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Module: LCKVivox | Version: 1.0 | Platforms: All

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Overview

LCKVivox integrates with the Vivox voice chat SDK to capture both outgoing microphone audio and incoming voice chat audio. It uses Vivox’s audio callbacks and thread-safe atomics for lock-free data handoff between the Vivox audio thread and the game thread.

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Supported Channels

ChannelSupportedDescription
GameYesIncoming voice chat audio (mapped from Vivox render callback)
MicrophoneYesOutgoing mic audio (mapped from Vivox capture callback)
VoiceChatNoNot used — Vivox audio mapped to Game/Microphone channels

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FLCKVivoxSource

Audio source class that captures microphone and voice chat audio through Vivox SDK callbacks. Implements ILCKFeatureInstance with dual-channel support. 
class FLCKVivoxSource : public ILCKFeatureInstance
{
public:
    // ILCKFeatureInstance interface
    virtual bool StartCapture() noexcept override;
    virtual bool StartCapture(TLCKAudioChannelsMask Channels) noexcept override;
    virtual void StopCapture() noexcept override;
    virtual float GetVolume() const noexcept override;
    virtual const FString& GetSourceName() const noexcept override;

protected:
    TLCKAudioChannelsMask CaptureChannels =
        ELCKAudioChannel::Game | ELCKAudioChannel::Microphone;
};

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ILCKFeatureInstance Methods

MethodBehavior
StartCapture()Registers Vivox capture and render callbacks for mic and voice chat
StartCapture(Channels)Registers callbacks for the specified channel mask only
StopCapture()Unregisters all Vivox callbacks and stops capture
GetVolume()Returns current RMS volume across active channels (0.0-1.0)
GetSourceName()Returns "LCKVivox"

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Thread Safety

FLCKVivoxSource uses atomic operations for lock-free data exchange between threads:
  • Vivox audio callbacks run on a dedicated Vivox audio thread
  • Audio data is written to an atomic buffer by the callback
  • The game thread reads from the atomic buffer when StereoMix is called
  • No mutex contention on the audio hot path
// Internal threading model (simplified)
// Vivox thread: writes PCM data via atomic swap
// Game thread:  reads PCM data via atomic swap
// No locks on the audio path

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FLCKVivoxModule

Module that manages the lifecycle of FLCKVivoxSource. 
class FLCKVivoxModule : public IModuleInterface
{
public:
    virtual void StartupModule() override;
    virtual void ShutdownModule() override;

private:
    TSharedPtr<FLCKVivoxSource> FeatureInstance;
};

IMPLEMENT_MODULE(FLCKVivoxModule, LCKVivox)
On startup, the module creates an FLCKVivoxSource and registers it as a modular feature. On shutdown, it unregisters Vivox callbacks, unregisters the modular feature, and destroys the source.
LCKVivox requires the Vivox plugin to be installed and configured in your project. The module will not load if the Vivox SDK is unavailable.

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Log Category

DECLARE_LOG_CATEGORY_EXTERN(LogLCKVivox, Log, All);

Audio Overview

Audio system API overview

ILCKFeatureInstance

Full interface specification