Strange behaviour with forced subtitles

[donniedarko83 2]

Hello! 

I am at a bit of a loss. I have films that have forced subtitles, once the films need to be transcoded, the film only runs for a few minutes at a time, then stops for about 20 seconds and then continues. It then does this for the whole film. This behaviour only occurs with Android (TV) and Samsung TV. Not with Web Player or LG App. How can I fix this? This only affects films that cannot be played directly. Only if transcoding is required. In the local network or remote does not matter. And only with forced subtitles (SUBRIP), normal subtitles SRT work. Huh?   
I have already tried all possible subtitle options. I just don't know what to do. I have also sent a report within the Android TV app if that helps. Time 3:42 pm File Road House 2024 User Kevin 

Thank you for you help

ffmpeg-transcode-462ed87b-80a9-4e98-9f28-5e327e0df6f9_1.txt embyserver (1).txt

[ebr 14913]

It sounds like your server isn't fast enough to transcode the item but it could also possibly be related to the item having so many subtitle tracks.  Can you try removing some of them?

[Luke 37071]

Hi, also have you tinkered with the diagnostics plugin? If you have, then please reset any changes there, then try this again. If you're still having an issue at that point, then please attach the log examples from that. Thanks.

[donniedarko83 2]

15 hours ago, Luke said:

Hi, also have you tinkered with the diagnostics plugin? If you have, then please reset any changes there, then try this again. If you're still having an issue at that point, then please attach the log examples from that. Thanks.

Afterwards, yes. But I reset the changes. And my server should be strong enough to transcode. Anyhow I removed most of the subtitles as ebr suggested and now it seems to be working without stutter. Strange, I must keep this in mind. I also tried several other files with forced subtitiles (and just a few subtitles in total) and no problem at all. So it must be realted with the amount of subtitles. 

Thank you for you kind help and suppoert. I will monitor this but I think it is solved for now!

[donniedarko83 2]

Unfortunately I am still having this problem. I hope you can help me. What I have observed 

- The problem only occurs on Android based devices.

- I can select any other subtitle without any problem. Only the forced subtitles cause buffering.

- It doesn't matter how many subtitles the file has.

- It happens most often with HDR HEVC files, not so often with 1080p streams.

- My server has no problem with transcoding, even with normal subtitles. So I think my server is fast enough for this kind of tasks.

I have attached some logs. I hope someone can help me.

ffmpeg-transcode-dcf6fa1d-1647-4948-9fd6-dcf0d32a3fd1_1.txt embyserver (2).txt

[ebr 14913]

Hi.  The above example is from the Android mobile app on a phone, correct?

[donniedarko83 2]

Yes in this example. But it is the same on my Nvidia shield

[donniedarko83 2]

What can this mean? It is from the transcode log. 

/config/transcoding-temp/2A1E3D/2A1E3D_s5.m3u8.tmp' for writing

18:25:50.552 SegmentComplete=video:1 Index=731 Start=2193.024000 End=2196.026000 Duration=3.002000 offset_pts=0 start_pts=2193024000 Frames=72 filename=2A1E3D_s5_731.vtt

18:25:50.552 [segment @ 0x8abfc0] Opening '/config/transcoding-temp/2A1E3D/2A1E3D_s5_732.vtt.tmp' for writing

18:25:50.575 subtitle_kickoff: resend - pts: 2197654

18:25:50.575 subtitle_kickoff: call subtitle_resend_current 2197664 frame->format: 3

18:25:50.650 Too many packets buffered for output stream 1:1.

18:25:50.659 Conversion failed!

18:25:50.659 EXIT

I think in the moment it starts to buffer this message appears in the transcode logfile

[donniedarko83 2]

Why does my file don't show any progress if the transcode progress starts? Normally I see something like 250 fps and a red bar. With this file there is basically no progress and all of a sudden it is at 100 percent. As soon as the message error is shown in the log file it starts to buffer. I am pretty sure there is something wrong here 

[donniedarko83 2]

That's with the LG app. I have no buffering issues with the app and the transcode file does not show any error message 

[Luke 37071]

Hi, do you still have customizations from the diagnostics plugin?

[donniedarko83 2]

I have removed the diagnostics plugin. But yesterday after a lot of testing I googled the error message "Too many packets buffered for output stream 1:1" and there I found a solution. Someone mentioned to Disable HLS Subtitles in the diagnostics plugin to solve this issue. I installed the plugin again and now it works without any issue! But I don't really understand what this does, because I am still able to see the subtitles. And after every restart I must disable the HLS subtitles in the diagnostics plugin. Is it somehow possible to always disable the HLS subtitles?