Video thumbnail arrayadopter is slow on scroll - 【StackMirror】|android|video|thumbnails|android-arrayadapter

I have created an adopter to display images thumbnail of video form the specific folder but when I scroll it lags a little but why is that?

Below is the code:

Main activity class

public class TestvideolistingActivity extends ListActivity {

    String filename = null;
    String filePath = null;
    String dirNameSlash = "/videotest/";
    String dirName = "videotest";
    String path = Environment.getExternalStorageDirectory() + dirNameSlash ;
    String[] values;
    String deleteFile ;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // getting the own adapter
        getInit();
    }

    @Override
    protected void onResume() {
        getInit();
        super.onResume();
    }
    public void getInit() {

        deleteFile = null;
        values = getFilesArrayFromSdCard();
        setListAdapter(new MyAdapter(this, values));
    }

    protected void onListItemClick(ListView l, View v, int position, long id) {
        String item = (String) getListAdapter().getItem(position);
        Intent intentToPlayVideo = new Intent(Intent.ACTION_VIEW);
        intentToPlayVideo.setDataAndType(Uri.parse(path + item), "video/*");
        startActivity(intentToPlayVideo);
    }

    public String[] getFilesArrayFromSdCard() {
        String[] fileList = null;
        File videoFiles = new File(path);
        if (videoFiles.isDirectory()) {
            fileList = videoFiles.list();
        }
        return fileList;
    }
}

this the adopter class which show;s the text and the thumbnail 



public class MyAdapter extends ArrayAdapter<String> {

    private final Activity context;
    private final String[] names;
    private String filePath = null;
    private Bitmap bmThumbnail;

    private String dateFormat = "dd/MM/yyyy HH:mm:ss";
    private SimpleDateFormat formatter;
    private String filename;
    String dirNameSlash = "/videotest/";

    static class ViewHolder {
        // value for the name of the file
        public TextView text;
        // video file thumbnail
        public ImageView image;
    }

    public MyAdapter(Activity context, String[] names) {
        super(context, R.layout.rowlayout, names);
        this.context = context;
        this.names = names;
        filePath = Environment.getExternalStorageDirectory() + dirNameSlash;
        formatter = new SimpleDateFormat(dateFormat);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View rowView = convertView;
        if (rowView == null) {
            LayoutInflater inflater = context.getLayoutInflater();
            rowView = inflater.inflate(R.layout.rowlayout, null);
            ViewHolder viewHolder = new ViewHolder();
            viewHolder.text = (TextView) rowView.findViewById(R.id.label);
            viewHolder.image = (ImageView) rowView.findViewById(R.id.icon);
            rowView.setTag(viewHolder);
        }

        ViewHolder holder = (ViewHolder) rowView.getTag();
        // Video file name
        String s = names[position];

        holder.text.setText(s);

        bmThumbnail = ThumbnailUtils.createVideoThumbnail(filename, Thumbnails.MICRO_KIND);
        holder.image.setImageBitmap(bmThumbnail);

        return rowView;
    }
}

This is the error by using Akhil code

    04-04 18:09:59.078: E/AndroidRuntime(10625): FATAL EXCEPTION: main
04-04 18:09:59.078: E/AndroidRuntime(10625): java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
04-04 18:09:59.078: E/AndroidRuntime(10625):    at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:257)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at java.util.ArrayList.get(ArrayList.java:311)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at com.koders.testvideolisting.MyPerformanceArrayAdapter.getView(MyPerformanceArrayAdapter.java:111)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.AbsListView.obtainView(AbsListView.java:1315)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.ListView.makeAndAddView(ListView.java:1727)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.ListView.fillDown(ListView.java:652)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.ListView.fillFromTop(ListView.java:709)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.ListView.layoutChildren(ListView.java:1580)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.AbsListView.onLayout(AbsListView.java:1147)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.view.View.layout(View.java:7034)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.view.View.layout(View.java:7034)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1249)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1125)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1042)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.view.View.layout(View.java:7034)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.view.View.layout(View.java:7034)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.view.ViewRoot.performTraversals(ViewRoot.java:1049)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.view.ViewRoot.handleMessage(ViewRoot.java:1744)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.os.Looper.loop(Looper.java:144)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at android.app.ActivityThread.main(ActivityThread.java:4937)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at java.lang.reflect.Method.invokeNative(Native Method)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at java.lang.reflect.Method.invoke(Method.java:521)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-04 18:09:59.078: E/AndroidRuntime(10625):    at dalvik.system.NativeStart.main(Native Method)

