Subtitles on MKV selectable but not playing on Amazon Fire TV 2

General Discussions
1

Dear support, dear @cayars , dear @“MovieFan.Plex” , @ChuckPA ,

I promised to show my case of subtitles not playing when I get home to have access to my systems:

My setting:

  • Plex Media Server 1.5.1 (QNAP NAS)
  • Amazon FireTV generation 2 (FireOS 5.2.4.0 / Plex App version 5.6.1.505)
  • cabled network

Symptoms: I have movies in MKV format which have subtitles shown by Plex. These are fully selectable via Plex Web and Plex FireTV app. But they are not showing while playing the movies.

Test case: I identified one of many movies that has subtitles, created a test library for the purpose of testing the symptoms. That file contains TWO embedded vobsup subtitle tracks. Furthermore, I downloaded external SRT subtitles as well as extracted IDX/SUB subtitles from the source file.

I then took the source file and used “mkvmerge” to create three other versions of the same movie file, two files containing only one of the two original embedded subtitle tracks and one without any subtitles (to use with the external subtitle formats).

The movie contains (and therefore all five files contain) one video track and two audio tracks… here’s the info:

video: Codec-ID: V_MPEGH/ISO/HEVC (h.265 profile Main @L4.0); 1920x800 (black bars cropped)
audio1 & 2: A_AC3 (48000 hz, 6 channels)

I now renamed those five movie files and copied these to five different movie folders (to simulate different movies to make it easier for me to identify the subtitle situation in the logs). In order not to pollute my other libraries Watched status, I took movie names of movies I do not own (it is just a test case after all):

A) Kick-Ass (2010):
Original file containing two embedded subtitle tracks
These two embedded subtitles are shown within Plex as “German (VOBSUB) - forced” and “German (VOBSUB)”.

B) Kick-Ass 2 (2013):
file containing the first embedded subtitle track only

C) Kickboxer (1989):
no embedded subtitles, added the idx/sub external subtitle

D) Kickboxer 2 (1991):
no embedded subtitles, added the SRT external subtitle

E) Kickboxer 3 (1992):
file containing only the second embedded subtitle track

All movies were properly identified in the new library (and were never part of any of my libraries before). From now on, I will reference the files by A) to E)…

Using Plex Web, I selected the first of the two embedded subtitle tracks on movie A) and selected the single external or internal subtitles on B), C), D) and E).

I then took the XML info of all five files and attached it to this post (file: A-E.xml.txt).

With these subtitles enabled to play, I started logging on the Plex App on FireTV and started playing the movies starting with A, ending with E. I noted down the results, grabbed the logs from the FireTV and restarted the FireTV to log from a clean sheet.

A) result: DirectPlay, movie plays flawlessly, no subtitles are showing (filename: A-logs.txt)
B) result: DirectPlay, movie plays flawlessly, no subtitles are showing (filename: B-Logs.txt)
C) result: transcoding (because idx not supported in container mkv), movie stutters heavily, subtitles are showing (filename: C-logs.txt)
D) result: DirectPlay, movie plays flawlessly, subtitles are showing (filename: D-logs.txt)
E) result: DirectPlay, movie plays flawlessly, no subtitles are showing (filename: E-logs.txt)

I tested A) once again with the second of the two subtitle tracks selected, the result was the same (no logs).
I tested all FOUR subtitles in VLC and they played flawlessly.

First results:
VOBSUB subtitles are not playing (even though the logs say, client and server are happy to play it), IDX/SUB is transcoding (nay! on HEVC), SRT is playing well.

While I was on track for this bug, I took the SRT from test case D and copied it to movie folder from A with the two embedded tracks, renamed it to match the file name of A. I then selected the external SRT subtitle on A using Plex Web.

To my surprise, the same SRT file which plays well if the same movie does NOT have embedded subtitle tracks, does not show subtitles with the two embedded subtitle tracks present (log filename: combined-AD-logs.txt).

This is definitely a bug, gentlemen.

Thank you for taking care of it…

2

Sorry, forgot to attach the combined A-D logs…
Here you go.

3

Hey guys,

I’ve been busy for a few days, but I am surprised that nobody answers to this call. Any Plex ninja or Team member available to have a look at it?

Any further things you need to work on it?
Support is yelling for logs in other threads, but I am not sure, if anyone is aware of this yet?

Comments, anyone?

4

This was a bit hard to follow. You are using HEVC files so if you have to do any transcoding at all due to subtitles you are probably going to get stuttering. Your CPU isn’t fast enough to transcode them most likely.

