Server Version#:1.13.9.5439
Player Version#:Web Client 3.73.1 running on Chrome under Windows 10
My Plex server is running on Linux Mint 19 using an Intel NUC NUC7PJYH. For a TV tuner I am using the HDHomeRun Quatro.
When I start to play a live channel or a DVR recording, the playback looks fine for a few seconds and then starts to pixelate for a period of 20 or more seconds. The amount of time it pixelates seems to increase for SD broadcast as compared to HD broadcasts. It appears that the server is trying to adjust the transcode quality during this time since the amount of pixelation varies, and then it decides it can transcode to the max quality, which it had no problem with before the pixelation started. After that, playback is fine.
This is a pain since it means changing channels takes almost a minute before you get a good picture. It’s also a pain because it frequently happens after fast forwarding a DVR recording.
This happens on ANY Plex client that requires live tv to be transcoded to H.264, like the Roku or the web client running in the Chrome browser.
What you see is directly related to signal bitrate from the provider.
I their bitrate is low, knowing the LiveTV/DVR must catch up to the reference frame(s), it will take time.
Access your tuner’s UI and look at the signal quality and bitrate. This will tell you a great deal.
The signal strength, quality, and symbol quality are 100% on the tested channel, 1080i. The network rate is jumping around from 12->16 Mbps. That is not the issue, but it is an easy answer. There is no issue when watching with the HDHomerun apps and it doesn’t explain the problem with the DVR recordings doing the same thing when I start them and after I FF or REW them. It also doesn’t explain why it only happens at the start of play and not after.
Plex DVR/LiveTV segments each recording into 1 second blocks.
When you FF/Rew , it goes to the point where you selected and starts playing it.
Once sufficient data has been streamed, you then see the image as it should be.
That sounds good, but the problems go away when I disable HW transcoding. Of course, then the CPU is about maxed out doing the one transcode. I tested the same system but running Windows 10, and for some reason, there is still no support for HW transcoding in the Windows Plex server for this GPU after all this time?
If you watch this video, https://www.youtube.com/watch?v=4Kn6zMVWGgM&t=240s, at about 2:20 you will see an example of the issue I have been talking about with Live TV on the Roku. He’s using a My Cloud PR2100 as the Plex server.
A NUC7 covers a wide range of processors, from the low end such as mine to an i7.
Your QNAP isn’t what I would call a SOHO NAS with that processor and at that price point. I can get a very high-end Synology NAS for a fraction of the cost of that QNAP.
I’m not surprised that with higher-end Intel processors you can’t replicate this issue. I have a NUC8 Haydes Canyon running Windows 10 and I don’t see the problem there. I can’t say if it is Linux vs Windows issue since I am not going to bother building a Linux Mint system for my NUC8, and as I said, H/W transcoding is still not working for my NUC7 after the issue was reported way back in April. See this https://www.youtube.com/watch?v=o82NWFnoDZw&t=400s video from a Plex supporter.
The issue is only when DVR playback or live TV starts up. Neither the CPU or GPU are anywhere near maxed out in this case on my NUC7 running Linux Mint. After the issue clears up there are no further problems. The fact that the problem does not occur with HW transcoding disabled on that NUC, and that the problem is only at startup, tells me there is an issue in the HW transcoding.
Before you say I need a more powerful CPU, see this https://www.youtube.com/watch?v=TIzvr3EVCOs. According to this, the slightly less powerful CPU used in this NAS is Plex approved.
I think that would be an i3-7100, no such thing as an i7-7100. The 7 in Nuc7 refers to the Intel Generation. The CPU would be roughly equivalent to the J5005 on my NUC. Mine has 4 cores and no hyper-threading well the i3-7100 has 2 cores and is hyperthreaded. The big difference would be in the Intel GPU. The i3-7100 has a 620 vs the J5005’s 605, roughly 33% more performance due to 24 vs 18 execution units. The My Cloud NAS I’ve referred to has a 405 GPU with 16 execution units. The GPU base and boost clock frequencies are also less.
Mint is Ubuntu+ and the transcoder and plex server run fine on Mint.
Being the primary Linux support provider, I can tell you Mint, while a Ubuntu derivative, is not Ubuntu.
I cannot begin to count how many have attempted Mint and failed.
Should you choose to use it, I can offer no support.
Agree, not the stations fault. Its has to be a Plex issue. I have run nextPVR and Hauppage Win85 using the 1230 PCIe Hauppage card and do not have this issue. I have now added the HDHomerun Quatro and when using HDHomerun software the picture is perfect when I use either of these tuners, Hauppage or Quatro via the Plex player I get the pixelation shortly after startup and randomly thereafter. Experience with both live broadcasts and DVR. I have not purchased the DVR package from SiliconDust as of yet. Also PC system consists of W10, I7-980X, GeForce 730 w/2GB ram.
