Record Last 30 Seconds (Instant Replay)

Scenario: Continuously record the last 30 seconds. When player presses a key, save those 30 seconds.

Solution

cpp

// Start circular buffer recording
void AGameMode::BeginPlay()
{
    Super::BeginPlay();
    
    URuntimeVideoRecorder* Recorder = GEngine->GetEngineSubsystem<URuntimeVideoRecorder>();
    if (Recorder)
    {
        FRuntimeEncoderSettings Settings;
        Settings.VideoBitrate = 20000000;
        
        // LastSecondsToRecord = 30.0f enables circular buffer
        Recorder->StartRecording(
            TEXT("%auto%"),
            30,              // 30 FPS
            1920, 1080,
            Settings,
            true,            // Record UI
            true,            // Enable audio
            false,           // Frame rate dependent
            false,           // Auto capture
            30.0f,           // ← Circular buffer: last 30 seconds
            false,           // On-the-fly encoding
            nullptr          // All audio
        );
        
        UE_LOG(LogTemp, Log, TEXT("Circular buffer recording started (last 30 seconds)"));
    }
}

// Save replay when player does something cool
void AMyCharacter::OnKillEnemy()
{
    URuntimeVideoRecorder* Recorder = GEngine->GetEngineSubsystem<URuntimeVideoRecorder>();
    if (Recorder && Recorder->IsRecordingInProgress())
    {
        // Stop recording - this saves the last 30 seconds
        Recorder->StopRecording_NativeAPI();
        
        UE_LOG(LogTemp, Log, TEXT("Saved last 30 seconds as replay!"));
        
        // Start recording again for next replay
        FTimerHandle TimerHandle;
        GetWorld()->GetTimerManager().SetTimer(TimerHandle, [this]()
        {
            // Restart circular buffer recording after previous one finishes
            AGameMode* GM = Cast<AGameMode>(GetWorld()->GetAuthGameMode());
            if (GM)
            {
                GM->BeginPlay(); // Restart recording
            }
        }, 2.0f, false);
    }
}

Key Point: With LastSecondsToRecord = 30.0f, RVR continuously records but only keeps the most recent 30 seconds in memory. When you stop, it saves those 30 seconds.

Record Last 30 Seconds (Instant Replay) ​

Solution ​

See Also ​

Record Last 30 Seconds (Instant Replay)

Solution

See Also