Exoplayer 2，如何检测字幕更改？

Question

我正在用ExoPlayer 2在Android上开发视频播放器
我正在寻找在SubtitleView（屏幕上部）中检测字幕更改的方法，以在TextView（屏幕下部）中自动滚动字幕<似乎没有听众这么做<我试了几个听众的字幕，但没有效果<你有什么想法吗

Answer 1

我通过简单的代码解决了这个问题。

https://github.com/yuseisako/TangoPlayer/blob/master/app/src/main/java/me/yusei/tangoplayer/VideoPlayerActivity.java#L527

scrollSubtitleRunnable = new Runnable() {

    List<Caption> subtitles = new ArrayList<>(timedTextObject.captions.values());

    @Override
    public void run() {
        if(mMediaPlayer != null && mMediaPlayer.isPlaying()){
            float currentPos = mMediaPlayer.getTime();
            int index = 0;

            for (Caption caption : subtitles) {
                if (currentPos >= caption.start.mseconds - subtitleDelay
                        && currentPos <= caption.end.mseconds - subtitleDelay) {
                    listView.setItemChecked(index,true);
                    int height = listView.getHeight();
                    listView.setSelectionFromTop(index, height/2);
                    setSubtitleTextView(caption);
                    break;
                } else {
                    setSubtitleTextView(null);
                    if(currentPos < caption.end.mseconds - subtitleDelay){
                        break;
                    }
                }
                index++;
            }
        }

        scrollSubtitleHandler.postDelayed(this, 300);
    }
};
scrollSubtitleHandler.post(scrollSubtitleRunnable);