createVideoThumbnail loading images slowly. How to improve performance?

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I have two GridViews that are populated with the VideoThumbnailAdapter below and another very similar adapter ImageThumbnailAdapter -- both of which call on the same AsyncThumbnailLoader with a different variable: either THREAD_VIDEO or THREAD_IMAGE.

My approach to loading thumbnails for images is from their URI using the getThumbnail(Uri) function called from doInBackground(Object...params) in AsyncThumbnailLoader . These image thumbnails are loading quite quickly; I believe this is because the Bitmap is being treated carefully in the getThumbnail(URI) function (however I am not certain of this).

For video thumbnails, I am using ThumbnailUtils.createVideoThumbnail(videoPath, MediaStore.Images.Thumbnails.MICRO_KIND) to obtain a Bitmap which is directly being passed on to the ImageView for the Adapter to use.

The problem is that the GridView is taking a lot of time to populate the thumbnails, even when the number of items is as little as 16. This is especially true for the video thumbnails, which take almost a second each to load. I have also noticed that the first four or five thumbnails load almost instantly (for images and/or video), but loading slows down after this. I am not sure where the poor performance can be improved. Optimizing the videoThumbnail bitmaps? Recycling bitmaps? Getting the videoThumbnail Uri manually? Something to do with cache? Can I clear the memory so the rest of the thumbnails load as fast as the first few? Downsampling?

I considered using http://ift.tt/Ucbphw but I have no idea where to start. Guidance would be incredibly appreciated! Thank you for taking the time.

VideoThumbnailAdapter used to populate GridView:

public class VideoThumbnailAdapter extends BaseAdapter {
    private Context mContext;
    /* Methods: constructor, getCount(), getItem(int), getItemId(int) */

    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        imageView = new ImageView(mContext);
        new AsyncThumbnailLoader(imageView, true, position, THREAD_VIDEO).execute();
        return imageView;
    }
}

The AysncTask getting the thumbnails for the Video/ImageThumbnailAdapter:

private class AsyncThumbnailLoader extends AsyncTask<Object, Void, Bitmap> {

    boolean enable_animation = false;
    private ImageView imageView;
    int position;
    String videoPath;
    int picture_video_audio;

    public AsyncThumbnailLoader(ImageView imageView, Boolean animation, int position, int picture_video_audio)
    { /* Constructor assignments to local variables */ }

    @Override
    protected void onPreExecute() {
        imageView.setLayoutParams(new GridView.LayoutParams(
                THUMBNAIL_SIZE, THUMBNAIL_SIZE));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(2, 2, 2, 2);

        if (picture_video_audio == THREAD_VIDEO) {
            Uri myUri = Uri.parse(videoURIlist[position]);
            videoPath = getRealPathFromURI(getBaseContext(), myUri);
            if (videoPath.length() == 0) {
                videoPath = myUri.getPath();
            }
    }

    @Override
    protected Bitmap doInBackground(Object... params) {
        if (picture_video_audio == THREAD_VIDEO) {
            return ThumbnailUtils.createVideoThumbnail(videoPath, MediaStore.Images.Thumbnails.MICRO_KIND);
        } else { // if (picture_video_audio == THREAD_IMAGE)
            try {
                return getThumbnail(Uri.parse(imageURIlist[position]));
            } catch (Exception e) {
                return null; // TODO Put placeholder image thumbnail
            }
        }
        return null;
    }

    @Override
    protected void onPostExecute(Bitmap result) {
        imageView.setImageBitmap(result);
    }
}

The getThumbnail(Uri) function:

    public Bitmap getThumbnail(Uri uri) throws FileNotFoundException,
        IOException {
    InputStream input = this.getContentResolver().openInputStream(uri);

    BitmapFactory.Options onlyBoundsOptions = new BitmapFactory.Options();
    onlyBoundsOptions.inJustDecodeBounds = true;
    onlyBoundsOptions.inDither = true;// optional
    onlyBoundsOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;// optional
    BitmapFactory.decodeStream(input, null, onlyBoundsOptions);
    input.close();
    if ((onlyBoundsOptions.outWidth == -1)
            || (onlyBoundsOptions.outHeight == -1))
        return null;

    int originalSize = (onlyBoundsOptions.outHeight > onlyBoundsOptions.outWidth) ? onlyBoundsOptions.outHeight
            : onlyBoundsOptions.outWidth;

    double ratio = (originalSize > THUMBNAIL_SIZE) ? (originalSize / THUMBNAIL_SIZE)
            : 1.0;

    BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
    bitmapOptions.inSampleSize = getPowerOfTwoForSampleRatio(ratio);
    bitmapOptions.inDither = true;// optional
    bitmapOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;// optional
    input = this.getContentResolver().openInputStream(uri);
    Bitmap bitmap = BitmapFactory.decodeStream(input, null, bitmapOptions);
    input.close();
    return bitmap;
}

asked 13 secs ago

Umair Saad

1