Live TV/Recordings have glitches/artifacts - hdhomerun

[seanzi01 0]

I'm currently using NextPVR/Kodi but trying to switch to Emby. I'm doing this because eventually I'd like to do all my recording and media storage on a NAS instead of the single Win 7 PC I'm using today. 

 

To see how everyone in my house likes Emby I'm just running Emby server and Emby Theater on the same Win 7 box I've been using for NPVR/Kodi. However, I've noticed that my recordings and live TV tend to have more glitches or artifacts in them when using Emby than when i use NPVR/Kodi. The gliteches occur often enough that it makes atching TV or recordings kind of annoying. And a barrier to a full switch to Emby. I'd say it's a signal strength problem but these issues only occur on Emby. I've done several tests and Emby always has more glitches than NPVR/Kodi. I even tried recording the same show on the same channel with the same HDHomeRun tuner in NPVR and Emby at the same time. The NPVR recording is nice and smooth and the Emby glitches. I realize 2 simultaneous recording is more work for the PC but the same issue occurs when doing a single recording with just Emby. I see the glitches when playing back in Emby Theater or Windows Media Player. So I'm pretty sure it's a recording issue.

 

Is there anything I can do to fix the glitching issue?

 

Here is a screenshot of what I'm talking about. This same spot in the NPVR recording looks just fine.

 

Thanks for the help.

embyserver.txt

[Luke 42078]

Hi there, was there an ffmpeg log? Can you please attach that too? Thanks !

[bla8291 1]

I've seen this happen on my system too. It only happens on some channels. I don't think it's Emby though because when I stream those channels directly from the HDHR, it still happens.

[seanzi01 0]

Luke,

 

Thanks for getting back to me. There were actually several ffmeg logs from around the time of the recording. I don't know which one is relevant so I attached them all. Hopefully that is helpful.

 

Based on @@bla8291 comment I tried watching TV through the HDHomeRun interface. Watching a few different channels, including the one I made my recording in, I see almost zero glitches. I saw none on the channel I recorded earlier. And only 1 on another channel. I also had to watch a good bit longer to see a glitch than I do when using Emby.

ffmpeg-directstream-2be8f299-ca3d-414e-b1ab-3d55603c0be9_1.txt

ffmpeg-directstream-6d5f573c-dfcd-4a27-9e11-7e04b71e97f5_1.txt

ffmpeg-directstream-80df3d34-cd09-429e-8869-f8ea580c6613_1.txt

ffmpeg-directstream-b22ed97d-fa1e-4f40-a64b-0b8275c4a98b_1.txt

ffmpeg-directstream-cc3f4b29-b8c6-4c77-bc51-c9a9d8f0ce25_1.txt

[Luke 42078]

If you lower the in-app quality setting to force a full transcode, how does that differ?

[seanzi01 0]

I'm attempting to lower the in-app quality but I don't see that setting. I think it should be under Setting->Playback but I don't see anything for video quality.

 

Do I somehow have something setup wrong that's preventing me from being able to adjust the in-app quality?

 

Here is what I see under Settings->Playback:

[Luke 42078]

Yes, on the server you must have restricted user access to transcoding features.

[Marc_G 95]

Hi guys,

 

I'll pop in with some observations I've had. I too suffer from random glitches in recordings from my HDHomerun (I have an Extend unit). I'm prone to see it on any channel I watch recordings of. The easy answer would be "artifacts due to poor signal" but I don't think it's the case. When I watch the channel directly via the same tuner / antenna, I essentially never see any glitches, ever, even on windy days, unless there's lightning about of course. I rarely watch live TV but have done so for testing purposes (oh god, the commercials, make them stop!).

 

My observations:

Watching directly via the HDHomerun software live TV on the tuner (as in, the config GUI, playing after I tune the channel manually): No glitches

Watching directly via Emby Theater: Occasional glitch

Recording via Emby, then watching via any means (Emby, MPC-HT etc.): many more glitches

 

The glitches are rare in the first 30 minutes of any program I record, but more likely after that. I can't explain this, but it's an observation from years of watching Nova and Supergirl... :-)  The glitches often get so bad Emby Theater will bork and I'll have to restart it.

 

Sometimes, few or no glitches, but almost always there are some for 30min+ programs, usually worse in the second half.

 

Documenting this is difficult, in part because I usually watch recordings weeks or months later; all logs of the time it was recorded are long gone.

 

What I think is happening is that software that displays the live stream is more fault tolerant than whatever process happens when the stream is recorded and then played back; the recording is more challenging to display than the live stream. I've tried various settings on the Extend (native, etc) without much change. Because it's an intermittent thing, it's hard to pin down.

 

These are just some observations. It's a bit frustrating because I get nervous every time I play back a recording, because "you never know what you gonna get."

 

If there's something I can do when I get back from my current bout of travel, I'm happy to do it. Anything to improve the fidelity of the recording, for sure.

 

Marc

 

PS: All channels I record are clustered in an antenna farm about 7-8 miles away, direct line of sight, on flat terrain, and my antenna is pointed right at them. I have 100% strength and usually 100% or close to it signal quality.

Edited January 21, 2019 by Marc_G

[seanzi01 0]

Got the trans-coding turned back on. However, I still see the issue with glitches/artifacts. Though if I lower the quality far enough they are harder to pick out   Anyway, I tried several quality settings, all they way down to 480p - 420kbps, and I still see the glitches/artifacts. This happens on live TV and recordings. Basically, forcing the transcode made no difference in the problem I'm seeing.

 

Anything else I should try?

 

Marc_G, its interesting that you are seeing a similar issue. one difference is that I see glitches almost immediately, in the first 30 seconds or so, where you often have to wait 30min. But otherwise it sounds like the same, or at least a very similar, issue.

Edited January 22, 2019 by seanzi01

[seanzi01 0]

I tried uninstalling and reinstalling both Emby server and Emby theater. But that did not help. I'm not sure what else to try. Just seems weird that other things can play/record ok but Emby is having issues.

[Luke 42078]

What if you play the recordings in some other player such as vlc?

[seanzi01 0]

I tried watching a recording in Emby Theater, through the Emby web interface, Windows Media player, and VLC. I all of them I saw the artifacts. The artifacts showed up a little different in each player, but it happened in all of them. Actually Emby theater was one of the better ones. But I'd still see artifacts every 10-30 seconds or so. And I still don't see the artifacts when recording via NPVR/Kodi.

[Luke 42078]

Thanks for the info. We'll take a look at this.