refs #58, Update README

Examples/iOS/AppDelegate.swift

@@ -13,16 +13,19 @@ final class AppDelegate: UIResponder, UIApplicationDelegate {
         // Logboard.with(HaishinKitIdentifier).level = .trace
         let session = AVAudioSession.sharedInstance()
         do {
-            try session.setPreferredSampleRate(44_100)
             // https://stackoverflow.com/questions/51010390/avaudiosession-setcategory-swift-4-2-ios-12-play-sound-on-silent
             if #available(iOS 10.0, *) {
                 try session.setCategory(.playAndRecord, mode: .default, options: [.defaultToSpeaker, .allowBluetooth])
             } else {
-                session.perform(NSSelectorFromString("setCategory:withOptions:error:"), with: AVAudioSession.Category.playAndRecord, with: [AVAudioSession.CategoryOptions.allowBluetooth])
+                session.perform(NSSelectorFromString("setCategory:withOptions:error:"), with: AVAudioSession.Category.playAndRecord, with: [
-                try? session.setMode(.default)
+                    AVAudioSession.CategoryOptions.allowBluetooth,
+                    AVAudioSession.CategoryOptions.defaultToSpeaker]
+                )
+                try session.setMode(.default)
             }
             try session.setActive(true)
         } catch {
+            logger.error(error)
         }
         return true
     }

Examples/iOS/LiveViewController.swift

@@ -4,8 +4,6 @@ import Photos
 import UIKit
 import VideoToolbox
 
-let sampleRate: Double = 44_100
-
 final class ExampleRecorderDelegate: DefaultAVRecorderDelegate {
     static let `default` = ExampleRecorderDelegate()
 
@@ -62,9 +60,6 @@ final class LiveViewController: UIViewController {
             .width: 720,
             .height: 1280
         ]
-        rtmpStream.audioSettings = [
-            .sampleRate: sampleRate
-        ]
         rtmpStream.mixer.recorder.delegate = ExampleRecorderDelegate.shared
 
         videoBitrateSlider?.value = Float(RTMPStream.defaultVideoBitrate) / 1024

Examples/iOS/Preference.swift

@@ -1,6 +1,6 @@
 struct Preference {
     static var defaultInstance = Preference()
 
-    var uri: String? = "rtmp://192.168.1.4/live"
+    var uri: String? = "rtmp://192.168.1.8/live"
     var streamName: String? = "live"
 }

Examples/iOS/Screencast/SampleHandler.swift

@@ -15,15 +15,8 @@ open class SampleHandler: RPBroadcastSampleHandler {
         logger.level = .debug
         logger.appender = socket
         */
-        print("broadcastStarted")
+        broadcaster.streamName = Preference.defaultInstance.streamName
-        super.broadcastStarted(withSetupInfo: setupInfo)
+        broadcaster.connect(Preference.defaultInstance.uri, arguments: nil)
-        guard
-            let endpointURL: String = setupInfo?["endpointURL"] as? String,
-            let streamName: String = setupInfo?["streamName"] as? String else {
-            return
-        }
-        broadcaster.streamName = streamName
-        broadcaster.connect(endpointURL, arguments: nil)
     }
 
     override open func processSampleBuffer(_ sampleBuffer: CMSampleBuffer, with sampleBufferType: RPSampleBufferType) {

Examples/macOS/MainViewController.swift

@@ -40,8 +40,8 @@ final class MainViewController: NSViewController {
 
     override func viewWillAppear() {
         super.viewWillAppear()
-        //rtmpStream.attachAudio(DeviceUtil.device(withLocalizedName: audioPopUpButton.titleOfSelectedItem!, mediaType: .audio))
+        rtmpStream.attachAudio(DeviceUtil.device(withLocalizedName: audioPopUpButton.titleOfSelectedItem!, mediaType: .audio))
-        //rtmpStream.attachCamera(DeviceUtil.device(withLocalizedName: cameraPopUpButton.titleOfSelectedItem!, mediaType: .video))
+        rtmpStream.attachCamera(DeviceUtil.device(withLocalizedName: cameraPopUpButton.titleOfSelectedItem!, mediaType: .video))
         lfView?.attachStream(rtmpStream)
     }
 
@@ -155,7 +155,7 @@ final class MainViewController: NSViewController {
         }
         switch code {
         case RTMPConnection.Code.connectSuccess.rawValue:
-            rtmpStream!.play(Preference.defaultInstance.streamName)
+            rtmpStream!.publish(Preference.defaultInstance.streamName)
         default:
             break
         }

