MediaMetadataretriver getFrameAtTıme is not working

Question

if (requestCode == SELECT_CODE && data != null) {
        Uri uri = data.getData();
        if (uri != null) {

               nwretriver = new MediaMetadataRetriever();
            try {
                nwretriver.setDataSource(getApplicationContext(), uri);
            } finally {
            }

               String duraiton                                                                                                                                                                                                                             
                      =nwretriver.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);

            assert duraiton != null;

               int time = Integer.parseInt(duraiton);
               int period = 1000000; 

               int len =  time / period;

               List<Bitmap> frames =  new ArrayList<>();


            for(int i = 0; i<len; i++){
                Bitmap frame = nwretriver.getFrameAtTime(i *  
                period,MediaMetadataRetriever.OPTION_CLOSEST); 
                if (frame != null) {
                    frames.add(frame);
                } else {
                    Log.e("Frame extraction", "Frame at time " + i * period + " is null");
                }
            }

            Toast.makeText(this, ""+frames.isEmpty(), Toast.LENGTH_LONG).show();
            try {
                nwretriver.release();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }


            
            for(Bitmap frame: frames) {

               
            
              
                frames.add(resultBitmap);
            }





          

            try {
                MediaItem mediaItem1 = MediaItem.fromUri(uri);
                player.setMediaItem(mediaItem1);
                player.prepare();
                player.play();
            } catch (Exception e) {
                Log.e("ExoPlayer", "Error playing video:", e);
                
            }
        }
    }
}

I am having problems witht the getFrameAtTime ı tried to upload a video from the gallery extract the frames out of it put the frames to a arraylist then display the video but when ı apply a toast message after the frame exctraction and it says frame arraylist is empty how can ı make this works does anyone know ?