version bump

* Allow playing custom streams

This lets users implement custom streams that can be played. For
example, I have a websocket interface that I fetch data from. I
can wrap that stream into a CoreAudioStreamSource and add that to
the player.

* Add example of using a custom stream

* Add ability to queue custom streams

AudioPlayer/AudioPlayer.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		42BE42F52C9322AA00C0E448 /* CustomStreamSource.swift in Sources */ = {isa = PBXBuildFile; fileRef = 42BE42F42C9322AA00C0E448 /* CustomStreamSource.swift */; };
 		9806E8182BC5D12500757370 /* App.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9806E8172BC5D12500757370 /* App.swift */; };
 		9806E81A2BC5D12500757370 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9806E8192BC5D12500757370 /* ContentView.swift */; };
 		9806E81C2BC5D12700757370 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 9806E81B2BC5D12700757370 /* Assets.xcassets */; };
@@ -47,6 +48,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		42BE42F42C9322AA00C0E448 /* CustomStreamSource.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CustomStreamSource.swift; sourceTree = "<group>"; };
 		9806E8142BC5D12500757370 /* AudioPlayer.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = AudioPlayer.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		9806E8172BC5D12500757370 /* App.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = App.swift; sourceTree = "<group>"; };
 		9806E8192BC5D12500757370 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
@@ -195,6 +197,7 @@
 		98E3921C2BD845E100B586E9 /* AudioPlayer */ = {
 			isa = PBXGroup;
 			children = (
+				42BE42F42C9322AA00C0E448 /* CustomStreamSource.swift */,
 				9806E8302BC6927D00757370 /* AudioPlayerModel.swift */,
 				9806E8292BC68F8700757370 /* AudioPlayerView.swift */,
 				98BFB41C2BCD7BB800E812C0 /* EqualizerView.swift */,
@@ -292,6 +295,7 @@
 				9816A8BB2BC87BC200AD1299 /* AudioPlayerService.swift in Sources */,
 				984DE9572BDAFC7E004B427A /* AudioPlayerControlsView.swift in Sources */,
 				9806E8182BC5D12500757370 /* App.swift in Sources */,
+				42BE42F52C9322AA00C0E448 /* CustomStreamSource.swift in Sources */,
 				989E08E72BF7A4E300599F17 /* PrefersTabNavigationEnvironmentKey.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

AudioPlayer/AudioPlayer/Common/AudioContent.swift

@@ -19,6 +19,7 @@ enum AudioContent {
     case remoteWave
     case local
     case localWave
+    case loopBeatFlac
     case custom(String)
 
     var title: String {
@@ -49,6 +50,8 @@ enum AudioContent {
             return "Jazzy Frenchy"
         case .nonOptimized:
             return "Jazzy Frenchy"
+        case .loopBeatFlac:
+            return "Beat loop"
         case .custom(let url):
             return url
         }
@@ -82,6 +85,8 @@ enum AudioContent {
             return "Music by: bensound.com - m4a optimized"
         case .nonOptimized:
             return "Music by: bensound.com - m4a non-optimized"
+        case .loopBeatFlac:
+            return "Remote flac"
         case .custom:
             return ""
         }
@@ -117,6 +122,8 @@ enum AudioContent {
             return URL(fileURLWithPath: path)
         case .remoteWave:
             return URL(string: "https://github.com/dimitris-c/sample-audio/raw/main/5-MB-WAV.wav")!
+        case .loopBeatFlac:
+            return URL(string: "https://github.com/dimitris-c/sample-audio/raw/main/drumbeat-loop.flac")!
         case .custom(let url):
             return URL(string: url)!
         }

AudioPlayer/AudioPlayer/Content/AudioPlayer/AudioPlayerControlsView.swift

@@ -4,6 +4,7 @@
 
 import AVFoundation
 import SwiftUI
+import AudioStreaming
 
 struct AudioPlayerControls: View {
     @State var model: Model
@@ -247,11 +248,23 @@ extension AudioPlayerControls {
         func play(_ track: AudioTrack) {
             if track != currentTrack {
                 currentTrack?.status = .idle
-                audioPlayerService.play(url: track.url)
-                currentTrack = track
+                if track.url.scheme == "custom" {
+                    let source = createStreamSource()
+                    let audioFormat = AVAudioFormat(
+                        commonFormat: .pcmFormatFloat32, sampleRate: 44100, channels: 2, interleaved: false
+                    )!
+                    audioPlayerService.play(source: source, entryId: track.url.absoluteString, format: audioFormat)
+                    currentTrack = track
+                } else {
+                    audioPlayerService.play(url: track.url)
+                }
             }
         }
 
+        func createStreamSource() -> CoreAudioStreamSource {
+            return CustomStreamAudioSource(underlyingQueue: audioPlayerService.player.sourceQueue)
+        }
+
         func onTick() {
             let duration = audioPlayerService.duration
             let progress = audioPlayerService.progress