Some of it I didn’t fully understand, for example:
A) result: DirectPlay, movie plays flawlessly, no subtitles are showing (filename: A-logs.txt)

I tested A) once again with the second of the two subtitle tracks selected, the result was the same (no logs).

This is just one example but I’m confused. First no subtitles are there then they are? Or did you just mean they were there but not selected?

Can you break down and just let us know what isn’t working?

5

Thank you for trying to follow:

The movie A) has TWO embedded subtitle tracks. I selected the first one. The movie itself played, but the selected subtitle did not SHOW UP. I repeated the same test with the same movie and the second subtitle being selected, and the subtitles did not show up during playback either. As far as I understand the logs, I should have seen subtitles…

6

Sh*t, I accidently accepted my response as an answer. Can somebody reset that? :confused:

7

The title says it all, the selected embedded subtitles do not play while the movie itself is playing (DirectPlay). The logs say, that client and server do agree to show the subtitles but they are NOT VISIBLE during playback.

Forget about the idx/sub subtitles. They were just included to make the test case complete.

8

Hi supporters,

to make it clearer to anyone, I did some photos last night…

They show the original movie. I Access it via Plex web and choose one of the two embedded subtitle track in the movie Detail page:

I then start Plex on Amazon Fire-TV 2ndgen… I go to the Movie pre-Play Screen, it Looks like that (you can see that the subtitle is selected):

When starting playback of that movie on Amazon Fire-TV, the subtitles do not appear (as you can see, DirectPlay is used, there should be German subtitles below the English text now):

As a comparison, I played the file on a PC using VLC Player and the embedded subtitles DO APPEAR:

I checked the Plex logs on the client and Client and Server agree that the subtitles SHOULD show up via DirectPlay, but they are not.

If I rip out all embedded subtitle tracks and add an SRT external subtitle, that one is displayed during playback.
But if I leave These embedded subtitles untouched, not even the external SRT subtitles are displayed.

So there is something amiss with subtitle management, I guess.

9

Ahh, pictures make it much clearer. I thought you were saying Plex doesn’t display the subtitle options to choose from. Now I understand what you meant. The subtitle options show up but just don’t work.

I’m not a subtitle user as I only speak English and typically only load English movies in my library. I probably only have a dozen foreign films with SRT subtitles so please excuse my ignorance if I say or ask something stupid. :slight_smile:

Couple of questions I would wonder about. What browser were you using? Was it Chrome? Does Chrome or your browser support VOBSUB subtitles? Again I could be wrong but I don’t think they do.

Have you tried playing these files with a hardware based client that you know supports vobsub files? If so what happened?

In either case it would appear you found a bug of some type. Either it should work or Plex shouldn’t display subtitles that don’t work on the platform you are using or should fall back to transcoding to use the subtitles. But it’s still to early to tell exactly what’s going on.

Carlo

10

In the case of VOBSUB subtitles, the following applies:
Full support for VOBSUB deliver only Plex Media Player and OpenPHT (Plex4Kodi probably too)
All other Plex clients require transcoding on the server to display these subs.

Some few Android TV client do support VOBSUB subtitles if the file is Direct Played. But only then.
In the case of a HEVC-encoded video, this still the exception - there are not so much devices which can decode HEVC by themselves.

All other Plex clients require transcoding on the server, which will overstrain many, many servers. Even those which have no problem to transcode AVC (H.264) video.

Either stay away from HEVC encoded files
or convert the subtitles into SRT format, for which there is much better support among Plex clients.

11

this appears in the C-log:

03-26 17:20:30.616  i: [MediaDecisionEngine] Original quality selected, skipping resolution/bitrate check
03-26 17:20:30.617  i: [MediaDecisionEngine] Codec (idx) nicht unterstützt im Behälter (external)

external VOBSUB files are rarely supported, and of course if they are external, the file cannot be Direct Played anymore.
VOBSUB need to be muxed in with the video in most cases for them to work.

12

@OttoKerner Thank you very much for your Kind answer.

Could you please tell me why the Amazon Fire TV gen2 (which is capable of DirectPlay HVEC) is not showing those embedded subtitles?

