@ -20,11 +20,11 @@ struct AudioConvertInfo {
 }
 
 enum FileStreamProcessorEffect {
-    case proccessSource
+    case processSource
     case raiseError(AudioPlayerError)
 }
 
-/// An object that handles the proccessing of AudioFileStream, its packets etc.
+/// An object that handles the processing of AudioFileStream, its packets etc.
 final class AudioFileStreamProcessor {
     private let maxCompressedPacketForBitrate = 4096
 
@@ -38,8 +38,9 @@ final class AudioFileStreamProcessor {
     internal var audioConverter: AudioConverterRef?
     internal var discontinuous: Bool = false
     internal var inputFormat = AudioStreamBasicDescription()
-    internal var fileFormat: String = ""
-    internal let fa4mFormat = "fa4m"
+
+    internal var currentFileFormat: String = ""
+    internal let fileFormatsForDelayedConverterCreation: Set = ["fa4m", "f4pm"]
 
     var isFileStreamOpen: Bool {
         audioFileStream != nil
@@ -165,7 +166,7 @@ final class AudioFileStreamProcessor {
 
         var classDesc = AudioClassDescription()
         var outputFormat = toFormat
-        if getHardwareCodecClassDescripition(formatId: inputFormat.mFormatID, classDesc: &classDesc) {
+        if getHardwareCodecClassDescription(formatId: inputFormat.mFormatID, classDesc: &classDesc) {
             AudioConverterNewSpecific(&inputFormat, &outputFormat, 1, &classDesc, &audioConverter)
         }
 
@@ -178,11 +179,12 @@ final class AudioFileStreamProcessor {
             }
         }
         self.inputFormat = inputFormat
+        assignMagicCookieToConverterIfNeeded()
+    }
 
+    private func assignMagicCookieToConverterIfNeeded() {
         // magic cookie info
-        let fileHint = playerContext.audioReadingEntry?.audioFileHint
-        let isProperFormat = fileHint != kAudioFileAAC_ADTSType && fileHint != kAudioFileM4AType && fileHint != kAudioFileMPEG4Type
-        if let fileStream = audioFileStream, isProperFormat {
+        if let fileStream = audioFileStream {
             var cookieSize: UInt32 = 0
             guard AudioFileStreamGetPropertyInfo(fileStream, kAudioFileStreamProperty_MagicCookieData, &cookieSize, nil) == noErr else {
                 return
@@ -193,7 +195,7 @@ final class AudioFileStreamProcessor {
             }
             guard let converter = audioConverter else {
                 fileStreamCallback?(.raiseError(.audioSystemError(.fileStreamError(.unknownError))))
-                 return
+                return
             }
             guard AudioConverterSetProperty(converter, kAudioConverterDecompressionMagicCookie, cookieSize, cookie) == noErr else {
                 fileStreamCallback?(.raiseError(.audioSystemError(.fileStreamError(.unknownError))))
@@ -229,9 +231,9 @@ final class AudioFileStreamProcessor {
         case kAudioFileStreamProperty_AudioDataByteCount:
             processDataByteCount(fileStream: fileStream)
         case kAudioFileStreamProperty_AudioDataPacketCount:
-            proccessAudioDataPacketCount(fileStream: fileStream)
+            processAudioDataPacketCount(fileStream: fileStream)
         case kAudioFileStreamProperty_ReadyToProducePackets:
-            // check converter for discontious stream
+            // check converter for discontinuous stream
             processReadyToProducePackets(fileStream: fileStream)
         case kAudioFileStreamProperty_FormatList:
             processFormatList(fileStream: fileStream)
@@ -239,7 +241,7 @@ final class AudioFileStreamProcessor {
         }
     }
 
-    // MARK: AudioFileStream properties Proccessing
+    // MARK: AudioFileStream properties Processing
 
     private func processDataOffset(fileStream: AudioFileStreamID) {
         var offset: UInt64 = 0
@@ -263,7 +265,7 @@ final class AudioFileStreamProcessor {
         var size = UInt32(4)
         AudioFileStreamGetProperty(fileStream, kAudioFileStreamProperty_FileFormat, &size, &fileFormat)
         if let stringFileFormat = String(data: Data(fileFormat), encoding: .utf8) {
-            self.fileFormat = stringFileFormat
+            currentFileFormat = stringFileFormat
         }
     }
 
@@ -293,7 +295,7 @@ final class AudioFileStreamProcessor {
                 entry.processedPacketsState.bufferSize = packetBufferSize
             }
 
-            if fileFormat != fa4mFormat {
+            if !fileFormatsForDelayedConverterCreation.contains(currentFileFormat) {
                 createAudioConverter(from: entry.audioStreamFormat, to: outputAudioFormat)
             }
         }
@@ -306,7 +308,7 @@ final class AudioFileStreamProcessor {
         entry.audioStreamState.dataByteCount = audioDataByteCount
     }
 