AudioPlayer/AudioPlayer/Content/AudioPlayer/AudioPlayerModel.swift

@@ -58,12 +58,14 @@ public class AudioPlayerModel {
 }
 
 private let radioTracks: [AudioContent] = [.offradio, .enlefko, .pepper966, .kosmos, .kosmosJazz, .radiox]
-private let audioTracks: [AudioContent] = [.khruangbin, .piano, .optimized, .nonOptimized, .remoteWave, .local, .localWave]
+private let audioTracks: [AudioContent] = [.khruangbin, .piano, .optimized, .nonOptimized, .remoteWave, .local, .localWave, .loopBeatFlac]
+private let customStreams: [AudioContent] = [.custom("custom://sinwave")]
 
 func audioTracksProvider() -> [AudioPlaylist] {
     [
         AudioPlaylist(title: "Radio", tracks: radioTracks.map { AudioTrack.init(from: $0) }),
-        AudioPlaylist(title: "Tracks", tracks: audioTracks.map { AudioTrack.init(from:$0) })
+        AudioPlaylist(title: "Tracks", tracks: audioTracks.map { AudioTrack.init(from:$0) }),
+        AudioPlaylist(title: "Generated", tracks: customStreams.map { AudioTrack.init(from:$0) })
     ]
 }
 

AudioPlayer/AudioPlayer/Content/AudioPlayer/CustomStreamSource.swift

@@ -0,0 +1,139 @@
+//
+//  CustomStreamSource.swift
+//  AudioPlayer
+//
+//  Created by Jackson Harper on 12/9/24.
+//
+
+import AVFoundation
+import Foundation
+
+import AudioStreaming
+
+// This is a basic example of playing a custom audio stream. We generate
+// a small audio data on load and then pass it off to AudioStreaming.
+final class CustomStreamAudioSource: NSObject, CoreAudioStreamSource {
+    weak var delegate: AudioStreamSourceDelegate?
+
+    var underlyingQueue: DispatchQueue
+
+    var position = 0
+    var length = 0
+
+    var audioFileHint: AudioFileTypeID {
+        kAudioFileWAVEType
+    }
+
+    init(underlyingQueue: DispatchQueue) {
+        self.underlyingQueue = underlyingQueue
+    }
+
+    // no-op
+    func close() {}
+
+    // no-op
+    func suspend() {}
+
+    func resume() {}
+
+    func seek(at _: Int) {
+        // The streaming process is started by a seek(0) call from AudioStreaming
+        generateData()
+    }
+
+    private func generateData() {
+        let frequency = 440.0
+        let sampleRate = 44100
+        let duration = 20.0
+
+        let lpcmData = generateSineWave(frequency: frequency, sampleRate: sampleRate, duration: duration)
+        let waveFile = createWavFile(using: lpcmData)
+
+        // We enqueue this because during startup the seek call will be made, but the player
+        // is not completely setup and ready to handle data yet, as its expected to be
+        // generated asyncronously.
+        underlyingQueue.asyncAfter(deadline: .now().advanced(by: .milliseconds(100))) {
+            self.delegate?.dataAvailable(source: self, data: waveFile)
+        }
+    }
+}
+
+// Functions for generating some sample data
+
+// Function to generate a sine wave as Data
+func generateSineWave(frequency: Double, sampleRate: Int, duration: Double, amplitude: Double = 0.5) -> Data {
+    let numberOfSamples = Int(Double(sampleRate) * duration)
+    let twoPi = 2.0 * Double.pi
+    var lpcmData = Data()
+
+    for sampleIndex in 0 ..< numberOfSamples {
+        let time = Double(sampleIndex) / Double(sampleRate)
+        let sampleValue = amplitude * sin(twoPi * frequency * time)
+
+        let pcmValue = Int16(sampleValue * Double(Int16.max))
+        withUnsafeBytes(of: pcmValue.littleEndian) { lpcmData.append(contentsOf: $0) }
+    }
+
+    return lpcmData
+}
+
+func createWavFile(using rawData: Data) -> Data {
+    let waveHeaderFormate = createWaveHeader(data: rawData) as Data
+    let waveFileData = waveHeaderFormate + rawData
+    return waveFileData
+}
+
+// from: https://stackoverflow.com/questions/49399823/in-ios-how-to-create-audio-file-wav-mp3-file-from-data
+private func createWaveHeader(data: Data) -> NSData {
+    let sampleRate: Int32 = 44100
+    let chunkSize: Int32 = 36 + Int32(data.count)
+    let subChunkSize: Int32 = 16
+    let format: Int16 = 1
+    let channels: Int16 = 2
+    let bitsPerSample: Int16 = 16
+    let byteRate: Int32 = sampleRate * Int32(channels * bitsPerSample / 8)
+    let blockAlign: Int16 = channels * bitsPerSample / 8
+    let dataSize = Int32(data.count)
+
+    let header = NSMutableData()
+
+    header.append([UInt8]("RIFF".utf8), length: 4)
+    header.append(intToByteArray(chunkSize), length: 4)
+
+    // WAVE
+    header.append([UInt8]("WAVE".utf8), length: 4)
+
+    // FMT
+    header.append([UInt8]("fmt ".utf8), length: 4)
+
+    header.append(intToByteArray(subChunkSize), length: 4)
+    header.append(shortToByteArray(format), length: 2)
+    header.append(shortToByteArray(channels), length: 2)
+    header.append(intToByteArray(sampleRate), length: 4)
+    header.append(intToByteArray(byteRate), length: 4)
+    header.append(shortToByteArray(blockAlign), length: 2)
+    header.append(shortToByteArray(bitsPerSample), length: 2)
+
+    header.append([UInt8]("data".utf8), length: 4)
+    header.append(intToByteArray(dataSize), length: 4)
+
+    return header
+}
+
+private func intToByteArray(_ i: Int32) -> [UInt8] {
+    return [
+        // little endian
+        UInt8(truncatingIfNeeded: i & 0xFF),
+        UInt8(truncatingIfNeeded: (i >> 8) & 0xFF),
+        UInt8(truncatingIfNeeded: (i >> 16) & 0xFF),
+        UInt8(truncatingIfNeeded: (i >> 24) & 0xFF),
+    ]
+}
+
+private func shortToByteArray(_ i: Int16) -> [UInt8] {
+    return [
+        // little endian
+        UInt8(truncatingIfNeeded: i & 0xFF),
+        UInt8(truncatingIfNeeded: (i >> 8) & 0xFF),
+    ]
+}