HaishinKit.xcodeproj/project.pbxproj

@@ -354,6 +354,10 @@
 		29FD1B5422FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift in Sources */ = {isa = PBXBuildFile; fileRef = 29FD1B5322FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift */; };
 		29FD1B5522FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift in Sources */ = {isa = PBXBuildFile; fileRef = 29FD1B5322FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift */; };
 		29FD1B5622FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift in Sources */ = {isa = PBXBuildFile; fileRef = 29FD1B5322FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift */; };
+		BC44A1A923D31E92002D4297 /* AudioBuffer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC44A1A823D31E92002D4297 /* AudioBuffer.swift */; };
+		BC44A1AA23D31E92002D4297 /* AudioBuffer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC44A1A823D31E92002D4297 /* AudioBuffer.swift */; };
+		BC44A1AB23D31E92002D4297 /* AudioBuffer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC44A1A823D31E92002D4297 /* AudioBuffer.swift */; };
+		BC4C9EAC23F00F3A004A14F2 /* Preference.swift in Sources */ = {isa = PBXBuildFile; fileRef = 291468161E581C7D00E619BA /* Preference.swift */; };
 		BC9CFA9323BDE8B700917EEF /* NetStreamRenderer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC9CFA9223BDE8B700917EEF /* NetStreamRenderer.swift */; };
 		BC9CFA9423BDE8B700917EEF /* NetStreamRenderer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC9CFA9223BDE8B700917EEF /* NetStreamRenderer.swift */; };
 		BC9CFA9523BDE8B700917EEF /* NetStreamRenderer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC9CFA9223BDE8B700917EEF /* NetStreamRenderer.swift */; };
@@ -645,6 +649,7 @@
 		29F97F232336A4FA00A4C317 /* SettingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingTests.swift; sourceTree = "<group>"; };
 		29FD1B4F22FF13190095A0BE /* VTSessionPropertyKey.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VTSessionPropertyKey.swift; sourceTree = "<group>"; };
 		29FD1B5322FF1C2D0095A0BE /* VTCompressionSessionPropertyKey.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VTCompressionSessionPropertyKey.swift; sourceTree = "<group>"; };
+		BC44A1A823D31E92002D4297 /* AudioBuffer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AudioBuffer.swift; sourceTree = "<group>"; };
 		BC9CFA9223BDE8B700917EEF /* NetStreamRenderer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NetStreamRenderer.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -747,6 +752,7 @@
 			children = (
 				298BCF321DD4C44A007FF86A /* AnyUtil.swift */,
 				29DC17B221D0CC0600E26CED /* Atomic.swift */,
+				BC44A1A823D31E92002D4297 /* AudioBuffer.swift */,
 				29B876B81CD70B3900FC07DA /* ByteArray.swift */,
 				294B2D3123785E3800CE7BDC /* CircularBuffer.swift */,
 				29B876631CD70AB300FC07DA /* Constants.swift */,
@@ -1593,6 +1599,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				2930D0411E12D35400DA2DC5 /* SampleHandler.swift in Sources */,
+				BC4C9EAC23F00F3A004A14F2 /* Preference.swift in Sources */,
 				2957473E1E34F3DB00EF056E /* RTMPBroadcaster.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -1626,6 +1633,7 @@
 				294B2D3223785E3800CE7BDC /* CircularBuffer.swift in Sources */,
 				2958910E1EEB8D3C00CE51E1 /* FLVVideoCodec.swift in Sources */,
 				299B13271D3B751400A1E8F5 /* HKView.swift in Sources */,
+				BC44A1A923D31E92002D4297 /* AudioBuffer.swift in Sources */,
 				2926A9EC1DE6B71E0074E3D2 /* MachUtil.swift in Sources */,
 				29B876AF1CD70B2800FC07DA /* RTMPChunk.swift in Sources */,
 				29D3D4CF1ED04C4C00DD4AA6 /* VideoIOComponent+Extension.swift in Sources */,
@@ -1788,6 +1796,7 @@
 				2992D1541ED04A2C008D9DC1 /* VideoIOComponent+Extension-macOS.swift in Sources */,
 				2926A9EF1DE6B83F0074E3D2 /* MachUtil.swift in Sources */,
 				2976A47F1D48FD6900B53EF2 /* AVRecorder.swift in Sources */,
+				BC44A1AA23D31E92002D4297 /* AudioBuffer.swift in Sources */,
 				29B877071CD70D5A00FC07DA /* SoundTransform.swift in Sources */,
 				29B877081CD70D5A00FC07DA /* VideoIOComponent.swift in Sources */,
 				294CC9B422D9BEC000F9DD5C /* DisplayLink-macOS.swift in Sources */,
@@ -1881,6 +1890,7 @@
 				29EB3DF01ED05768001CAE8B /* H264Encoder.swift in Sources */,
 				29EB3E351ED05A33001CAE8B /* DeviceUtil.swift in Sources */,
 				29DC17B521D0CC0600E26CED /* Atomic.swift in Sources */,
+				BC44A1AB23D31E92002D4297 /* AudioBuffer.swift in Sources */,
 				29EB3E261ED05A07001CAE8B /* RTMPStream.swift in Sources */,
 				29DF20642312A3DD004057C3 /* RTMPNWSocket.swift in Sources */,
 				29EB3E111ED05881001CAE8B /* IOComponent.swift in Sources */,

