Pixelation on Bottom of Picture

Reception, channel detection, network issues, CableCARD setup, etc.
DisneyFanatic4
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Joined: Mon Jun 29, 2020 6:56 pm

Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

I have two HDHomeRun Prime's and I think since the last firmware upgrade, I'm getting pixelation at the bottom portion of the picture. It's only happening on cable channels (Disney, FX, USA, etc) and not my local channels (ABC, CBS, NBC, etc). I had my cable company come out today to check my levels and all levels are healthy. Now I'm leaning towards the May firmware. Has anyone else experienced this?

djp952
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Re: Pixelation on Bottom of Picture

Post by djp952 »

I have for quite some time. I've been meaning to try and capture it for SD to analyze but it's the same set of channels on FiOS, pretty much anything Disney cable (but also not ABC for me). Disney Channel, Disney XD, Freeform, etc. It's certainly been happening for me way longer than recent F/W updates. I'd say at least a year if not longer.

One thing I haven't been able to corroborate, and therefore not capture anything for SD, is if it happens only when streaming through the HDHomeRun PRIME directly or if it's when HDHomeRun RECORD is involved. Do you run the RECORD engine, and what application(s)/platform do you see the problem on?

For me, I see it near constantly on Windows, and 'often' on Android (don't use Android that much, though). Happens with the HDHomeRun Application and a Kodi PVR addon.

Up until now I've thought I was the only person that sees this and was content to blame Windows so I never really spent that much time on it. Perhaps if we can compare notes on our setups, there is a common denominator that we could use to get some samples to SD to see if it's a hardware or software concern.

My guess, for what it's worth, is that it's a software problem. Something in the transport stream that trips up the decoder. I believe HDHomeRun App uses the same decoder (ffmpeg) that Kodi does. ffmpeg is a complex beast.

NedS
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Re: Pixelation on Bottom of Picture

Post by NedS »

Can one of you guys take a picture of this so we can see what you're seeing?

jasonl
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Re: Pixelation on Bottom of Picture

Post by jasonl »

On Windows it's easy to test. If you have the Microsoft MPEG-2 whatsit installed, the HDHomeRun app will offload decoding to the GPU (assuming you have a GPU that isn't 3 generations obsolete and can decode MPEG2). You can uninstall that whatsit via Window Settings > Apps, and then the HDHomeRun app will then software decode. If the problem goes away when software decoding is used, then your GPU sucks at decoding. Most NVIDIA GPUs are known to suck at decoding certain streams. It's most common on 1080i channels, but it could presumably affect 720p as well. I can't watch my local NBC or ABC stations (both 1080i) using hardware decoding on my Windows PC with a GTX1050Ti or my Shield without random garbage any time it hits the trigger (usually fast camera pans or graphic wipes). FFmpeg software decode handles the same streams perfectly.

DisneyFanatic4
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Joined: Mon Jun 29, 2020 6:56 pm

Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

djp952 wrote:
Mon Jun 29, 2020 7:36 pm
I have for quite some time. I've been meaning to try and capture it for SD to analyze but it's the same set of channels on FiOS, pretty much anything Disney cable (but also not ABC for me). Disney Channel, Disney XD, Freeform, etc. It's certainly been happening for me way longer than recent F/W updates. I'd say at least a year if not longer.

One thing I haven't been able to corroborate, and therefore not capture anything for SD, is if it happens only when streaming through the HDHomeRun PRIME directly or if it's when HDHomeRun RECORD is involved. Do you run the RECORD engine, and what application(s)/platform do you see the problem on?

For me, I see it near constantly on Windows, and 'often' on Android (don't use Android that much, though). Happens with the HDHomeRun Application and a Kodi PVR addon.

Up until now I've thought I was the only person that sees this and was content to blame Windows so I never really spent that much time on it. Perhaps if we can compare notes on our setups, there is a common denominator that we could use to get some samples to SD to see if it's a hardware or software concern.

