【发布时间】：2018-06-25 13:37:25
【问题描述】：
我知道这个帖子是这个帖子的副本，但没有得到答复。
Receving weird Json Error from custom Chromecast recevier app
我正在尝试从 Android 应用程序投射到 chromecast。我遵循了 Google 的以下示例。
https://developers.google.com/cast/docs/android_sender_integrate
https://developers.google.com/cast/docs/caf_receiver_basic
我可以成功连接到 chromecast，它会在电视上显示我的自定义 html 以及应用名称。
当我发送视频时出现错误，它说 JSON 对音量没有价值。它显示图像、名称和描述的元数据，但不播放它
public void playOnChromecast() {
CastSession session =CastContext.getSharedInstance(this).getSessionManager().getCurrentCastSession();
if(session == null) return;
MediaMetadata movieMetadata = new MediaMetadata(MediaMetadata.MEDIA_TYPE_MOVIE);
movieMetadata.putString(MediaMetadata.KEY_TITLE, this.video.getName());
movieMetadata.putString(MediaMetadata.KEY_SUBTITLE, this.video.getDescription());
movieMetadata.addImage(new WebImage(Uri.parse(this.video.getThumbnail())));
movieMetadata.addImage(new WebImage(Uri.parse(this.video.getThumbnail())));
MediaLoadOptions.Builder mediaLoadOptionsBuilder = new MediaLoadOptions.Builder();
mediaLoadOptionsBuilder.setAutoplay(true);
mediaLoadOptionsBuilder.setPlayPosition(0);
MediaTrack track = new MediaTrack.Builder(this.video.getId(), MediaTrack.TYPE_VIDEO)
.setName(this.video.getName())
.setSubtype(MediaTrack.SUBTYPE_NONE)
.setContentId(String.valueOf(this.video.getId()))
.setLanguage("es").build();
ArrayList<MediaTrack> tracks = new ArrayList<MediaTrack>();
tracks.add(track);
JSONObject jsonObj = null;try {
jsonObj = new JSONObject();
jsonObj.put("description", this.video.getDescription());
} catch (JSONException e) {
e.printStackTrace();
}
MediaInfo mediaInfo = new MediaInfo.Builder("http://clips.vorwaerts-gmbh.de/VfE_html5.mp4")
.setStreamType(MediaInfo.STREAM_TYPE_BUFFERED)
.setContentType("video/mp4")
.setMetadata(movieMetadata)
.setMediaTracks(tracks)
.setCustomData(jsonObj)
.build();
RemoteMediaClient remoteMediaClient = session.getRemoteMediaClient();
remoteMediaClient.load(mediaInfo, mediaLoadOptionsBuilder.build());
}
这样做的结果是什么都没有。在控制台中，我收到以下消息。
W/MediaControlChannel：消息格式不正确（级别没有值）； 忽略：（JSON）
作为 (JSON) SDK 发送到设备的一堆 JSON 数据。
{"type":"MEDIA_STATUS","status":[{"mediaSessionId":1,"playbackRate":1,"playerState":"IDLE","supportedMediaCommands":15,"volume":{},"media":{"contentId":"http://clips.vorwaerts-gmbh.de/VfE_html5.mp4","streamType":"BUFFERED","contentType":"video/mp4","metadata":{"metadataType":1,"images":[{"url":"http://cachepicapica.gomovil.co/videos-transcoded/fd42e6b6-b1f8-4eee-87c9-9b024ea41f0b/thumbnail.jpg","width":0,"height":0},{"url":"http://cachepicapica.gomovil.co/videos-transcoded/fd42e6b6-b1f8-4eee-87c9-9b024ea41f0b/thumbnail.jpg","width":0,"height":0}],"title":"Susanita","subtitle":"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit"},"tracks":[{"trackId":3,"type":"VIDEO","trackContentId":"3","name":"Susanita","language":"es"}],"customData":{"description":"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit"}},"currentItemId":1,"extendedStatus":{"playerState":"LOADING","media":{"contentId":"http://clips.vorwaerts-gmbh.de/VfE_html5.mp4","streamType":"BUFFERED","contentType":"video/mp4","metadata":{"metadataType":1,"images":[{"url":"http://cachepicapica.gomovil.co/videos-transcoded/fd42e6b6-b1f8-4eee-87c9-9b024ea41f0b/thumbnail.jpg","width":0,"height":0},{"url":"http://cachepicapica.gomovil.co/videos-transcoded/fd42e6b6-b1f8-4eee-87c9-9b024ea41f0b/thumbnail.jpg","width":0,"height":0}],"title":"Susanita","subtitle":"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit"},"tracks":[{"trackId":3,"type":"VIDEO","trackContentId":"3","name":"Susanita","language":"es"}],"customData":{"description":"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit"}}},"repeatMode":"REPEAT_OFF"}],"requestId":0}
我在 JSON 中看到 volume 字段是空的，它应该有一个 level 字段和 mute 字段。我想这是错误，但我不知道如何修复它，因为该 json 是从 Google SDK 构建的。
有什么想法吗？
谢谢！
更新：尝试改用 Styled 接收器，它仅适用于 MP4 文件，但不适用于 HLS 流。在这两次尝试中，上面显示的错误都没有出现。
【问题讨论】：
标签： java android json chromecast