README.md

@@ -104,16 +104,19 @@ Make sure you setup and activate your AVAudioSession.
 import AVFoundation
 let session = AVAudioSession.sharedInstance()
 do {
-    try session.setPreferredSampleRate(44_100)
     // https://stackoverflow.com/questions/51010390/avaudiosession-setcategory-swift-4-2-ios-12-play-sound-on-silent
     if #available(iOS 10.0, *) {
         try session.setCategory(.playAndRecord, mode: .default, options: [.defaultToSpeaker, .allowBluetooth])
     } else {
-        session.perform(NSSelectorFromString("setCategory:withOptions:error:"), with: AVAudioSession.Category.playAndRecord, with:  [AVAudioSession.CategoryOptions.allowBluetooth])
+        session.perform(NSSelectorFromString("setCategory:withOptions:error:"), with: AVAudioSession.Category.playAndRecord, with: [
+            AVAudioSession.CategoryOptions.allowBluetooth,
+            AVAudioSession.CategoryOptions.defaultToSpeaker]
+        )
+        try session.setMode(.default)
     }
-    try session.setMode(AVAudioSessionModeDefault)
     try session.setActive(true)
 } catch {
+    print(error)
 }
 ```
 ## RTMP Usage
@@ -143,24 +146,6 @@ rtmpStream.publish("streamName")
 
 ### Settings
 ```swift
-let sampleRate:Double = 44_100
-
-// see: #58
-#if(iOS)
-let session = AVAudioSession.sharedInstance()
-do {
-    try session.setPreferredSampleRate(44_100)
-    // https://stackoverflow.com/questions/51010390/avaudiosession-setcategory-swift-4-2-ios-12-play-sound-on-silent
-    if #available(iOS 10.0, *) {
-        try session.setCategory(.playAndRecord, mode: .default, options: [.allowBluetooth])
-    } else {
-        session.perform(NSSelectorFromString("setCategory:withOptions:error:"), with: AVAudioSession.Category.playAndRecord, with:  [AVAudioSession.CategoryOptions.allowBluetooth])
-    }
-    try session.setActive(true)
-} catch {
-}
-#endif
-
 var rtmpStream = RTMPStream(connection: rtmpConnection)
 
 rtmpStream.captureSettings = [
@@ -173,7 +158,6 @@ rtmpStream.captureSettings = [
 rtmpStream.audioSettings = [
     .muted: false, // mute audio
     .bitrate: 32 * 1000,
-    .sampleRate: sampleRate, 
 ]
 rtmpStream.videoSettings = [
     .width: 640, // video output width

Sources/Codec/AudioConverter.swift

@@ -42,7 +42,6 @@ public class AudioConverter {
     /// 0 means according to a input source
     public static let defaultSampleRate: Double = 0
     public static let defaultMaximumBuffers: Int = 1
-    public static let defaultBufferListSize: Int = AudioBufferList.sizeInBytes(maximumBuffers: 1)
 
     public var destination: Destination = .aac
     public weak var delegate: AudioConverterDelegate?
@@ -52,6 +51,7 @@ public class AudioConverter {
             settings.observer = self
         }
     }
+    private static let numSamples: Int = 1024
 
