Added multi-capture functionality as microphone.

Examples/iOS/IngestViewController.swift

@@ -67,7 +67,7 @@ final class IngestViewController: UIViewController {
                 logger.warn(error)
             }
         }
-        stream.attachAudio(AVCaptureDevice.default(for: .audio), automaticallyConfiguresApplicationAudioSession: false) { error in
+        stream.attachAudio(AVCaptureDevice.default(for: .audio)) { _, error in
             logger.warn(error)
         }
         let front = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front)
@@ -350,7 +350,7 @@ extension IngestViewController: UIPickerViewDelegate {
         } catch {
             logger.warn("can't set supported setPreferredDataSource")
         }
-        stream.attachAudio(AVCaptureDevice.default(for: .audio), automaticallyConfiguresApplicationAudioSession: false) { error in
+        stream.attachAudio(AVCaptureDevice.default(for: .audio)) { _, error in
             logger.warn(error)
         }
     }

Examples/iOS/Screencast/SampleHandler.swift

@@ -15,7 +15,7 @@ open class SampleHandler: RPBroadcastSampleHandler {
     }()
 
     private lazy var rtmpStream: RTMPStream = {
-        FeatureUtil.setEnabled(feature: .multiTrackAudioMixing, isEnabled: true)
+        FeatureUtil.setEnabled(for: .multiTrackAudioMixing, isEnabled: true)
         return RTMPStream(connection: rtmpConnection)
     }()
 

Examples/iOSSwiftUI/Model/ViewModel.swift

@@ -93,11 +93,15 @@ final class ViewModel: ObservableObject {
     }
 
     func registerForPublishEvent() {
-        rtmpStream.attachAudio(AVCaptureDevice.default(for: .audio)) { error in
-            logger.error(error)
+        rtmpStream.attachAudio(AVCaptureDevice.default(for: .audio)) { _, error in
+            if let error {
+                logger.error(error)
+            }
         }
         rtmpStream.attachCamera(AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: currentPosition)) { _, error  in
-            logger.error(error)
+            if let error {
+                logger.error(error)
+            }
         }
         rtmpStream.publisher(for: \.currentFPS)
             .sink { [weak self] currentFPS in

Examples/macOS/AppDelegate.swift

@@ -10,5 +10,6 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 
     func applicationDidFinishLaunching(_ aNotification: Notification) {
         LBLogger.with(HaishinKitIdentifier).level = .info
+        FeatureUtil.setEnabled(for: .multiTrackAudioMixing, isEnabled: true)
     }
 }

Examples/macOS/CameraIngestViewController.swift

@@ -35,10 +35,17 @@ final class CameraIngestViewController: NSViewController {
     override func viewDidAppear() {
         super.viewDidAppear()
         stream.attachAudio(DeviceUtil.device(withLocalizedName: audioPopUpButton.titleOfSelectedItem!, mediaType: .audio))
+
+        var audios = AVCaptureDevice.devices(for: .audio)
+        audios.removeFirst()
+        if let device = audios.first, FeatureUtil.isEnabled(for: .multiTrackAudioMixing) {
+            stream.attachAudio(device, track: 1)
+        }
+
         stream.attachCamera(DeviceUtil.device(withLocalizedName: cameraPopUpButton.titleOfSelectedItem!, mediaType: .video), track: 0)
-        var devices = AVCaptureDevice.devices(for: .video)
-        devices.removeFirst()
-        if let device = devices.first {
+        var videos = AVCaptureDevice.devices(for: .video)
+        videos.removeFirst()
+        if let device = videos.first {
             stream.attachCamera(device, track: 1)
         }
     }

README.md

@@ -181,8 +181,10 @@ do {
 let connection = RTMPConnection()
 let stream = RTMPStream(connection: connection)
 
-stream.attachAudio(AVCaptureDevice.default(for: .audio)) { error in
-  // print(error)
+stream.attachAudio(AVCaptureDevice.default(for: .audio)) { _, error in
+  if let error {
+    logger.warn(error)
+  }
 }
 
 stream.attachCamera(AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back), track: 0) { _, error in

Sources/IO/IOAudioCaptureUnit.swift

@@ -2,24 +2,31 @@
 import AVFoundation
 import Foundation
 
+/// Configuration calback block for IOAudioCaptureUnit.
 @available(tvOS 17.0, *)
-final class IOAudioCaptureUnit: IOCaptureUnit {
-    typealias Output = AVCaptureAudioDataOutput
-
-    let track: UInt8
-    private(set) var device: AVCaptureDevice?
-    var input: AVCaptureInput?
-    var output: Output?
-    var connection: AVCaptureConnection?
+public typealias IOAudioCaptureConfigurationBlock = (IOAudioCaptureUnit?, IOAudioUnitError?) -> Void
+
+/// An object that provides the interface to control the AVCaptureDevice's transport behavior.
+@available(tvOS 17.0, *)
+public final class IOAudioCaptureUnit: IOCaptureUnit {
+    public typealias Output = AVCaptureAudioDataOutput
+
+    public let track: UInt8
+    public private(set) var input: AVCaptureInput?
+    public private(set) var device: AVCaptureDevice?
+    public private(set) var output: Output? {
+        didSet {
+            oldValue?.setSampleBufferDelegate(nil, queue: nil)
+        }
+    }
+    public private(set) var connection: AVCaptureConnection?
     private var dataOutput: IOAudioCaptureUnitDataOutput?
 
