Stuttering playback on Apple TV (Windows Server 2019)

Channels Apple TV Troubleshooting
#23

If we've ruled out the network, the next obvious candidate is the I/O or CPU capacity of the DVR server.

Things that are confusing us about this situation:

  • We don't see anything in the logs that say there were issues decoding the content
  • We don't see anything in the logs that say it is dropping frames due to not being able to decode fast enough

The thing we do see is the amount of data cached in the client continuing to drop as you watch, which looks like it is unable to download more content fast enough.

This would lead us to believe that the issue is either in:

  • The network not being able to keep up with the sustained bitrate
  • The disk of the DVR not being able to keep up with the sustained bitrate
  • The CPU of the DVR not being able to respond to requests fast enough to send the data

It doesn't appear there's anything wrong with the content or the Apple TV app that we can see.

#24

Okay so we are getting somewhere now. I highly doubt the server is the issue here. Ill post the specs but the storage is based on a RAID 5 with 8 Disks installed. The Hyper-V Switch is dedicated to 1 of the two NICs in the server.

As mentioned before, i have no other issues with Live TV or Streaming 4K content from Plex which are all on the same physical box. 17

#25

Server logs from the Data drive. Let me know if im looking in the wrong place

https://www.icloud.com/iclouddrive/0TFjFTkt1u7tpWY11FFn1DuHg#Logs

#26

Go to http://localhost:8089/log to see the DVR logs.

#27

DVR Logs:

https://www.icloud.com/iclouddrive/07rqhafd3T8Lg8HJIr1Kor4DA#Channels_Logs

#28

Also please see disk speed test for the VM.

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Screenshot 2020-01-30 at 18.38.30.png978×708 427 KB

#29

Are we any further forward?

#30

Also I don’t think this is a network issue as if you reboot the Apple TV the remaining playback is fine and usually the next programme after that is fine as well.

#31

I have an Apple TV and its not a Channels DVR issue. I have this happen several times a week. You just have to restart your Apple TV when this issue occurs. When the Apple TV is up the issues go away.
When I goto my HD Home Run App. The stuttering occurs also. Reboot then all is normal. Must be something with the buffer on these Units.

#32

That must be pretty frustrating. I guess it is an easy fix to restart the AppleTV, but still weird. I haven't experienced this on my 2019 Nvidia Shield box, but I did have it happen twice on my 2019 Tube Shield. A restart took care of that then as well.

Strangely enough the problem hasn't come back as long as I leave the shield on the list of tv shows in the Channels App. If I exit out to the main menu, that is when I would get the stuttering issue on the 2019 tube shield. Not enough data points to say if backing out to the main menu causes an issue, but the problem hasn't returned for a few weeks since I have been leaving it in the channels app.

#33

Nope not frustrating. It's like computers, You have to reboot them from time to time. At least the Apple TV doesn't take 10 minutes to reboot like the old ones did. 30 secs and up and away. All devices have to be rebooted at some point. I'm used to it and don't mind. Its when they reboot and same issue occurs or new issues. Also learned that Apple TV likes hardwired better than the WIFI. Most streaming issues occur with WIFI on mine.

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#34

Do you still have one of the recordings that had this issue? If you mark it as un-watched and then go to a little before the spot it had the problem does it happen again at the same place?

If it isn’t an issue with the DVR or the network, the only other thing I can think of is an issue with the content.

#35

Yes I have the files. It happened again tonight, stopped the recording and watched the rest of it on my iPad with no issues at all.

#36

If you play the same recording on your Apple TV again can you make it happen again?

#37

I'm also seeing this issue across three different ATV 4Ks. When it happens, it looks exactly like the video that Danny uploaded.

I've got both the Channels beta and generally available app installed on my ATVs and am using the pre-release version (2020.01.23.0005) of the DVR server.

If I see the issue happening in the GA release, I can switch over to the beta app, and it happens there, too. It also happens at different points in the content and on different shows.

If I stop playback and resume it, it might resolve itself for a couple of minutes, but then it starts stuttering again. As others have mentioned, rebooting the ATV always resolves it.

Like Danny, I'm also using Server 2019, but it's a bare-metal install with 8GB RAM and 2x WD Red drives in a mirrored pair using Storage Spaces with ReFS. When the issue happens, the CPU isn't pegged, the network utilization is at 1-2%, and memory usage is low. I'm also hardwired at 1 Gbps.

I've been experimenting with different NIC settings to see if anything there might help. I've tried changing the EEE profile, disabling EEE, adjusting the number of RSS queues, and adjusting the receive and transmit buffer values. The frequency I've seen it happen has gone down what seems like a good bit since adjusting the settings, but I don't know if it's just purely coincidental.

#38

I noticed you have a non-4K Apple TV and are watching iTV. I wonder if we're running into issues de-interlacing the video on the Apple TV.

#39

I’ve wondered the same thing, as I’ve also had noticeable but subtle stuttering on interlaced content. And it seems to get worse the longer you watch. Makes me wonder if the chips are struggling to keep up, and as they really heat up they are being throttled for heat management, making the stuttering even more pronounced. The non-4K models have passive cooling only.

#40

It’s completely random as to when it happens. I can close the recording and play it again and it will play fine for 10 minutes and then happen again. As other people have said, a reboot of the Apple TV fixes the issue.

#41

Issue also happens across most channels, even SD content.

#42

Wow. That’s a very interesting data point. There’s certainly something odd going on.