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Module: LCKCore | Version: 0.9.2 | Platforms: Windows, Android

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Overview

The LCK Core plugin provides the fundamental recording infrastructure including video encoding, audio mixing, and scene capture management. It serves as the foundation for all other LCK plugins.

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Key Components

ULCKRecorderSubsystem

World subsystem managing the recording lifecycle, frame capture, and encoder coordination

ILCKEncoder

Platform-specific video encoder interface with hardware acceleration

FLCKAudioMix

Multi-source audio mixer aggregating all registered audio sources

ILCKAudioSource

Modular audio source interface for game audio, microphone, and voice chat

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Architecture

┌─────────────────────────────────────────────────────────┐
│                 ULCKRecorderSubsystem                   │
│              (World Subsystem - Tick)                   │
├─────────────────────────────────────────────────────────┤
│  ┌─────────────────┐      ┌─────────────────┐          │
│  │ SceneCapture    │      │  FLCKAudioMix   │          │
│  │   Component     │      │  (Audio Mixer)  │          │
│  └────────┬────────┘      └────────┬────────┘          │
│           │                        │                    │
│           ▼                        ▼                    │
│  ┌─────────────────────────────────────────────┐       │
│  │              ILCKEncoder                     │       │
│  │    (Platform-Specific Implementation)        │       │
│  └─────────────────────────────────────────────┘       │
└─────────────────────────────────────────────────────────┘
                            │
            ┌───────────────┴───────────────┐
            ▼                               ▼
┌───────────────────────┐      ┌───────────────────────┐
│   FLCKWindowsEncoder  │      │   FLCKAndroidEncoder  │
│  (Media Foundation)   │      │    (MediaCodec)       │
└───────────────────────┘      └───────────────────────┘

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Recording Workflow

1

Setup

Configure recording parameters (resolution, bitrate, framerate)
2

Register Capture

Register a SceneCaptureComponent2D as the video source
3

Start Recording

Initialize encoder and begin frame capture
4

Capture Loop

Each tick: capture frame, mix audio, encode data
5

Stop Recording

Finalize encoding and save to file

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Supported Formats

ComponentFormatDetails
VideoH.264 (AVC)Hardware-accelerated, Baseline to High profile
AudioAAC-LC44.1/48 kHz, stereo
ContainerMP4Standard fragmented MP4

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Quick Example

#include "LCKRecorderSubsystem.h"

void AMyRecorder::SetupRecording()
{
    ULCKRecorderSubsystem* Recorder = GetWorld()->GetSubsystem<ULCKRecorderSubsystem>();

    // Configure parameters
    FLCKRecorderParams Params;
    Params.Width = 1920;
    Params.Height = 1080;
    Params.Framerate = 30;
    Params.VideoBitrate = 8 << 20;  // 8 Mbps
    Params.AudioBitrate = 256 << 10; // 256 Kbps
    Params.Samplerate = 48000;

    // Setup with scene capture component
    Recorder->SetupRecorder(Params, MySceneCaptureComponent);

    // Start recording
    Recorder->StartRecording();
}

void AMyRecorder::StopRecording()
{
    ULCKRecorderSubsystem* Recorder = GetWorld()->GetSubsystem<ULCKRecorderSubsystem>();
    Recorder->StopRecording();
}

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Log Categories

DECLARE_LOG_CATEGORY_EXTERN(LogLCK, Log, All);
DECLARE_LOG_CATEGORY_EXTERN(LogLCKEncoding, Log, All);
Enable verbose logging with LogLCK=VeryVerbose and LogLCKEncoding=VeryVerbose in your DefaultEngine.ini for debugging.

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Next Steps

Recording

Recording system details

Encoding

Encoder implementation

API Reference

Complete API documentation