Debug toggle to enable/disable SRT(LA) packet padding.

Common/Localizable.xcstrings

@@ -203660,6 +203660,9 @@
           }
         }
       }
+    },
+    "SRT(LA) packet padding" : {
+
     },
     "SRT(LA) port number missing" : {
       "localizations" : {

Moblin/Media/Srtla/Client/RemoteConnection.swift

@@ -77,6 +77,7 @@ class RemoteConnection: @unchecked Sendable {
     private(set) var destinationHost: NWEndpoint.Host?
     private(set) var destinationPort: NWEndpoint.Port?
     private let mpegtsPacketsPerPacket: Int
+    private let packetPadding: Bool
     var typeString: String {
         switch type {
         case .wifi:
@@ -100,6 +101,7 @@ class RemoteConnection: @unchecked Sendable {
     init(
         type: NWInterface.InterfaceType?,
         mpegtsPacketsPerPacket: Int,
+        packetPadding: Bool,
         interface: NWInterface?,
         networkInterfaces: SrtlaNetworkInterfaces,
         priority: Float,
@@ -108,6 +110,7 @@ class RemoteConnection: @unchecked Sendable {
     ) {
         self.type = type
         self.mpegtsPacketsPerPacket = mpegtsPacketsPerPacket
+        self.packetPadding = packetPadding
         self.interface = interface
         self.networkInterfaces = networkInterfaces
         self.priority = priority
@@ -360,7 +363,7 @@ class RemoteConnection: @unchecked Sendable {
             packetsInFlight.insert(getSrtSequenceNumber(packet: packet))
             var numberOfMpegTsPackets = (packet.count - 16) / MpegTsPacket.size
             numberOfNonNullPacketsSent += UInt64(numberOfMpegTsPackets)
-            if numberOfMpegTsPackets < mpegtsPacketsPerPacket {
+            if packetPadding, numberOfMpegTsPackets < mpegtsPacketsPerPacket {
                 var paddedPacket = packet
                 while numberOfMpegTsPackets < mpegtsPacketsPerPacket {
                     paddedPacket.append(nullPacket)

Moblin/Media/Srtla/Client/SrtlaClient.swift

@@ -42,6 +42,7 @@ class SrtlaClient: NSObject, @unchecked Sendable {
 
     private let networkPathMonitor = NWPathMonitor()
     private let mpegtsPacketsPerPacket: Int
+    private let packetPadding: Bool
     private var host: String = ""
     private var port: Int = 0
     private var groupId: Data?
@@ -56,6 +57,7 @@ class SrtlaClient: NSObject, @unchecked Sendable {
         delegate: any SrtlaDelegate,
         passThrough: Bool,
         mpegtsPacketsPerPacket: Int,
+        packetPadding: Bool,
         networkInterfaceNames: [SettingsNetworkInterfaceName],
         connectionPriorities: SettingsStreamSrtConnectionPriorities,
         srtImplementation: SettingsStreamSrtImplementation
@@ -63,6 +65,7 @@ class SrtlaClient: NSObject, @unchecked Sendable {
         self.delegate = delegate
         self.passThrough = passThrough
         self.mpegtsPacketsPerPacket = mpegtsPacketsPerPacket
+        self.packetPadding = packetPadding
         networkInterfaces = .init()
         self.connectionPriorities = .init()
         self.srtImplementation = srtImplementation
@@ -74,6 +77,7 @@ class SrtlaClient: NSObject, @unchecked Sendable {
             remoteConnections.append(RemoteConnection(
                 type: nil,
                 mpegtsPacketsPerPacket: mpegtsPacketsPerPacket,
+                packetPadding: packetPadding,
                 interface: nil,
                 networkInterfaces: networkInterfaces,
                 priority: 1.0
@@ -151,6 +155,7 @@ class SrtlaClient: NSObject, @unchecked Sendable {
             let remoteConnection = RemoteConnection(
                 type: .other,
                 mpegtsPacketsPerPacket: self.mpegtsPacketsPerPacket,
+                packetPadding: self.packetPadding,
                 interface: nil,
                 networkInterfaces: self.networkInterfaces,
                 priority: self.getRelayConnectionPriority(relayId: id),
@@ -319,6 +324,7 @@ class SrtlaClient: NSObject, @unchecked Sendable {
             newRemoteConnections.append(RemoteConnection(
                 type: interface.type,
                 mpegtsPacketsPerPacket: mpegtsPacketsPerPacket,
+                packetPadding: self.packetPadding,
                 interface: interface,
                 networkInterfaces: networkInterfaces,
                 priority: getConnectionPriority(name: name)

