Release 5.0.0

Fix radio streaming playback to be smooth

Example/Pods/Pods.xcodeproj/project.pbxproj

@@ -48,6 +48,7 @@
 		A470FE0925F9ADF800F135FF /* DownloadProgressDirector.swift in Sources */ = {isa = PBXBuildFile; fileRef = A470FE0725F9ADF800F135FF /* DownloadProgressDirector.swift */; };
 		A470FE1C25F9AEB900F135FF /* AudioQueueDirector.swift in Sources */ = {isa = PBXBuildFile; fileRef = A470FE1B25F9AEB900F135FF /* AudioQueueDirector.swift */; };
 		A470FE2125F9AF1400F135FF /* AudioQueue.swift in Sources */ = {isa = PBXBuildFile; fileRef = A470FE2025F9AF1400F135FF /* AudioQueue.swift */; };
+		A4827771262A216C00B6918A /* StreamingDownloadDirector.swift in Sources */ = {isa = PBXBuildFile; fileRef = A4827770262A216C00B6918A /* StreamingDownloadDirector.swift */; };
 		A4B4CC122223ED2A0045554B /* SAPlayerDownloader.swift in Sources */ = {isa = PBXBuildFile; fileRef = A4B4CC112223ED2A0045554B /* SAPlayerDownloader.swift */; };
 		A4FBA6B5221B74C900D5A353 /* SALockScreenInfo.swift in Sources */ = {isa = PBXBuildFile; fileRef = A4FBA6B3221B74C900D5A353 /* SALockScreenInfo.swift */; };
 		A4FBA6B7221BAC3D00D5A353 /* SAPlayerUpdateSubscription.swift in Sources */ = {isa = PBXBuildFile; fileRef = A4FBA6B6221BAC3D00D5A353 /* SAPlayerUpdateSubscription.swift */; };
@@ -135,6 +136,7 @@
 		A470FE0725F9ADF800F135FF /* DownloadProgressDirector.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DownloadProgressDirector.swift; sourceTree = "<group>"; };
 		A470FE1B25F9AEB900F135FF /* AudioQueueDirector.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AudioQueueDirector.swift; sourceTree = "<group>"; };
 		A470FE2025F9AF1400F135FF /* AudioQueue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AudioQueue.swift; sourceTree = "<group>"; };
+		A4827770262A216C00B6918A /* StreamingDownloadDirector.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StreamingDownloadDirector.swift; sourceTree = "<group>"; };
 		A4B4CC112223ED2A0045554B /* SAPlayerDownloader.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SAPlayerDownloader.swift; sourceTree = "<group>"; };
 		A4FBA6B3221B74C900D5A353 /* SALockScreenInfo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SALockScreenInfo.swift; sourceTree = "<group>"; };
 		A4FBA6B6221BAC3D00D5A353 /* SAPlayerUpdateSubscription.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SAPlayerUpdateSubscription.swift; sourceTree = "<group>"; };
@@ -378,6 +380,7 @@
 				A470FE0725F9ADF800F135FF /* DownloadProgressDirector.swift */,
 				A470FE0625F9ADF800F135FF /* AudioClockDirector.swift */,
 				A470FE1B25F9AEB900F135FF /* AudioQueueDirector.swift */,
+				A4827770262A216C00B6918A /* StreamingDownloadDirector.swift */,
 			);
 			path = Directors;
 			sourceTree = "<group>";
@@ -553,6 +556,7 @@
 				A4681FC72201138B0018AB51 /* SAPlayerDelegate.swift in Sources */,
 				A4681FD5220113BD0018AB51 /* AudioParserErrors.swift in Sources */,
 				A4681FC9220113920018AB51 /* LockScreenViewProtocol.swift in Sources */,
+				A4827771262A216C00B6918A /* StreamingDownloadDirector.swift in Sources */,
 				A4681FD6220113BF0018AB51 /* AudioThrottler.swift in Sources */,
 				A4681FCC2201139B0018AB51 /* AudioDiskEngine.swift in Sources */,
 				A4681FDE220113DE0018AB51 /* Date.swift in Sources */,

Example/SwiftAudioPlayer/Base.lproj/Main.storyboard

@@ -72,8 +72,8 @@
                                 <rect key="frame" x="16" y="60" width="343" height="32"/>
                                 <segments>
                                     <segment title="Soundbite"/>
-                                    <segment title="Acquired"/>
-                                    <segment title="Y Combinator"/>
+                                    <segment title="Podcast"/>
+                                    <segment title="Radio"/>
                                 </segments>
                                 <connections>
                                     <action selector="audioSelected:" destination="vXZ-lx-hvc" eventType="valueChanged" id="oYE-yq-348"/>