2012-04-04 05:07
by Iori

check the modified code in answe - Akhil 2012-04-04 15:04

The listview is lagging because you are creating new Thumbnails in getView() every time. There is just no caching or re-use. As the use scrolls up/down , getView() is called and time consuming process of creating thumbnails happen, hence the lag. You will also run Out of Memory soon.

Create and keep an Array of Bitmaps, with the same length as the number of elements in the datasource and store your thumbnails in the array. Take out the bitmap from the array for that particular position inside getView(). This should considerably increase the performance.

EDIT I have added a Hasmap of bitmaps to demonstrate the re-use.

 public MyAdapter(Activity context, String[] names) {
    super(context, R.layout.rowlayout, names);
    this.context = context;
    this.names = names;
    filePath = Environment.getExternalStorageDirectory() + dirNameSlash;
    formatter = new SimpleDateFormat(dateFormat);
cacheBitmap = new HashMap<String, Bitmap>(names.length);
initCacheBitmap();
}

private void initCacheBitmap() {
    for(String string:names)
        cacheBitmap.put(string, ThumbnailUtils.createVideoThumbnail(filePath+string, Thumbnails.MICRO_KIND));

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View rowView = convertView;
    if (rowView == null) {
        LayoutInflater inflater = context.getLayoutInflater();
        rowView = inflater.inflate(R.layout.rowlayout, null);
        ViewHolder viewHolder = new ViewHolder();
        viewHolder.text = (TextView) rowView.findViewById(R.id.label);
        viewHolder.image = (ImageView) rowView.findViewById(R.id.icon);
        rowView.setTag(viewHolder);
    }

    ViewHolder holder = (ViewHolder) rowView.getTag();
    // Video file name
    String s = names[position];

    holder.text.setText(s);


    holder.image.setImageBitmap(cacheBitmap.get(s));

    return rowView;
}}

2012-04-04 05:49
by Akhil

@stema I wrote that because some new users don't accept even correct answers, or don't know they have to. I have seen this happen. I have put that "if the answers is correct ", so begging is not what it is. Anyway, thanks for your opinion - Akhil 2012-04-04 07:06

Sorry buddy ur code did not work, i am think if i use ayncTask maybe that will work - Iori 2012-04-04 11:45

u got any errors? or there was no performance gain - Akhil 2012-04-04 11:51

plz check the error above, i cannot add it her - Iori 2012-04-04 13:17

HI, please check the edited code. I have tested it and it works now. I have made some change - Akhil 2012-04-04 14:55

Thanks @Akhil, it really i was working on AsyncTask, the code was twice much more and it has errors, will thankx agian : - Iori 2012-04-04 15:26

One question, u are calling initCacheBitmap() when the arrayadopter is called, if the video files are more than 1000 then do u think this code will work, little worried dont i put stress on the mobil - Iori 2012-04-04 15:29

you can put a max limit on the hashmap size. And if the size exceeds, start calling bitmap.recycle() on the new bitmaps which you are not storing and are getting out of screen. Also you can later create and store thumbnails on sdcard beforehand and just read them back - Akhil 2012-04-04 17:08

Don't forget to declare HashMap cacheBitmap - CGR 2017-10-17 21:54

Since you are creating Thumnail for video inside getView() it slow down your scrolling.

So you have to save your bitmap in Arrarys and list it i scroll.. Try this Sample for this will really helps you for fast scrolling. This Sample includes images , you have to change for Video in Media Content Providers. Fast Scroll Sample

2012-04-04 06:07
by Venky