     var muted: Bool = false
     var bitrate: UInt32 = AudioConverter.defaultBitrate {
@@ -83,30 +83,19 @@ public class AudioConverter {
     var lockQueue = DispatchQueue(label: "com.haishinkit.HaishinKit.AudioConverter.lock")
     var inSourceFormat: AudioStreamBasicDescription? {
         didSet {
-            logger.info("\(String(describing: self.inSourceFormat))")
+            guard let inSourceFormat = inSourceFormat else {
-            guard let inSourceFormat: AudioStreamBasicDescription = self.inSourceFormat else {
                 return
             }
-            let nonInterleaved: Bool = inSourceFormat.mFormatFlags & kAudioFormatFlagIsNonInterleaved != 0
+            logger.info("\(String(describing: self.inSourceFormat))")
+            let nonInterleaved = inSourceFormat.mFormatFlags & kAudioFormatFlagIsNonInterleaved != 0
             maximumBuffers = nonInterleaved ? Int(inSourceFormat.mChannelsPerFrame) : AudioConverter.defaultMaximumBuffers
-            bufferListSize = nonInterleaved ? AudioBufferList.sizeInBytes(maximumBuffers: maximumBuffers) : AudioConverter.defaultBufferListSize
+            currentAudioBuffer = AudioBuffer(inSourceFormat, numSamples: AudioConverter.numSamples)
         }
     }
     var effects: Set<AudioEffect> = []
-    private var maximumBuffers: Int = AudioConverter.defaultMaximumBuffers {
+    private let numSamples = AudioConverter.numSamples
-        didSet {
+    private var maximumBuffers: Int = AudioConverter.defaultMaximumBuffers
-            guard oldValue != maximumBuffers else {
+    private var currentAudioBuffer = AudioBuffer(AudioStreamBasicDescription(mSampleRate: 0, mFormatID: 0, mFormatFlags: 0, mBytesPerPacket: 0, mFramesPerPacket: 0, mBytesPerFrame: 0, mChannelsPerFrame: 1, mBitsPerChannel: 0, mReserved: 0))
-                return
-            }
-            currentBufferList.unsafeMutablePointer.deallocate()
-            currentBufferList = AudioBufferList.allocate(maximumBuffers: maximumBuffers)
-        }
-    }
-    private var filled = false
-    private var bufferListSize: Int = AudioConverter.defaultBufferListSize
-    private lazy var currentBufferList: UnsafeMutableAudioBufferListPointer = {
-        AudioBufferList.allocate(maximumBuffers: maximumBuffers)
-    }()
     private var _inDestinationFormat: AudioStreamBasicDescription?
     private var inDestinationFormat: AudioStreamBasicDescription {
         get {
@@ -154,10 +143,6 @@ public class AudioConverter {
         settings.observer = self
     }
 
-    deinit {
-        currentBufferList.unsafeMutablePointer.deallocate()
-    }
-
     private var _converter: AudioConverterRef?
     private var converter: AudioConverterRef {
         var status: OSStatus = noErr
@@ -179,14 +164,19 @@ public class AudioConverter {
     }
 
     public func encodeBytes(_ bytes: UnsafeMutableRawPointer?, count: Int, presentationTimeStamp: CMTime) {
-        currentBufferList.unsafeMutablePointer.pointee.mBuffers.mNumberChannels = 1
+        guard isRunning.value else {
-        currentBufferList.unsafeMutablePointer.pointee.mBuffers.mData = bytes
+            currentAudioBuffer.clear()
-        currentBufferList.unsafeMutablePointer.pointee.mBuffers.mDataByteSize = UInt32(count)
+            return
-        convert(Int(1024 * destination.bytesPerFrame), presentationTimeStamp: presentationTimeStamp)
+        }
+        currentAudioBuffer.input.unsafeMutablePointer.pointee.mBuffers.mNumberChannels = 1
+        currentAudioBuffer.input.unsafeMutablePointer.pointee.mBuffers.mData = bytes
+        currentAudioBuffer.input.unsafeMutablePointer.pointee.mBuffers.mDataByteSize = UInt32(count)
+        convert(numSamples * Int(destination.bytesPerFrame), presentationTimeStamp: presentationTimeStamp)
     }
 