AudioPlayer/AudioPlayer/Dependencies/AudioPlayerService.swift

@@ -17,7 +17,7 @@ protocol AudioPlayerServiceDelegate: AnyObject {
 final class AudioPlayerService {
     weak var delegate: AudioPlayerServiceDelegate?
 
-    private var player: AudioPlayer
+    var player: AudioPlayer
     private var audioSystemResetObserver: Any?
 
     var duration: Double {
@@ -60,6 +60,11 @@ final class AudioPlayerService {
         player.play(url: url)
     }
 
+    func play(source: CoreAudioStreamSource, entryId: String, format: AVAudioFormat) {
+        activateAudioSession()
+        player.play(source: source, entryId: entryId, format: format)
+    }
+
     func queue(url: URL) {
         activateAudioSession()
         player.queue(url: url)

AudioStreaming.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name = 'AudioStreaming'
-  s.version = '1.2.3'
+  s.version = '1.2.6'
   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

@@ -743,7 +743,7 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MACOSX_DEPLOYMENT_TARGET = 13.0;
-				MARKETING_VERSION = 1.1.0;
+				MARKETING_VERSION = 1.2.6;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -803,7 +803,7 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MACOSX_DEPLOYMENT_TARGET = 13.0;
-				MARKETING_VERSION = 1.1.0;
+				MARKETING_VERSION = 1.2.6;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;
@@ -833,7 +833,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.2.3;
+				MARKETING_VERSION = 1.2.6;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_BUNDLE_IDENTIFIER = com.decimal.AudioStreaming;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
@@ -865,7 +865,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.2.3;
+				MARKETING_VERSION = 1.2.6;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_BUNDLE_IDENTIFIER = com.decimal.AudioStreaming;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";

AudioStreaming/Core/Helpers/Lock.swift

@@ -4,6 +4,7 @@
 //
 
 import Foundation
+import os
 
 protocol Lock {
     func lock()
@@ -14,24 +15,96 @@ protocol Lock {
 
     // Execute a closure while acquiring a lock
     func withLock(body: () -> Void)
+
+    func deallocate()
 }
 
 /// A wrapper for `os_unfair_lock`
 /// - Tag: UnfairLock
 final class UnfairLock: Lock {
-    @usableFromInline let unfairLock: UnsafeMutablePointer<os_unfair_lock>
+
+    var unfairLock: Lock
+
+    init() {
+        if #available(iOS 16.0, *), #available(macOS 13.0, *) {
+            unfairLock = OSStorageLock()
+        } else {
+            unfairLock = UnfairStorageLock()
+        }
+    }
+
+    deinit {
+        deallocate()
+    }
+
+    func deallocate() {
+        unfairLock.deallocate()
+    }
+
+    @inlinable
+    func withLock<Result>(body: () throws -> Result) rethrows -> Result {
+        try unfairLock.withLock(body: body)
+    }
+
+    @inlinable
+    func withLock(body: () -> Void) {
+        unfairLock.withLock(body: body)
+    }
+
+    @inlinable
+    func lock() {
+        unfairLock.lock()
+    }
+
+    @inlinable
+    func unlock() {
+        unfairLock.unlock()
+    }
+}
+
+@available(iOS 16.0, *)
+@available(macOS 13, *)
+private class OSStorageLock: Lock {
+    @usableFromInline
+    let osLock = OSAllocatedUnfairLock()
+
+    @inlinable
+    func lock() {
+        osLock.lock()
+    }
+
+    @inlinable
+    func unlock() {
+        osLock.unlock()
+    }
+
+    func withLock<Result>(body: () throws -> Result) rethrows -> Result {
+        try osLock.withLockUnchecked(body)
+    }
+
+    func withLock(body: () -> Void) {
+        osLock.withLockUnchecked(body)
+    }
+
+    func deallocate() {} // no-op
+}
+
+private class UnfairStorageLock: Lock {
+
+    @usableFromInline
+    let unfairLock: UnsafeMutablePointer<os_unfair_lock>
 
     init() {
         unfairLock = .allocate(capacity: 1)
         unfairLock.initialize(to: os_unfair_lock())
     }
 