-    private func proccessAudioDataPacketCount(fileStream: AudioFileStreamID) {
+    private func processAudioDataPacketCount(fileStream: AudioFileStreamID) {
         guard let entry = playerContext.audioReadingEntry else { return }
         var audioDataPacketCount: UInt64 = 0
         fileStreamGetProperty(value: &audioDataPacketCount, fileStream: fileStream, propertyId: kAudioFileStreamProperty_AudioDataPacketCount)
@@ -331,7 +333,7 @@ final class AudioFileStreamProcessor {
             i += step
         }
 
-        if fileFormat == fa4mFormat {
+        if fileFormatsForDelayedConverterCreation.contains(currentFileFormat) {
             if let inputStreamFormat = playerContext.audioReadingEntry?.audioStreamFormat {
                 createAudioConverter(from: inputStreamFormat, to: outputAudioFormat)
             }
@@ -346,12 +348,12 @@ final class AudioFileStreamProcessor {
                              inPacketDescriptions: UnsafeMutablePointer<AudioStreamPacketDescription>?)
     {
         guard let entry = playerContext.audioReadingEntry else { return }
-        guard entry.audioStreamState.processedDataFormat, !playerContext.disposedRequested else { return }
+        guard entry.audioStreamState.processedDataFormat else { return }
 
         if let playingEntry = playerContext.audioPlayingEntry,
            playingEntry.seekRequest.requested, playingEntry.calculatedBitrate() > 0
         {
-            fileStreamCallback?(.proccessSource)
+            fileStreamCallback?(.processSource)
             if rendererContext.waiting.value {
                 rendererContext.packetsSemaphore.signal()
             }
@@ -375,11 +377,11 @@ final class AudioFileStreamProcessor {
             convertInfo.audioBuffer.mNumberChannels = playingAudioStreamFormat.mChannelsPerFrame
         }
 
-        updateProccessedPackets(inPacketDescriptions: inPacketDescriptions,
-                                inNumberPackets: inNumberPackets)
+        updateProcessedPackets(inPacketDescriptions: inPacketDescriptions,
+                               inNumberPackets: inNumberPackets)
 
         var status: OSStatus = noErr
-        packetProccess: while status == noErr {
+        packetProcess: while status == noErr {
             rendererContext.lock.lock()
             let bufferContext = rendererContext.bufferContext
             var used = bufferContext.frameUsedCount
@@ -401,8 +403,7 @@ final class AudioFileStreamProcessor {
                     if framesLeftInBuffer > 0 {
                         break
                     }
-                    if playerContext.disposedRequested
-                        || playerContext.internalState == .disposed
+                    if playerContext.internalState == .disposed
                         || playerContext.internalState == .pendingNext
                         || playerContext.internalState == .stopped
                     {
@@ -412,7 +413,7 @@ final class AudioFileStreamProcessor {
                     if let playingEntry = playerContext.audioPlayingEntry,
                        playingEntry.seekRequest.requested, playingEntry.calculatedBitrate() > 0
                     {
-                        fileStreamCallback?(.proccessSource)
+                        fileStreamCallback?(.processSource)
                         if rendererContext.waiting.value {
                             rendererContext.packetsSemaphore.signal()
                         }
@@ -457,7 +458,7 @@ final class AudioFileStreamProcessor {
                 framesToDecode = start
                 if framesToDecode == 0 {
                     fillUsedFrames(framesCount: framesAdded)
-                    continue packetProccess
+                    continue packetProcess
                 }
                 prefillLocalBufferList(bufferList: localBufferList,
                                        dataOffset: 0,
@@ -475,9 +476,9 @@ final class AudioFileStreamProcessor {
                 if status == AudioConvertStatus.done.rawValue {
                     fillUsedFrames(framesCount: framesAdded)
                     return
-                } else if status == AudioConvertStatus.proccessed.rawValue {
+                } else if status == AudioConvertStatus.processed.rawValue {
                     fillUsedFrames(framesCount: framesAdded)
-                    continue packetProccess
+                    continue packetProcess
                 } else if status != 0 {
                     fileStreamCallback?(.raiseError(.codecError))
                     return
@@ -502,9 +503,9 @@ final class AudioFileStreamProcessor {
                 if status == AudioConvertStatus.done.rawValue {
                     fillUsedFrames(framesCount: framesAdded)
                     return
-                } else if status == AudioConvertStatus.proccessed.rawValue {
+                } else if status == AudioConvertStatus.processed.rawValue {
                     fillUsedFrames(framesCount: framesAdded)
-                    continue packetProccess
+                    continue packetProcess
                 } else if status != 0 {
                     fileStreamCallback?(.raiseError(.codecError))
                     return
@@ -545,8 +546,8 @@ final class AudioFileStreamProcessor {
     }
 
