chromecast 接收器 <video> 元素 onEnded

Question

在我的应用程序中，用户可以在视频结束后从头重新开始。

为了实现这一点，我在自定义接收器中重写了接收器库MediaManager.onEnded() 方法，并向发送者发送自定义消息，而不是调用resetMediaElement，这是该方法的默认行为。

此时，用户点击播放按钮，发送方调用RemoteMediaPlayer.play() 方法，这将导致接收方库调用<video> 元素上的play() 方法。

但相反，接收器库发回一条消息说 INVALID REQUEST，INVALID_MEDIA_SESSSION_ID。

还有。接收器库记录了一条消息“

意外命令，播放器处于 IDLE 状态，因此媒体会话 ID 无效

但是接收方的最后一次状态更新在接收方和发送方日志中都显示播放器处于 PLAYING 状态。

这是接收者日志：

::mmOnLoad() mediacast.js:480
url: http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4 mediacast.js:498
duration: 0 mediacast.js:500
::showVideo()- message:[object Object] mediacast.js:257
url:http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4 mediacast.js:259
::fadeOutOldMediaElement() mediacast.js:384
::mmOnLoad()- presenting video from http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4, duration 0 mediacast.js:552
::fadeOutOldMediaElement0() mediacast.js:393
::videoFadedOut()- url: http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4 mediacast.js:265
::videoFadedOut()- setting media element [object HTMLVideoElement] mediacast.js:279
::removeMediaElementOrOverlay() mediacast.js:398
::removeOldMediaElement() mediacast.js:432
::removeOverlay() mediacast.js:427
 [ 40.701s] [cast.receiver.MediaManager] Metadata loaded
 cast_receiver.javascript:574
 [ 40.736s] [cast.receiver.MediaManager] Sending broadcast status message
 cast_receiver.javascript:574
>>>>>the media element state is paused mediacast.js:603
media element networkState = 2, readyState = 1 mediacast.js:605
 [ 40.802s] [cast.receiver.IpcChannel] IPC message sent: {"namespace":"urn:x-cast:com.google.cast.media","senderId":"*:*","data":"{\"type\":\"MEDIA_STATUS\",\"status\":[{\"mediaSessionId\":1,\"playbackRate\":1,\"playerState\":\"PAUSED\",\"currentTime\":0,\"supportedMediaCommands\":15,\"volume\":{\"level\":0.06666666666666667,\"muted\":false},\"media\":{\"customData\":{\"volume\":0.06666666666666667,\"pauseAfter\":true,\"pauseBefore\":true,\"rotation\":0},\"streamType\":\"BUFFERED\",\"duration\":42.4,\"contentType\":\"video/mp4\",\"contentId\":\"http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4\",\"metadata\":{\"metadataType\":1}}}],\"requestId\":1}"}
 cast_receiver.javascript:574
::videoLoaded() mediacast.js:291
::videoLoaded0() mediacast.js:302
::addVideo() mediacast.js:421
::videoLoaded1() mediacast.js:309
 [ 48.434s] [cast.receiver.IpcChannel] Received message: {"data":"{\"type\":\"PLAY\",\"requestId\":2,\"mediaSessionId\":1}","namespace":"urn:x-cast:com.google.cast.media","senderId":"51:name.renkel.james.mediacast-6"}
 cast_receiver.javascript:574
 [ 48.440s] [cast.receiver.CastMessageBus] Dispatching CastMessageBus message [urn:x-cast:com.google.cast.media, 51:name.renkel.james.mediacast-6]: {"type":"PLAY","requestId":2,"mediaSessionId":1}
 cast_receiver.javascript:574
 [ 48.446s] [cast.receiver.MediaManager] MediaManager message received [51:name.renkel.james.mediacast-6] {"type":"PLAY","requestId":2,"mediaSessionId":1}
 cast_receiver.javascript:574
 [ 48.449s] [cast.receiver.MediaManager] Dispatching MediaManager play event
 cast_receiver.javascript:574
 [ 48.457s] [cast.receiver.MediaManager] onPlay
 cast_receiver.javascript:574
 [ 48.473s] [cast.receiver.MediaManager] Sending broadcast status message
