Emby or Shield Bug ? Nvidia Shield / PGS subtitles / image loss when the subtitle disappear from screen

[iomgui 0]

Hello,

I wanted to know if the following was a known problem on emby and / or shield TV (2019 pro) ?

When the source has HD audio (tested with DTS HD and True HD atmos) in 1080p or 4k HDR (i list only what i have tested), and when using PGS subtitles, no transcoding done for any reason, i experience a very subtle problem that can be not seen, but when you ve seen it then you can no longer, not see it ...

When a PGS subtitle disappear, i experience the loss of a few frames (it freeze for a few frames then jump to the frame where it should be). And each time PGS subtitle disappear from the screen, though its hardly perciptible when its not on traveling / moving scenes.

For info i compared the same source played directly from an oppo on the same network from the same nas server, and with no problem.

If i remove the subtitles, no problem either with emby on shield TV, no more loss of a few frames. This 2 tests allows to exclude any server or network problem.

So far i did a factory reset of the shield TV, but same problem.

Any idea if this problem is emby related or shield TV related or else ?

Edited July 7, 2021 by iomgui

[ebr 14903]

Hi.  I've never seen nor heard of this before but it could be a bit of processor overload I guess.  Is there any way for you to capture it in a video?

[iomgui 0]

Yea thats why i made a factory reset to do the tests again with same result though. I ll check if there s a way to access cpu% and ram% during a video playback just in case ...

I tried a blind test with friends, they dont see it unless they know what to expect (and for that to happen you need the subtitle to disappear during a travelling, if not its extremly subtle).

In a video i doubt it would be "efficient" because of adding another layer of frame out of sync of the original video ... Easiest test would be to order a brand new shield and do the same tests, as i know what to look for.

[freddecc 0]

Yeah, this sounds like the issue I have as well. Hard to notice in static scenes. I think it started with version 2 of the app. I'm downloading SRT subs for all movies for now...

[iomgui 0]

Tested with a brand new shield pro, same issue. Also manage to capture it in viddeo, its still subtel, though i dont think i can share the video (legally i mean).

Thanks for confirming by the way. have you figured if it was emby related ot shield related ? (reason why i mentioned the same problem on 4k video was because upscaling is deactivated in that case)

Really to lazy to try other solution like plex to see if the problem is the same, but my undertsanding is plex use the same "engine" so not sure it would proove anything ...

[dpandkp 1]

I have the same issue and due to hearing loss in one ear, need subtitles on for every movie we watch. I would describe similarly to the other reporters; on "end" of a subtitle timeframe it seems as though the video drops a frame because there is a noticeable stutter. Never happens when a subittle appears only when each disappears. Much more obvious when subtitle appears over a long panning shot.

I have tested on my android phone and it doesnt exhibit the issue nor does an iPad the kids stream on. I have also rebooted server multiple times to ensure that a fresh instance was serving up the frames. Restarts had no effect. Server is a 24-core, 32GB machine that rarely logs more than single digit CPU usage.

Would love to help solve this issue if there are any logs that could be supplied to aid in identification.

Thank you.

[Carlo 4330]

17 minutes ago, dpandkp said:

I have the same issue and due to hearing loss in one ear, need subtitles on for every movie we watch. I would describe similarly to the other reporters; on "end" of a subtitle timeframe it seems as though the video drops a frame because there is a noticeable stutter. Never happens when a subittle appears only when each disappears. Much more obvious when subtitle appears over a long panning shot.

I have tested on my android phone and it doesnt exhibit the issue nor does an iPad the kids stream on. I have also rebooted server multiple times to ensure that a fresh instance was serving up the frames. Restarts had no effect. Server is a 24-core, 32GB machine that rarely logs more than single digit CPU usage.

Would love to help solve this issue if there are any logs that could be supplied to aid in identification.

Thank you.

Have you tried downloading and using SRT subs?  If this works that would be the best/easiest method to solve your issue.

[dpandkp 1]

Just now, cayars said:

Have you tried downloading and using SRT subs?  If this works that would be the best/easiest method to solve your issue.

SRT subs do not exhibit the same problem but my goal is to get PGS working smoothly again for this particular device. The simple workflow of buy, rip, scan library, play is ideal compared to going and looking for the right subtitle file that matches up to the retail versions of what I buy, testing it, naming it, etc. Unfortunately it's way too much overhead.

For others reading this thread and may view using SRT as a workaround to the issue, I can confirm in my limited testing that I cannot reproduce the issue when using subtitle files of that type.

[dpandkp 1]

A quick followup in case it helps someone or informs research but after re-reading the thread carefully, especially the post by freddecc, I attempted to sideload the newest version of the Emby apk that wasn't a 2.0 version (v1.8.80 as far as I could find). After testing 3 titles with embedded PGS subs that were previously stuttering on subtitle out, I can confirm that all three play smooth as butter. I don't know what positive updates to the app are being discarded going back a few versions but I will continue to test/use this version on the shield in the meantime.

[Luke 37008]

9 hours ago, dpandkp said:

A quick followup in case it helps someone or informs research but after re-reading the thread carefully, especially the post by freddecc, I attempted to sideload the newest version of the Emby apk that wasn't a 2.0 version (v1.8.80 as far as I could find). After testing 3 titles with embedded PGS subs that were previously stuttering on subtitle out, I can confirm that all three play smooth as butter. I don't know what positive updates to the app are being discarded going back a few versions but I will continue to test/use this version on the shield in the meantime.