-    public func encodeSampleBuffer(_ sampleBuffer: CMSampleBuffer) {
+    public func encodeSampleBuffer(_ sampleBuffer: CMSampleBuffer, offset: Int = 0) {
-        guard let format: CMAudioFormatDescription = sampleBuffer.formatDescription, isRunning.value else {
+        guard let format = sampleBuffer.formatDescription, sampleBuffer.isValid && isRunning.value else {
+            currentAudioBuffer.clear()
             return
         }
 
@@ -194,42 +184,28 @@ public class AudioConverter {
             inSourceFormat = format.streamBasicDescription?.pointee
         }
 
-        var blockBuffer: CMBlockBuffer?
+        do {
-        CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(
+            let numSamples = try currentAudioBuffer.write(sampleBuffer, offset: offset)
-            sampleBuffer,
+            if currentAudioBuffer.isReady {
-            bufferListSizeNeededOut: nil,
-            bufferListOut: currentBufferList.unsafeMutablePointer,
-            bufferListSize: bufferListSize,
-            blockBufferAllocator: kCFAllocatorDefault,
-            blockBufferMemoryAllocator: kCFAllocatorDefault,
-            flags: 0,
-            blockBufferOut: &blockBuffer
-        )
-
-        if blockBuffer == nil {
-            logger.warn("IllegalState for blockBuffer")
-            return
-        }
-
-        if !effects.isEmpty {
                 for effect in effects {
-                effect.execute(currentBufferList, format: inSourceFormat)
+                    effect.execute(currentAudioBuffer.input, format: inSourceFormat)
                 }
-        }
-
                 if muted {
-            for i in 0..<currentBufferList.count {
+                    currentAudioBuffer.muted()
-                memset(currentBufferList[i].mData, 0, Int(currentBufferList[i].mDataByteSize))
                 }
+                convert(currentAudioBuffer.maxLength, presentationTimeStamp: currentAudioBuffer.presentationTimeStamp)
+            }
+            if numSamples < sampleBuffer.numSamples {
+                encodeSampleBuffer(sampleBuffer, offset: numSamples)
+            }
+        } catch {
+            logger.error(error)
         }
-
-        convert(blockBuffer!.dataLength, presentationTimeStamp: sampleBuffer.presentationTimeStamp)
     }
 
     @inline(__always)
     private func convert(_ dataBytesSize: Int, presentationTimeStamp: CMTime) {
-        filled = false
+        var finished = false
-        var finished: Bool = false
         repeat {
             var ioOutputDataPacketSize: UInt32 = destination.packetSize
 
@@ -241,7 +217,7 @@ public class AudioConverter {
                 outOutputData[i].mData = UnsafeMutableRawPointer.allocate(byteCount: dataBytesSize, alignment: 0)
             }
 
-            let status: OSStatus = AudioConverterFillComplexBuffer(
+            let status = AudioConverterFillComplexBuffer(
                 converter,
                 inputDataProc,
                 Unmanaged.passUnretained(self).toOpaque(),
@@ -252,7 +228,8 @@ public class AudioConverter {
 
             switch status {
                 // kAudioConverterErr_InvalidInputSize: perhaps mistake. but can support macOS BuiltIn Mic #61
-            case noErr, kAudioConverterErr_InvalidInputSize:
+                case noErr,
+                     kAudioConverterErr_InvalidInputSize:
                 delegate?.sampleOutput(
                     audio: outOutputData,
                     presentationTimeStamp: presentationTimeStamp
@@ -292,19 +269,20 @@ public class AudioConverter {
         _ ioNumberDataPackets: UnsafeMutablePointer<UInt32>,
         ioData: UnsafeMutablePointer<AudioBufferList>,
         outDataPacketDescription: UnsafeMutablePointer<UnsafeMutablePointer<AudioStreamPacketDescription>?>?) -> OSStatus {
-        guard !filled else {
+        guard currentAudioBuffer.isReady else {
             ioNumberDataPackets.pointee = 0
             return -1
         }
 