 cast_receiver.javascript:574
>>>>>the media element state is buffering mediacast.js:603
media element networkState = 1, readyState = 4 mediacast.js:605
 [ 48.491s] [cast.receiver.IpcChannel] IPC message sent: {"namespace":"urn:x-cast:com.google.cast.media","senderId":"*:*","data":"{\"type\":\"MEDIA_STATUS\",\"status\":[{\"mediaSessionId\":1,\"playbackRate\":1,\"playerState\":\"BUFFERING\",\"currentTime\":0.033322,\"supportedMediaCommands\":15,\"volume\":{\"level\":0.06666666666666667,\"muted\":false}}],\"requestId\":2}"}
 cast_receiver.javascript:574
 [ 49.071s] [cast.receiver.MediaManager] Buffering state changed, isPlayerBuffering: false old time: 0.033322 current time: 0.433322
 cast_receiver.javascript:574
 [ 49.077s] [cast.receiver.MediaManager] Sending broadcast status message
 cast_receiver.javascript:574
>>>>>the media element state is playing mediacast.js:603
media element networkState = 2, readyState = 4 mediacast.js:605
 [ 49.090s] [cast.receiver.IpcChannel] IPC message sent: {"namespace":"urn:x-cast:com.google.cast.media","senderId":"*:*","data":"{\"type\":\"MEDIA_STATUS\",\"status\":[{\"mediaSessionId\":1,\"playbackRate\":1,\"playerState\":\"PLAYING\",\"currentTime\":0.433322,\"supportedMediaCommands\":15,\"volume\":{\"level\":0.06666666666666667,\"muted\":false}}],\"requestId\":0}"}
 cast_receiver.javascript:574
::onEnded(VIDEO) mediacast.js:369
::onEnded- network state:1 mediacast.js:370
::onEnded-   ready state:4 mediacast.js:371
::onEnded-        paused:true mediacast.js:372
::onEnded-         ended:true mediacast.js:373
::sendMessage({"indication":"ended"}) mediacast.js:108
 [ 90.955s] [cast.receiver.IpcChannel] IPC message sent: {"namespace":"urn:x-cast:name.renkel.james.mediacast","senderId":"51:name.renkel.james.mediacast-6","data":"{\"indication\":\"ended\"}"}
 cast_receiver.javascript:574
 [110.341s] [cast.receiver.IpcChannel] Received message: {"data":"{\"type\":\"PLAY\",\"requestId\":3,\"mediaSessionId\":1}","namespace":"urn:x-cast:com.google.cast.media","senderId":"51:name.renkel.james.mediacast-6"}
 cast_receiver.javascript:574
 [110.350s] [cast.receiver.CastMessageBus] Dispatching CastMessageBus message [urn:x-cast:com.google.cast.media, 51:name.renkel.james.mediacast-6]: {"type":"PLAY","requestId":3,"mediaSessionId":1}
 cast_receiver.javascript:574
 [110.358s] [cast.receiver.MediaManager] Unexpected command, player is in IDLE state so the media session ID is not valid yet
 cast_receiver.javascript:574ib cast_receiver.javascript:574gb.Gb cast_receiver.javascript:562B.log cast_receiver.javascript:361E cast_receiver.javascript:412Z.M cast_receiver.javascript:1654W.ra cast_receiver.javascript:1181Hb cast_receiver.javascript:885g.dispatchEvent cast_receiver.javascript:856g.M cast_receiver.javascript:1104Hb cast_receiver.javascript:885g.dispatchEvent cast_receiver.javascript:856g.M cast_receiver.javascript:968
 [110.362s] [cast.receiver.MediaManager] Sending error message to 51:name.renkel.james.mediacast-6
 cast_receiver.javascript:574
 [110.368s] [cast.receiver.IpcChannel] IPC message sent: {"namespace":"urn:x-cast:com.google.cast.media","senderId":"51:name.renkel.james.mediacast-6","data":"{\"requestId\":3,\"type\":\"INVALID_REQUEST\",\"reason\":\"INVALID_MEDIA_SESSION_ID\"}"}
 cast_receiver.javascript:574