Example/SwiftAudioPlayer/Model.swift

@@ -13,18 +13,18 @@ struct AudioInfo: Hashable {
     
     var urls: [URL] = [URL(string: "https://www.fesliyanstudios.com/musicfiles/2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com/15SecVersion2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com.mp3")!,
                        URL(string: "https://chtbl.com/track/18338/traffic.libsyn.com/secure/acquired/acquired_-_armrev_2.mp3?dest-id=376122")!,
-                       URL(string: "https://backtracks.fm/ycombinator/pr/0f685f72-29b1-11e9-9bcf-0ece7a7d2472/111---jake-klamka-and-kevin-hale---y-combinator.mp3?s=1&sd=1&u=1549423185")!]
+                       URL(string: "https://ice6.somafm.com/groovesalad-256-mp3")!]
     
     var url: URL {
         switch index {
         case 0:
-            return URL(string: "https://www.fesliyanstudios.com/musicfiles/2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com/15SecVersion2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com.mp3")!
+            return urls[0]
         case 1:
-            return URL(string: "https://chtbl.com/track/18338/traffic.libsyn.com/secure/acquired/acquired_-_armrev_2.mp3?dest-id=376122")!
+            return urls[1]
         case 2:
-            return URL(string: "https://backtracks.fm/ycombinator/pr/0f685f72-29b1-11e9-9bcf-0ece7a7d2472/111---jake-klamka-and-kevin-hale---y-combinator.mp3?s=1&sd=1&u=1549423185")!
+            return urls[2]
         default:
-            return URL(string: "https://www.fesliyanstudios.com/musicfiles/2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com/15SecVersion2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com.mp3")!
+            return urls[0]
         }
     }
     
@@ -33,9 +33,9 @@ struct AudioInfo: Hashable {
         case 0:
             return "Soundbite"
         case 1:
-            return "Acquired"
+            return "Podcast"
         case 2:
-            return "Y Combinator"
+            return "Radio"
         default:
             return "Soundbite"
         }

Example/SwiftAudioPlayer/ViewController.swift

@@ -311,7 +311,12 @@ class ViewController: UIViewController {
     
     @IBAction func streamTouched(_ sender: Any) {
         if !isStreaming {
-            SAPlayer.shared.startRemoteAudio(withRemoteUrl: selectedAudio.url)
+            if selectedAudio.index == 2 { // radio
+                SAPlayer.shared.startRemoteAudio(withRemoteUrl: selectedAudio.url, bitrate: .low)
+            } else {
+                SAPlayer.shared.startRemoteAudio(withRemoteUrl: selectedAudio.url)
+            }
+
             lastPlayedAudioIndex = selectedAudio.index
             streamButton.setTitle("Cancel streaming", for: .normal)
             downloadButton.isEnabled = false

README.md

@@ -17,6 +17,7 @@ Thus, using [AudioToolbox](https://developer.apple.com/documentation/audiotoolbo
 1. Play locally saved audio with the same API
 1. Download audio
 1. Queue up downloaded and streamed audio for autoplay
+1. Uses only 1-2% CPU for optimal performance for the rest of your app
 1. You're able to install taps and any other AVAudioEngine features to do cool things like skipping silences
 
 ### Special Features
@@ -33,7 +34,7 @@ iOS 10.0 and higher.
 ### Running the Example Project
 
 1. Clone repo
-2. CD to directory
+2. CD to the `Example` folder where the Example app lives
 3. Run `pod install` in terminal
 4. Build and run
 
@@ -145,9 +146,9 @@ Known supported file types are `.mp3` and `.wav`.
 
 To set up player with audio to play, use either: 
 * `startSavedAudio(withSavedUrl url: URL, mediaInfo: SALockScreenInfo?)` to play audio that is saved on the device.
-* `startRemoteAudio(withRemoteUrl url: URL, mediaInfo: SALockScreenInfo?)` to play audio streamed from a remote location.
+* `startRemoteAudio(withRemoteUrl url: URL, bitrate: SAPlayerBitrate, mediaInfo: SALockScreenInfo?)` to play audio streamed from a remote location.
 
-Both of these expect a URL of the location of the audio and an optional media information to display on the lockscreen. 
+Both of these expect a URL of the location of the audio and an optional media information to display on the lockscreen.  For streamed audio you can optionally set the bitrate to be `.high` or `.low`. High is more performant but won't work well for radio streams; for radio streams you should use low. The default bitrate if you don't set it is `.high`.
 
 For streaming remote audio, subscribe to `SAPlayer.Updates.StreamingBuffer` for updates on streaming progress.
 

Source/Directors/StreamingDownloadDirector.swift

@@ -0,0 +1,53 @@
+//
+//  StreamingDownloadDirector.swift
+//  SwiftAudioPlayer
+//
+//  Created by Tanha Kabir on 4/16/21.
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+
+import Foundation
+
+class StreamingDownloadDirector {
+    static let shared = StreamingDownloadDirector()
+    
+    var closures: DirectorThreadSafeClosures<Double> = DirectorThreadSafeClosures()
+    
+    private init() {}
+    
+    func create() {}
+    
+    func clear() {
+        closures.clear()
+    }
+    
+    func attach(closure: @escaping (Key, Double) throws -> Void) -> UInt {
+        return closures.attach(closure: closure)
+    }
+    
+    func detach(withID id: UInt) {
+        closures.detach(id: id)
+    }
+}
+
+extension StreamingDownloadDirector {
+    func didUpdate(_ key: Key, networkStreamProgress: Double) {
+        closures.broadcast(key: key, payload: networkStreamProgress)
+    }
+}

