Can't seek live transcoding

[MBDino 2]

I'm resuming playback of a 2 hour-long movie on my Chromecast. Emby will need to seek to the time where I left off and resume playback. However, it never starts playback, or at least not within 30 minutes of waiting.

This happens with a lot of movies. I believe it only happens if Emby decides it's necessary to transcode the audio track (no doubt, rightly so). If I resume the same movie on my desktop then it works fine and there is no Emby transcoding. If I use Handbrake to transcode the movie, the transcoded movie works fine on Chromecast.

Playing from the start works fine. However, if I seek then it will similarly just stop playing back.

Attached is an image of the session. I believe the red bar indicates it's finished the Emby transcoding.

This is with Emby v 4.8.10.0, though I had the same problem with v 4.7.14.0.

 

[Gilgamesh_48 1240]

I have noticed that as well, i think. I have found that if I attempt any trick play on a stream that is currently being recorded or for about 10 minutes after the stream ends. For me this has not been a problem for me but it is something I have noticed. It seems that live TV that is recording must do some kind of post-processing and, without that, trick play just does not work well. I know Emby has some problems with live TV playback of a currently recording show in that the "end" time is in constant flux and something about playback requires that the end be unmoving. 

I very rarely run into the issue because I do not join in-progress programs more often than once every three weeks or so but I hope Emby is digging into improving the watching of an in-progress program. 

I want Emby to be perfect but I understand there is only room for one "perfect" entity and I fill that spot quite well.   

[MBDino 2]

Bump on this, still a problem. I imagine Emby should be able to seek even if it has to do a transcode?

 

Gilgamesh_48, your issue might be similar, though I'm not playing a recording from TV and I don't see it fix itself after 10 minutes. 

 

[Carlo 4561]

On 10/6/2024 at 10:13 PM, MBDino said:

I'm resuming playback of a 2 hour-long movie on my Chromecast. Emby will need to seek to the time where I left off and resume playback. However, it never starts playback, or at least not within 30 minutes of waiting.

This happens with a lot of movies. I believe it only happens if Emby decides it's necessary to transcode the audio track (no doubt, rightly so). If I resume the same movie on my desktop then it works fine and there is no Emby transcoding. If I use Handbrake to transcode the movie, the transcoded movie works fine on Chromecast.

Playing from the start works fine. However, if I seek then it will similarly just stop playing back.

Attached is an image of the session. I believe the red bar indicates it's finished the Emby transcoding.

This is with Emby v 4.8.10.0, though I had the same problem with v 4.7.14.0.

 

 

Hi there, let's look at an example. Please attach the information requested in how to report a media playback issue. Thanks!

 

[MBDino 2]

Thanks @Carlo. I worked through the information request. It is attached, slightly anonymized for my privacy. No error messages on my TV screen. Emby App is on Android.

Let me know if this is what you need.

 

embyserver.txt ffmpeg-remux-e1a6b1f7-354f-43bf-84a8-75ef3ebdb2d6_1.txt

[Carlo 4561]

What kind of device is your Chromecast?

[iiiJoe 62]

Following. I too have experienced a similiar issue with watching recordings in progress on a client device (Shield). In my case, when trying to seek the stream will freeze completely or go back to the very first frame of the recording and freeze there. Sometimes if I wait long enough it will restart, other times I have to restart the stream. I've found that if I FF through large chunks of video it happens almost every time whereas if I seek slowly it happens less frequently.

[MBSki 1114]

Yea, this is an extremely well known issue and I'm not aware of anything being changed to fix this issue. @CarloIt would be great if you were taking over as point on this issue. You've seen all the other traffic regarding seeking live recordings right? There are plenty of examples to choose from.

[Carlo 4561]

44 minutes ago, iiiJoe said:

Following. I too have experienced a similiar issue with watching recordings in progress on a client device (Shield). In my case, when trying to seek the stream will freeze completely or go back to the very first frame of the recording and freeze there. Sometimes if I wait long enough it will restart, other times I have to restart the stream. I've found that if I FF through large chunks of video it happens almost every time whereas if I seek slowly it happens less frequently.

Hi,

Are these recordings being transcoded while watching by any chance?
If you look at the server dashboard for the user playback of the transcode, is the server having to transcode the file and play catch up to where you FF to? 

Carlo

PS If you install the Diagnostic Plugin from the catalog you will have a new menu option called User Sessions which gives you a nice view of playback information.

2 hours ago, MBSki said:

@CarloIt would be great if you were taking over as point on this issue. You've seen all the other traffic regarding seeking live recordings right?

I'm watching and asking for information I think might be useful to aid the devs, but this is something the devs needs to look at and diagnose/fix.

Carlo

[MBSki 1114]

I know you weren't asking me, but my recordings are NOT being transcoded that I know of. However, the only way I can get seem to work at all is to FORCE transcoding by changing the quality.

[ebr 16184]

13 minutes ago, MBSki said:

I know you weren't asking me, but my recordings are NOT being transcoded that I know of. However, the only way I can get seem to work at all is to FORCE transcoding by changing the quality.

If they are still TS files, some players are not going to be able to seek those as they aren't designed to be seekable.

[iiiJoe 62]

1 hour ago, Carlo said:

Hi,

Are these recordings being transcoded while watching by any chance?
If you look at the server dashboard for the user playback of the transcode, is the server having to transcode the file and play catch up to where you FF to? 

