android capture video frame

The following works for me:

public static Bitmap getVideoFrame(FileDescriptor FD) {
        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
        try {
            retriever.setDataSource(FD);
            return retriever.getFrameAtTime();
        } catch (IllegalArgumentException ex) {
            ex.printStackTrace();
        } catch (RuntimeException ex) {
            ex.printStackTrace();
        } finally {
            try {
                retriever.release();
            } catch (RuntimeException ex) {
            }
        }
        return null;
    }

Also works if you use a path instead of a filedescriptor.