Pixelation on Bottom of Picture

Reception, channel detection, network issues, CableCARD setup, etc.
DisneyFanatic4
Posts: 9
Joined: Mon Jun 29, 2020 6:56 pm

Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

nickk,

Any updates on reviewing our recordings? Should we reach out to Channels and Plex support for resolution? If so, what is the best way of expressing what this issue is so I can communicate it to their support teams?

DisneyFanatic4
Posts: 9
Joined: Mon Jun 29, 2020 6:56 pm

Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

nickk,

So I've done further testing and I discovered something interesting.

On Apple TV 4K with both the Channels app and the Plex app, the pixelation occurs on the Disney channel.
On Roku TV with both the HDHomeRun app and the Plex app, the pixelation does NOT occur on the Disney channel.
On MacBook Pro in Google Chrome watching live tv from Plex, the pixelation occurs on the Disney channel.

Is there any way to downgrade the firmware on my Prime's to the previous versions for testing only?

NedS
Silicondust
Posts: 1383
Joined: Mon Dec 10, 2018 12:38 pm

Re: Pixelation on Bottom of Picture

Post by NedS »

Nothing in the PRIME's firmware would affect that. It's most certainly a software issue.

DisneyFanatic4
Posts: 9
Joined: Mon Jun 29, 2020 6:56 pm

Re: Pixelation on Bottom of Picture

Post by DisneyFanatic4 »

So I just downloaded the HDHomeRun app on my iPhone, and I'm able to replicate the pixelation on the Disney channel. I couldn't replicate it on the Roku app, but I'm able to on the iOS app. This would lead me to believe it could still be a firmware issue since it's happening on multiple platforms and multiple software vendors.

nickk
Silicondust
Posts: 15989
Joined: Tue Jan 13, 2004 9:39 am

Re: Pixelation on Bottom of Picture

Post by nickk »

DisneyFanatic4 - I was able to reproduce the problem.

When played on a Windows 10 PC with hardware decode or with VLC the video plays perfectly.

When played with software decode there are minor glitches at the bottom of the screen in places.

Looks to be a software bug in the app - we are investigating.

Nick

djp952
Posts: 1242
Joined: Wed Oct 01, 2008 8:46 pm
Device ID: 131EB7F7;131ED0E0
Location: Elkridge, MD USA

Re: Pixelation on Bottom of Picture

Post by djp952 »

Hi Nick, did you find any problems with the sample I sent? If there is a software issue, like an ffmpeg thing, knowing what it is/was will help me to let the folks that control such things know what might need to be done to fix it.

Thank you as always!

nickk
Silicondust
Posts: 15989
Joined: Tue Jan 13, 2004 9:39 am

Re: Pixelation on Bottom of Picture

Post by nickk »

djp952 - I think your sample is showing a different problem.

djp952
Posts: 1242
Joined: Wed Oct 01, 2008 8:46 pm
Device ID: 131EB7F7;131ED0E0
Location: Elkridge, MD USA

Re: Pixelation on Bottom of Picture

Post by djp952 »

nickk wrote:
Wed Jul 15, 2020 6:34 pm
djp952 - I think your sample is showing a different problem.
Isn't that pretty much always the case with me? LOL :)

Whatever you can find out, I will do what I can to help the community at large to fix it provided it's a software issue, which seems likely. Any info will be greatly appreciated and acted upon as best I am able ...

tmm1
Posts: 258
Joined: Tue Nov 03, 2015 12:03 pm
Contact:

Re: Pixelation on Bottom of Picture

Post by tmm1 »

This appears to be a bug in ffmpeg's software mpeg2 decoder. I have filed a bug report here: https://trac.ffmpeg.org/ticket/8792

djp952
Posts: 1242
Joined: Wed Oct 01, 2008 8:46 pm
Device ID: 131EB7F7;131ED0E0
Location: Elkridge, MD USA

Re: Pixelation on Bottom of Picture

Post by djp952 »

tmm1 wrote:
Thu Jul 16, 2020 11:42 am
This appears to be a bug in ffmpeg's software mpeg2 decoder. I have filed a bug report here: https://trac.ffmpeg.org/ticket/8792
Hi tmm1! I finally got back around to this, and in my samples I'm not seeing the same problems (or any for that matter) using the ffmpeg options you outlined in the bug report.

This problem really (no pun intended) bugs the ^%$&@^$ out of me, we spend so much time watching Disney-owned channels and it's a constant issue. If I were to PM you a link to a sample file would you mind seeing if you can find anything wrong with it with ffmpeg? I've used ffmpeg, I've used TSDuck, bubkis. I have *not* taken the time to isolate the exact MPEG-TS packet(s) causing the problem yet, but I think I'll have to go that deep :(

If I can get closer to the root cause there may be something I could propose (along the lines of "-ec 0") to Kodi as a solution. For me, I'm seeing it on Windows, Linux, and Android, so ffmpeg is the only real common denominator (or a headend issue, of course).

Thank you!

edit: nevermind, I see what the problem is -- a whole bunch of nothing. I never actually looked at the bits themselves, the stream is just dying and sending a ton of zeros, which would definitely cause a video glitch. Now I just need to see if it's coming from the tuner or coming from RECORD and let SD know... clearly nothing I could do about this, the data is just not there.

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