Upgrade Guide

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Before You Begin

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Upgrade Steps

# Windows
xcopy /E /I "YourProject\Plugins\LCK" "YourProject\Plugins\LCK_backup"
xcopy /E /I "YourProject\Plugins\LCKTablet" "YourProject\Plugins\LCKTablet_backup"

YourProject/
└── Plugins/
    ├── LCK/              ← Delete
    ├── LCKTablet/        ← Delete
    ├── LCKUI/            ← Delete
    ├── LCKAudio/         ← Delete
    ├── LCKUnrealAudio/   ← Delete (if present, new in v1.0)
    ├── LCKStreaming/     ← Delete (if present, new in v1.0)
    ├── LCKFMOD/          ← Delete (if present)
    ├── LCKWwise/         ← Delete (if present)
    ├── LCKVivox/         ← Delete (if present)
    └── LCKOboe/          ← Delete (if present)

YourProject/
└── Plugins/
    ├── LCK/           ← New version
    ├── LCKTablet/     ← New version
    └── ...

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Version Compatibility

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Breaking Changes by Version

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1.0

1. Audio delegate renamed and re-typed — FOnRenderAudioDelegate is now a typedef for a multicast delegate invocation, not a single-cast delegate The parent delegate type has been renamed from FOnRenderAudioDelegate to FDelegateRenderAudio and changed from a single-cast delegate to a multicast delegate (DECLARE_MULTICAST_DELEGATE_FourParams). The old name FOnRenderAudioDelegate still exists as a typedef for the inner FDelegate type, so existing variable declarations compile — but binding semantics have changed. Additionally, the delegate signature gained a fourth parameter (SampleRate).
   // Before (v0.9.2) — single-cast delegate, 3 params
   AudioSource->OnAudioDataDelegate.BindLambda(
       [](TArrayView<const float> PCM, int32 Channels, ELCKAudioChannel Source)
       {
           // Process audio...
       }
   );
   
   // After (v1.0) — multicast delegate, 4 params (added SampleRate)
   // OnAudioDataDelegate is now FOnRenderAudioDelegate (typedef for FDelegateRenderAudio::FDelegate)
   // You must use multicast binding via the parent delegate
   AudioSource->OnAudioDataDelegate.BindLambda(
       [](TArrayView<const float> PCM, int32 Channels, int32 SampleRate, ELCKAudioChannel Source)
       {
           // Process audio — SampleRate is now available directly
       }
   );
   
   Even though FOnRenderAudioDelegate still exists as a typedef, your lambda must accept four parameters or it will not compile. Update all audio delegate bindings to include int32 SampleRate as the third parameter.
2. bEnableStreaming added to developer settings — Streaming is disabled by default A new bEnableStreaming setting has been added to ULCKDeveloperSettings. When false (the default), RTMP streaming libraries are not packaged and streaming API calls return LCK_STREAMING_NOT_AVAILABLE.
   // Enable streaming in Project Settings > Plugins > LCK SDK > Features
   // Or set directly:
   ULCKDeveloperSettings* Settings = ULCKDeveloperSettings::Get();
   Settings->bEnableStreaming = true;
   
   If you do not need streaming, leave this disabled to reduce APK size. The streaming .so/.dll files will not be included in the build.
3. AcquireEncoder() / ReleaseEncoder() added — New encoder lifecycle management ULCKRecorderSubsystem now uses reference-counted encoder ownership. Recording and streaming can share the same encoder instance. If you call StartRecording() / StopRecording() through ULCKService, this is handled automatically. Only update if you use the recorder subsystem directly.
   ULCKRecorderSubsystem* Recorder = GetWorld()->GetSubsystem<ULCKRecorderSubsystem>();
   
   // Acquire encoder (ref count +1)
   // bNeedsDisk: true if you need MP4 file output
   // Optional overrides for video/audio bitrate
   bool bSuccess = Recorder->AcquireEncoder(/*bNeedsDisk=*/ true);
   
   // ... use encoder for recording or streaming ...
   
