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psxlover

Subtitles going out of sync when transcoding sound

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psxlover

I have a series with DTS audio on which Emby (correctly) decides to transcode the audio when playing it on my Samsung TV through the app (although in dashboard it appears as direct streaming, not sure if that is intended).

 

Playback seems to be fine, until I seek forwards/backwards, which causes the subtitles (.srt) to go out of sync.

Also if I stop the video (not pause), and then resume from where I left of, the subtitles start out of sync as well.

When resuming, the subtitles seem to start counting time immediately when I resume, so they are ahead of the video based on how much time the loading wheel has being displayed.

If I start the video from the beginning the subtitles are in sync, no matter how much time the loading takes.

 

It doesn't happen 100% of the time, I may move a couple of times without the subs going out of sync, and while testing I saw that sometimes resuming may start with the subs in sync as well.

Also it may not be a subtitle issue per se, it seems when I stop the video, it stops to where the subtitles where and not where the video was, so i seems more like the app's time is out of sync with the video.

 

 

(Hope I didn't forget something, this is the second fourth time I post this, seems like the first time I tried the post was lost)

 

Emby server: 4.3.1.0

Samsung app: 1.0.76

embyserver.txt

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psxlover
Posted (edited)

Seems like putting an image directly into the post I was being redirected to the top of the board with my post getting lost...

 

Edit: I put the image as an attachment

post-36045-0-06069900-1584800755_thumb.png

Edited by psxlover

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FrostByte
Posted (edited)

When it says direct streaming it is converting audio only (video is not being converted).  So that is correct.  Direct play is when video and audio are not converted.

Edited by FrostByte

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psxlover

 

Direct streaming
The media is compatible with the device regarding resolution and media type (H.264, AC3, etc.), but is in an incompatible file container (.mkv, .avi, .wmv, etc.). The video will be re-packaged on the fly before streaming it to the device.

 

 

Direct Streaming a file uses very little processing power without any loss in video quality.

 

The text should be changed to reflect that then, since it seems to imply that when direct streaming the issue is the container, which is not the case here since the issue is the audio is being transcoded ;)

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Luke

Yes we need to improve that display. Thanks for the feedback.

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psxlover

What about the original issue (the subtitles/video getting out of sync).

Were you able to reproduce it?

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Luke

Is it a full transcode or just a remux with a video stream copy?

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psxlover

It says it is direct streaming, and there is no buffering (the server usually can't handle transcoding), so I guess only the audio is modified, and the video is simply copied.

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Luke

Ok so yes i can confirm this is only when stream copying the video. It's just a consequence of the way we segment the video as part of the delivery process. Ultimately we're going to have to segment the .ass subtitles together with the video as part of the same process, but that will require new development to accomplish that. We already have this capability for plain text subtitles, but for .ass/.ssa it will be a new thing. We will get there.

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psxlover

I run into this issue when using .srt subtitles, not .ass subtitles (don't have any video with DTS audio and .ass subs to check if the same issue happens there as well).

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Luke

Can you attach the ffmpeg log? thanks.

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Luke

Ok thanks for the info.I know why this is happening.

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Embyuser3600

Hello, 

Has this issue been resolved? I too experience subtitles going out of sync on my samsung tv when using the skip/rewind function while the emby app is transcoding sound.

As a broader question, am I correct in assuming that all files in true HD will be transcoded until samsung rolls out a firmware update for my tv?

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Luke

We are looking into this. Thanks for reporting.

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FrostByte
Posted (edited)
On 6/14/2020 at 5:55 AM, Embyuser3600 said:

As a broader question, am I correct in assuming that all files in true HD will be transcoded until samsung rolls out a firmware update for my tv?

Do you have one of the models which supports eARC? 

What happens right now if you turn off audio transcoding in your user settings?  Does it passthrough to your soundbar that supports TrueHD, or does it throw up a furball?

 

  @SamES and Luke might need to account for these models

https://www.hardwarezone.com.sg/tech-news-these-are-2020-samsung-qled-tvs-support-hdmi-21-4k-120hz-and-earc

 

Dolby Atmos via TrueHD via eARC  Yes
DTS:X via DTS-HD MA via eARC  No

 

Edited by FrostByte

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FrostByte

Using .81 when playing a movie which converts an unsupported audio I can pause and resume a movie with no subtitle issues, but if I skip forward or backward the subtitles are immediately out of sync.

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psxlover
Posted (edited)

Pausing/resuming in the video player (if that's what you are talking about @FrostByte) was not an issue, it was stopping the video completely and later resuming it.

@Luke I will hopefully test it over the weekend, I believe I've kept at least on episode.

Edited by psxlover
Stupid space triggered send...

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Luke
43 minutes ago, FrostByte said:

Using .81 when playing a movie which converts an unsupported audio I can pause and resume a movie with no subtitle issues, but if I skip forward or backward the subtitles are immediately out of sync.

What format subtitles?

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FrostByte

I was using SRT.  It only took one skip forward to make it go off.  

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Luke

Can you attach the ffmpeg log? thanks.

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psxlover

One thing I noticed, is that playing ssa subtitles is broken. Not sure if it was broken by this version, or a previous one, I think I was using .77 or .78 before.

Seems like that as soon as the subtitle is extracted/transmitted to the application, the screen turns black (up till that point it is displaying the video).
Will have to troubleshoot when I get the time.

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psxlover

ssa subtitles issue introduced in .79, so I guess I'll open another thread for it when I get the chance to gather logs (unless if someone else reproduces it/posts logs).

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