RecyclerView очень запаздывает при прокрутке

Question

Я пытаюсь создать видеоплеер. Теперь я перестал кодировать, потому что приложение не работает, как я ожидал. Я не знаю в чем проблема. Я только начинающий в android студии. Вот мой код.

Основная активность. java:

package com.shyam.videoplayer;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.core.view.ViewCompat;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.widget.Toast;
import java.io.File;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    RecyclerView videoList;
    VideolistAdapter videolistAdapter;
    File directory;
    boolean permission=false;
    public static ArrayList<File> fileArrayList=new ArrayList<>();
    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        videoList=findViewById(R.id.videolistRecyclerView);
        directory=new File("/mnt/");
        GridLayoutManager manager=new GridLayoutManager(MainActivity.this,2);
        videoList.setLayoutManager(manager);
        permissions();
        if(permission){
            getFile(directory);
            videolistAdapter=new VideolistAdapter(getApplicationContext(),fileArrayList);
            videoList.setAdapter(videolistAdapter);
        }
    }
    private void getFile(File directory) {
        File[] file = directory.listFiles();
        if(file!=null && file.length>0){
            for (File value : file) {
                if (value.isDirectory() && !value.getName().startsWith(".")) {
                    getFile(value);
                } else {
                    permission = false;
                    if (value.getName().endsWith(".mp4") || value.getName().endsWith(".mkv") || value.getName().endsWith(".3gp")) {
                        fileArrayList.add(value);
                    }
                }
            }
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if(requestCode==1){
            if(grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED){
                Toast.makeText(this, "Permission Granted", Toast.LENGTH_SHORT).show();
                permission=true;
                getFile(directory);
                videolistAdapter=new VideolistAdapter(getApplicationContext(),fileArrayList);
                videoList.setAdapter(videolistAdapter);
            }else{
                Toast.makeText(this, "Please Allow Permissions.", Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }
    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
    private void permissions(){
        if(ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},1);
        }else {
            permission=true;
        }
    }
}

VideolistAdapter. java:

package com.shyam.videoplayer;

import android.content.Context;
import android.graphics.Bitmap;
import android.media.ThumbnailUtils;
import android.provider.MediaStore;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.io.File;
import java.util.ArrayList;

public class VideolistAdapter extends RecyclerView.Adapter<VideoHolder> {
    private Context context;
    private ArrayList<File> videoArrayList;
    VideolistAdapter(Context context, ArrayList<File> videoArrayList) {
        this.context = context;
        this.videoArrayList = videoArrayList;
    }
    @NonNull
    @Override
    public VideoHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(context).inflate(R.layout.video_list,parent,false);
        return new VideoHolder(view);
    }
    @Override
    public void onBindViewHolder(@NonNull VideoHolder holder, int position) {
        holder.filename.setText(videoArrayList.get(position).getName());
        Bitmap bitmap= ThumbnailUtils.createVideoThumbnail(videoArrayList.get(position).getPath(), MediaStore.Images.Thumbnails.MINI_KIND);
        holder.videothumbnail.setImageBitmap(bitmap);
    }
    @Override
    public int getItemCount() {
        if(videoArrayList.size()>0)
            return videoArrayList.size();
        else
            return 1;
    }
}
class VideoHolder extends RecyclerView.ViewHolder{
    TextView filename;
    ImageView videothumbnail;
    VideoHolder(View view){
        super(view);
        filename = view.findViewById(R.id.videolisttext);
        videothumbnail = view.findViewById(R.id.videolistimage);
    }
}

main_activity. xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".MainActivity">
    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:id="@+id/videolistRecyclerView"
        android:background="#000000"
        android:layout_height="wrap_content">
    </androidx.recyclerview.widget.RecyclerView>
</LinearLayout>

video_list. xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="160dp"
        app:cardElevation="3dp"
        android:layout_gravity="center"
        android:layout_margin="4dp"
        android:id="@+id/videolistcardview"
        app:cardUseCompatPadding="true">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:weightSum="5">
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="4"
                android:scaleType="centerCrop"
                android:layout_gravity="center"
                android:id="@+id/videolistimage"
                tools:ignore="ContentDescription" />
            <TextView
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:layout_margin="5dp"
                android:maxLines="1"
                android:text="@string/file_name"
                android:id="@+id/videolisttext"/>
        </LinearLayout>
    </androidx.cardview.widget.CardView>

</LinearLayout>

При использовании этого кода прокрутка очень запаздывает. пожалуйста, предложите способ решить эту проблему.