FPS Gradually goes down when editing performed on CMSampleBuffer

Question

I am doing a livestream where i need to send video from camera and an overlay from UIView It started working But Fps go down after some seconds. If i send CMSampleBuffer directly FPS is Ok But if convert CMSampleImage and perform editing on it FPS decreases after some seconds.

i am attaching the code below where i get CMSampleBuffer from captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection)

I am also attaching FPS graph from facebook livestream sdk.

func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
    let pts:CMTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer) as CMTime
    let newPts =  CMTimeMakeWithSeconds(CMTimeGetSeconds(pts) + 5, preferredTimescale: pts.timescale);
    let image  = self.imageFromSampleBuffer(sampleBuffer: sampleBuffer)
    let drawableRect = self.window.size.width > 800 ? CGRect(x: 73, y: 0, width: self.window.size.width - 147, height: self.window.size.height) : CGRect(x: 0, y: 0, width: self.window.size.width, height: self.window.size.height)
    let webViewImage: UIImage = self.webview.screenShotWithoutDrawHierarchy(drawableRect: drawableRect) ?? UIImage()
    let compositeImage = self.composite(image: image!, overlay: webViewImage, drawableRect: drawableRect)
    
    if #available(iOS 13, *){
        let newSampleBuffer = compositeImage?.createCMSampleBuffer(presentationTimeStamp: newPts, duration:CMTime.invalid, decodeTimeStamp: sampleBuffer.decodeTimeStamp)
        self.rtmpStream.appendSampleBuffer(newSampleBuffer!, withType: .video)
    }
}
func composite(image:UIImage, overlay:(UIImage), scaleOverlay: Bool = false, drawableRect:CGRect)->UIImage?{
    UIGraphicsBeginImageContext(drawableRect.size)
    image.draw(in: drawableRect)
    UIColor(red: 0, green: 0, blue: 0, transparency: 0)?.setFill()
    overlay.draw(in: drawableRect)
    let newimage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return newimage
}

private func imageFromSampleBuffer(sampleBuffer: CMSampleBuffer) -> UIImage? {
    guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return nil }
    let ciImage = CIImage(cvPixelBuffer: imageBuffer)
    return self.convert(cmage:ciImage)
}

// Convert CIImage to UIImage
func convert(cmage: CIImage) -> UIImage {
     let context = CIContext(options: nil)
     let cgImage = context.createCGImage(cmage, from: cmage.extent)!
     let image = UIImage(cgImage: cgImage)
     return image
}

// clean up AVCapture
func stopCamera(){
    session.stopRunning()
}
}



extension UIImage {
    var cvPixelBuffer: CVPixelBuffer? {
        let attrs = [
            String(kCVPixelBufferCGImageCompatibilityKey): kCFBooleanTrue,
            String(kCVPixelBufferCGBitmapContextCompatibilityKey): kCFBooleanTrue
            ] as [String: Any]
        var buffer: CVPixelBuffer?
        let window = UIApplication.shared.keyWindow!
        let drawableRect = window.size.width > 800 ? CGRect(x: 73, y: 0, width: window.size.width - 147, height: window.size.height) : CGRect(x: 0, y: 0, width: window.size.width, height: window.size.height)
        let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(drawableRect.size.width), Int(drawableRect.size.height), kCVPixelFormatType_32ARGB, attrs as CFDictionary, &buffer)
        guard status == kCVReturnSuccess else {
            return nil
        }

    CVPixelBufferLockBaseAddress(buffer!, CVPixelBufferLockFlags(rawValue: 0))
    let pixelData = CVPixelBufferGetBaseAddress(buffer!)

    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
    let context = CGContext(data: pixelData, width: Int(window.size.width), height: Int(window.size.height), bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(buffer!), space: rgbColorSpace, bitmapInfo: CGImageAlphaInfo.noneSkipFirst.rawValue)

    context?.translateBy(x: 0, y: window.size.height)
    context?.scaleBy(x: 1.0, y: -1.0)
    let newRect = CGRect(x: 0, y: 0, width: window.size.width, height: window.size.height)
    UIGraphicsPushContext(context!)
    UIColor.clear.setFill()
    UIRectFill(newRect)
    self.draw(in: newRect)
    UIGraphicsPopContext()
    CVPixelBufferUnlockBaseAddress(buffer!, CVPixelBufferLockFlags(rawValue: 0))

    return buffer
}
   
func createCMSampleBuffer(presentationTimeStamp: CMTime, duration:CMTime, decodeTimeStamp:CMTime ) -> CMSampleBuffer? {
        let pixelBuffer = cvPixelBuffer
        var newSampleBuffer: CMSampleBuffer?
        var info = CMSampleTimingInfo()
        var videoInfo: CMVideoFormatDescription?
        info.presentationTimeStamp = presentationTimeStamp
        info.duration = duration
        info.decodeTimeStamp = CMTime.invalid
        CMVideoFormatDescriptionCreateForImageBuffer(allocator: nil, imageBuffer: pixelBuffer!, formatDescriptionOut: &videoInfo)
        CMSampleBufferCreateForImageBuffer(allocator: kCFAllocatorDefault,
                                           imageBuffer: pixelBuffer!,
                                           dataReady: true,
                                           makeDataReadyCallback: nil,
                                           refcon: nil,
                                           formatDescription: videoInfo!,
                                           sampleTiming: &info,
                                           sampleBufferOut: &newSampleBuffer)
        return newSampleBuffer!
    }

}

Note: I am using Hashinkit but with my custom camera preview layer not attaching it to MTHKView becuase with view and camera both usage its getting heat warnings on Hashinkit