-    deinit {
+    func deallocate() {
+        unfairLock.deinitialize(count: 1)
         unfairLock.deallocate()
     }
 
     @inlinable
-    @inline(__always)
     func withLock<Result>(body: () throws -> Result) rethrows -> Result {
         os_unfair_lock_lock(unfairLock)
         defer { os_unfair_lock_unlock(unfairLock) }
@@ -39,7 +112,6 @@ final class UnfairLock: Lock {
     }
 
     @inlinable
-    @inline(__always)
     func withLock(body: () -> Void) {
         os_unfair_lock_lock(unfairLock)
         defer { os_unfair_lock_unlock(unfairLock) }
@@ -47,13 +119,11 @@ final class UnfairLock: Lock {
     }
 
     @inlinable
-    @inline(__always)
     func lock() {
         os_unfair_lock_lock(unfairLock)
     }
 
     @inlinable
-    @inline(__always)
     func unlock() {
         os_unfair_lock_unlock(unfairLock)
     }

AudioStreaming/Streaming/Audio Source/AudioStreamSource.swift

@@ -6,7 +6,7 @@
 import AudioToolbox
 import Foundation
 
-protocol AudioStreamSourceDelegate: AnyObject {
+public protocol AudioStreamSourceDelegate: AnyObject {
     /// Indicates that there's data available
     func dataAvailable(source: CoreAudioStreamSource, data: Data)
     /// Indicates an error occurred
@@ -17,7 +17,7 @@ protocol AudioStreamSourceDelegate: AnyObject {
     func metadataReceived(data: [String: String])
 }
 
-protocol CoreAudioStreamSource: AnyObject {
+public protocol CoreAudioStreamSource: AnyObject {
     /// An `Int` that represents the position of the audio
     var position: Int { get }
     /// The length of the audio in bytes

AudioStreaming/Streaming/Audio Source/RemoteAudioSource.swift

@@ -13,13 +13,13 @@ enum RemoteAudioSourceError: Error {
 }
 
 public class RemoteAudioSource: AudioStreamSource {
-    weak var delegate: AudioStreamSourceDelegate?
+    public weak var delegate: AudioStreamSourceDelegate?
 
-    var position: Int {
+    public var position: Int {
         return seekOffset + relativePosition
     }
 
-    var length: Int {
+    public var length: Int {
         guard let parsedHeader = parsedHeaderOutput else { return 0 }
         return parsedHeader.fileLength
     }
@@ -40,7 +40,7 @@ public class RemoteAudioSource: AudioStreamSource {
     private var shouldTryParsingIcycastHeaders: Bool = false
     private let icycastHeadersProcessor: IcycastHeadersProcessor
 
-    var audioFileHint: AudioFileTypeID {
+    public var audioFileHint: AudioFileTypeID {
         guard let output = parsedHeaderOutput, output.typeId != 0 else {
             return audioFileType(fileExtension: url.pathExtension)
         }
@@ -49,7 +49,7 @@ public class RemoteAudioSource: AudioStreamSource {
 
     private let mp4Restructure: RemoteMp4Restructure
 
-    let underlyingQueue: DispatchQueue
+    public let underlyingQueue: DispatchQueue
     let streamOperationQueue: OperationQueue
     let netStatusService: NetStatusProvider
     var waitingForNetwork = false
@@ -114,7 +114,7 @@ public class RemoteAudioSource: AudioStreamSource {
                   httpHeaders: [:])
     }
 
-    func close() {
+    public func close() {
         retrierTimeout.cancel()
         streamOperationQueue.isSuspended = false
         streamOperationQueue.cancelAllOperations()
@@ -125,7 +125,7 @@ public class RemoteAudioSource: AudioStreamSource {
         streamRequest = nil
     }
 
-    func seek(at offset: Int) {
+    public func seek(at offset: Int) {
         close()
 
         relativePosition = 0
@@ -144,11 +144,11 @@ public class RemoteAudioSource: AudioStreamSource {
         performOpen(seek: offset)
     }
 
-    func suspend() {
+    public func suspend() {
         streamOperationQueue.isSuspended = true
     }
 
-    func resume() {
+    public func resume() {
         streamOperationQueue.isSuspended = false
     }
 