     @inline(__always)
-    private func updateProccessedPackets(inPacketDescriptions: UnsafeMutablePointer<AudioStreamPacketDescription>?,
-                                         inNumberPackets: UInt32)
+    private func updateProcessedPackets(inPacketDescriptions: UnsafeMutablePointer<AudioStreamPacketDescription>?,
+                                        inNumberPackets: UInt32)
     {
         guard let inPacketDescriptions = inPacketDescriptions else { return }
         guard let readingEntry = playerContext.audioReadingEntry else { return }
@@ -618,12 +619,12 @@ private func _converterCallback(inAudioConverter _: AudioConverterRef,
     ioNumberDataPackets.pointee = convertInfo.pointee.numberOfPackets
     convertInfo.pointee.done = true
 
-    return AudioConvertStatus.proccessed.rawValue
+    return AudioConvertStatus.processed.rawValue
 }
 
 // MARK: HardwareCodedClass method
 
-private func getHardwareCodecClassDescripition(formatId: UInt32, classDesc: UnsafeMutablePointer<AudioClassDescription>) -> Bool {
+private func getHardwareCodecClassDescription(formatId: UInt32, classDesc: UnsafeMutablePointer<AudioClassDescription>) -> Bool {
     #if os(iOS)
         var size: UInt32 = 0
         let formatIdSize = UInt32(MemoryLayout.size(ofValue: formatId))

AudioStreaming/Streaming/AudioPlayer/Processors/FrameFilterProcessor.swift

@@ -0,0 +1,175 @@
+//
+//  Created by Dimitrios C on 19/05/2021.
+//  Copyright © 2021 Decimal. All rights reserved.
+//
+
+import AVFoundation
+
+///
+/// - parameter buffer: A buffer of audio captured from the output of an AVAudioNode.
+/// - parameter when: The time the buffer was captured.
+///
+public typealias FilterCallback = (_ buffer: AVAudioPCMBuffer,
+                                   _ when: AVAudioTime) -> Void
+
+/// A value type whose instances are used for frame filter
+/// - Note:
+/// The filter block will be called from a thread other than the main thread
+public struct FilterEntry: Equatable {
+    /// A string value indicating the name of the filter
+    public let name: String
+
+    /// A block in which you apply any filtering
+    public let filter: FilterCallback
+
+    public init(name: String, filter: @escaping FilterCallback) {
+        self.name = name
+        self.filter = filter
+    }
+
+    public static func == (lhs: FilterEntry, rhs: FilterEntry) -> Bool {
+        lhs.name == rhs.name
+    }
+}
+
+public protocol FrameFiltering {
+    /// A Boolean value indicating whether there are filter entries
+    var hasEntries: Bool { get }
+
+    /// Adds a filter entry at the end of the queue
+    /// - Parameter entry: An instance of `FilterEntry`
+    func add(entry: FilterEntry)
+
+    /// Adds a filter entry after the specified name of another entry
+    /// - Parameters:
+    ///   - entry: An instance of `FilterEntry`
+    ///   - named: The name of a previously added filter
+    func add(entry: FilterEntry, afterEntry named: String)
+
+    /// Adds a filter entry with the given parameters
+    /// - Parameters:
+    ///   - named: The name of the entry to be added
+    ///   - filter: The block for the filter handling
+    func add(entry named: String, filter: @escaping FilterCallback)
+
+    /// Adds a filter entry with the given parameters
+    /// - Parameters:
+    ///   - name: The name for the new entry
+    ///   - filterName: The name of a previously added filters
+    ///   - filter: The block for the filter handling
+    func add(entry named: String, after filterName: String, filter: @escaping FilterCallback)
+
+    /// Removes a filter entry
+    /// - Parameter entry: An instance of `FilterEntry` to be removed
+    func remove(entry: FilterEntry)
+
+    /// Attempts to remove a filter entry by its name
+    /// - Parameter named: A `String` representing the name of the filter entry
+    func remove(entry named: String)
+
+    /// Removes all filter entries
+    func removeAll()
+}
+
+final class FrameFilterProcessor: NSObject, FrameFiltering {
+    public var hasEntries: Bool {
+        lock.lock(); defer { lock.unlock() }
+        return !entries.isEmpty
+    }
+
+    private let lock = UnfairLock()
+    private let mixerNode: AVAudioMixerNode
+
+    private(set) var entries: [FilterEntry] = []
+
+    private var hasInstalledTap: Bool = false
+
+    init(mixerNode: AVAudioMixerNode) {
+        self.mixerNode = mixerNode
+    }
+
+    public func add(entry: FilterEntry) {
+        lock.lock(); defer { lock.unlock() }
+        entries.append(entry)
+        installTapIfNeeded()
+    }
+
+    public func add(entry: FilterEntry, afterEntry named: String) {
+        lock.lock(); defer { lock.unlock() }
+        guard let entryIndex = entries.firstIndex(where: { $0.name == named }) else {
+            return
+        }
+        if entryIndex.advanced(by: 1) > entries.count {
+            entries.append(entry)
+        } else {
+            entries.insert(entry, at: entryIndex + 1)
+        }
+        installTapIfNeeded()
+    }
+
+    public func add(entry named: String, filter: @escaping FilterCallback) {
+        lock.lock(); defer { lock.unlock() }
+        entries.append(FilterEntry(name: named, filter: filter))
+        installTapIfNeeded()
+    }
+
+    func add(entry named: String, after filterName: String, filter: @escaping FilterCallback) {
+        let entry = FilterEntry(name: named, filter: filter)
+        add(entry: entry, afterEntry: filterName)
+    }
+
+    public func remove(entry: FilterEntry) {
+        lock.lock(); defer { lock.unlock() }
+        guard let entryIndex = entries.firstIndex(where: { $0 == entry }) else {
+            return
+        }
+        entries.remove(at: entryIndex)
+        if entries.isEmpty {
+            removeTap()
+        }
+    }
+
+    public func remove(entry named: String) {
+        lock.lock(); defer { lock.unlock() }
+        guard let entryIndex = entries.firstIndex(where: { $0.name == named }) else {
+            return
+        }
+        entries.remove(at: entryIndex)
+        if entries.isEmpty {
+            removeTap()
+        }
+    }
+
+    public func removeAll() {
+        lock.lock(); defer { lock.unlock() }
+        entries.removeAll()
+        removeTap()
+    }
+
+    private func process(buffer: AVAudioPCMBuffer, when: AVAudioTime) {
+        lock.lock(); defer { lock.unlock() }
+        guard !entries.isEmpty else { return }
+        for entry in entries {
+            entry.filter(buffer, when)
+        }
+    }
+
+    private func installTapIfNeeded() {
+        guard !hasInstalledTap else { return }
+        hasInstalledTap = true
+        let format = mixerNode.outputFormat(forBus: 0)
+        mixerNode.installTap(onBus: 0, bufferSize: 1024, format: format) { [weak self] buffer, when in
+            guard let self = self else { return }
+            guard self.hasEntries else { return }
+            self.process(
+                buffer: buffer,
+                when: when
+            )
+        }
+    }
+
+    private func removeTap() {
+        hasInstalledTap = false
+        mixerNode.removeTap(onBus: 0)
+    }
+}

