Show in LiveTV pixelates a lot but its recording is Ok

Channels Apple TV
#1

Since this morning , I have issues with LiveTv.
The image pixelates like if the signal was pretty weak. It happens with all channels. If I record the show and look at it later it’s ok.

I’ve rebooted the server and the AppleTv . it still happens. (does not happen with LiveTv with the Browser nor iOS app)

Any ideas?

Server: 2021.01.15.1649
AppleTV : 4.3.3

BTW: I haven’t upgraded the server since my first install few months ago. I’m really surprised to see the version I have. Is there an option that makes the server upgrades itself automatically?

#2

What is the source? By default, live TV streams go from the tuner to the client, bypassing the server. If that's the case for you, that indicates a network issue between your client device and the tuner.

#3

The source is OTA channels with HDHomeRun DUAL.
Is the LiveTV stream direct with iOS client too? Because I have no issues with my iPhone in the same room as the AppleTV.
TBH, I'm quite sceptical about a network issue but we never know. I'm gonna try to plug an ethernet cable to the AppleTV to be sure in not the WiFi.

#4

@racameron, thanks for the help.
I have tested with the HDHomeRun native app and the same error occurs.
I'll investigate.

#5

By default, yes. This is controlled on a per-client basis with the Tuner sharing option. When that option is enabled, OTA streams pass through the DVR server before being served to the client.

If you have no problems with recorded content, you may want to try enabling that option in your clients to see if it helps.

Since this is happening there, too, it reasons that the issue is between your client and the tuner. By extension, to me that points inherently to a network issue.

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#6

Since this is happening there, too, it reasons that the issue is between your client and the tuner. By extension, to me that points inherently to a network issue.

Unfortunately, I have to admit you are right :stuck_out_tongue:
Turning the option on fixes the issue.

I'm really surprised that it can be a network issue because I have gigabit everywhere and I only enable 5 Ghz band. The maximum bandwidth required by OTA channels in my area is 19 Mbit/s. My local network should be able to support this without any issue. (Speedtest reports from the AppleTV 300 Mbit/s with 0 packets loss).

Any idea how to figure out where the issue could be?

#7

Interference is a common issue, as is traffic/noise on the wireless network. Move your wireless AP/router 3ft away from other electronics, as well as each client.

Remove as many points between source and client to narrow it down.

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#8

I'm using ubiquiti APs mounted on the ceiling. It's gonna be hard to move it 3ft away ;-(
Thanks again

#9

In that case, when you have some down time in your network you may want to do an RF scan on each AP to see which channels have the least interference. Also, if you're using current generation APs, it'd be best to give each AP its own channel rather than the same or overlapping channel numbers. (Older UAPs needed the same channel number across APs to use the zero-handoff feature.)

But, if hardwiring is an option, that is always the recommended choice.

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#10

As I said, I'm only using the 5 Ghz band, so overlapping is pretty rare. According to the controller everything is fine.
Thank you for your advice.
I know what are my plans this week-end: Go through walls and plug my AppleTV with an ethernet cable :wink:

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#11

I experienced a similar issue when I relied on my 5 GHz WiFi. Theoretically, the bandwidth should be available.

It all went away when I ran ethernet to every Çhannels box.

It is a bit of a hassle but it makes an incredible difference.

#12

My personal experience with Unifi/Ubiquiti isn't especially favourable recently - there have been a LOT of bugs for me, using AC Pros the firmwares have been hit or miss at best, when adding in tagged VLANs often throughput plummets. Not to mention all their 'auto optimize network' stuff often causes more problems than anything.

I completely skipped, rolling back every 4.3.x release, 4.0.80 was a nice stable firmware on my AC Pros - so I stayed with that. Eventually, only in the last few weeks, did I start playing with 5.43.x branch - again, for me, 5.43.23 on switches and 5.43.24 on my AC Pros is comparable to the earlier 4.0.80 (4.3 was utterly horrendous for me).

#13

I could not see anything which could explain the problem I had. According to the controller, the interference are low in the channel I use. I do have the "auto optimize network" turned on which - IMHO - does it job in my case.
Anyway, ethernet cable is almost there, the problem should be fixed.

#14

Hello again,

@racameron, one more question? Why having the stream served by the server instead the HDHomeRun, changes something?
I mean if the issue is related to interferences on the WiFi band, the interference still occurs whatever the source? Maybe the server re-encode the stream at a lower bitrate or/and use a buffer to catch up in case of lost packets?

#15

The path the network stream takes is different. Without knowing your network topology, I can't answer that question more specifically. Unless you've changed the "Streaming Quality" setting in the client, the stream that is received by the client is exactly the same.

The default client setup goes:

  • Live stream is requested from tuner
  • Tuner sends stream to client ( tuner -> network -> client)

With "Tuner sharing", it goes:

  • Live stream is requested from the DVR server
  • Server requests stream from the tuner (tuner -> network -> server)
  • Server sends stream to client (server -> network -> client)

Based upon that information, it might be that there is some issue in network hops between the tuner and the client device that do not exist between either the server and the tuner, nor the server and the client.

     tuner
    /     \
   /bad    \ok
  /         \
client --- server
        ok
#16

Thanks for your very detailed answer.
The server, the UniFi AP (AC-LR v2), the HDHomeRun are plugged in the same switch. I haven't touched any settings so it should be the same.

In that case:

  • tuner -> switch -> UAP-AC -> AppleTV
    vs
  • tuner -> switch -> server -> switch -> UAP-AC -> AppleTV

So I cannot figure out where the issue can take place.

#17

Does protocol vary? UDP from tuner, TCP from server?

I don’t have an HDhomerun, just throwing it out there

#18

For older HDHomeRun tuner models that do not support it (Gen 3 and earlier, except for the Prime and Expand), the tuners must be accessed with libhdhomerun, over UDP/RTP. For current Gen4+ (and the older Prime and Expand), streaming happens over HTTP/TCP.

If your tuners are current, then everything is TCP.

#19

Mine is old :wink: Gen 2.

#20

If that's the case, potentially when you stream direct it's UDP - when it goes via the server it's UDP to the server, TCP from the server.

UDP can be susceptible to loss if the network is 'iffy'- this is/was one of my major issues with Unifi recently, UDP goes walkies on some firmwares with my AC Pros, and on the off chance you have any Flex Mini's, seen it with those too.

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