AudioStreaming/Streaming/AudioPlayer/AudioPlayer.swift

@@ -124,7 +124,7 @@ open class AudioPlayer {
     private let frameFilterProcessor: FrameFilterProcessor
 
     private let serializationQueue: DispatchQueue
-    private let sourceQueue: DispatchQueue
+    public let sourceQueue: DispatchQueue
 
     private let entryProvider: AudioEntryProviding
 
@@ -190,6 +190,20 @@ open class AudioPlayer {
     /// - parameter headers: A `Dictionary` specifying any additional headers to be pass to the network request.
     public func play(url: URL, headers: [String: String]) {
         let audioEntry = entryProvider.provideAudioEntry(url: url, headers: headers)
+        play(audioEntry: audioEntry)
+    }
+
+    /// Starts the audio playback for the supplied stream
+    ///
+    /// - parameter source: A `CoreAudioStreamSource` that will providing streaming data
+    /// - parameter entryId: A `String` that provides a unique id for this item
+    /// - parameter format: An `AVAudioFormat` the format of this audio source
+    public func play(source: CoreAudioStreamSource, entryId: String, format: AVAudioFormat) {
+        let audioEntry = AudioEntry(source: source, entryId: AudioEntryId(id: entryId), outputAudioFormat: format)
+        play(audioEntry: audioEntry)
+    }
+
+    private func play(audioEntry: AudioEntry) {
         audioEntry.delegate = self
 
         checkRenderWaitingAndNotifyIfNeeded()
@@ -247,6 +261,16 @@ open class AudioPlayer {
         queue(url: url, headers: [:], after: afterUrl)
     }
 
+    /// Queues the specified audio stream
+    ///
+    /// - parameter source: A `CoreAudioStreamSource` that will providing streaming data
+    /// - parameter entryId: A `String` that provides a unique id for this item
+    /// - parameter format: An `AVAudioFormat` the format of this audio source
+    public func queue(source: CoreAudioStreamSource, entryId: String, format: AVAudioFormat) {
+        let audioEntry = AudioEntry(source: source, entryId: AudioEntryId(id: entryId), outputAudioFormat: format)
+        queue(audioEntry: audioEntry)
+    }
+
     public func removeFromQueue(url: URL) {
         serializationQueue.sync {
             if let item = entriesQueue.items(type: .upcoming).first(where: { $0.id.id == url.absoluteString }) {
@@ -268,21 +292,8 @@ open class AudioPlayer {
     /// - Parameter url: A `URL` specifying the audio content to be played.
     /// - parameter headers: A `Dictionary` specifying any additional headers to be pass to the network request.
     public func queue(url: URL, headers: [String: String], after afterUrl: URL? = nil) {
-        serializationQueue.sync {
-            let audioEntry = entryProvider.provideAudioEntry(url: url, headers: headers)
-            audioEntry.delegate = self
-            if let afterUrl = afterUrl {
-                if let afterUrlEntry = entriesQueue.items(type: .upcoming).first(where: { $0.id.id == afterUrl.absoluteString }) {
-                    entriesQueue.insert(item: audioEntry, type: .upcoming, after: afterUrlEntry)
-                }
-            } else {
-                entriesQueue.enqueue(item: audioEntry, type: .upcoming)
-            }
-        }
-        checkRenderWaitingAndNotifyIfNeeded()
-        sourceQueue.async { [weak self] in
-            self?.processSource()
-        }
+        let audioEntry = entryProvider.provideAudioEntry(url: url, headers: headers)
+        queue(audioEntry: audioEntry, after: afterUrl)
     }
 
     /// Queues the specified URLs
@@ -303,6 +314,23 @@ open class AudioPlayer {
         }
     }
 
+    private func queue(audioEntry: AudioEntry, after afterUrl: URL? = nil) {
+        serializationQueue.sync {
+            audioEntry.delegate = self
+            if let afterUrl = afterUrl {
+                if let afterUrlEntry = entriesQueue.items(type: .upcoming).first(where: { $0.id.id == afterUrl.absoluteString }) {
+                    entriesQueue.insert(item: audioEntry, type: .upcoming, after: afterUrlEntry)
+                }
+            } else {
+                entriesQueue.enqueue(item: audioEntry, type: .upcoming)
+            }
+        }
+        checkRenderWaitingAndNotifyIfNeeded()
+        sourceQueue.async { [weak self] in
+            self?.processSource()
+        }
+    }
+
     /// Stops the audio playback
     public func stop(clearQueue: Bool = true) {
         guard playerContext.internalState != .stopped else { return }
@@ -805,7 +833,7 @@ open class AudioPlayer {
 }
 
 extension AudioPlayer: AudioStreamSourceDelegate {
-    func dataAvailable(source: CoreAudioStreamSource, data: Data) {
+    public func dataAvailable(source: CoreAudioStreamSource, data: Data) {
         guard let readingEntry = playerContext.audioReadingEntry, readingEntry.has(same: source) else {
             return
         }
@@ -835,12 +863,12 @@ extension AudioPlayer: AudioStreamSourceDelegate {
         }
     }
 
-    func errorOccurred(source: CoreAudioStreamSource, error: Error) {
+    public func errorOccurred(source: CoreAudioStreamSource, error: Error) {
         guard let entry = playerContext.audioReadingEntry, entry.has(same: source) else { return }
         raiseUnexpected(error: .networkError(.failure(error)))
     }
 
