Scrubbing problem

[Hercules20 4]

Hi there, through some searches about my issue, I’d also like to add that I am experiencing a similar issue.

I’ll point out that similar to RTVstyle, the Apple apps seem to have trouble with direct play with MKV containers. I do see during playback that the file plays correctly, but I can only skip forward and backward. I am not able to scrub to a specific time in the file. I’ve encountered this issue on Apple TV, iPad, and iPhone.

If I convert the file to MP4, I am able to scrub as normal. 

[Luke 37070]

Hi @Hercules20what exactly happens when you try to scrub an mkv? Can we please look at an example?

How to Report a Problem

Thanks.

[Hercules20 4]

When I scrub an MKV file on Apple apps generally, I see two potential examples.

Example 1: I see the MKV file play from the beginning on direct play. When I scrub forward, the video plays as normal and ignores the attempt. I can skip forward and backward however many times I like, but I cannot scrub. I can change the quality of the file low enough to transcode the playback, and then I am able to scrub normally.

Example 2: I see the MKV file play from the beginning on direct play. When I scrub forward, the video playback returns to the beginning, plays for 1 second, then returns the beginning again, and resumes regular playback. I can skip forward and backward normally. If I scrub, then video playback returns to the beginning of the file.

This happens as well on Google Chrome, and Brave Browser.

When I read that the problem may be associated with MKV, I ran a conversion within Emby to MP4. Apple apps appear to playback the MP4 file without issue, and I was able to scrub normally.

This log was with Apple TV.embyserver (1).txt

[Hercules20 4]

A follow up question. 

So far I've worked around this by simply changing the Internet streaming bitrate limit to 2 - for the most part triggering transcoding.

Is there an option to transcode mkv to mp4 on demand?

[Luke 37070]

@Hercules20Hi, can you please try Emby for iOS 2.2.14 and let us know how that compares? Thanks.

[Hercules20 4]

On 03/11/2023 at 12:03, Luke said:

@Hercules20Hi, can you please try Emby for iOS 2.2.14 and let us know how that compares? Thanks.

No change.

If my issue is observed, then it will typically be an MKV file. 

Only reliable solution appears to be converting the MKV to another container, such as MP4.

Alternatively, if the player adjusts quality automatically and triggers hardware transcoding, the player is able to play the file as expected.

Of course, the user can also adjust the quality down until hardware transcoding is triggered.

Another option is to use an app mentioned elsewhere, such as Infuse, to playback files without issues.

[pwhodges 1531]

3 hours ago, Hercules20 said:

If my issue is observed, then it will typically be an MKV file. 

"Typically" implies that sometimes it is not an MKV file...  So is it always an MKV file, or is it sometimes not an MKV file?  And do all MKV files have the problem, or only some?

Paul

[Hercules20 4]

13 hours ago, pwhodges said:

"Typically" implies that sometimes it is not an MKV file...  So is it always an MKV file, or is it sometimes not an MKV file?  And do all MKV files have the problem, or only some?

Paul

MKV files for movies have this scrubbing problem consistently.

Some MKV files for TV shows that are typically shorter in duration have this problem. But, some times these MKV files playback normally or they take a longer period of time to start playback, but plays normally once it gets going. 

I note that it is nice some times during playback on browsers that the player triggers transcoding and sets the quality at nearly the same as the original file so I can enjoy the same quality.

[speechles 1919]

What is the MKV made of?

All MKV are not the same.

Using MKVToolNix GUI you can see inside the container. You might see these things called "Global tags" as entries.

I know these "Global tags" cause problems with the Roku as it must have the entire file before it can change audio streams and/or subtitles/captions. Try using MKVToolNix and see if you need to remove tags then start remux. Once you remux it will create a stream friendly MKV. That might be all you need to do. Also, some ripping programs (handbrake is one of them) will place chapters at the end of the file rather than the front. This will cause the issue of needing to download the entire file before you can seek. Using MKVToolNix (a simple remux) will properly arrange these at the beginning so they allowing seeking the stream immediately.

 

Edited November 7, 2023 by speechles

[Hercules20 4]

Thank you all for your responses.

@speechlesI'll have to take more time to explore this issue as you suggest. I was not able to open the MKVToolNix application since it seems the app is not immediately well supported on MacOS. 

With the time I did have though - and definitely a rabbit trail of my own making - I was originally running the binhex docker for Emby. I did casually wonder if it was a docker issue and moved over to linuxserver. I am at least pleased to report that the same MKV playback issues are observed in both projects.

In the meantime, I did discover the Automatic Conversions feature within Emby so in the interest of trying to resolve my issue in a timely fashion I will be solving this.

For what it's worth, using Emby to convert an MKV file to an MKV file does not solve any of the observed issues with playback. Perhaps one day a solution can involve having Emby bring an MKV file back into some acceptable form for normal playback.

From what I can tell going through posts in the forums and elsewhere online, this issue appears to be an evergreen issue over the years.

[Hercules20 4]

As of the most recent Emby update released recently (4.8.0.80), I would like to share that the scrubbing issues noted here appear resolved.

From my experience using the Emby App for iPhone, I no longer observe the scrubbing issues after the update.

Congratulations to the Emby Team for rolling out this update.

[Luke 37070]

Thanks for following up.