> ## Documentation Index
> Fetch the complete documentation index at: https://docs.liv.tv/llms.txt
> Use this file to discover all available pages before exploring further.

# Core SDK API Reference

> Complete API reference for the LIV Camera Kit (LCK) Core module in Unreal Engine, including ULCKRecorderSubsystem, ILCKEncoder, ILCKAudioSource, structs, enums, and delegates.

## Classes

### ULCKRecorderSubsystem

<ResponseField name="ULCKRecorderSubsystem" type="class">
  World subsystem managing video recording lifecycle.

  **Parent:** `UTickableWorldSubsystem`

  **Module:** `LCKCore`
</ResponseField>

#### Properties

| Property           | Type                        | Access            | Description           |
| ------------------ | --------------------------- | ----------------- | --------------------- |
| `CaptureComponent` | `USceneCaptureComponent2D*` | BlueprintReadOnly | Active scene capture  |
| `RenderTarget`     | `UTextureRenderTarget2D*`   | BlueprintReadOnly | Capture render target |

#### Methods

| Method                             | Return  | Description            |
| ---------------------------------- | ------- | ---------------------- |
| `SetupRecorder(Params, Component)` | `void`  | Initialize recorder    |
| `StartRecording()`                 | `bool`  | Begin recording        |
| `StopRecording()`                  | `bool`  | Stop recording         |
| `TakePhoto()`                      | `bool`  | Capture single frame   |
| `StartPreview()`                   | `void`  | Start preview mode     |
| `StopPreview()`                    | `void`  | Stop preview mode      |
| `IsRecording()`                    | `bool`  | Check recording state  |
| `GetTime()`                        | `float` | Get recording duration |
| `GetMicrophoneVolume()`            | `float` | Get mic level (0-1)    |
| `SetMicrophoneEnabled(bool)`       | `void`  | Enable/disable mic     |
| `IsMicrophoneEnabled()`            | `bool`  | Check mic state        |

***

### ILCKEncoder

<ResponseField name="ILCKEncoder" type="interface">
  Abstract video encoder interface.

  **Module:** `LCKCore`
</ResponseField>

#### Methods

| Method                         | Return  | Description                               |
| ------------------------------ | ------- | ----------------------------------------- |
| `Open()`                       | `bool`  | Initialize encoder, allocate resources    |
| `IsEncoding()`                 | `bool`  | Check if encoder is active                |
| `EncodeTexture(Texture, Time)` | `void`  | Encode a video frame                      |
| `EncodeAudio(PCMData)`         | `void`  | Encode audio samples                      |
| `Save(ProgressCallback)`       | `void`  | Finalize and write MP4 file               |
| `GetAudioTime()`               | `float` | Get current audio timestamp               |
| `SetRecordToDisk(bRecord)`     | `void`  | Control whether encoder writes to disk    |
| `AddPacketSink(Sink)`          | `void`  | Register a packet sink for encoded output |
| `RemovePacketSink(Sink)`       | `void`  | Unregister a packet sink                  |
| `GetNativeEncoderHandle()`     | `void*` | Get native encoder handle (Android only)  |

***

### ILCKEncoderFactory

<ResponseField name="ILCKEncoderFactory" type="interface">
  Factory for creating platform-specific encoders.

  **Interface:** `IModularFeature`, `TSharedFromThis<ILCKEncoderFactory, ESPMode::ThreadSafe>`

  **Module:** `LCKCore`
</ResponseField>

#### Methods

| Method                    | Return                                         | Description             |
| ------------------------- | ---------------------------------------------- | ----------------------- |
| `GetModularFeatureName()` | `FName`                                        | Static feature name     |
| `GetEncoderName()`        | `const FString&`                               | Encoder identifier      |
| `CreateEncoder(...)`      | `TSharedPtr<ILCKEncoder, ESPMode::ThreadSafe>` | Create encoder instance |

***

### ILCKAudioSource

<ResponseField name="ILCKAudioSource" type="interface">
  Audio source interface for modular audio capture.