   // Release encoder (ref count -1, encoder destroyed when count reaches 0)
   // bSaveFile: true to finalize MP4 and copy to gallery
   Recorder->ReleaseEncoder(/*bSaveFile=*/ true);
   
4. ILCKStreamingFeature interface added — Streaming backend contract A new modular feature interface for streaming backends. Implementations are discovered at runtime via IModularFeatures. You do not need to implement this unless you are building a custom streaming backend.
   // Check if a streaming feature is available
   auto& MF = IModularFeatures::Get();
   if (MF.IsModularFeatureAvailable(ILCKStreamingFeature::GetModularFeatureName()))
   {
       ILCKStreamingFeature& Streaming = MF.GetModularFeature<ILCKStreamingFeature>(
           ILCKStreamingFeature::GetModularFeatureName());
   
       Streaming.OnStreamStartedDelegate.AddLambda([]() {
           UE_LOG(LogLCK, Log, TEXT("Stream started"));
       });
   
       Streaming.StartLogin();
   }
   
5. ILCKPacketSink interface added — Packet routing contract Encoders can now route encoded H.264/AAC packets to arbitrary sinks (RTMP streams, network transports, etc.) via ILCKPacketSink. You do not need to implement this unless you are building a custom packet consumer.
   // Register a custom packet sink with the encoder
   Encoder->AddPacketSink(MyCustomSink);
   
   // ILCKPacketSink methods you must implement:
   // Open(), OnVideoFormatReady(), OnAudioFormatReady(),
   // SendVideoPacket(), SendAudioPacket(), Close(), IsOpen()
   
6. ELCKStreamingState enum added — UI must handle streaming states If you build custom UI, you must handle the new streaming states:
   // ELCKStreamingState values:
   // Idle      — No streaming activity
   // Pairing   — Waiting for pairing code entry
   // Paired    — Authenticated, ready to stream
   // Streaming — Live stream active
   // Error     — Stream error occurred
   
7. ELCKTabletMode enum added — Camera/Stream mode switching The tablet now supports two modes. Custom UI must handle mode switching:
   // ELCKTabletMode values:
   // Camera — Recording mode (default, same as v0.9.2 behavior)
   // Stream — Live streaming mode
   
8. Plugin version bumped to 1.0 — All .uplugin files updated Update any version checks or minimum-version guards in your build scripts.

• Live Streaming — RTMP streaming support via LCKStreaming module
• Encoder Sharing — Recording and streaming can share a single encoder instance
• Packet Sink Architecture — Extensible encoded packet routing
• Streaming UI — Tablet mode switching between Camera and Stream
• Hub Integration — LaunchHub() and IsHubInstalled() for LIV Hub companion app

• LCKStreaming — RTMP streaming implementation (optional, requires bEnableStreaming)
• LCKUnrealAudio — Extracted Unreal Engine audio capture (previously bundled in LCKAudio)

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0.9.2

1. FLCKMetaData.Build — Changed from int32 to FString
   // Before (v0.9.1)
   int32 BuildNumber = MetaData.Build;
   
   // After (v0.9.2)
   FString BuildString = MetaData.Build;
   
2. Mic state type — Use ELCKMicState enum instead of bool
   // Before (v0.9.1)
   bool bMicEnabled = true;
   
   // After (v0.9.2)
   ELCKMicState MicState = ELCKMicState::On;
   // Values: On, Off, No_Access
   

• PCVR Support — single implementation for PCVR and Meta Quest Standalone
• Microphone Mute Control with SetMicrophoneEnabled() API
• Audio Config Validation with editor warnings
• Debug Mode System with ILCKVisuallyDebuggable interface
• Improved Android microphone permission flow

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0.9.1

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Handling Custom Modifications

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Recommended Approach

1. Custom Blueprints — Create Blueprint subclasses of LCK actors
2. Custom Widgets — Create widget variants based on LCK widgets
3. Custom Materials — Create Material Instances, don’t modify base materials
4. Custom Scripts — Extend LCK classes in your own modules

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If You Have Modifications

1. Document all changes before upgrading
2. After upgrade, reapply changes to new version
3. Consider refactoring to use extension approach

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Troubleshooting Upgrades

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Downgrading

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Clean Installation

# 1. Remove all LCK plugins
rm -rf YourProject/Plugins/LCK*

# 2. Remove cached data
rm -rf YourProject/Intermediate
rm -rf YourProject/Binaries
rm -rf YourProject/DerivedDataCache
rm -rf YourProject/Saved/Config  # Optional: resets all settings

# 3. Install new SDK
# Extract new SDK to Plugins/

# 4. Regenerate project
# Right-click .uproject > Generate Project Files

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See Also