Source/Engine/AudioStreamEngine.swift

@@ -59,7 +59,7 @@ class AudioStreamEngine: AudioEngine {
     //Constants
     private let MAX_POLL_BUFFER_COUNT = 300 //Having one buffer in engine at a time is choppy.
     private let MIN_BUFFERS_TO_BE_PLAYABLE = 1
-    private let PCM_BUFFER_SIZE: AVAudioFrameCount = 8192
+    private var PCM_BUFFER_SIZE: AVAudioFrameCount = 8192
     
     private let queue = DispatchQueue(label: "SwiftAudioPlayer.StreamEngine", qos: .userInitiated)
     
@@ -68,6 +68,7 @@ class AudioStreamEngine: AudioEngine {
     
     //Fields
     private var currentTimeOffset: TimeInterval = 0
+    private var streamChangeListenerId: UInt?
     
     private var numberOfBuffersScheduledInTotal = 0 {
         didSet {
@@ -133,15 +134,31 @@ class AudioStreamEngine: AudioEngine {
         }
     }
     
-    init(withRemoteUrl url: AudioURL, delegate:AudioEngineDelegate?) {
+    init(withRemoteUrl url: AudioURL, delegate:AudioEngineDelegate?, bitrate: SAPlayerBitrate) {
         Log.info(url)
         super.init(url: url, delegate: delegate, engineAudioFormat: AudioEngine.defaultEngineAudioFormat)
+        
+        switch bitrate {
+        case .high:
+            PCM_BUFFER_SIZE = 8192
+        case .low:
+            PCM_BUFFER_SIZE = 4096
+        }
+        
         do {
             converter = try AudioConverter(withRemoteUrl: url, toEngineAudioFormat: AudioEngine.defaultEngineAudioFormat, withPCMBufferSize: PCM_BUFFER_SIZE)
         } catch {
             delegate?.didError()
         }
         
+        streamChangeListenerId = StreamingDownloadDirector.shared.attach { [weak self] (key, progress) in
+            guard let self = self else { return }
+            guard key == url.key else { return }
+
+            // polling for buffers when we receive data. This won't be throttled on fresh new audio or seeked audio but in all other cases it most likely will be throttled
+            self.pollForNextBuffer() //  no buffer updates because thread issues if I try to update buffer status in streaming listener
+        }
+        
         
         let timeInterval = 1 / (converter.engineAudioFormat.sampleRate / Double(PCM_BUFFER_SIZE))
         
@@ -149,22 +166,36 @@ class AudioStreamEngine: AudioEngine {
             guard let self = self else { return }
             guard self.playingStatus != .ended else { return }
             
-            self.pollForNextBufferRecursive()
-            self.updateNetworkBufferRange()
-            self.updateNeedle()
-            self.updateIsPlaying()
-            self.updateDuration()
+            self.repeatedUpdates()
         }
     }
     
+    deinit {
+        if let id = streamChangeListenerId {
+            StreamingDownloadDirector.shared.detach(withID: id)
+        }
+    }
+    
+    private func repeatedUpdates() {
+        self.pollForNextBuffer()
+        self.updateNetworkBufferRange() // thread issues if I try to update buffer status in streaming listener
+        self.updateNeedle()
+        self.updateIsPlaying()
+        self.updateDuration()
+    }
+    
     //MARK:- Timer loop
     
     //Called when
     //1. First time audio is finally parsed
     //2. When we run to the end of the network buffer and we're waiting again
-    private func pollForNextBufferRecursive() {
+    private func pollForNextBuffer() {
         guard shouldPollForNextBuffer else { return }
         
+        pollForNextBufferRecursive()
+    }
+    
+    private func pollForNextBufferRecursive() {
         do {
             var nextScheduledBuffer: AVAudioPCMBuffer! = try converter.pullBuffer()
             numberOfBuffersScheduledFromPoll += 1
@@ -174,7 +205,7 @@ class AudioStreamEngine: AudioEngine {
             queue.async { [weak self] in
                 if #available(iOS 11.0, *) {
                     // to make sure the pcm buffers are properly free'd from memory we need to nil them after the player has used them
-                    self?.playerNode.scheduleBuffer(nextScheduledBuffer, completionCallbackType: .dataRendered, completionHandler: { (_) in
+                    self?.playerNode.scheduleBuffer(nextScheduledBuffer, completionCallbackType: .dataConsumed, completionHandler: { (_) in
                         nextScheduledBuffer = nil
                         self?.numberOfBuffersScheduledInTotal -= 1
                         self?.pollForNextBufferRecursive()
@@ -286,6 +317,16 @@ class AudioStreamEngine: AudioEngine {
         super.pause()
     }
     
