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Version: 7.1

Video modifier

The video modifier feature allows you to modify local video frames before they are transmitted. This feature enables your application to apply real-time effects, filters, or transformations to the outgoing video stream.

Supported call typeMinimum SDK version
1-to-1 call, group call (conference)PlanetKit 7.0
Note
  • The video modifier only applies to local video captured from the camera.
  • Video modification processing should be designed to minimize computational cost and latency in order to prevent frame drops and quality degradation.

Use cases​

The main use cases for video modifiers are as follows.

  • Real-time video effects and filters
  • Beauty filters and facial enhancements
  • Color correction and adjustments

Implementation steps​

To implement the video modifier feature, follow these steps.

Implement a video modifier​

Create a class that inherits from IVideoInterceptor to modify video frames.

#include "PlanetKit.h"
#include "IPlanetKitVideoInterceptor.h"

class VideoModifier : public PlanetKit::IVideoInterceptor {
public:
    PlanetKit::SVideoFrame* ProcessVideoFrame(PlanetKit::SVideoFrame* pVideoFrame) override {
        if (!pVideoFrame) {
            return nullptr;
        }

        // Access video frame properties from SVideoFrame structure:
        // - pVideoFrame->pbuffer: Pointer to the frame buffer
        // - pVideoFrame->unBufferSize: Allocated buffer size
        // - pVideoFrame->unDataLength: Actual length (in bytes) of buffer data
        // - pVideoFrame->unWidth: Frame width in pixels
        // - pVideoFrame->unHeight: Frame height in pixels
        // - pVideoFrame->llTick: Tick count in microseconds
        // - pVideoFrame->llTimeStamp: Timestamp
        // - pVideoFrame->llDuration: Frame duration
        // - pVideoFrame->eRotation: Rotation angle
        // - pVideoFrame->bSubgroupMain: Whether frame belongs to main room
        // - pVideoFrame->szSubgroupName: Subgroup name (if bSubgroupMain is false)

        // Process the frame and apply your effects
        // You can either:
        // 1. Process synchronously: Modify the frame and return the pointer
        // 2. Process asynchronously: Return nullptr and call delegate->onProcessFinished later

        // Example: Apply your custom effect synchronously
        ApplyVideoEffect(pVideoFrame);

        // Return the modified frame pointer for synchronous processing
        // Return nullptr if processing asynchronously (must register a delegate)
        return pVideoFrame;
    }

    bool RegisterDelegate(PlanetKit::IVideoInterceptorDelegate* pDelegate) override {
        m_pDelegate = pDelegate;
        return true;
    }

    bool DeregisterDelegate() override {
        m_pDelegate = nullptr;
        return true;
    }

private:
    void ApplyVideoEffect(PlanetKit::SVideoFrame* pVideoFrame) {
        // Implement your video effect logic here
        // Note: This runs on the camera capture thread, keep processing lightweight
    }

    PlanetKit::IVideoInterceptorDelegate* m_pDelegate = nullptr;
};

Set the video modifier​

Register the modifier with the camera controller to start modifying video frames.

// Get camera controller instance
PlanetKit::CameraControllerPtr pCameraController = PlanetKit::PlanetKitManager::GetInstance()->GetCameraController();

// Create and register the modifier
PlanetKit::IVideoInterceptorPtr pVideoModifier = PlanetKit::MakeAutoPtr<VideoModifier>();

bool success = pCameraController->RegisterVideoInterceptor(pVideoModifier);
if (!success) {
    // Handle error
}

Clear the video modifier​

Unregister the modifier to stop modifying video frames.

PlanetKit::CameraControllerPtr pCameraController = PlanetKit::PlanetKitManager::GetInstance()->GetCameraController();

// Deregister the modifier
bool success = pCameraController->DeregisterVideoInterceptor();
if (!success) {
    // Handle error
}

The APIs related to the video modifier feature are as follows.