-    func endOfFileOccurred(source: CoreAudioStreamSource) {
+    public func endOfFileOccurred(source: CoreAudioStreamSource) {
         let hasSameSource = playerContext.audioReadingEntry?.has(same: source) ?? false
         guard playerContext.audioReadingEntry == nil || hasSameSource else {
             source.delegate = nil
@@ -877,7 +905,7 @@ extension AudioPlayer: AudioStreamSourceDelegate {
         }
     }
 
-    func metadataReceived(data: [String: String]) {
+    public func metadataReceived(data: [String: String]) {
         asyncOnMain { [weak self] in
             guard let self = self else { return }
             self.delegate?.audioPlayerDidReadMetadata(player: self, metadata: data)

AudioStreaming/Streaming/AudioPlayer/AudioPlayerConfiguration.swift

@@ -26,7 +26,7 @@ public struct AudioPlayerConfiguration: Equatable {
                                                            bufferSizeInSeconds: 10,
                                                            secondsRequiredToStartPlaying: 1,
                                                            gracePeriodAfterSeekInSeconds: 0.5,
-                                                           secondsRequiredToStartPlayingAfterBufferUnderrun: 1,
+                                                           secondsRequiredToStartPlayingAfterBufferUnderrun: 7,
                                                            enableLogs: false)
     /// Initializes the configuration for the `AudioPlayer`
     ///

AudioStreaming/Streaming/AudioPlayer/AudioPlayerState.swift

@@ -13,11 +13,11 @@ extension AudioPlayer {
 
         static let initial = InternalState([])
         static let running = InternalState(rawValue: 1)
-        static let playing = InternalState(rawValue: 1 << 1 | InternalState.running.rawValue)
-        static let rebuffering = InternalState(rawValue: 1 << 2 | InternalState.running.rawValue)
-        static let waitingForData = InternalState(rawValue: 1 << 3 | InternalState.running.rawValue)
-        static let waitingForDataAfterSeek = InternalState(rawValue: 1 << 4 | InternalState.running.rawValue)
-        static let paused = InternalState(rawValue: 1 << 5 | InternalState.running.rawValue)
+        static let playing = InternalState(rawValue: (1 << 1) | InternalState.running.rawValue)
+        static let rebuffering = InternalState(rawValue: (1 << 2) | InternalState.running.rawValue)
+        static let waitingForData = InternalState(rawValue: (1 << 3) | InternalState.running.rawValue)
+        static let waitingForDataAfterSeek = InternalState(rawValue: (1 << 4) | InternalState.running.rawValue)
+        static let paused = InternalState(rawValue: (1 << 5) | InternalState.running.rawValue)
         static let stopped = InternalState(rawValue: 1 << 9)
         static let pendingNext = InternalState(rawValue: 1 << 10)
         static let disposed = InternalState(rawValue: 1 << 30)

AudioStreaming/Streaming/AudioPlayer/AudioRendererContext.swift

@@ -20,9 +20,9 @@ final class AudioRendererContext {
 
     let packetsSemaphore = DispatchSemaphore(value: 0)
 
-    let framesRequiredToStartPlaying: UInt32
-    let framesRequiredAfterRebuffering: UInt32
-    let framesRequiredForDataAfterSeekPlaying: UInt32
+    let framesRequiredToStartPlaying: Double
+    let framesRequiredAfterRebuffering: Double
+    let framesRequiredForDataAfterSeekPlaying: Double
 
     let waitingForDataAfterSeekFrameCount = Atomic<Int32>(0)
 
@@ -33,9 +33,9 @@ final class AudioRendererContext {
 
         let canonicalStream = outputAudioFormat.basicStreamDescription
 
-        framesRequiredToStartPlaying = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.secondsRequiredToStartPlaying)
-        framesRequiredAfterRebuffering = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.secondsRequiredToStartPlayingAfterBufferUnderrun)
-        framesRequiredForDataAfterSeekPlaying = UInt32(canonicalStream.mSampleRate) * UInt32(configuration.gracePeriodAfterSeekInSeconds)
+        framesRequiredToStartPlaying = Double(canonicalStream.mSampleRate) * Double(configuration.secondsRequiredToStartPlaying)
+        framesRequiredAfterRebuffering = Double(canonicalStream.mSampleRate) * Double(configuration.secondsRequiredToStartPlayingAfterBufferUnderrun)
+        framesRequiredForDataAfterSeekPlaying = Double(canonicalStream.mSampleRate) * Double(configuration.gracePeriodAfterSeekInSeconds)
 
         let dataByteSize = Int(canonicalStream.mSampleRate * configuration.bufferSizeInSeconds) * Int(canonicalStream.mBytesPerFrame)
         inOutAudioBufferList = allocateBufferList(dataByteSize: dataByteSize)