+    override func play() {
+        queue.async { [weak self] in
+            self?.playHelperDispatchQueue()
+        }
+    }
+    
+    private func playHelperDispatchQueue() {
+        super.play()
+    }
+    
     override func invalidate() {
         super.invalidate()
         converter.invalidate()

Source/Engine/AudioThrottler.swift

@@ -27,74 +27,30 @@ import Foundation
 
 protocol AudioThrottleDelegate: AnyObject {
     func didUpdate(totalBytesExpected bytes: Int64)
-    func didUpdate(networkStreamProgress progress: Double)
-    func shouldProcess(networkData data: Data)
 }
 
 protocol AudioThrottleable {
     init(withRemoteUrl url: AudioURL, withDelegate delegate: AudioThrottleDelegate)
-    func tellAudioFormatFound()
-    func tellByteOffset(offset: UInt64)
+    func pullNextDataPacket(_ callback: @escaping (Data?) -> ())
     func tellSeek(offset: UInt64)
-    func tellBytesPerAudioPacket(count: UInt64)
     func pollRangeOfBytesAvailable() -> (UInt64, UInt64)
     func invalidate()
 }
 
 class AudioThrottler: AudioThrottleable {
-    private class NetworkDataWrapper: NSObject {
-        let startOffset: UInt
-        var data: Data
-        var alreadySent: Bool
-        var next: NetworkDataWrapper?
-        
-        var byteCount: UInt {
-            return UInt(data.count)
-        }
-        
-        var endOffset: UInt {
-            return startOffset + UInt(data.count) - 1
-        }
-        
-        init(startingOffset: UInt, data: Data) {
-            self.startOffset = startingOffset
-            self.data = data
-            self.alreadySent = false
-        }
-        
-        func containsOffset(_ offset: UInt) -> Bool {
-            return startOffset <= offset && offset <= endOffset
-        }
-        
-        func isNextSent() -> Bool {
-            return next?.alreadySent ?? false
-        }
-        
-        //FIXME: what is the offset was at the edge of the split? We will have empty data
-        func splitToRight(atOffset offset: UInt) -> NetworkDataWrapper {
-            let splitPoint:Int = Int(offset - startOffset)
-            let leftData = data.subdata(in: 0..<splitPoint)
-            let rightData = data.subdata(in: splitPoint..<data.count)
-            
-            data = leftData
-            
-            let rightWrapper:NetworkDataWrapper = NetworkDataWrapper(startingOffset: offset, data: rightData)
-            rightWrapper.next = next
-            next = rightWrapper
-            
-            return rightWrapper
-        }
-        
-        override var description: String {
-            return "startOffset:\(startOffset), endOffset:\(endOffset), dataCount:\(data.count), sent:\(alreadySent), next:\(next != nil ?"hasNext":"noNext")"
-        }
-    }
+    private let queue = DispatchQueue(label: "SwiftAudioPlayer.Throttler", qos: .userInitiated)
     
     //Init
     let url: AudioURL
     weak var delegate: AudioThrottleDelegate?
     
-    private var networkData: [NetworkDataWrapper] = []
+    private var networkData: [Data] = [] {
+        didSet {
+//            Log.test("NETWORK DATA \(networkData.count)")
+        }
+    }
+    private var lastSentDataPacketIndex = -1
+    
     var shouldThrottle = false
     var byteOffsetBecauseOfSeek: UInt = 0
     
@@ -116,131 +72,103 @@ class AudioThrottler: AudioThrottleable {
         AudioDataManager.shared.startStream(withRemoteURL: url) { [weak self] (pto: StreamProgressPTO) in
             guard let self = self else {return}
             Log.debug("received stream data of size \(pto.getData().count) and progress: \(pto.getProgress())")
-            self.delegate?.didUpdate(networkStreamProgress: pto.getProgress())
-            
+
             if let totalBytesExpected = pto.getTotalBytesExpected() {
                 self.totalBytesExpected = totalBytesExpected
             }
             