AudioStreaming/Streaming/AudioPlayer/Processors/IcycastHeadersProcessor.swift

@@ -26,7 +26,6 @@ import Foundation
 /// ```
 
 final class IcycastHeadersProcessor {
-
     private var icecastHeaders = Data(capacity: 1024)
     private var searchComplete = false
     private var iceHeaderAvailable = false
@@ -38,31 +37,32 @@ final class IcycastHeadersProcessor {
     }
 
     @inline(__always)
-    func proccess(data: Data) -> (Data?, Data) {
-        let stopProccessingCheckOne: [UInt8] = Array("\n\n".utf8)
-        let stopProccessingCheckTwo: [UInt8] = Array("\r\n\r\n".utf8)
+    func process(data: Data) -> (Data?, Data) {
+        let stopProcessingCheckOne: [UInt8] = Array("\n\n".utf8)
+        let stopProcessingCheckTwo: [UInt8] = Array("\r\n\r\n".utf8)
         let icyPrefix: [UInt8] = Array("ICY ".utf8)
         let httpPrefix: [UInt8] = Array("HTTP".utf8)
         return data.withUnsafeBytes { buffer -> (Data?, Data) in
+            guard !buffer.isEmpty else { return (nil, data) }
             var bytesRead = 0
             let bytes = buffer.baseAddress!.assumingMemoryBound(to: UInt8.self)
             // Read through the bytes and stop when our search is complete
-            // Since we don't know the amount of bytes to be proccessed
+            // Since we don't know the amount of bytes to be processed
             // we add each character up until we found on of the checks as defined above.
             while bytesRead < buffer.count, !searchComplete {
                 let pointer = bytes + bytesRead
                 icecastHeaders.append(pointer, count: 1)
 
-                if icecastHeaders.count >= stopProccessingCheckOne.count {
-                    if icecastHeaders.suffix(stopProccessingCheckOne.count) == stopProccessingCheckOne {
+                if icecastHeaders.count >= stopProcessingCheckOne.count {
+                    if icecastHeaders.suffix(stopProcessingCheckOne.count) == stopProcessingCheckOne {
                         iceHeaderAvailable = true
                         searchComplete = true
                         break
                     }
                 }
 
