Playback quality issue

[Michael K. 24]

Issue: poor quality playback on Apple TV with specific videos

 

Symptoms:

- stuttering (not smooth video playback)

- video pause while audio continues (a few seconds of video will play and then the video freezes while audio continues to play)

- pixelation (very noticeable artifacts in the video quality)

 

Conditions:

- Direct Stream

- MKV containers not compressed - 1:1 ISO rip

- Occurs with SD (480) and HD (1080)

- I've noticed this issue for about 2 years of using Emby

 

Troubleshooting:

- built new server a few times (hardware)

- clean reinstall of Emby server software with each new server hardware build (did not migrate any settings)

- tested different Apple TV versions (upgraded from Apple TV 3rd gen and 4K)

- changed all network equipment (wiring, router, switch)

- tried wireless vs. wired Gbe

- ripped new ISO and converted new MKV container

 

Workaround:

I can eliminate all of the symptoms and accomplish smooth playback by forcing the video to trans-code. I force the trans-code by selecting a subtitle.

 

Logs attached

- embyserver.txt - I restarted the server/Apple TV, played one of the videos, observed issue, and then saved that log

- ffmpeg.txt - i noticed this log has the same time stamp.

 

Please advise, thanks.

Edited August 17, 2018 by Michael K.

[Luke 37063]

Hi, can you try setting the server's transcoding temporary folder back to the default value, rather than on your E: drive? thanks.

[Michael K. 24]

I just changed it back to default, restarted, and tried again, but playback did not improve.

 

Note: the alternate trans-coding path I have set (E: drive) is a an SSD Samsung EVO 960. I have tried different drives while building new servers, with default and alternative paths, but all produced the same result.

 

Please advise, thanks.

[Luke 37063]

Can you try with some lower bitrate content? Thanks thanks.

[Michael K. 24]

I just took a look at the bitrates of 16 of the videos that I've identified with issues:

 

the lowest bitrate is 21,891

the highest bitrate is 42,345

 

Here is the list of bitrates:

21,891

23,311

24,253

24,295

30,911

31,820

33,428

35,105

35,174

36,456

36,675

36,937

39,538

40,144

40,332

42,345

 

I just looked at videos within this same bitrate range, which play fine with direct stream:

30,422

32,777

36,000

39,929

41,045

 

Please advise, thanks.

[corey 312]

Unfortunately Apple's player is a bit finicky about what it supports and there's no documented information regarding upper bounds on content that may be too high a bitrate. There's probably a few other dimensions to consider as well. This issue has been reported a number of times as well and I've experienced it myself with a few scenes in Blade Runner 2049. We've reached out to Apple but haven't gotten the help we've wanted.

 

With that said we're currently working on replacing the Apple player with a custom one so hopefully these issues will be resolved once and for all.

[Michael K. 24]

Interesting. I didn't think it was my server or network. I suspected it was the Apple TV not handling the stream/format. I wasn't expecting a quick fix, but at least we know more or less what the issue is. I can work around it for the moment.

 

Can't wait for the new player!!

 

Thanks to both of you for the quick responses. Keep up the good work.

Edited August 24, 2018 by Michael K.

[Michael K. 24]

@@corey,

 

Do you know of a way I can force transcoding (avoid direct stream/play)?

 

The reason is that when watching on my Apple TV via my LAN, Emby detects the stream to be capable and therefore sends a direct stream. As we know, Apple TV can't handle the bitrate, but Emby doesn't detect it... so I need to force trancoding as a work around until a new player becomes available.

[Luke 37063]

Yes just set the max quality setting in the app's settings, and that will keep the bitrate under whatever value you specify.

[Michael K. 24]

I'll play around with that. Thanks!