-            let lastItem = self.networkData.last
-            let startoffset = lastItem == nil ? self.byteOffsetBecauseOfSeek : lastItem!.endOffset + 1
-            let wrappedNetworkData = NetworkDataWrapper(startingOffset: startoffset, data: pto.getData())
-            lastItem?.next = wrappedNetworkData
-            self.networkData.append(wrappedNetworkData)
-            
-            if !self.shouldThrottle {
-                Log.debug("sending up packet from stream untrottled at start: \(wrappedNetworkData.startOffset)")
-                //NOTE: the order here matters.
-                //We have to set to true before sending up to be processed because
-                //tellByteOffset() is ran in a separate thread than this one
-                //We got in a state where 10% of the time an episode will keep polling because
-                //the first 30 buffers have not been filled
-                wrappedNetworkData.alreadySent = true
-                delegate.shouldProcess(networkData: wrappedNetworkData.data)
-            }
-        }
-    }
-    
-    func tellAudioFormatFound() {
-        shouldThrottle = true //the above layer has enough info that we can throttle
-    }
-    
-    func tellBytesPerAudioPacket(count: UInt64) {
-        if count > largestPollingOffsetDifference {
-            largestPollingOffsetDifference = count
-        }
-    }
-    
-    func tellByteOffset(offset: UInt64) {
-        Log.debug("offset \(offset)")
-        
-        for wrappedNetworkData in networkData {
-            if wrappedNetworkData.containsOffset(UInt(offset)) {
-                Log.debug("offset: \(offset) within network packet of range: \(wrappedNetworkData.startOffset) to \(wrappedNetworkData.endOffset) is next sent: \(wrappedNetworkData.isNextSent())")
-                
-                if wrappedNetworkData.alreadySent {
-                    Log.debug("already sent offset: \(offset) within network packet of range: \(wrappedNetworkData.startOffset) to \(wrappedNetworkData.endOffset)")
-                    
-                    var bytesSent: UInt = 0
-                    var current = wrappedNetworkData
-                    
-                    // Sometimes the next data packet is smaller than a full audio chunk size, so we need to ensure we send up enough packets for the audio chunk. This prevented Issue #4 where tsreaming would randomly get stuck in a state needing more data up the chain.
-                    // https://github.com/tanhakabir/SwiftAudioPlayer/issues/4
-                    while bytesSent < largestPollingOffsetDifference {
-                        if let next = current.next {
-                            if !next.alreadySent {
-                                Log.info("Sending next network packet with range: \(next.startOffset) to \(next.endOffset), have sent \(bytesSent) bytes so far from \(largestPollingOffsetDifference) bytes")
-                                next.alreadySent = true
-                                delegate?.shouldProcess(networkData: next.data)
-                            }
-                            bytesSent += next.byteCount
-                            current = next
-                        } else {
-                            Log.debug("next package doesn't exist, bytes sent so far: \(bytesSent)")
-                            return
-                        }
-                    }
-                    
-                    return
-                }
-                
-                Log.info("Found network packet  to send with range: \(wrappedNetworkData.startOffset) to \(wrappedNetworkData.endOffset)")
-                wrappedNetworkData.alreadySent = true
-                delegate?.shouldProcess(networkData: wrappedNetworkData.data)
-                return
+            self.queue.async { [weak self] in
+                self?.networkData.append(pto.getData())
+                StreamingDownloadDirector.shared.didUpdate(url.key, networkStreamProgress: pto.getProgress())
             }
         }
     }
+
     
     func tellSeek(offset: UInt64) {
         Log.info("seek with offset: \(offset)")
         
+        self.queue.async { [weak self] in
+            self?.seekQueueHelper(offset)
+        }
+    }
+    
+    func seekQueueHelper(_ offset: UInt64) {
+        let offsetToFind = Int(offset) - Int(byteOffsetBecauseOfSeek)
+        
+        var shouldStartNewStream: Bool = false
+        
+        // if we have no data start a new stream after seek
         if networkData.count == 0 {
+            shouldStartNewStream = true
+        }
+        
+        // if what we're looking for is outside of available data, start a new stream
+        if offset < byteOffsetBecauseOfSeek || offsetToFind > networkData.sum {
+            shouldStartNewStream = true
+        }
+        
+        // we should have the data within our cache. find it and save the index for the next pull
+        if let indexOfDataContainingOffset = networkData.getIndexContainingByteOffset(offsetToFind) {
+            lastSentDataPacketIndex = indexOfDataContainingOffset - 1
+        }
+        
+        if shouldStartNewStream {
             byteOffsetBecauseOfSeek = UInt(offset)
+            lastSentDataPacketIndex = -1
             AudioDataManager.shared.seekStream(withRemoteURL: url, toByteOffset: offset)
             
             networkData = []
             return
         }
         
-        if let finalOffset = networkData.last?.endOffset, let firstOffset = networkData.first?.startOffset {
-            if offset < firstOffset || offset > finalOffset {
-                byteOffsetBecauseOfSeek = UInt(offset)
-                AudioDataManager.shared.seekStream(withRemoteURL: url, toByteOffset: offset)
-                
-                networkData = []
-                return
-            }
-        }
-        
-        for (i, d) in networkData.enumerated() {
-            if offset > d.endOffset {
-                d.alreadySent = false
-                continue
-            }
-            
-            if d.containsOffset(UInt(offset)) {
-                let wrappedData = d.splitToRight(atOffset: UInt(offset))
-                networkData.insert(wrappedData, at: i+1)
-                
-                d.alreadySent = false
-                wrappedData.alreadySent = true
-                Log.info("\(d) ::: \(wrappedData)")
-                
-                delegate?.shouldProcess(networkData: wrappedData.data)
-                return
-            }
-        }
+        Log.error("83672 Should not get here")
     }
     
     func pollRangeOfBytesAvailable() -> (UInt64, UInt64) {
-        let start = networkData.first?.startOffset ?? 0
-        let end = networkData.last?.endOffset ?? 0
+        let start = byteOffsetBecauseOfSeek
+        let end = networkData.sum + Int(byteOffsetBecauseOfSeek)
         
