获取本地视频，网络视频的第一帧图片，并显示出来

new Thread(new Runnable() {
    @Override
    public void run() {
        MediaMetadataRetriever mediaMetadataRetriever = new MediaMetadataRetriever();
        Bitmap bitmap = null;
        try {
            HashMap<String, String> params = new HashMap<>();
            params.put("Accept-Encoding", "gzip, deflate, sdch");
            params.put("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
            mediaMetadataRetriever.setDataSource(mediaPlayer.getCurrentURI().toString(), params);
            // 获取图片
            bitmap = mediaMetadataRetriever.getFrameAtTime(currentPlayPosition, MediaMetadataRetriever.OPTION_NEXT_SYNC);
            //将图片保持到相册中
            saveBitmapToGallery(bitmap);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            mediaMetadataRetriever.release();
            if (bitmap != null) {
                bitmap.recycle();
            }
        }
    }
}).start();