As can be seen on the Images, I do not need transcoding to play the movies.
The logs clearly say

03-26 16:40:08.183  i: [MediaDecisionEngine] Starting media decision for: Kick-Ass (part index 0)
03-26 16:40:08.250  i: [MediaDecisionEngine] Analyzing media: 1920x800 2049kbps (Container: mkv, Video: hevc, Audio: ac3)
03-26 16:40:08.261  i: [MediaDecisionEngine] Original quality selected, skipping resolution/bitrate check
03-26 16:40:08.262  i: [MediaDecisionEngine] Selected subtitle (vobsub) can be direct played
03-26 16:40:08.550  i: [MediaDecisionEngine] Server was happy with client's original decision
03-26 16:40:08.551  i: [MediaDecisionEngine] Decision: CanPlay: true CanDirectPlay: true CanDirectStreamVideo: true CanDirectStreamAudio: true CanDirectPlaySubtitle: true CanTranscodeSubtitle: false 
03-26 16:40:08.567  i: [video] Decision made, transcode: false
...
03-26 16:40:10.362  i: [ExoVideoPlayer] Selecting track (1 / 0)
03-26 16:40:10.362  i: [ExoVideoPlayer] Found new stream via index.
03-26 16:40:10.363  i: [ExoVideoPlayer] Selecting track (3 / 0)
03-26 16:40:10.363  i: [TranscodeSession] Direct Play

So, I still do not understand why the Client thinks it is displaying the subtitles but it isn’t…

thank you for getting involved…

13

@cayars said:
…
Couple of questions I would wonder about. What browser were you using? Was it Chrome? Does Chrome or your browser support VOBSUB subtitles? Again I could be wrong but I don’t think they do.

Have you tried playing these files with a hardware based client that you know supports vobsub files? If so what happened?

In either case it would appear you found a bug of some type. Either it should work or Plex shouldn’t display subtitles that don’t work on the platform you are using or should fall back to transcoding to use the subtitles. But it’s still to early to tell exactly what’s going on.

I only play movies through Amazon Fire TV 2nd Generation (Hardware). I do not use any browser to play movies.
The description of what happens is based on my experience with playback on Amazon Fire TV ONLY.

14

OK, what happens if you try and play this file directly on the Amazon Fire TV without going through Plex?

Do the subtitles work correctly then?

15

@OttoKerner said:

Some few Android TV client do support VOBSUB subtitles if the file is Direct Played. But only then.

Oh yes, my original files can be DIRECT PLAYED. This is case A… all other scenarii are for test purposes ONLY.

In the case of a HEVC-encoded video, this still the exception - there are not so much devices which can decode HEVC by themselves.

Amazon Fire TV does … still, VOBSUB subtitles do not get displayed.

Either stay away from HEVC encoded files
or convert the subtitles into SRT format, for which there is much better support among Plex clients.

Erm… excuse me?
I have a client which can handle HVEC, I have Plex which is thinking that everything is great including subtitles.
Converting These movies back to H264 is not an Option (BIG deal of data and lots of more space needed).
Extracting SRT from those files is also no Option since SRT does not get displayed as long as VOBSUB subtitles are still there (the second bug I experienced).

I would be most grateful if we can focus on fixing subtitle support to plex clients that can handle the HVEC Format like Amazon Fire TV?

16

@OttoKerner said:
this appears in the C-log:

03-26 17:20:30.616  i: [MediaDecisionEngine] Original quality selected, skipping resolution/bitrate check
03-26 17:20:30.617  i: [MediaDecisionEngine] Codec (idx) nicht unterstützt im Behälter (external)

external VOBSUB files are rarely supported, and of course if they are external, the file cannot be Direct Played anymore.
VOBSUB need to be muxed in with the video in most cases for them to work.

Oh yes, this was just pure testing… C is not what my files look like… it is what I get when I extract subtitles from my embedded subtitle tracks. This works, but Needs transcoding which is not a good think with HVEC.

My movies are case A … this is my original… all other scenarii are just test cases to find the bug.

17

@cayars said:
OK, what happens if you try and play this file directly on the Amazon Fire TV without going through Plex?

Do the subtitles work correctly then?

I haven’t rooted my boxes, so I am not sure if it is even possible to Play files directly from usb storage devices.
I will try when I get home.

18

@rossinior said:
03-26 16:40:10.362 i: [ExoVideoPlayer] Selecting track (1 / 0)
03-26 16:40:10.362 i: [ExoVideoPlayer] Found new stream via index.
03-26 16:40:10.363 i: [ExoVideoPlayer] Selecting track (3 / 0)

A developer indicated to me that this may be connected to a bug which is getting fixed in the next release of the Anvergo (Android with PMP user interface) client.

19

@OttoKerner …
Anvergo … never heard of it. Do you mean there are chances that it gets fixed for Amazon Fire TV boxes also?
Sorry for my complete ignorance of insider terms.
Or will I have to buy new boxes (I own three Amazon Fire TVs)?

20

@OttoKerner

What about the second bug:

If I have a file HVEC (MKV) and I do NOT HAVE embedded subtitle tracks, adding SRT (external) subtitle works like a charme.
If I have These embedded subtitle tracks, adding SRT does not help. SRT does not get displayed in this case.