         return (UInt64(start), UInt64(end))
     }
     
+    func pullNextDataPacket(_ callback: @escaping (Data?) -> ()) {
+        queue.async { [weak self] in
+            guard let self = self else { return }
+            guard self.lastSentDataPacketIndex < self.networkData.count - 1 else {
+                callback(nil)
+                return
+            }
+            
+            self.lastSentDataPacketIndex += 1
+            
+            callback(self.networkData[self.lastSentDataPacketIndex])
+        }
+    }
+    
     func invalidate() {
         AudioDataManager.shared.deleteStream(withRemoteURL: url)
     }
 }
+
+extension Array where Element == Data {
+    var sum: Int {
+        get {
+            return self.reduce(0) { $0 + $1.count }
+        }
+    }
+    
+    func getIndexContainingByteOffset(_ offset: Int) -> Int? {
+        var dataCount = 0
+        
+        for (i, data) in self.enumerated() {
+            if offset >= dataCount && offset <= dataCount + data.count {
+                return i
+            }
+            
+            dataCount += data.count
+        }
+        
+        return nil
+    }
+}

Source/Engine/Converter/AudioConverter.swift

@@ -85,7 +85,7 @@ class AudioConverter: AudioConvertable {
         self.pcmBufferSize = size
         
         do {
-            parser = try AudioParser(withRemoteUrl: url, parsedFileAudioFormatCallback: {
+            parser = try AudioParser(withRemoteUrl: url, bufferSize: Int(size), parsedFileAudioFormatCallback: {
                 [weak self] (fileAudioFormat: AVAudioFormat) in
                 guard let strongSelf = self else { return }
                 

Source/Engine/Parser/AudioParser.swift

@@ -53,6 +53,9 @@ import AVFoundation
 //TODO: what if user seeks beyond the data we have? What if we're done but user seeks even further than what we have
 
 class AudioParser: AudioParsable {
+    private var MIN_PACKETS_TO_HAVE_AVAILABLE_BEFORE_THROTTLING_PARSING = 8192  // this will be modified when we know the file format to be just enough packets to fill up 1 pcm buffer
+    private var framesPerBuffer: Int = 1
+    
     //MARK:- For OS parser class
     var parsedAudioHeaderPacketCount: UInt64 = 0
     var parsedAudioPacketDataSize: UInt64 = 0
@@ -61,8 +64,8 @@ class AudioParser: AudioParsable {
     public var fileAudioFormat: AVAudioFormat? {
         didSet {
             if let format = fileAudioFormat, oldValue == nil {
+                MIN_PACKETS_TO_HAVE_AVAILABLE_BEFORE_THROTTLING_PARSING = framesPerBuffer/Int(format.streamDescription.pointee.mFramesPerPacket)
                 parsedFileAudioFormatCallback(format)
-                throttler.tellAudioFormatFound()
             }
         }
     }
@@ -100,14 +103,7 @@ class AudioParser: AudioParsable {
         return predictedCount
     }
     
-    var sumOfParsedAudioBytes:UInt32 = 0 {
-        didSet {
-            if let byteCount = averageBytesPerPacket {
-                throttler.tellBytesPerAudioPacket(count: UInt64(byteCount))
-            }
-        }
-    }
-    
+    var sumOfParsedAudioBytes:UInt32 = 0
     var numberOfPacketsParsed:UInt32 = 0
     var audioPackets: [(AudioStreamPacketDescription?,Data)] = [] { 
         didSet {
@@ -122,6 +118,7 @@ class AudioParser: AudioParsable {
             //TODO: duration will not be accurate with WAV or AIFF
         }
     }
+    var lastSentAudioPacketIndex = -1
     
     /**
      Audio packets varry in size. The first one parsed in a batch of audio
@@ -148,10 +145,26 @@ class AudioParser: AudioParsable {
         return audioPackets.count == totalPredictedPacketCount
     }
     
+    var streamChangeListenerId: UInt?
     
-    init(withRemoteUrl url: AudioURL, parsedFileAudioFormatCallback: @escaping(AVAudioFormat) -> ()) throws {
+    init(withRemoteUrl url: AudioURL, bufferSize: Int,  parsedFileAudioFormatCallback: @escaping(AVAudioFormat) -> ()) throws {
         self.url = url
+        self.framesPerBuffer = bufferSize
         self.parsedFileAudioFormatCallback = parsedFileAudioFormatCallback
+        
+        streamChangeListenerId = StreamingDownloadDirector.shared.attach { [weak self] (key, progress) in
+            guard let self = self else { return }
+            guard key == url.key else { return }
+            self.networkProgress = progress
+            
+            // initially parse a bunch of packets
+            if self.fileAudioFormat == nil {
+                self.processNextDataPacket()
+            } else if self.audioPackets.count - self.lastSentAudioPacketIndex < self.MIN_PACKETS_TO_HAVE_AVAILABLE_BEFORE_THROTTLING_PARSING {
+                self.processNextDataPacket()
+            }
+        }
+        
         self.throttler = AudioThrottler(withRemoteUrl: url, withDelegate: self)
         
         let context = unsafeBitCast(self, to: UnsafeMutableRawPointer.self)
@@ -161,10 +174,14 @@ class AudioParser: AudioParsable {
         }
     }
     