  **Interface:** `IModularFeature`, `TSharedFromThis<ILCKAudioSource>`

  **Module:** `LCKAudio`
</ResponseField>

#### Properties

| Property              | Type                     | Description                           |
| --------------------- | ------------------------ | ------------------------------------- |
| `OnAudioDataDelegate` | `FOnRenderAudioDelegate` | Audio data callback (single delegate) |

**Protected Members:**

| Property            | Type                    | Description                                          |
| ------------------- | ----------------------- | ---------------------------------------------------- |
| `SupportedChannels` | `TLCKAudioChannelsMask` | Supported channel mask (set in subclass constructor) |

#### Methods

| Method                   | Return                  | Description             |
| ------------------------ | ----------------------- | ----------------------- |
| `StartCapture()`         | `bool`                  | Start all channels      |
| `StartCapture(Channels)` | `bool`                  | Start specific channels |
| `StopCapture()`          | `void`                  | Stop capture            |
| `GetVolume()`            | `float`                 | Current volume (0-1)    |
| `GetSourceName()`        | `const FString&`        | Source identifier       |
| `GetSupportedChannels()` | `TLCKAudioChannelsMask` | Channel mask            |

<Warning>
  `OnAudioDataDelegate` is a **single delegate**, not multicast. Use `BindLambda()` to bind and `ExecuteIfBound()` to fire.
</Warning>

***

## Structures

### FLCKRecorderParams

```cpp theme={null}
USTRUCT(BlueprintType)
struct LCKCORE_API FLCKRecorderParams
{
    GENERATED_BODY()

    UPROPERTY(Category="LCK", EditAnywhere, BlueprintReadWrite)
    int32 Width = 1920;

    UPROPERTY(Category="LCK", EditAnywhere, BlueprintReadWrite)
    int32 Height = 1080;

    UPROPERTY(Category="LCK", EditAnywhere, BlueprintReadWrite)
    int32 Framerate = 30;

    UPROPERTY(Category="LCK", EditAnywhere, BlueprintReadWrite)
    int32 VideoBitrate = 2 << 20;

    UPROPERTY(Category="LCK", EditAnywhere, BlueprintReadWrite)
    int32 Samplerate = 48000;

    UPROPERTY(Category="LCK", EditAnywhere, BlueprintReadWrite)
    int32 AudioBitrate = 256 << 10;
};
```

***

## Enumerations

### ELCKAudioChannel

```cpp theme={null}
enum ELCKAudioChannel : uint64
{
    None       = 0,           // No audio channel
    Game       = 1,           // Game audio output
    Microphone = 1 << 1,      // Microphone input
    VoiceChat  = 1 << 2,      // Voice chat audio (Vivox)
    Max        = 1 << 3       // Maximum value marker
};
```

| Value        | Bit | Description                             |
| ------------ | --- | --------------------------------------- |
| `None`       | 0   | No audio                                |
| `Game`       | 1   | Game audio, FMOD, Wwise, Vivox incoming |
| `Microphone` | 2   | Mic input, Oboe, Vivox outgoing         |
| `VoiceChat`  | 4   | Voice chat audio (used by LCKVivox)     |

***

## Delegates

### FOnLCKRecorderBoolResult

```cpp theme={null}
DECLARE_DELEGATE_OneParam(FOnLCKRecorderBoolResult, bool /*bSuccess*/);
```

### FOnLCKRecorderProgress

```cpp theme={null}
DECLARE_DELEGATE_OneParam(FOnLCKRecorderProgress, float /*Progress*/);
```

### FDelegateRenderAudio

```cpp theme={null}
DECLARE_MULTICAST_DELEGATE_FourParams(FDelegateRenderAudio,
    TArrayView<const float>/*PCM-interleaved*/,
    int32/*Channels*/,
    int32/*SampleRate*/,
    ELCKAudioChannel/*SourceChannel*/);

typedef FDelegateRenderAudio::FDelegate FOnRenderAudioDelegate;
```

***

## Type Definitions

### TLCKAudioChannelsMask

```cpp theme={null}
typedef uint64 TLCKAudioChannelsMask;

// Usage
TLCKAudioChannelsMask Channels = ELCKAudioChannel::Game | ELCKAudioChannel::Microphone;
```

***

## Log Categories

```cpp theme={null}
DECLARE_LOG_CATEGORY_EXTERN(LogLCK, Log, All);
DECLARE_LOG_CATEGORY_EXTERN(LogLCKEncoding, Log, All);
DECLARE_LOG_CATEGORY_EXTERN(LogLCKAudio, Log, All);
```