Jerky video on 4K TV

Discussion in 'TiVo Bolt DVR/Streamer' started by pgoelz, Mar 22, 2021.

  1. pgoelz

    pgoelz Active Member

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    Just bought a lovely 55" LG OLED and for the most part, everything looks great. However, certain OTA recordings on the Bolt play back with an odd jerk every 5 seconds or so. When this is happening, the pattern is very repeatable and can be observed when playing in slow motion. The video skips ahead a couple frames, backs up a frame or so, then jumps forward and resumes. This is only noticeable if I have any form of motion smoothing on..... with no motion smoothing, the jerks are not visible. However, on an OLED, strobing is very distracting at 30P and sometimes 60P so motion smoothing is required.

    FWIW, commercials in the same recording DO NOT have these jerks. Also, the show we are watching currently says it is 720P but with motion smoothing off I could swear it is playing at 30 FPS so I wonder if it was converted from 480i to 720p without deinterlacing or conversion to 60fps.

    I have tried every combination of motion smoothing settings and every other HDMI input setting and Tivo output setting I can find (including activating freesync on the TV) and nothing stops the jerks.

    Anyone have any insights? Internet and Tivo forum searches didn't turn up much other than generic suggestions.

    Paul
     
  2. mattyro7878

    mattyro7878 Well-Known Member

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    Nobody is broadcasting in 4k. Maybe change the resolution settings on your Bolt to 1080 i or p? or native?
     
  3. pgoelz

    pgoelz Active Member

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    Yes, I am aware that OTA and Bolt streaming apps are limited to 1080 (and some OTA channels here are actually 720). I have tried ALL settings on the Bolt video output page from 480 up and they all show the same jerk. In between the periodic jerks, it is perfect.

    This happens only on specific programs (but on multiple episodes of the same series) and like I said, the commercials do NOT have the jerk. There is something different about the program material but I don't know what.

    My best guess is that this is a motion smoothing artifact caused by.... not sure what. It is almost as if the frame rate is slightly variable and that confuses the motion smoothing.

    And I gotta say that while we love the picture on out LG OLED, there are so many interacting settings that are VERY poorly documented that the whole 4K HDR setup experience has been way WAY more frustrating than it should have been. And then there is lipsync...... ;)

    Paul
     
  4. High Technology

    High Technology Member

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    It seems like either bad de-interlacing/cadence detection, possibly combined with something in the motion smoothing that is causing the issue. You seem to have a good grasp on the issues, so as you know a lot of TV was still shot on film even 5-10 years ago (24fps), whereas nearly all commercials are shot on video (30/60fps). Since the TV has to output a multiple of 60hz, any 24fps content has to be changed to 60fps (by repeating frames in a 3-2-3-2, etc. cadence, which causes "judder" if the cadence gets out of sync). Commercials don't need that since they are an even multiple of 60fps (2-2-2-2-2 cadence). Your TV is likely a 120hz (fps) model, so it can actually do film by repeating each frame 5 times, and video by repeating 4 times -- theoretically, no judder despite the original frame rate...

    Having the TiVo change the frame rate to 60fps (eg, to 4k/60fps) and then using the TV to double it to 120fps and add the motion processing might cause them to "trip over each other" since the TiVo may no longer be outputting the frame rate flags (or worse output the original flags, despite the fact the output is 60fps), which might be messing up the TV's ability to detect the frame rate when it doubles it to 120hz. It is always best (in my not so humble opinion) to have one device (not two) do as much of the post-processing (frame rates, motion processing, and noise reduction, etc.) as possible.

    So I would go back to the resolution and try selecting ONLY the 1080i output (uncheck every other resolution), which is what most HD is broadcast at. This will let the TV do ALL video processing, including upconverting to 4k, as well as frame rate and motion smoothing. Hopefully using only 1 device to do your video processing will resolve this issue.

    I do realize the 1080i setting means no 4K output (from streaming apps), but let's just see if this fixes the issue. If it does, then you should be able to ALSO check the 4k 24/25/30fps setting (have both 1080i and 4k passthrough boxes checked simultaneously) That should allow the TiVo to output live/recorded TV at 1080i (and allow 4k apps to stream at 4k), while still allowing the TV to handle the frame rates and motion smoothing.

    I DO NOT recommend checking the 4K/60fps box if you are using any of the TV processing features. While that may be the "recommended" setting (aka the highest setting your TV supports), that would have the TiVO upconvert everything to 4K/60fps and then have the TV do it's thing after that. I don't think any apps do 4k/60fps natively, but if they do, I would reconsider this recommendation (I'm still using 1080P plasma sets so no 4k for me yet)

    Since you say this only happens on certain shows / certain channels, then it could be a technical glitch with that program/broadcaster which is exacerbated by the motion smoothing.
     
    Last edited: Mar 31, 2021
  5. Apr 1, 2021 #5 of 18
    pgoelz

    pgoelz Active Member

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    I checked only the 1080i setting in the Tivo video settings and the jerking was un-changed. I have also tried checking just 720p (which is what the Tivo says is the source resolution) as well as all other combinations. No difference that I can detect.