-                if icecastHeaders.count >= stopProccessingCheckTwo.count {
-                    if icecastHeaders.suffix(stopProccessingCheckTwo.count) == stopProccessingCheckTwo {
+                if icecastHeaders.count >= stopProcessingCheckTwo.count {
+                    if icecastHeaders.suffix(stopProcessingCheckTwo.count) == stopProcessingCheckTwo {
                         iceHeaderAvailable = true
                         searchComplete = true
                         break
@@ -71,8 +71,9 @@ final class IcycastHeadersProcessor {
 
                 if icecastHeaders.count >= icyPrefix.count {
                     // in case the first 4 chars are not "ICY " nor "HTTP" then we stop the flow
-                    if icecastHeaders[..<icyPrefix.count].elementsEqual(icyPrefix) == false &&
-                        icecastHeaders[..<httpPrefix.count].elementsEqual(httpPrefix) == false {
+                    if icecastHeaders[..<icyPrefix.count].elementsEqual(icyPrefix) == false,
+                       icecastHeaders[..<httpPrefix.count].elementsEqual(httpPrefix) == false
+                    {
                         iceHeaderAvailable = false
                         searchComplete = true
                     }

AudioStreaming/Streaming/AudioPlayer/Processors/MetadataStreamProcessor.swift

@@ -12,16 +12,16 @@ protocol MetadataStreamSourceDelegate: AnyObject {
 protocol MetadataStreamSource {
     var delegate: MetadataStreamSourceDelegate? { get set }
 
-    /// Returns `true` when the stream header has indicated that we can proccess metadata, otherwise `false`.
-    var canProccessMetadata: Bool { get }
+    /// Returns `true` when the stream header has indicated that we can process metadata, otherwise `false`.
+    var canProcessMetadata: Bool { get }
 
     /// Assigns the metadata step of the metadata
     func metadataAvailable(step: Int)
 
-    /// Proccess the received data and extract the metadata if any, returns audio data only.
+    /// Process the received data and extract the metadata if any, returns audio data only.
     /// - parameter data: A `Data` object for parsing any metadata
     /// - returns: The extracted audio `Data`
-    func proccessMetadata(data: Data) -> Data
+    func processMetadata(data: Data) -> Data
 
     /// Resets the processor
     func reset()
@@ -44,7 +44,7 @@ protocol MetadataStreamSource {
 final class MetadataStreamProcessor: MetadataStreamSource {
     weak var delegate: MetadataStreamSourceDelegate?
 
-    var canProccessMetadata: Bool {
+    var canProcessMetadata: Bool {
         return metadataStep > 0
     }
 
@@ -73,10 +73,10 @@ final class MetadataStreamProcessor: MetadataStreamSource {
         audioDataBytesRead = 0
     }
 
-    // MARK: Proccess Metadata
+    // MARK: Process Metadata
 
     @inline(__always)
-    func proccessMetadata(data: Data) -> Data {
+    func processMetadata(data: Data) -> Data {
         data.withUnsafeBytes { buffer -> Data in
             guard !buffer.isEmpty else { return data }
             var audioData = Data()

AudioStreaming/Streaming/Parsers/HTTPHeaderParser.swift

@@ -14,7 +14,7 @@ struct HeaderField {
 }
 
 enum IcyHeaderField {
-    public static let icyMentaint = "icy-metaint"
+    public static let icyMetaint = "icy-metaint"
 }
 
 struct HTTPHeaderParserOutput {
@@ -64,7 +64,7 @@ struct HTTPHeaderParser: HTTPHeaderParsing {
         }
 
         var metadataStep = 0
-        if let icyMetaint = value(forHTTPHeaderField: IcyHeaderField.icyMentaint, in: input),
+        if let icyMetaint = value(forHTTPHeaderField: IcyHeaderField.icyMetaint, in: input),
            let intValue = Int(icyMetaint)
         {
             metadataStep = intValue

AudioStreaming/Streaming/Parsers/IcycastHeaderParser.swift

@@ -9,9 +9,7 @@
 import Foundation
 
 struct IcycastHeaderParser: Parser {
-
     func parse(input: Data) -> HTTPHeaderParserOutput? {
-
         guard let icecastValue = String(data: input, encoding: .utf8) else {
             return nil
         }
@@ -23,7 +21,7 @@ struct IcycastHeaderParser: Parser {
                 result[String(key)] = String(value)
             }
         }
-        let metadataStep = Int(result[IcyHeaderField.icyMentaint] ?? "") ?? 0
+        let metadataStep = Int(result[IcyHeaderField.icyMetaint] ?? "") ?? 0
         let contentType = result[HeaderField.contentType.lowercased()] ?? "audio/mpeg"
         let typeId = audioFileType(mimeType: contentType)
 