-    func pullPacket(atIndex index: AVAudioPacketCount) throws -> (AudioStreamPacketDescription?, Data) {
-        if let offset = getOffset(fromPacketIndex: index) {
-            throttler.tellByteOffset(offset: offset)
+    deinit {
+        if let id = streamChangeListenerId {
+            StreamingDownloadDirector.shared.detach(withID: id)
         }
+    }
+    
+    func pullPacket(atIndex index: AVAudioPacketCount) throws -> (AudioStreamPacketDescription?, Data) {
+        determineIfMoreDataNeedsToBeParsed(index: index)
         
         // Check if we've reached the end of the packets. We have two scenarios:
         //     1. We've reached the end of the packet data and the file has been completely parsed
@@ -180,9 +197,16 @@ class AudioParser: AudioParsable {
             }
         }
         
+        lastSentAudioPacketIndex = Int(packetIndex)
         return audioPackets[Int(packetIndex)]
     }
     
+    private func determineIfMoreDataNeedsToBeParsed(index: AVAudioPacketCount) {
+        if index > audioPackets.count - MIN_PACKETS_TO_HAVE_AVAILABLE_BEFORE_THROTTLING_PARSING {
+            processNextDataPacket()
+        }
+    }
+    
     func tellSeek(toIndex index: AVAudioPacketCount) {
         //Already within the processed audio packets. Ignore
         if indexSeekOffset <= index && index < audioPackets.count + Int(indexSeekOffset) {
@@ -202,6 +226,7 @@ class AudioParser: AudioParsable {
         audioPackets = []
         
         throttler.tellSeek(offset: byteOffset)
+        processNextDataPacket()
     }
     
     private func getOffset(fromPacketIndex index: AVAudioPacketCount) -> UInt64? {
@@ -281,6 +306,30 @@ class AudioParser: AudioParsable {
         
     }
     
+    private func processNextDataPacket() {
+        throttler.pullNextDataPacket { [weak self] (d) in
+            guard let self = self else { return }
+            guard let data = d else { return }
+            
+            Log.debug("processing data count: \(data.count) :: already had \(self.audioPackets.count) audio packets")
+            self.shouldPreventPacketFromFillingUp = false
+            do {
+                let sID = self.streamID!
+                let dataSize = data.count
+                
+                _ = try data.accessBytes({ (bytes: UnsafePointer<UInt8>) in
+                    let result:OSStatus = AudioFileStreamParseBytes(sID, UInt32(dataSize), bytes, [])
+                    guard result == noErr else {
+                        Log.monitor(ParserError.failedToParseBytes(result).errorDescription as Any)
+                        throw ParserError.failedToParseBytes(result)
+                    }
+                })
+            } catch {
+                Log.monitor(error.localizedDescription)
+            }
+        }
+    }
+    
 }
 
 //MARK:- AudioThrottleDelegate
@@ -288,27 +337,4 @@ extension AudioParser: AudioThrottleDelegate {
     func didUpdate(totalBytesExpected bytes: Int64) {
         expectedFileSizeInBytes = UInt64(bytes)
     }
-    
-    func didUpdate(networkStreamProgress progress: Double) {
-        networkProgress = progress
-    }
-    
-    func shouldProcess(networkData data: Data) {
-        Log.debug("processing data count: \(data.count) :: already had \(audioPackets.count) audio packets")
-        self.shouldPreventPacketFromFillingUp = false
-        do {
-            let sID = self.streamID!
-            let dataSize = data.count
-            
-            _ = try data.accessBytes({ (bytes: UnsafePointer<UInt8>) in
-                let result:OSStatus = AudioFileStreamParseBytes(sID, UInt32(dataSize), bytes, [])
-                guard result == noErr else {
-                    Log.monitor(ParserError.failedToParseBytes(result).errorDescription as Any)
-                    throw ParserError.failedToParseBytes(result)
-                }
-            })
-        } catch {
-            Log.monitor(error.localizedDescription)
-        }
-    }
 }

Source/SAPlayer.swift

@@ -297,6 +297,14 @@ public class SAPlayer {
     }
 }
 
+public enum SAPlayerBitrate {
+    /// This bitrate is good for radio streams that are passing ittle amounts of audio data at a time. This will allow the player to process the audio data in a fast enough rate to not pause or get stuck playing. This rate however ends up using more CPU and is worse for your battery-life and performance of your app.
+    case low
+    
+    /// This bitrate is good for streaming saved audio files like podcasts where most of the audio data will be received from the remote server at the beginning in a short time. This rate is more performant by using much less CPU and being better for your battery-life and app performance.
+    case high // go for audio files being streamed. This is uses less CPU and
+}
+
 //MARK: - External Player Controls
 extension SAPlayer {
     /**
@@ -442,17 +450,18 @@ extension SAPlayer {
      - Note: Subscribe to `SAPlayer.Updates.StreamingBuffer` to see updates in streaming progress.
      
