如何从R.raw文件夹中获取视频缩略图？

Question

The code below can not get the video thumbnails of videos which were located in R.raw folder.

I want to use a gallery to show the thumbnails of videos. Videos were put into R.raw folder (actually I'm new to Android, so I don't really know where to put these videos, so I put them in R.raw folder). Now I want to get the thumbnails of the videos. But someone told that thumbnails can only be got from the SD card. So is it true? And what should I do next? Thanks.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    final Gallery gallery = (Gallery) findViewById(R.id.gallery);
    final String[] videoFileList = new String[] { "R.raw.01", "R.raw.02" };

    BaseAdapter adapter = new BaseAdapter() {

        public int getCount() {
            return videoFileList.length;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView imageView = new ImageView(Select.this);
            Bitmap bmThumbnail;
            bmThumbnail = ThumbnailUtils.createVideoThumbnail("android.resource://" + getPackageName() + "/"
                    + videoFileList[position], Thumbnails.MINI_KIND);
            System.out.println(videoFileList[position]);
            imageView.setImageBitmap(bmThumbnail);
            imageView.setScaleType(ImageView.ScaleType.FIT_XY);
            TypedArray typedArray = obtainStyledAttributes(R.styleable.Gallery);
            imageView.setBackgroundResource(typedArray.getResourceId(
                    R.styleable.Gallery_android_galleryItemBackground, 0));
            return imageView;
        }
    };
    gallery.setAdapter(adapter);
    gallery.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(Select.this, Play.class);
            intent.putExtra("image", videoFileList[position]);

            startActivity(intent);
            Select.this.finish();
        }

        public void onNothingClick(AdapterView<?> parent) {
        }
    });
}

Answer 1

On Android 5, createVideoThumbnail() always returned null when asking for the thumbnail of a video in resources. Here's what worked for me in the end:

Uri videoURI = Uri.parse("android.resource://" + getActivity().getPackageName() + "/raw/animation");
MediaMetadataRetriever retriever = new MediaMetadataRetriever();              
retriever.setDataSource(getActivity().getApplicationContext(), videoURI);
Bitmap thumb = retriever.getFrameAtTime(10, MediaMetadataRetriever.OPTION_PREVIOUS_SYNC);
videoView.setBackground(new BitmapDrawable(getResources(), thumb));

Answer 2

Have you looked at, createVideoThumbnail() from ThumbnailUtils Class?

Actually, Your video files are in resource/raw directory so you have to create Thumbnails for it.

If your video files are in External Storage then Android Media Store itself creates for you. And you can get it by MediaStore.Video.Thumbnails Class.

Answer 3

Video on res/raw folder of your application isn't managed by Android Media Content Provider, so you cannot obtain their thumbnail from it.

Alternatively, you can try to save them as normal file in your SD and, then, ask to media provider for thumbnail or create it directly via ThumbnailUtils.createVideoThumbnail class (only Android 2.2 or above)