AudioStreaming/Streaming/Parsers/MetadataParser.swift

@@ -18,13 +18,17 @@ struct MetadataParser: Parser {
 
     func parse(input: Data) -> MetadataOutput {
         guard let string = String(data: input, encoding: .utf8) else { return .failure(.unableToParse) }
-        // remove added bytes (zeros) and seperate the string on every ';' char
+        // remove added bytes (zeros) and separate the string on every ';' char
         let pairs = string.trimmingCharacters(in: CharacterSet(charactersIn: "\0")).components(separatedBy: ";")
-        let temp: [String: String] = [:]
-        let metadata = pairs.reduce(into: temp) { result, next in
-            let paired = next.components(separatedBy: "=")
-            if let key = paired.first,
-               let value = paired.last?.replacingOccurrences(of: "'", with: ""), !key.isEmpty
+        let metadata = pairs.reduce(into: [String: String]()) { result, next in
+            let split = next.split(
+                separator: "=",
+                maxSplits: 1,
+                omittingEmptySubsequences: true
+            )
+            .map(String.init)
+            if let key = split.first,
+               let value = split.last?.replacingOccurrences(of: "'", with: ""), !key.isEmpty
             {
                 result[key] = value
             }

AudioStreamingTests/Streaming/Metadata Stream Processor/MetadataStreamProcessorTests.swift

@@ -18,19 +18,19 @@ class MetadataStreamProcessorTests: XCTestCase {
         let processor = MetadataStreamProcessor(parser: parser.eraseToAnyParser())
 
         // without calling `metadataAvailable(step:)` it should be false
-        XCTAssertFalse(processor.canProccessMetadata)
+        XCTAssertFalse(processor.canProcessMetadata)
 
         // calling `metadataAvailable(step:)` with zero
         processor.metadataAvailable(step: 0)
 
         // it should be false
-        XCTAssertFalse(processor.canProccessMetadata)
+        XCTAssertFalse(processor.canProcessMetadata)
 
         // calling `metadataAvailable(step:)` with greater zero
         processor.metadataAvailable(step: 1)
 
         // it should be true
-        XCTAssertTrue(processor.canProccessMetadata)
+        XCTAssertTrue(processor.canProcessMetadata)
     }
 
     func test_Processor_Outputs_Correct_Metadata_ForStep_WithEmptyMetadata() throws {
@@ -45,7 +45,7 @@ class MetadataStreamProcessorTests: XCTestCase {
         // this is the step value as received from the http headers
         processor.metadataAvailable(step: 16000)
 
-        let audio = processor.proccessMetadata(data: data)
+        let audio = processor.processMetadata(data: data)
         XCTAssertFalse(audio.isEmpty)
 
         XCTAssertTrue(metadataDelegateSpy.receivedMetadata.called)
@@ -64,7 +64,7 @@ class MetadataStreamProcessorTests: XCTestCase {
         // this is the step value as received from the http headers
         processor.metadataAvailable(step: 16000)
 
-        let audio = processor.proccessMetadata(data: data)
+        let audio = processor.processMetadata(data: data)
         XCTAssertFalse(audio.isEmpty)
 
         XCTAssertTrue(metadataDelegateSpy.receivedMetadata.called)
@@ -83,7 +83,7 @@ class MetadataStreamProcessorTests: XCTestCase {
         // this is the step value as received from the http headers
         processor.metadataAvailable(step: 8000)
 
-        let audio = processor.proccessMetadata(data: data)
+        let audio = processor.processMetadata(data: data)
         XCTAssertFalse(audio.isEmpty)
 
         XCTAssertTrue(metadataDelegateSpy.receivedMetadata.called)
@@ -106,7 +106,7 @@ class MetadataStreamProcessorTests: XCTestCase {
         // this is the step value as received from the http headers
         processor.metadataAvailable(step: 16000)
 
-        let audio = processor.proccessMetadata(data: data)
+        let audio = processor.processMetadata(data: data)
         XCTAssertFalse(audio.isEmpty)
 
         XCTAssertFalse(metadataDelegateSpy.receivedMetadata.called)
@@ -122,7 +122,7 @@ class MetadataStreamProcessorTests: XCTestCase {
         // this is the step value as received from the http headers
         processor.metadataAvailable(step: 16000)
 
-        let audio = processor.proccessMetadata(data: data)
+        let audio = processor.processMetadata(data: data)
         XCTAssertTrue(audio.isEmpty)
 
         XCTAssertFalse(metadataDelegateSpy.receivedMetadata.called)