      - Parameter withRemoteUrl: The URL of the remote audio.
+     - Parameter bitrate: The bitrate of the streamed audio. By default the bitrate is set to high for streaming saved audio files. If you want to stream radios then you should use the `low` bitrate option.
      - Parameter mediaInfo: The media information of the audio to show on the lockscreen media player (optional).
      */
-    public func startRemoteAudio(withRemoteUrl url: URL, mediaInfo: SALockScreenInfo? = nil) {
+    public func startRemoteAudio(withRemoteUrl url: URL, bitrate: SAPlayerBitrate = .high, mediaInfo: SALockScreenInfo? = nil) {
         self.mediaInfo = mediaInfo
-        presenter.handlePlayStreamedAudio(withRemoteUrl: url)
+        presenter.handlePlayStreamedAudio(withRemoteUrl: url, bitrate: bitrate)
     }
     
     @available(*, deprecated, renamed: "startRemoteAudio")
     public func initializeRemoteAudio(withRemoteUrl url: URL, mediaInfo: SALockScreenInfo? = nil) {
         self.mediaInfo = mediaInfo
-        presenter.handlePlayStreamedAudio(withRemoteUrl: url)
+        presenter.handlePlayStreamedAudio(withRemoteUrl: url, bitrate: .high)
     }
     
     /**
@@ -495,8 +504,8 @@ extension SAPlayer: SAPlayerDelegate {
         player = AudioDiskEngine(withSavedUrl: url, delegate: presenter)
     }
     
-    func startAudioStreamed(withRemoteUrl url: AudioURL) {
-        player = AudioStreamEngine(withRemoteUrl: url, delegate: presenter)
+    func startAudioStreamed(withRemoteUrl url: AudioURL, bitrate: SAPlayerBitrate) {
+        player = AudioStreamEngine(withRemoteUrl: url, delegate: presenter, bitrate: bitrate)
     }
     
     func clearEngine() {

Source/SAPlayerDelegate.swift

@@ -31,7 +31,7 @@ protocol SAPlayerDelegate: AnyObject, LockScreenViewProtocol {
     var skipBackwardSeconds: Double { get set }
     
     func startAudioDownloaded(withSavedUrl url: AudioURL)
-    func startAudioStreamed(withRemoteUrl url: AudioURL)
+    func startAudioStreamed(withRemoteUrl url: AudioURL, bitrate: SAPlayerBitrate)
     func clearEngine()
     func playEngine()
     func pauseEngine()

Source/SAPlayerFeatures.swift

@@ -58,10 +58,10 @@ extension SAPlayer {
                     Log.debug("meterLevel: \(meterLevel)")
                     if meterLevel < 0.6 { // below 0.6 decibels is below audible audio
                         SAPlayer.shared.rate = originalRate + 0.5
-                        Log.test("speed up rate to \(String(describing: SAPlayer.shared.rate))")
+                        Log.debug("speed up rate to \(String(describing: SAPlayer.shared.rate))")
                     } else {
                         SAPlayer.shared.rate = originalRate
-                        Log.test("slow down rate to \(String(describing: SAPlayer.shared.rate))")
+                        Log.debug("slow down rate to \(String(describing: SAPlayer.shared.rate))")
                     }
                 }
                 

Source/SAPlayerPresenter.swift

@@ -87,13 +87,13 @@ class SAPlayerPresenter {
         delegate?.startAudioDownloaded(withSavedUrl: url)
     }
     
-    func handlePlayStreamedAudio(withRemoteUrl url: URL) {
+    func handlePlayStreamedAudio(withRemoteUrl url: URL, bitrate: SAPlayerBitrate) {
         // Because we support queueing, we want to clear off any existing players.
         // Therefore, instantiate new player every time, destroy any existing ones.
         // This prevents a crash where an owning engine already exists.
         handleClear()
         attachForUpdates(url: url)
-        delegate?.startAudioStreamed(withRemoteUrl: url)
+        delegate?.startAudioStreamed(withRemoteUrl: url, bitrate: bitrate)
     }
     
     func handleQueueStreamedAudio(withRemoteUrl url: URL) {
@@ -252,7 +252,7 @@ extension SAPlayerPresenter {
             
             switch nextAudioURL.0 {
             case .remote:
-                self.handlePlayStreamedAudio(withRemoteUrl: nextAudioURL.1)
+                self.handlePlayStreamedAudio(withRemoteUrl: nextAudioURL.1, bitrate: .high) // TODO fix to add option for low birate
                 break
             case .disk:
                 self.handlePlaySavedAudio(withSavedUrl: nextAudioURL.1)

SwiftAudioPlayer.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'SwiftAudioPlayer'
-  s.version          = '4.0.0'
+  s.version          = '5.0.0'
   s.summary          = 'SwiftAudioPlayer is a Swift based audio player that can handle streaming from a remote location and audio manipulation.'
 
 # This description is used to generate tags and improve search results.