-        memcpy(ioData, currentBufferList.unsafePointer, bufferListSize)
+        memcpy(ioData, currentAudioBuffer.input.unsafePointer, currentAudioBuffer.listSize)
         ioNumberDataPackets.pointee = 1
 
         if destination == .pcm && outDataPacketDescription != nil {
-            audioStreamPacketDescription.mDataByteSize = currentBufferList.unsafePointer.pointee.mBuffers.mDataByteSize
+            audioStreamPacketDescription.mDataByteSize = currentAudioBuffer.input.unsafePointer.pointee.mBuffers.mDataByteSize
             outDataPacketDescription?.pointee = audioStreamPacketDescriptionPointer
         }
-        filled = true
+
+        currentAudioBuffer.clear()
 
         return noErr
     }

Sources/Extension/CMSampleBuffer+Extension.swift

@@ -10,6 +10,13 @@ extension CMSampleBuffer {
         }
     }
 
+    @available(iOS, obsoleted: 13.0)
+    @available(tvOS, obsoleted: 13.0)
+    @available(macOS, obsoleted: 10.15)
+    var isValid: Bool {
+        CMSampleBufferIsValid(self)
+    }
+
     @available(iOS, obsoleted: 13.0)
     @available(tvOS, obsoleted: 13.0)
     @available(macOS, obsoleted: 10.15)

Sources/Util/AudioBuffer.swift

@@ -0,0 +1,85 @@
+import AVFoundation
+import Foundation
+
+final class AudioBuffer {
+    enum AudioBufferError: Error {
+        case notReady
+    }
+
+    static let numSamples = 1024
+
+    let input: UnsafeMutableAudioBufferListPointer
+
+    var isReady: Bool {
+        numSamples == index
+    }
+
+    var maxLength: Int {
+        numSamples * bytesPerFrame
+    }
+
+    let listSize: Int
+
+    private var index = 0
+    private var buffers: [Data]
+    private let numSamples: Int
+    private let bytesPerFrame: Int
+    private let maximumBuffers: Int
+    private(set) var presentationTimeStamp: CMTime = .invalid
+
+    deinit {
+        input.unsafeMutablePointer.deallocate()
+    }
+
+    init(_ inSourceFormat: AudioStreamBasicDescription, numSamples: Int = AudioBuffer.numSamples) {
+        let nonInterleaved = inSourceFormat.mFormatFlags & kAudioFormatFlagIsNonInterleaved != 0
+        self.numSamples = nonInterleaved ? numSamples / 2 : numSamples
+        bytesPerFrame = Int(inSourceFormat.mBytesPerFrame)
+        maximumBuffers = nonInterleaved ? Int(inSourceFormat.mChannelsPerFrame) : 1
+        listSize = AudioBufferList.sizeInBytes(maximumBuffers: maximumBuffers)
+        buffers = .init(repeating: .init(repeating: 0, count: self.numSamples * bytesPerFrame), count: maximumBuffers)
+        input = AudioBufferList.allocate(maximumBuffers: maximumBuffers)
+        input.unsafeMutablePointer.pointee.mNumberBuffers = UInt32(maximumBuffers)
+        for i in 0..<maximumBuffers {
+            input[i].mNumberChannels = nonInterleaved ? 1 : inSourceFormat.mChannelsPerFrame
+            input[i].mDataByteSize = UInt32(buffers[i].count)
+            buffers[i].withUnsafeMutableBytes { pointer in
+                input[i].mData = pointer.baseAddress
+            }
+        }
+    }
+
+    func write(_ sampleBuffer: CMSampleBuffer, offset: Int) throws -> Int {
+        guard let data = sampleBuffer.dataBuffer?.data, !isReady else {
+            throw AudioBufferError.notReady
+        }
+        if presentationTimeStamp == .invalid {
+            let offsetTimeStamp: CMTime = offset == 0 ? .zero : CMTime(value: CMTimeValue(offset), timescale: sampleBuffer.presentationTimeStamp.timescale)
+            presentationTimeStamp = CMTimeAdd(sampleBuffer.presentationTimeStamp, offsetTimeStamp)
+        }
+        let numSamples = min(self.numSamples - index, sampleBuffer.numSamples - offset)
+        for i in 0..<maximumBuffers {
+            buffers[i].replaceSubrange(index * bytesPerFrame..<index * bytesPerFrame + numSamples * bytesPerFrame, with: data.advanced(by: offset * bytesPerFrame + numSamples * bytesPerFrame * i))
+        }
+        index += numSamples
+        return numSamples
+    }
+
+    func muted() {
+        for i in 0..<maximumBuffers {
+            buffers[i].resetBytes(in: 0...)
+        }
+    }
+
+    func clear() {
+        presentationTimeStamp = .invalid
+        index = 0
+    }
+}
+
+extension AudioBuffer: CustomDebugStringConvertible {
+    // MARK: CustomDebugStringConvertible
+    var debugDescription: String {
+        Mirror(reflecting: self).debugDescription
+    }
+}