AudioStreamingTests/Streaming/Parsers/HTTPHeaderParserTests.swift

@@ -34,7 +34,7 @@ class HTTPHeaderParserTests: XCTestCase {
         let headers: [String: String] =
             [HeaderField.contentLength: "1000",
              HeaderField.contentType: "audio/mp3",
-             IcyHeaderField.icyMentaint: "16000"]
+             IcyHeaderField.icyMetaint: "16000"]
         let httpURLResponse = HTTPURLResponse(url: URL(string: "www.google.com")!,
                                               statusCode: 200,
                                               httpVersion: "",
@@ -57,7 +57,7 @@ class HTTPHeaderParserTests: XCTestCase {
         let headers: [String: String] =
             [HeaderField.contentLength.lowercased(): "1000",
              HeaderField.contentType.lowercased(): "audio/mp3",
-             IcyHeaderField.icyMentaint.lowercased(): "16000"]
+             IcyHeaderField.icyMetaint.lowercased(): "16000"]
         let httpURLResponse = HTTPURLResponse(url: URL(string: "www.google.com")!,
                                               statusCode: 200,
                                               httpVersion: "",

AudioStreamingTests/Streaming/Parsers/MetadataParser.swift

@@ -50,6 +50,26 @@ class MetadataParserTests: XCTestCase {
         }
     }
 
+    func testParserOutputsCorrectResultWhenEntryContainsEqualSign() throws {
+        let string = "StreamTitle=\'Gramatik - In This Whole World (Original Mix)\';StreamUrl=\'\';track_info=\'k4Smc3RhdHVzoUihQNJiGp6BpHR5cGWhVKJpZKhNWDUxMTYzNISmc3RhdHVzoUOhQNJiGp9cpHR5cGWhVKJpZKhNWDUxMDM3MoSmc3RhdHVzoUOhQNJiGqAqpHR5cGWhVKJpZKhNWDUxMjA5Ng==\';UTC=\'20220226T214447.206\';\0\0\0\0\0\0\0\0\0"
+        let data = string.data(using: .utf8)!
+
+        let parser = MetadataParser()
+
+        let output = parser.parse(input: data)
+
+        switch output {
+        case let .success(values):
+            XCTAssertFalse(values.isEmpty)
+            XCTAssertEqual(values["StreamTitle"], "Gramatik - In This Whole World (Original Mix)")
+            XCTAssertEqual(values["StreamUrl"], "")
+            XCTAssertEqual(values["track_info"], "k4Smc3RhdHVzoUihQNJiGp6BpHR5cGWhVKJpZKhNWDUxMTYzNISmc3RhdHVzoUOhQNJiGp9cpHR5cGWhVKJpZKhNWDUxMDM3MoSmc3RhdHVzoUOhQNJiGqAqpHR5cGWhVKJpZKhNWDUxMjA5Ng==")
+            XCTAssertEqual(values["UTC"], "20220226T214447.206")
+        case .failure:
+            XCTFail()
+        }
+    }
+
     func testParserOutputsFailureOnEmptyStringData() throws {
         let data = "".data(using: .utf8)!
         let parser = MetadataParser()

Package.swift

@@ -17,7 +17,7 @@ let package = Package(
         .target(
             name: "AudioStreaming",
             path: "AudioStreaming"
-        )
+        ),
     ],
     swiftLanguageVersions: [.v5]
 )

README.md

@@ -3,15 +3,15 @@
 # AudioStreaming
 An AudioPlayer/Streaming library for iOS written in Swift, allows playback of online audio streaming, local file as well as gapless queueing.
 
-Under the hood `AudioStreaming` uses `AVAudioEngine` and `CoreAudio` for playback and provides an easy way of applying real-time [audio enhancements](https://developer.apple.com/documentation/avfoundation/audio_playback_recording_and_processing/avaudioengine/audio_units?language=swift).
+Under the hood `AudioStreaming` uses `AVAudioEngine` and `CoreAudio` for playback and provides an easy way of applying real-time [audio enhancements](https://developer.apple.com/documentation/avfaudio/audio_engine/audio_units).
 
 #### Supported audio
-- Online streaming (Shoutcast/ICY streams) with metadata parsing 
+- Online streaming (Shoutcast/ICY streams) with metadata parsing
 - AIFF, AIFC, WAVE, CAF, NeXT, ADTS, MPEG Audio Layer 3, AAC audio formats
 - M4A (_Optimized files only_)
 
 Known limitations: 
-- As described above non-optimised M4A files are not supported this is a limitation of [AudioFileStream Services](https://developer.apple.com/documentation/audiotoolbox/audio_file_stream_services?language=swift) 
+- As described above non-optimised M4A files are not supported this is a limitation of [AudioFileStream Services](https://developer.apple.com/documentation/audiotoolbox/audio_file_stream_services?language=swift)
 
