Android MediaCodec encoding + camera2 how to create a black screen for pause and resume

I have created a surface with the MediaCodec and added it as a target to the camera2 api. Now I want to sometime pause the MediaCodec encoding and then resume it. What I expect is the encoded video to become black when I pause and continue when I resume. Using MediaCodec.PARAMETER_KEY_SUSPEND doesn't do the job since the output is a frozen frame, and if the paused happens at the beginning of encoding the time starts when I resume. So I was thinking of feeding the encoder with black image, but how can I draw on the surface? Thanks!

Edit: Here is some of the code I use to make the camera2 work with MediaCodec.

1. I create a simple MediaCodec:

   try {
       mediaCodec =
           MediaCodec.createEncoderByType(mime)
       Logger.d(TAG, "MediaCodec info " + mediaCodec.codecInfo.name)
   
   
   } catch (e: IOException) {
       e.printStackTrace()
   }
   mediaCodec.configure(mediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE)
   
   val inputSurface = mediaCodec.createInputSurface() //<-- this is passed to the camera2
   

2. I add the surface to the camera:

   captureRequestBuilder.addTarget(inputSurface);
   List<Surface> surfaceList = new ArrayList<>();
           surfaceList.add(cameraFrame.getSurface());
           surfaceList.add(inputSurface);
   
           camera.createCaptureSession(
                   surfaceList,
                   captureSessionObserver,
                   cameraThreadHandler
           );
   

And then in a loop I read the mediaCodec output buffers and write them into a muxer.