My guess, for what it's worth, is that it's a software problem. Something in the transport stream that trips up the decoder. I believe HDHomeRun App uses the same decoder (ffmpeg) that Kodi does. ffmpeg is a complex beast.
For my setup, I only use Apple TV's with the Channels app to watch Live TV and I use the Channels DVR too. I have the HDHomeRun's in Plex too, but I never watch TV that way. I did notice that live TV in Plex also has this issue so I'm fairly confident that it's not a software-related issue. I'm going to record one of the affected channels to see if recordings are affected or only live TV. I'll also try to grab a picture to share.

nickk
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Re: Pixelation on Bottom of Picture

Post by nickk »

Hi,

Please test using the HDHomeRun app rather than a 3rd party app.

Some encoders will but large video frames across two PES segments and still flag the stream as aligned. If this isn't handled by the decoder correctly you will see corrupt video at the bottom of the screen.

Nick

DisneyFanatic4
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Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

nickk wrote:
Tue Jun 30, 2020 9:13 am
Hi,

Please test using the HDHomeRun app rather than a 3rd party app.

Some encoders will but large video frames across two PES segments and still flag the stream as aligned. If this isn't handled by the decoder correctly you will see corrupt video at the bottom of the screen.

Nick
Nick,

Thanks so much for the suggestion. I do have a Roku TV, so I downloaded the HDHomeRun app. I'm currently watching the Disney channel, which I'm always able to replicate this issue. It's currently NOT happening with the HDHomeRun app, so it looks like it's a software issue. With that said, it happens for both Plex, and the Channels app, so does that mean both pieces of software need to correct this issue? Or could it be a recent firmware update that changes how video is delivered to these third-party apps?

signcarver
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Re: Pixelation on Bottom of Picture

Post by signcarver »

Delivery is the same unless legacy methods are being used (both apps you mentioned can support both) then it could more easily be your network but your test seems more to confirm the decoder being used by those apps. The logs of the tuner will state if modern (http) or legacy methods are being used.

djp952
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Re: Pixelation on Bottom of Picture

Post by djp952 »

I'll record an episode of DuckTales or something relatively short on Disney XD and point out the time positions where it glitches and share it for you if it happens during playback via the HDHomeRun App. It will, it's just a matter of capturing it for you to look at.

DisneyFanatic4
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Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

I recorded a Disney channel show using my Channels DVR app and it's also affected. So it looks like the third-party live TV and DVR both have this streaming alignment issue.

nickk
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Re: Pixelation on Bottom of Picture

Post by nickk »

Can you upload a sample recording and PM me the link - I will test here.

Nick

DisneyFanatic4
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Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

nickk wrote:
Sat Jul 04, 2020 1:52 pm
Can you upload a sample recording and PM me the link - I will test here.

Nick
Looks like my account is too new to PM. How can I privately send you the link?

nickk
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Re: Pixelation on Bottom of Picture

Post by nickk »

DisneyFanatic4 wrote:
Sat Jul 04, 2020 8:07 pm
Looks like my account is too new to PM. How can I privately send you the link?
Fixed - please try again...

DisneyFanatic4
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Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

nickk wrote:
Sat Jul 04, 2020 8:11 pm
DisneyFanatic4 wrote:
Sat Jul 04, 2020 8:07 pm
Looks like my account is too new to PM. How can I privately send you the link?
Fixed - please try again...
Thanks! PM sent.

djp952
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Device ID: 131EB7F7;131ED0E0
Location: Elkridge, MD USA

Re: Pixelation on Bottom of Picture

Post by djp952 »

I just sent you a sample file link via PM as well, Nick. Hope it helps to corroborate DisneyFanatic4's issue.

Just happened to be watching Disney with the kid this morning when it happened and I grabbed the LiveTV file from RECORD and trimmed it down to a reasonable size. Glitch will be between the 00:20 and 00:21 time markers.

Thanks!

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