 
 # Requirements
@@ -22,18 +22,18 @@ Known limitations:
 
 ### Playing an audio source over HTTP
 Note: You need to keep a reference to the `AudioPlayer` object
-```
+```swift
 let player = AudioPlayer()
 player.play(url: URL(string: "https://your-remote-url/to/audio-file.mp3")!)
 ```
 
 ### Playing a local file 
-```
+```swift
 let player = AudioPlayer()
 player.play(url: URL(fileURLWithPath: "your-local-path/to/audio-file.mp3")!)
 ```
 ### Queueing audio files
-```
+```swift
 let player = AudioPlayer()
 // when you want to queue a single url
 player.queue(url: URL(string: "https://your-remote-url/to/audio-file.mp3")!)
@@ -46,7 +46,7 @@ player.queue(urls: [
 ```
 
 ### Adjusting playback properties
-```
+```swift
 let player = AudioPlayer()
 player.play(url: URL(fileURLWithPath: "your-local-path/to/audio-file.mp3")!)
 // adjust the playback rate
@@ -72,7 +72,7 @@ player.seek(to: 10)
 ```
 
 ### Audio playback properties
-```
+```swift
 let player = AudioPlayer()
 player.play(url: URL(fileURLWithPath: "your-local-path/to/audio-file.mp3")!)
 
@@ -93,7 +93,7 @@ let state = player.stopReason
 You can inspect various callbacks by using the `delegate` property of the `AudioPlayer` to get informed about the player state, errors etc.
 View the [AudioPlayerDelegate](AudioStreaming/Streaming/AudioPlayer/AudioPlayerDelegate.swift) for more details
 
-```
+```swift
 let player = AudioPlayer()
 player.play(url: URL(fileURLWithPath: "your-local-path/to/audio-file.mp3")!)
 
@@ -105,9 +105,9 @@ func audioPlayerStateChanged(player: AudioPlayer, with newState: AudioPlayerStat
 
 ### Adding custom audio nodes to AudioPlayer
 `AudioStreaming` provides an easy way to attach/remove `AVAudioNode`(s).
-This provides a powerful way of adjusting the playback audio with various enchncements 
+This provides a powerful way of adjusting the playback audio with various enhancements
 
-```
+```swift
 let reverbNode = AVAudioUnitReverb()
 reverbNode.wetDryMix = 50 
 
@@ -124,6 +124,41 @@ player.detachCustomAttachedNodes()
 
 The example project shows an example of adding a custom `AVAudioUnitEQ` node for adding equaliser to the `AudioPlayer`
 
+### Adding custom frame filter for recording and observation of audio data
+
+`AudioStreaming` allow for custom frame filters to be added so that recording or other observation for audio that's playing.
+
+You add a frame filter by using the `AudioPlayer`'s property `frameFiltering`.
+
+```swift
+let player = AudioPlayer()
+let format = player.mainMixerNode.outputFormat(forBus: 0)
+
+let settings = [
+    AVFormatIDKey: kAudioFormatMPEG4AAC,
+    AVSampleRateKey: format.sampleRate,
+    AVNumberOfChannelsKey: format.channelCount
+] as [String : Any]
+
+var audioFile = try? AVAudioFile(
+        forWriting: outputUrl,
+        settings: settings,
+        commonFormat: format.commonFormat,
+        interleaved: format.isInterleaved)
+
+let record = FilterEntry(name: "record") { buffer, when in
+    try? audioFile?.write(from: buffer)
+}
+
+player.frameFiltering.add(entry: record)
+```
+See the `FrameFiltering` protocol for more ways of adding and removing frame filters.
+The callback in which you observe a filter will be run on a thread other than the main thread.
+
+Under the hood the concrete class for frame filters, `FrameFilterProcessor` installs a tap on the `mainMixerNode` of  `AVAudioEngine` in which all the added filter will be called from.
+
+**Note** since the `mainMixerNode` is publicly exposed extra care should be taken to not install a tap directly and also use frame filters, this result in an exception because only one tap can be installed on an output node, as per Apple's documentation.
+
 # Installation
 
 ### Cocoapods
@@ -164,5 +199,5 @@ Visit [installation instructions](https://github.com/Carthage/Carthage#adding-fr
 AudioStreaming is available under the MIT license. See the LICENSE file for more info.
 
 # Attributions
-This librabry takes inspiration on the already battled-tested streaming library, [StreamingKit](https://github.com/tumtumtum/StreamingKit).
+This library takes inspiration on the already battled-tested streaming library, [StreamingKit](https://github.com/tumtumtum/StreamingKit).
 Big 🙏 to Thong Nguyen (@tumtumtum) and Matt Gallagher (@mattgallagher) for [AudioStreamer](https://github.com/mattgallagher/AudioStreamer)