     init(_ track: UInt8) {
         self.track = track
     }
 
-    func attachDevice(_ device: AVCaptureDevice?, audioUnit: IOAudioUnit) throws {
-        setSampleBufferDelegate(nil)
-        audioUnit.mixer?.session.detachCapture(self)
+    func attachDevice(_ device: AVCaptureDevice?) throws {
         guard let device else {
             self.device = nil
             input = nil
@@ -29,8 +36,6 @@ final class IOAudioCaptureUnit: IOCaptureUnit {
         self.device = device
         input = try AVCaptureDeviceInput(device: device)
         output = AVCaptureAudioDataOutput()
-        audioUnit.mixer?.session.attachCapture(self)
-        setSampleBufferDelegate(audioUnit)
     }
 
     func setSampleBufferDelegate(_ audioUnit: IOAudioUnit?) {

Sources/IO/IOAudioUnit.swift

@@ -6,6 +6,8 @@ import SwiftPMSupport
 
 /// The IOAudioUnit  error domain codes.
 public enum IOAudioUnitError: Swift.Error {
+    /// The IOAudioUnit failed to attach device.
+    case failedToAttach(error: (any Error)?)
     /// The IOAudioUnit  failed to create the AVAudioConverter.
     case failedToCreate(from: AVAudioFormat?, to: AVAudioFormat?)
     /// The IOAudioUnit  faild to convert the an audio buffer.
@@ -49,7 +51,7 @@ final class IOAudioUnit: IOUnit<IOAudioCaptureUnit> {
         return codec
     }()
     private lazy var audioMixer: any IOAudioMixerConvertible = {
-        if FeatureUtil.isEnabled(feature: .multiTrackAudioMixing) {
+        if FeatureUtil.isEnabled(for: .multiTrackAudioMixing) {
             var audioMixer = IOAudioMixerConvertibleByMultiTrack()
             audioMixer.delegate = self
             return audioMixer
@@ -63,18 +65,18 @@ final class IOAudioUnit: IOUnit<IOAudioCaptureUnit> {
 
     #if os(iOS) || os(macOS) || os(tvOS)
     @available(tvOS 17.0, *)
-    func attachAudio(_ device: AVCaptureDevice?, automaticallyConfiguresApplicationAudioSession: Bool) throws {
-        try mixer?.session.configuration { session in
+    func attachAudio(_ device: AVCaptureDevice?, track: UInt8, configuration: (_ capture: IOAudioCaptureUnit?) -> Void) throws {
+        try mixer?.session.configuration { _ in
+            mixer?.session.detachCapture(captures[track])
             guard let device else {
-                try captures[0]?.attachDevice(nil, audioUnit: self)
-                inputFormat = nil
+                try captures[track]?.attachDevice(nil)
                 return
             }
-            let capture = capture(for: 0)
-            try capture?.attachDevice(device, audioUnit: self)
-            #if os(iOS)
-            session.automaticallyConfiguresApplicationAudioSession = automaticallyConfiguresApplicationAudioSession
-            #endif
+            let capture = capture(for: track)
+            try capture?.attachDevice(device)
+            configuration(capture)
+            capture?.setSampleBufferDelegate(self)
+            mixer?.session.attachCapture(capture)
         }
     }
     #endif

Sources/IO/IOCaptureSession.swift

@@ -127,7 +127,10 @@ final class IOCaptureSession {
     }
 
     @available(tvOS 17.0, *)
-    func attachCapture(_ capture: any IOCaptureUnit) {
+    func attachCapture(_ capture: (any IOCaptureUnit)?) {
+        guard let capture else {
+            return
+        }
         #if !os(visionOS)
         if let connection = capture.connection {
             if let input = capture.input, session.canAddInput(input) {
@@ -151,7 +154,10 @@ final class IOCaptureSession {
     }
 
     @available(tvOS 17.0, *)
-    func detachCapture(_ capture: any IOCaptureUnit) {
+    func detachCapture(_ capture: (any IOCaptureUnit)?) {
+        guard let capture else {
+            return
+        }
         #if !os(visionOS)
         if let connection = capture.connection {
             if capture.output?.connections.contains(connection) == true {

Sources/IO/IOCaptureUnit.swift

@@ -5,9 +5,11 @@ import Foundation
 protocol IOCaptureUnit {
     associatedtype Output: AVCaptureOutput
 
