如何在 PlaybackTransportControlGlue android TV 上动态更改字幕

Posted 2023-04-15

【中文标题】如何在 PlaybackTransportControlGlue android TV 上动态更改字幕

【英文标题】：How to change subtile dynamically on PlaybackTransportControlGlue android TV

【发布时间】：2021-08-26 06:41:19

【问题描述】：

我正在为 android TV 构建一个视频播放器应用。我正在使用 https://developer.android.com/training/tv/playback/transport-controls 中解释的 Exoplayer 依赖依赖项。 到目前为止，我已经能够显示静态的视频标题，但我需要显示一个动态的字幕，它会随着视频播放的变化而变化。我该怎么做？ 下图显示了视频播放器的外观。我使用了一个字幕短语作为它应该出现的位置的占位符。

【参考方案1】：

我能够解决问题。我在 VideoSupportFragment 类 Player.EventListener 中添加了一个侦听器。 这样：

class VideoFragment(mediaItems: Map<String, Any>) : VideoSupportFragment(), Player.EventListener 
private var playerAdapter: ExoPlayerAdapter? = null
private var _mediaItems: Map<String, Any>? = null
private lateinit var mMediaPlayerGlue: VideoMediaPlayerGlue<ExoPlayerAdapter>
private var mItems: List<*>? = null

init 
    _mediaItems = mediaItems


private val mHost: VideoSupportFragmentGlueHost = VideoSupportFragmentGlueHost(this)
private fun playWhenReady(glue: PlaybackGlue) 
    if (glue.isPrepared) 
        glue.play()
     else 
        glue.addPlayerCallback(object : PlaybackGlue.PlayerCallback() 
            override fun onPreparedStateChanged(glue: PlaybackGlue) 
                if (glue.isPrepared) 
                    glue.removePlayerCallback(this);
                    glue.play()
                
            
        )
    



override fun onCreate(savedInstanceState: Bundle?) 
    super.onCreate(savedInstanceState)
    val mediaSource = _mediaItems?.get("media_source") as Map<*, *>
    playerAdapter = ExoPlayerAdapter(activity!!, _mediaItems!!)
    mMediaPlayerGlue =
        VideoMediaPlayerGlue(activity, playerAdapter!!)
    mMediaPlayerGlue.host = mHost;
    mMediaPlayerGlue.isControlsOverlayAutoHideEnabled = true
    mItems = mediaSource["media_items"] as List<*>
    mMediaPlayerGlue.title = mediaSource["title"] as CharSequence?

    mMediaPlayerGlue.playerAdapter.setDataSource()
    mMediaPlayerGlue.isSeekEnabled = true
    playerAdapter?.player?.addListener(this);

    playWhenReady(mMediaPlayerGlue)


override fun onPause() 
    super.onPause()
    playerAdapter?.player?.pause()


override fun onResume() 
    super.onResume()
    playerAdapter?.player?.play()


override fun onDestroy() 
    super.onDestroy()
    playerAdapter?.player?.removeListener(this);


override fun onMediaItemTransition(mediaItem: MediaItem?, reason: Int) 
    if (mItems?.size!! > 1)
        val item : Map<*, *> = mItems!![playerAdapter?.player?.currentWindowIndex!!] as Map<*, *>
        mMediaPlayerGlue.subtitle = item["subtitle"] as String