playMedia() on Nvidia Shield causes subscription failures

[jjlawren]

When sending a Client().playMedia() command, it seems that this command (which only specifies the server’s port) will cause the Plex app on Nvidia Shield devices to treat the plexapi request source as an actively listening controller. The Shield client will send POST requests back to the plexapi host on the server’s port which repeatedly fail.

Example logs from Shield:

02-26 21:58:39.517  i: [pms] /10.6.9.55:57992 - GET /player/timeline/subscribe
02-26 21:58:39.517  i: [Now Playing] New subscriber 0xcfe9033bf0a4 at 10.6.9.55:32400 with command id 23
02-26 21:58:39.519  i: Fetching [method:POST] http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU&includeExternalMedia=1
02-26 21:58:39.525  i: Time out fetching http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU.
02-26 21:58:39.667  i: [pms] /10.6.9.55:57996 - GET /player/playback/playMedia
02-26 21:58:43.325  i: Fetching [method:POST] http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU&includeExternalMedia=1
02-26 21:58:43.333  i: Time out fetching http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU.
02-26 21:58:44.383  i: Fetching [method:POST] http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU&includeExternalMedia=1
02-26 21:58:44.395  i: Time out fetching http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU.
02-26 21:58:45.382  i: Fetching [method:POST] http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU&includeExternalMedia=1
02-26 21:58:45.386  i: Time out fetching http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU.
02-26 21:58:46.384  i: Fetching [method:POST] http://10.6.9.55:32400/:/timeline?X-Plex-Token=...HBKU&includeExternalMedia=1

[jjlawren]

I don't see how the library can use the /player/timeline/subscribe command at all since it doesn't open a listening port for callbacks from the player.

From the Plex remote control API doc, it seems we should always use the /player/timeline/poll command:

This is an alternative to the subscribe command for controllers that cannot use persistent connections to receive updates from the player.

[Hellowlol]

I cant remember why this was needed. It was only a issue on pht. Just try to Replace it and see what happens

[jjlawren]

If I start a listening host before sending the timeline/subscribe command, the player delivers status updates for the next ~30s. I think using this subscribe command is incorrect for any player without providing a callback listener.

[jjlawren]

Skipping the /player/timeline/subscribe call avoids errors in the Shield client, but for some reason the playback status is not shown in the server's /status/sessions activity when playback is initiated from a /player/playback/playMedia call. I'm guessing a quirk of the client, but perhaps someone knows a workaround?

[blacktwin]

Probably something up with the client. Here another example of the Shield acting funny.

[jjlawren]

Yes, I'm sure it's something with the client itself. That being said, I think the current behavior of plexapi is incorrect when following the remote control specifications. We request a callback from the client which we have no intention of properly handling.

[Hellowlol]

Let’s fix it then. We just need to test that the commands still work.

[jjlawren]

Starting remote media playback still works if I remove this block around the timeline/subscribe call: https://github.com/pkkid/python-plexapi/blob/c3e16b2d369968433048ae9a5678294041eb084d/plexapi/client.py#L477-L484

However, I haven't opened a PR yet since the Shield client still doesn't report its playback status to the Plex server and I'm unclear if it's related. Since the timeline functionality is what triggers playback status reports I feel like I'm still missing something.

[Hellowlol]

Try replacing it with self.sendCommand('timeline/poll', wait=0)

[jjlawren]

Maybe the timeline subscription should be removed there completely, and we add Plex for Android (TV) to the product list here: https://github.com/pkkid/python-plexapi/blob/c3e16b2d369968433048ae9a5678294041eb084d/plexapi/client.py#L193-L198

[Hellowlol]

That part intended for others things, in short all commands on some client fail unless we send a timeline request ever 80 sec (or was it 90) i cant remember. (not just playback)

[jjlawren]

In testing various fixes I noticed that in addition to no server sessions being reported, timeline() calls to Shield clients weren't returning correct data. I've opened a thread on the Plex forums here: https://forums.plex.tv/t/no-session-status-when-starting-playback-on-shield-over-remote-control-api/555067.

[blacktwin]

Just a thought, what are the client.protocolCapabilities for the Shield you're using?

[jjlawren]

['timeline', 'playback', 'navigation', 'mirror', 'playqueues', 'provider-playback']

It reports back a valid response, but always shows it as "stopped" when playback is started via the /player/playback/playMedia endpoint.