-    var input: AVCaptureInput? { get set }
-    var output: Output? { get set }
-    var connection: AVCaptureConnection? { get set }
+    var track: UInt8 { get }
+    var input: AVCaptureInput? { get  }
+    var output: Output? { get }
+    var device: AVCaptureDevice? { get }
+    var connection: AVCaptureConnection? { get }
 
     init(_ track: UInt8)
 }

Sources/IO/IOStream.swift

@@ -333,16 +333,38 @@ open class IOStream: NSObject {
 
     #if os(iOS) || os(macOS) || os(tvOS)
     /// Attaches the audio device.
+    ///
+    /// You can perform multi-microphone capture by specifying as follows on macOS. Unfortunately, it seems that only one microphone is available on iOS.
+    /// ```
+    /// FeatureUtil.setEnabled(for: .multiTrackAudioMixing, isEnabled: true)
+    /// var audios = AVCaptureDevice.devices(for: .audio)
+    /// if let device = audios.removeFirst() {
+    ///    stream.attachAudio(device, track: 0)
+    /// }
+    /// if let device = audios.removeFirst() {
+    ///    stream.attachAudio(device, track: 1)
+    /// }
+    /// ```
     @available(tvOS 17.0, *)
-    public func attachAudio(_ device: AVCaptureDevice?, automaticallyConfiguresApplicationAudioSession: Bool = false, onError: ((_ error: any Error) -> Void)? = nil) {
+    public func attachAudio(_ device: AVCaptureDevice?, track: UInt8 = 0, configuration: IOAudioCaptureConfigurationBlock? = nil) {
         lockQueue.async {
             do {
-                try self.mixer.audioIO.attachAudio(device, automaticallyConfiguresApplicationAudioSession: automaticallyConfiguresApplicationAudioSession)
+                try self.mixer.audioIO.attachAudio(device, track: track) { capture in
+                    configuration?(capture, nil)
+                }
             } catch {
-                onError?(error)
+                configuration?(nil, IOAudioUnitError.failedToAttach(error: error))
             }
         }
     }
+
+    /// Returns the IOAudioCaptureUnit by track.
+    @available(tvOS 17.0, *)
+    public func audioCapture(for track: UInt8) -> IOAudioCaptureUnit? {
+        return mixer.audioIO.lockQueue.sync {
+            return self.mixer.audioIO.capture(for: track)
+        }
+    }
     #endif
 
     /// Appends a CMSampleBuffer.
@@ -404,6 +426,12 @@ open class IOStream: NSObject {
         }
     }
 
+    /// Configurations for the AVCaptureSession.
+    @available(tvOS 17.0, *)
+    func configuration(_ lambda: (_ session: AVCaptureSession) throws -> Void) rethrows {
+        try mixer.session.configuration(lambda)
+    }
+
     /// A handler that receives stream readyState will update.
     /// - Warning: Please do not call this method yourself.
     open func readyStateWillChange(to readyState: ReadyState) {

Sources/IO/IOVideoCaptureUnit.swift

@@ -1,7 +1,7 @@
 import AVFoundation
 import Foundation
 
-/// Configuration calback block for IOVideoUnit.
+/// Configuration calback block for IOVideoCaptureUnit.
 @available(tvOS 17.0, *)
 public typealias IOVideoCaptureConfigurationBlock = (IOVideoCaptureUnit?, IOVideoUnitError?) -> Void
 
@@ -16,7 +16,7 @@ public final class IOVideoCaptureUnit: IOCaptureUnit {
     public static let colorFormat = kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange
     #endif
 
-    typealias Output = AVCaptureVideoDataOutput
+    public typealias Output = AVCaptureVideoDataOutput
 
     /// The current video device object.
     public private(set) var device: AVCaptureDevice?
@@ -58,9 +58,9 @@ public final class IOVideoCaptureUnit: IOCaptureUnit {
     }
     #endif
 
-    let track: UInt8
-    var input: AVCaptureInput?
-    var output: Output? {
+    public let track: UInt8
+    public private(set) var input: AVCaptureInput?
+    public private(set) var output: Output? {
         didSet {
             guard let output else {
                 return
@@ -75,7 +75,7 @@ public final class IOVideoCaptureUnit: IOCaptureUnit {
             #endif
         }
     }
-    var connection: AVCaptureConnection?
+    public private(set) var connection: AVCaptureConnection?
     private var dataOutput: IOVideoCaptureUnitDataOutput?
 
     init(_ track: UInt8) {

Sources/Util/FeatureUtil.swift

@@ -29,13 +29,13 @@ public enum FeatureUtil {
     private static var flags: [String: Bool] = [:]
 
     /// Whether or not a flag is enabled.
-    public static func isEnabled(feature: Name) -> Bool {
+    public static func isEnabled(for feature: Name) -> Bool {
         return flags[feature.rawValue] ?? false
     }
 
     /// Setter for a feature flag.
     public static func setEnabled(
-        feature: Name,
+        for feature: Name,
         isEnabled: Bool
     ) {
         flags[feature.rawValue] = isEnabled