Emby does not play subtitles ASS

[redybr 0]

Hi everyone, my Emby server is on TrueNAS Scale, and it's generally working well, but I'm having trouble with ASS subtitles; they don't play in the browser, only in the Android app, for example. I'll attach the log.

ffmpeg-transcode-e6673968-3c9e-424b-a1d0-27f24ee832db_1.txt embyserver.txt

Edited November 7, 2025 by redybr

[guunter 49]

7 hours ago, redybr said:

Hi everyone, my Emby server is on TrueNAS Scale, and it's generally working well, but I'm having trouble with ASS subtitles; they don't play in the browser, only in the Android app, for example. I'll attach the log.

ffmpeg-transcode-e6673968-3c9e-424b-a1d0-27f24ee832db_1.txt 51.54 kB · 1 download embyserver.txt 434.82 kB · 2 downloads

In transcoding turn off subtitle extraction on the fly. This should force the server to burn the subtitles.

 

You may also need to install the diagnostic plugin to get the Subtitle Options in the admin menu. I'd set it to this.

 

[redybr 0]

I made the changes as you mentioned, but to no avail. When I try to play a video with ASS subtitles, I get the message that there are no streams available.

ffmpeg-transcode-a6de7506-bb85-4ea5-8567-084f2b9a4597_1.txt

[MediaEmby1968 47]

Have you tried disabling subtitles in the file and seeing if it plays or affects playback?

You can do this with MKVToolNix.

[guunter 49]

19 hours ago, redybr said:

I made the changes as you mentioned, but to no avail. When I try to play a video with ASS subtitles, I get the message that there are no streams available.

ffmpeg-transcode-a6de7506-bb85-4ea5-8567-084f2b9a4597_1.txt 44.57 kB · 2 downloads

Do you have transcoding enabled or premiere?

[redybr 0]

On 11/9/2025 at 6:55 AM, MediaEmby1968 said:

Have you tried disabling subtitles in the file and seeing if it plays or affects playback?

You can do this with MKVToolNix.

When I try to watch it without subtitles, it plays normally, so I believe the problem is with the ASS subtitles themselves.

[redybr 0]

20 hours ago, guunter said:

Do you have transcoding enabled or premiere?

I don't have Premiere, how can I be sure that transcoding is enabled correctly?

[MediaEmby1968 47]

I also had problems with ASS subtitles (which are the ones I use). These days they work fine without transcoding.

I have them set up as external subtitles, not embedded in the file (I think, but I'm not entirely sure, that's what was causing the transcoding and the freeze).

In the settings, under the transcoding section, there's a link that says something like "Allow subtitle extraction on the fly."

I have it unchecked.

[redybr 0]

2 minutes ago, MediaEmby1968 said:

I also had problems with ASS subtitles (which are the ones I use). These days they work fine without transcoding.

I have them set up as external subtitles, not embedded in the file (I think, but I'm not entirely sure, that's what was causing the transcoding and the freeze).

In the settings, under the transcoding section, there's a link that says something like "Allow subtitle extraction on the fly."

I have it unchecked.

So, my subtitles are embedded, but I haven't been able to get them to work in the browser yet; they only work in the Android app. Here are some photos of the settings.
 

 

[MediaEmby1968 47]

I watch the videos on my TV; I've never watched them on my PC. I don't know if it was malfunctioning before because I don't watch anything on my PC.

Your settings are the same as mine.

It's clearly a subtitle issue. I would try extracting the subtitle file and setting it as an external file to see if that works. Make sure to disable embedded subtitles first.

[guunter 49]

8 hours ago, redybr said:

So, my subtitles are embedded, but I haven't been able to get them to work in the browser yet; they only work in the Android app. Here are some photos of the settings.
 

 

Yeah it looks like mine but unsure how it works with out premiere. It should use the CPU anyways (software transocding) for the subs.

[Luke 42077]

On 11/7/2025 at 9:38 PM, guunter said:

In transcoding turn off subtitle extraction on the fly. This should force the server to burn the subtitles.

 

You may also need to install the diagnostic plugin to get the Subtitle Options in the admin menu. I'd set it to this.

 

Hi, please try updating to the latest server build, setting these options back to default, then try to play again. Then please attach the new server log file. Thanks.

[Luke 42077]

@redybr?