Thanks for the feedback !

[iomgui 0]

thanks all for the possible fix. 

Luke : any chance emby team would investigate it for an incoming update or is it considered as a low priority bug ?

[ebr 14903]

Hi.  What is the frame rate of the content with this problem and do you have auto refresh rate switching enabled?

[dpandkp 1]

51 minutes ago, ebr said:

Hi.  What is the frame rate of the content with this problem and do you have auto refresh rate switching enabled?

In my case the sources are all 23.976 and auto refresh rate switching is enabled.

One other thing I verified while getting this information for you was the format of each file. I think it was mostly blind luck that the first few titles I checked were all VC1, but ultimately turned out to be nothing since I was able to see it right away on another title that was MPEG4.

 

[ebr 14903]

11 minutes ago, dpandkp said:

In my case the sources are all 23.976 and auto refresh rate switching is enabled.

As a test, can you try disabling that option and see if the problem goes away?

Thanks.

[iomgui 0]

3 hours ago, ebr said:

As a test, can you try disabling that option and see if the problem goes away?

Thanks.

I disabled auto refresh rate (in latest emby version on shield TV), but it doesnt solve the problem. I will try using an apk lower than 2.0 as mentionned above (even though it would only be a workaround).

Edited July 19, 2021 by iomgui

[dpandkp 1]

 

3 hours ago, ebr said:

As a test, can you try disabling that option and see if the problem goes away?

Thanks.

 

28 minutes ago, iomgui said:

I disabled auto refresh rate (in latest emby version on shield TV), but it doesnt solve the problem. I will try using an apk lower than 2.0 as mentionned above (even though it would only be a workaround).

My result was a bit different than your outcome iomgui. To respond back to ebr with the best answer I could, I updated the older version of emby (1.8.80g) to the newest version available through the app store. I then opened each movie that I've observed the problem WITH auto refresh rate switching enabled and sure enough the problem came back. I then disabled auto refresh rate switching in the playback menu of settings, and reloaded each movie and I did NOT notice the stutter when a subtitle disappeared. I noticed other stuttering likely as a result of not syncing the 23.976 rate to the tv but to summarize this to satisfy ebr's request...it seems that disabling auto refresh rate switching minimized (if not completely preventing) the specific stutter that occurs when a subtitle disappears.

For additional context the titles I am returning to and testing each time there is a request for info are US retail versions of Inception, Inception (UHD), Indiana Jones and the Last Crusade, Indiana Jones and the Last Crusade (UHD), and Last of the Mohicans.

[dnmoka 3]

2 hours ago, dpandkp said:

 

 

My result was a bit different than your outcome iomgui. To respond back to ebr with the best answer I could, I updated the older version of emby (1.8.80g) to the newest version available through the app store. I then opened each movie that I've observed the problem WITH auto refresh rate switching enabled and sure enough the problem came back. I then disabled auto refresh rate switching in the playback menu of settings, and reloaded each movie and I did NOT notice the stutter when a subtitle disappeared. I noticed other stuttering likely as a result of not syncing the 23.976 rate to the tv but to summarize this to satisfy ebr's request...it seems that disabling auto refresh rate switching minimized (if not completely preventing) the specific stutter that occurs when a subtitle disappears.

For additional context the titles I am returning to and testing each time there is a request for info are US retail versions of Inception, Inception (UHD), Indiana Jones and the Last Crusade, Indiana Jones and the Last Crusade (UHD), and Last of the Mohicans.

Yeah, for me disabling Refresh Rate Switching and setting the Shield/TV to 60 Hz with proper 3:2 pulldown (you need to make sure it's enabled on your tv) fixes it completely on the newest beta version with no apparent stutter. Only affects 23/24p content from what i saw and PGS/DVDSUB/VOBSUB which are all image subtitles btw. Everything else didn't seem to matter including audio passthrough, buffer size and file type (although i didn't test too many so can't be sure)

[Luke 37008]

Thanks for the info. It sounds like there's something related to the combination of those two things being used together.

[iomgui 0]

in my case, if i disable auto refresh rate, my shield is set at 23,976 by default.

The projector i m using is also at 23,976 (capable) so there is no processing on either part to adapt the original framerate to the display framerate.

That being said, i uninstalled and reinstalled the emby application. After reintsallation, i can confirm that the problem disappears as long as i dont activate the auto refresh rate. When i desactivated in the previous post for a test, i didnt do a hard reboot of the shield, perhaps it was required. 

Was the old apk mentionned above allowing to use the auto refresh rate without any problem with PGS subs ? I only have a few movies that are not in 23.976 thats why i m asking, and could live with the auto refresh rate feature if needed.

Thanks again all for your answers, much appreciated

[Luke 37008]

OK we're looking into it. Thanks for reporting.

[dpandkp 1]

Hi Luke, ebr...

Did you ever come to any conclusions about this odd behavior?

Thanks.

[Luke 37008]

13 hours ago, dpandkp said:

Hi Luke, ebr...

Did you ever come to any conclusions about this odd behavior?

Thanks.

Hi, yes we have and we are working on it. Thanks.

[dpandkp 1]

7 hours ago, Luke said:

Hi, yes we have and we are working on it. Thanks.

Fantastic news. Thanks. Is it a server or client side fix so I can monitor the appropriate changelogs?

[Luke 37008]

Client-side.