Carlo

PS If you install the Diagnostic Plugin from the catalog you will have a new menu option called User Sessions which gives you a nice view of playback information.

I'm watching and asking for information I think might be useful to aid the devs, but this is something the devs needs to look at and diagnose/fix.

Carlo

Really nice plug in! Ty. Tried several devices and they're all direct play. Question: Looks like I'm decoding and encoding with software. Could the seek issue be mitigated through hardware decoding/encoding? Can you please advise how I would change the decoding/encoding options?

Edited October 10, 2024 by iiiJoe
update

[iiiJoe 62]

1 hour ago, iiiJoe said:

Really nice plug in! Ty. Tried several devices and they're all direct play. Question: Looks like I'm decoding and encoding with software. Could the seek issue be mitigated through hardware decoding/encoding? Can you please advise how I would change the decoding/encoding options?

Or force hardware use instead of software.

[Carlo 4561]

2 hours ago, iiiJoe said:

Really nice plug in! Ty. Tried several devices and they're all direct play. Question: Looks like I'm decoding and encoding with software. Could the seek issue be mitigated through hardware decoding/encoding? Can you please advise how I would change the decoding/encoding options?

Check the Transcode Menu in the Dashboard.

https://emby.media/support/articles/Transcoding.html

 

What client are you using?

Edited October 10, 2024 by Carlo

[Carlo 4561]

2 hours ago, ebr said:

If they are still TS files, some players are not going to be able to seek those as they aren't designed to be seekable.

Yes, but should it not transcode in that case, assuming Live TV settings are correct?

[MBDino 2]

12 hours ago, Carlo said:

What kind of device is your Chromecast?

@Carlo OP here. It's a Chromecast with Google TV (4K).

My logs are not a live TV recording nor are they from a TS file, they're from a file I copied to my hard drive.

In addition to the behavior I described, I also see what iiiJoe described below even through they're using a different playback device.

Quote

Following. I too have experienced a similiar issue with watching recordings in progress on a client device (Shield). In my case, when trying to seek the stream will freeze completely or go back to the very first frame of the recording and freeze there. Sometimes if I wait long enough it will restart, other times I have to restart the stream. I've found that if I FF through large chunks of video it happens almost every time whereas if I seek slowly it happens less frequently.

 

 

[MBDino 2]

I figured out the User Sessions thing. Attached is a screen shot in case it helps (excluding my name and info). You can see that audio transcoding was necessary and it's complete. The screen is still frozen. The Play Position time continues to increase even though the screen is still frozen. You'll see from my embyserver.txt that it's getting reports of increasing play position even though the screen is frozen.

 

[ebr 16184]

13 hours ago, Carlo said:

Yes, but should it not transcode in that case, assuming Live TV settings are correct?

Not necessarily.  Depends on the app.

[Carlo 4561]

1 hour ago, ebr said:

Not necessarily.  Depends on the app.

I guess that's kind of confusing at the UI. If a client can't use trick pl;ay on a particular file/stream type, would it not be better if we didn't allow those functions in the UI?

Could the AndroidTV approach work on more clients, where it can be configured to direct stream, if possible, but switch to transcoding for trick play during playback?

This doesn't answer why playback issues occurred for @MBDinoas this was an MKV file that appears to have fully transcoded/remuxed the stream.

Carlo

PS I'm aware TV's mpeg-2/TS (transport stream) format was designed for linear broadcast in a longtime past era. It can be a hot mess and cause of many compatibility' issues for advanced media servers like Emby, that push the technology far beyond its intended use, especially when trying to support client devices lacking proper functionality for this. It really is a truly amazing feat what Emby has been able achieve with LiveTV streaming, yet a few client/conditions often make for less than a stellar TV functionality despite these achievements.

@ebrI was thinking we could resolve many Live TV streaming and trickplay issues if the server were to transform/save/provide HLS segmented stream. This should normally be pretty trivial on server resources and would provide the timing info currently missing for proper trickplay functionality as well as fast resume play. Optionally, we could transcode the stream during transformation to reduce bandwidth and required segment transfers during viewing by the client(s).

This could provide numerous benefits like eliminating the need by each client to remux/transcode (not bandwidth related) the stream. The overall performance benefit would be more pronounced, the greater number of clients using the stream. Having the HLS segmented streams available with timing should allow fast resume play, on long duration recordings, regardless of resume watching position due to lack of often required remux/transcoding generally needed to find the resume point in the media.  It would be fantastic having 3 or 4 NFL games recording while being able to easily jump between them resuming where you left off. This in fact would be a "game" changing way to watch sports and no doubt help make Emby a "go to" solution for consuming sports.

Putting aside the optional transcoding, do you agree, having HLS segmented streams for TV/recordings could help resolve many issues and greatly improve the LiveTV experience?

[ebr 16184]

19 hours ago, Carlo said:

I was thinking we could resolve many Live TV streaming and trickplay issues if...

Once we get through 4.9 we should be able to start moving forward again with the Live TV enhancements Softworkz has made so that should hopefully take care of this stuff.

[MBDino 2]

I think my question spun off into a Live TV thing. 

@Carlo, what were you able to get from those log files I put together?

 

[Carlo 4561]

This is likely going to need new code to try and handle this better.

@ebrjust mentioned above that once 4.9 is done, we should be able to integrate Live TV enhancements Softworkz has already made.