val isAvailable = textureView?.isAvailable ?: false
        if (cameraDevice == null || !isAvailable) return@launch

        try {
            closePreviewSession()
            setUpMediaRecorder()
            val texture = textureView?.surfaceTexture.apply {
            this!!.setDefaultBufferSize(previewSize.width,
                   previewSize.height)
            }

        // Set up Surface for camera preview and MediaRecorder
            val previewSurface = Surface(texture)
            val recorderSurface = mediaRecorder!!.surface
            val surfaces = ArrayList<Surface>().apply {
                add(previewSurface)
                add(recorderSurface)
            }
            previewRequestBuilder =
           cameraDevice!!.createCaptureRequest(TEMPLATE_RECORD).apply {
                addTarget(previewSurface)
                addTarget(recorderSurface)
            }

  // Start a capture session
 // Once the session starts, we can update the UI and start recording
            cameraDevice?.createCaptureSession(
                    surfaces,
                    object : CameraCaptureSession.StateCallback() {
                    override fun onConfigured(cameraCaptureSession:
                    CameraCaptureSession) {
                            captureSession = cameraCaptureSession
                            updatePreview()
                            isRecordingVideo = true
                            mediaRecorder?.start()

                        }

                        override fun
      onConfigureFailed(cameraCaptureSession: CameraCaptureSession) {
                            if (activity != null) showToast("Failed")
                        }
                    }, backgroundHandler
            )
        } catch (e: CameraAccessException) {
            Log.e(TAG, e.toString())
        } catch (e: IOException) {
            Log.e(TAG, e.toString())
        }