AudioStreaming/Streaming/AudioPlayer/Processors/AudioFileStreamProcessor.swift

@@ -228,8 +228,9 @@ final class AudioFileStreamProcessor {
             processAudioDataPacketCount(entry: entry, fileStream: fileStream)
         case kAudioFileStreamProperty_ReadyToProducePackets:
             // check converter for discontinuous stream
-            processReadyToProducePackets(entry: entry, fileStream: fileStream)
+            assignMagicCookieToConverterIfNeeded()
             processPacketUpperBoundAndMaxPacketSize(entry: entry, fileStream: fileStream)
+            processReadyToProducePackets(entry: entry, fileStream: fileStream)
         case kAudioFileStreamProperty_FormatList:
             processFormatList(entry: entry, fileStream: fileStream)
         default:
@@ -242,7 +243,7 @@ final class AudioFileStreamProcessor {
     private func processDataOffset(entry: AudioEntry, fileStream: AudioFileStreamID) {
         var offset: UInt64 = 0
         fileStreamGetProperty(value: &offset, fileStream: fileStream, propertyId: kAudioFileStreamProperty_DataOffset)
-        entry.lock.lock(); defer { playerContext.audioReadingEntry?.lock.unlock() }
+        entry.lock.lock(); defer { entry.lock.unlock() }
         entry.audioStreamState.processedDataFormat = true
         entry.audioStreamState.dataOffset = offset
     }
@@ -253,7 +254,9 @@ final class AudioFileStreamProcessor {
         AudioFileStreamGetProperty(fileStream, kAudioFileStreamProperty_AudioDataPacketCount, &packetCountSize, &packetCount)
         entry.lock.lock(); defer { entry.lock.unlock() }
         entry.audioStreamState.dataPacketCount = Double(packetCount)
-        if entry.audioStreamFormat.mFormatID != kAudioFormatLinearPCM {
+        let entryFormatID = entry.audioStreamFormat.mFormatID
+        let isFLAC = entryFormatID == kAudioFormatFLAC
+        if entryFormatID != kAudioFormatLinearPCM && !isFLAC {
             discontinuous = true
         }
     }
@@ -370,6 +373,11 @@ final class AudioFileStreamProcessor {
         guard let entry = playerContext.audioReadingEntry else { return }
         guard entry.audioStreamState.processedDataFormat else { return }
 
+        guard let converter = audioConverter else {
+            Logger.error("Couldn't find audio converter", category: .audioRendering)
+            return
+        }
+
         if let playingEntry = playerContext.audioPlayingEntry,
            playingEntry.seekRequest.requested, playingEntry.calculatedBitrate() > 0
         {
@@ -380,25 +388,24 @@ final class AudioFileStreamProcessor {
             return
         }
 
-        guard let converter = audioConverter else {
-            Logger.error("Couldn't find audio converter", category: .audioRendering)
-            return
-        }
-
         // reset discontinuity
         discontinuous = false
 
-        var convertInfo = AudioConvertInfo(done: false,
-                                           numberOfPackets: inNumberPackets,
-                                           packDescription: inPacketDescriptions)
+        var convertInfo = AudioConvertInfo(
+            done: false,
+            numberOfPackets: inNumberPackets,
+            packDescription: inPacketDescriptions
+        )
         convertInfo.audioBuffer.mData = UnsafeMutableRawPointer(mutating: inInputData)
         convertInfo.audioBuffer.mDataByteSize = inNumberBytes
         if let playingAudioStreamFormat = playerContext.audioPlayingEntry?.audioStreamFormat {
             convertInfo.audioBuffer.mNumberChannels = playingAudioStreamFormat.mChannelsPerFrame
         }
 
-        updateProcessedPackets(inPacketDescriptions: inPacketDescriptions,
-                               inNumberPackets: inNumberPackets)
+        updateProcessedPackets(
+            inPacketDescriptions: inPacketDescriptions,
+            inNumberPackets: inNumberPackets
+        )
 
         var status: OSStatus = noErr
         packetProcess: while status == noErr {
@@ -406,7 +413,7 @@ final class AudioFileStreamProcessor {
             let bufferContext = rendererContext.bufferContext
             var used = bufferContext.frameUsedCount
             var start = bufferContext.frameStartIndex
-            var end = bufferContext.end
+            var end = (bufferContext.frameStartIndex + bufferContext.frameUsedCount) % bufferContext.totalFrameCount
 
             var framesLeftInBuffer = bufferContext.totalFrameCount - used
             rendererContext.lock.unlock()