这里是发件人日志：

11-10 13:36:36.631: D/MC_Sender(15051): ::showVideo()- url: http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4 11-10 13:36:36.732: D/MC_MainActivity.PagerAdapter(15051): ::setPrimaryItem(0)
11-10 13:36:36.732: D/MC_MainActivity(15051): ::setContentPosition(0)
11-10 13:36:40.325: D/MC_MediaPlayer(15051): ::onMessageReceived(): device-TV Room; namespace-urn:x-cast:com.google.cast.media; message-{"type":"MEDIA_STATUS","status":[{"mediaSessionId":2,"playbackRate":1,"playerState":"PAUSED","currentTime":0,"supportedMediaCommands":15,"volume":{"level":0.06666666666666667,"muted":false},"media":{"customData":{"volume":0.06666666666666667,"pauseAfter":true,"pauseBefore":true,"rotation":0},"streamType":"BUFFERED","duration":42.4,"contentType":"video/mp4","contentId":"http://192.168.1.50/apps/chromecast/videos/Inside%20Diamond%20Head-0001.mp4","metadata":{"metadataType":1}}}],"requestId":4}
11-10 13:36:40.375: D/MC_Listeners(15051): ::onStatusUpdated()- playerState=PAUSED
11-10 13:36:40.426: D/MC_Runner(15051): ::onSenderStateChange(PAUSED)- runState=LOADING
11-10 13:36:40.426: D/MC_Runner(15051): ::setRunState(RUNNING)- stopWhenRunning=false
11-10 13:36:40.426: D/MC_CastFragment(15051): ::runnerUpdate()
11-10 13:36:40.456: D/MC_Listeners(15051): ::onStatusUpdated()- playerState=PAUSED
11-10 13:36:40.456: D/MC_Listeners(15051): ::onMetadataUpdated()- mediaType=MOVIE
11-10 13:36:40.516: D/MC_MainActivity.PagerAdapter(15051): ::setPrimaryItem(0)
11-10 13:36:40.516: D/MC_MainActivity(15051): ::setContentPosition(0)
11-10 13:36:40.806: D/MC_Sender(15051): ::loadMedia()- statusCode: 0; success: true
11-10 13:36:40.806: D/MC_Runner(15051): LoadCallback::callback(true): wasStopped=false
...
11-10 13:38:47.201: D/MC_Sender(15051): ::playMedia()
11-10 13:38:47.391: D/MC_MediaPlayer(15051): ::onMessageReceived(): device-TV Room; namespace-urn:x-cast:com.google.cast.media; message-{"type":"MEDIA_STATUS","status":[{"mediaSessionId":1,"playbackRate":1,"playerState":"BUFFERING","currentTime":0.033322,"supportedMediaCommands":15,"volume":{"level":0.06666666666666667,"muted":false}}],"requestId":2}
11-10 13:38:47.411: D/MC_Listeners(15051): ::onStatusUpdated()- playerState=BUFFERING
11-10 13:38:47.531: D/MC_Runner(15051): ::onSenderStateChange(BUFFERING)- runState=RUNNING
11-10 13:38:47.671: D/MC_MainActivity.PagerAdapter(15051): ::setPrimaryItem(0)
11-10 13:38:47.671: D/MC_MainActivity(15051): ::setContentPosition(0)
11-10 13:38:48.372: D/MC_Sender(15051): ::playMedia()- statusCode: 0; success: true
11-10 13:38:48.382: D/MC_MediaPlayer(15051): ::onMessageReceived(): device-TV Room; namespace-urn:x-cast:com.google.cast.media; message-{"type":"MEDIA_STATUS","status":[{"mediaSessionId":1,"playbackRate":1,"playerState":"PLAYING","currentTime":0.6,"supportedMediaCommands":15,"volume":{"level":0.06666666666666667,"muted":false}}],"requestId":0}
...
11-10 13:39:29.736: D/MC_Listeners(15051): ::onMessageReceived()- nameSpace: urn:x-cast:name.renkel.james.mediacast; message: {"indication":"ended"}
11-10 13:39:29.806: D/MC_Runner(15051): ::onSenderStateChange(ENDED)- runState=RUNNING
...
11-10 13:42:19.918: D/MC_CastFragment(15051): ::onClick()
11-10 13:42:19.918: D/MC_Sender(15051): ::playMedia()
11-10 13:42:20.398: D/MC_MediaPlayer(15051): ::onMessageReceived(): device-TV Room; namespace-urn:x-cast:com.google.cast.media; message-{"requestId":3,"type":"INVALID_REQUEST","reason":"INVALID_MEDIA_SESSION_ID"}
11-10 13:42:20.418: D/MC_Sender(15051): ::playMedia()- statusCode: 1; success: false

Answer 1

我相信一旦视频结束，无论是否调用了 resetMediaElement，它都会进入 IDLE 状态。状态可能为 IDLE 的原因有多种，您可以指定：https://developers.google.com/cast/docs/reference/receiver/cast.receiver.media.IdleReason。

有点绕，但是根据https://developers.google.com/cast/docs/reference/receiver/cast.receiver.MediaManager列出的方法，你可以：

1) 检查视频是否播放成功

2) 设置空闲原因为 cast.receiver.media.IdleReason.FINISHED

然后，在您的发件人中，您可以覆盖customizedStatusCallback() 以检查状态和空闲原因，并在将其发送给您的发件人之前更改状态，以便它可以正确重播。