Moblin/Various/Media.swift

@@ -199,6 +199,7 @@ final class Media: NSObject, @unchecked Sendable {
         overheadBandwidth: Int32,
         maximumBandwidthFollowInput: Bool,
         mpegtsPacketsPerPacket: Int,
+        packetPadding: Bool,
         networkInterfaceNames: [SettingsNetworkInterfaceName],
         connectionPriorities: SettingsStreamSrtConnectionPriorities,
         dnsLookupStrategy: SettingsDnsLookupStrategy
@@ -213,6 +214,7 @@ final class Media: NSObject, @unchecked Sendable {
             overheadBandwidth: overheadBandwidth,
             maximumBandwidthFollowInput: maximumBandwidthFollowInput,
             mpegtsPacketsPerPacket: mpegtsPacketsPerPacket,
+            packetPadding: packetPadding,
             networkInterfaceNames: networkInterfaceNames,
             connectionPriorities: connectionPriorities
         )
@@ -229,6 +231,7 @@ final class Media: NSObject, @unchecked Sendable {
         overheadBandwidth: Int32,
         maximumBandwidthFollowInput: Bool,
         mpegtsPacketsPerPacket: Int,
+        packetPadding: Bool,
         networkInterfaceNames: [SettingsNetworkInterfaceName],
         connectionPriorities: SettingsStreamSrtConnectionPriorities
     ) {
@@ -245,6 +248,7 @@ final class Media: NSObject, @unchecked Sendable {
             delegate: self,
             passThrough: !isSrtla,
             mpegtsPacketsPerPacket: mpegtsPacketsPerPacket,
+            packetPadding: packetPadding,
             networkInterfaceNames: networkInterfaceNames,
             connectionPriorities: connectionPriorities,
             srtImplementation: srtImplementation

Moblin/Various/Model/ModelStream.swift

@@ -213,6 +213,7 @@ extension Model {
             overheadBandwidth: database.debug.srtOverheadBandwidth,
             maximumBandwidthFollowInput: database.debug.maximumBandwidthFollowInput,
             mpegtsPacketsPerPacket: srt.mpegtsPacketsPerPacket(),
+            packetPadding: database.debug.packetPadding,
             networkInterfaceNames: database.networkInterfaceNames,
             connectionPriorities: srt.connectionPriorities,
             dnsLookupStrategy: srt.dnsLookupStrategy

Moblin/Various/Settings/SettingsDebug.swift

@@ -51,6 +51,7 @@ class SettingsDebug: Codable, ObservableObject {
     @Published var videoBitrateChange: Bool = false
     @Published var highQualityDownsampling: Bool = false
     @Published var httpProxy: Bool = false
+    @Published var packetPadding: Bool = false
 
     enum CodingKeys: CodingKey {
         case logLevel
@@ -94,6 +95,7 @@ class SettingsDebug: Codable, ObservableObject {
         case videoBitrateChangeEnabled
         case highQualityDownsampling
         case httpProxy3
+        case packetPadding
     }
 
     func encode(to encoder: any Encoder) throws {
@@ -132,6 +134,7 @@ class SettingsDebug: Codable, ObservableObject {
         try container.encode(.videoBitrateChangeEnabled, videoBitrateChange)
         try container.encode(.highQualityDownsampling, highQualityDownsampling)
         try container.encode(.httpProxy3, httpProxy)
+        try container.encode(.packetPadding, packetPadding)
     }
 
     init() {}
@@ -184,5 +187,6 @@ class SettingsDebug: Codable, ObservableObject {
         videoBitrateChange = container.decode(.videoBitrateChangeEnabled, Bool.self, false)
         highQualityDownsampling = container.decode(.highQualityDownsampling, Bool.self, false)
         httpProxy = container.decode(.httpProxy3, Bool.self, false)
+        packetPadding = container.decode(.packetPadding, Bool.self, false)
     }
 }

Moblin/View/Settings/Debug/DebugSettingsView.swift

@@ -121,6 +121,7 @@ struct DebugSettingsView: View {
                     .onChange(of: debug.httpProxy) { _ in
                         model.httpProxyServerChanged()
                     }
+                Toggle("SRT(LA) packet padding", isOn: $debug.packetPadding)
             } header: {
                 Text("Experimental")
             }