AudioStreaming/Streaming/AudioPlayer/Processors/AudioPlayerRenderProcessor.swift

@@ -64,29 +64,30 @@ final class AudioPlayerRenderProcessor: NSObject {
         let frameSizeInBytes = bufferContext.sizeInBytes
         let used = bufferContext.frameUsedCount
         let start = bufferContext.frameStartIndex
-        let end = bufferContext.end
+        let end = (bufferContext.frameStartIndex + bufferContext.frameUsedCount) % bufferContext.totalFrameCount
         let signal = rendererContext.waiting.value && used < bufferContext.totalFrameCount / 2
 
         if let playingEntry = playingEntry {
             playingEntry.lock.lock()
             let framesState = playingEntry.framesState
             playingEntry.lock.unlock()
+
             if state == .waitingForData {
                 var requiredFramesToStart = rendererContext.framesRequiredToStartPlaying
                 if framesState.lastFrameQueued >= 0 {
-                    requiredFramesToStart = min(requiredFramesToStart, UInt32(playingEntry.framesState.lastFrameQueued))
+                    requiredFramesToStart = min(requiredFramesToStart, Double(playingEntry.framesState.lastFrameQueued))
                 }
-                if let readingEntry = readingEntry, readingEntry === playingEntry,
-                   framesState.queued < requiredFramesToStart
+
+                if readingEntry === playingEntry, framesState.queued < Int(requiredFramesToStart)
                 {
                     waitForBuffer = true
                 }
             } else if state == .rebuffering {
                 var requiredFramesToStart = rendererContext.framesRequiredAfterRebuffering
                 if framesState.lastFrameQueued >= 0 {
-                    requiredFramesToStart = min(requiredFramesToStart, UInt32(framesState.lastFrameQueued - framesState.queued))
+                    requiredFramesToStart = min(requiredFramesToStart, Double(framesState.lastFrameQueued - framesState.queued))
                 }
-                if used < requiredFramesToStart {
+                if used < Int(requiredFramesToStart) {
                     waitForBuffer = true
                 }
             } else if state == .waitingForDataAfterSeek {
@@ -102,7 +103,7 @@ final class AudioPlayerRenderProcessor: NSObject {
         rendererContext.lock.unlock()
 
         var totalFramesCopied: UInt32 = 0
-        if used > 0 && !waitForBuffer && state.contains(.running) && state != .paused {
+        if used > 0 && !waitForBuffer && playingEntry != nil && state.contains(.running) && state != .paused {
             if end > start {
                 let framesToCopy = min(inNumberFrames, used)
                 bufferList.mBuffers.mNumberChannels = 2
@@ -162,6 +163,7 @@ final class AudioPlayerRenderProcessor: NSObject {
                 bufferContext.frameUsedCount -= totalFramesCopied
                 rendererContext.lock.unlock()
             }
+
             if playerContext.internalState != .playing {
                 playerContext.setInternalState(to: .playing, when: { state -> Bool in
                     state.contains(.running) && state != .paused
@@ -175,7 +177,7 @@ final class AudioPlayerRenderProcessor: NSObject {
                 memset(mData + Int(totalFramesCopied * frameSizeInBytes), 0, Int(delta * frameSizeInBytes))
             }
 
-            if playingEntry != nil || AudioPlayer.InternalState.waiting.contains(state) {
+            if !(playingEntry == nil || state == .waitingForDataAfterSeek || state == .waitingForData || state == .rebuffering) {
                 if playerContext.internalState != .rebuffering {
                     playerContext.setInternalState(to: .rebuffering, when: { state -> Bool in
                         state.contains(.running) && state != .paused
@@ -184,7 +186,7 @@ final class AudioPlayerRenderProcessor: NSObject {
             } else if state == .waitingForDataAfterSeek {
                 if totalFramesCopied == 0 {
                     rendererContext.waitingForDataAfterSeekFrameCount.write { $0 += Int32(inNumberFrames - totalFramesCopied) }
-                    if rendererContext.waitingForDataAfterSeekFrameCount.value > rendererContext.framesRequiredForDataAfterSeekPlaying {
+                    if rendererContext.waitingForDataAfterSeekFrameCount.value > Int(rendererContext.framesRequiredForDataAfterSeekPlaying) {
                         if playerContext.internalState != .playing {
                             playerContext.setInternalState(to: .playing) { state -> Bool in
                                 state.contains(.running) && state != .playing

AudioStreaming/Streaming/AudioPlayer/UnitDescriptions.swift

@@ -5,10 +5,8 @@
 
 import AVFoundation
 
-private let outputChannels: UInt32 = 2
-
 enum UnitDescriptions {
-    static var output: AudioComponentDescription = {
+    static let output: AudioComponentDescription = {
         var desc = AudioComponentDescription()
         desc.componentType = kAudioUnitType_Output
         #if os(iOS)

AudioStreaming/Streaming/Helpers/AudioFileType.swift

@@ -33,6 +33,7 @@ let fileTypesFromMimeType: [String: AudioFileTypeID] =
         "video/3gpp": kAudioFile3GPType,
         "audio/3gp2": kAudioFile3GP2Type,
         "video/3gp2": kAudioFile3GP2Type,
+        "audio/flac": kAudioFileFLACType
     ]
 
 /// Method that converts mime type to AudioFileTypeID

README.md

@@ -8,7 +8,7 @@ Under the hood `AudioStreaming` uses `AVAudioEngine` and `CoreAudio` for playbac
 #### Supported audio
 - 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_)
+- M4A
 
 As of 1.2.0 version, there's support for non-optimized M4A, please report any issues