    I agree that it sounds like a frame rate or smoothing issue caused by issues in the source material but I don't know how to solve it.... if it is solvable. Never had these issues on our previous TV, a 1080 without motion smoothing.

    The jerky program last night was "The Good Doctor", which was recorded on the Tivo OTA and claims to be 720p. Commercials and opening credits were smooth. But oddly, every time there was a commercial break the jerking toggled on or off. Jerky video - commercial break - smooth video - commercial break - jerky video.

    This is an issue that I have NEVER seen before until we got the 4K TV but it is also the first TV we have ever had that has motion smoothing. Yes, I can turn off motion smoothing for the Tivo HDMI input but the resulting strobing is almost as bad as the jerking.

    For now, I switched the TV to Game Mode for the Tivo and put the Tivo video output back to "automatic", which turns off motion smoothing in the TV (among other things). The resulting strobing is more tolerable than the jerks (for now, anyway). That immediately revealed that the program and commercials are playing at 30fps, not the 60fps I would have expected. I think I can detect vestiges of the jerking but they are extremely mild if they are there at all. Which makes me wonder if for some reason the program has been converted from a higher frame rate to 720p/30fps incorrectly. IMDB says it was shot 16:9 on a Red Epic Dragon camera so I doubt the source was 720p/30fps. That makes me wonder if the local station is doing the down-rez to 720p for broadcast. When ATSC first arrived, all our local stations were broadcasting 1080i. Now some of them (including this one) are broadcasting 720p (30fps) I assume to make more bandwidth available for their subchannels.

    I think it would be interesting to try watching one of the three programs that jerk live as well as recording them to see if the image jerks when watching live. Which is all moot if there isn't anything I can do to get rid of the jerking.

    I must say the overall 4K experience on our nice new $1300 OLED TV has been difficult and frustrating. The picture is spectacular when I finally got it properly adjusted. But between the jerky Tivo video, trying to adjust all the myriad picture controls for a reasonably accurate image (default was awful) and various levels of lipsync errors, it seems all I do is tweek. And I have a video and engineering background. No idea what non-technical people do.

    Paul
     
  6. Apr 1, 2021 #6 of 18
    High Technology

    High Technology Member

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    Agree with everything you are saying. IF the original program was recorded at 1080p, downconverted to 1080i, then changed to 720P/30 by your local broadcaster, the TV might be very confused by what it is seeing. BY ANY CHANCE, is there some "autodetect" setting on the TV that can be turned off, and/or lock the TV into 120hz mode? I don't have a LG OLED, so not sure what the menu options are (though I know there are many, many settings in the newer sets).

    What's telling to me is that the issue happens/doesn't happen following the commercial breaks. That tells me something that the local station may be doing at the breaks may be a contributing factor. That's not to say the overall conversions from 1080p to 1080i to 720p/30 might not be the leading cause. So there may be nothing "wrong" with the TiVo or the TV, rather the broadcaster is mesing things up...

    I'm a semi-closeted audiophile/videophile. I've had my two plasmas ISF calibrated (and not by the Geek Squad), and had my prior CRT HDTV ISF calibrated as well. All done by very well known experts. I don't know if a good calibration would solve this issue or not - but if you find yourself tweaking over-and-over again, I would STRONGLY suggest consider the $400 or so for a good calibration. Each time, I've wondered if this was a waste of money, and each time I've been thrilled by the difference it makes. Even though the Theater/Movie mode for the LG OLEDs has a pretty flat and accurate color temperature, a good ISF tech can potentially adjust other things that can't be set in the user menus. Look for calibration reports or reviews from some of the well-known calibration experts to see what they can tweak.

    The fact it happens with certain programming only seems to suggest it is a technical issue with the programming (and not the devices). I haven't heard too much about OLED strobing issues, but haven't had to time read many reviews lately -- we're likely to relocate in a couple of years, so I decided to keep using the plasmas I have (and still love) until we move and just get new LG OLEDs when we move. That said, I understand how frustrating the picture issues can be -- after owning plasmas, I don't know if I could get used to LCD motion issues, so it's OLED or nothing for me, unless there is another technology on the horizon...

    FWIW, I would be curious if the same issue would exist if you streamed the program from somewhere (e.g., Hulu has the older seasons of that show)...
     
  7. Apr 1, 2021 #7 of 18
    pgoelz

    pgoelz Active Member

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    I don't think that a calibration will solve this issue. Calibration addresses color balance issues but there isn't anything to be "calibrated" that addresses motion smoothing that I have not already tried. I find the color response to be quite acceptable without calibration now that I have tweeked the LED and contrast settings and set a lower gamma. Possibly it could be improved but I'm not ready to shell out $400 to see. Too bad the LG does not have the same calibration function the TCLs we tried had. With TCL, you use a smartphone camera and app and it did a decent job. We would have kept the TCL but it had occasional worse lipsync issues and I did not like the narrow "sweet spot" where the blacks were deepest. Other than that, the TCL QLED was a great (and FAR cheaper) TV. We did not have it long enough to notice if it suffered from the jerky video issue.

    I am quite convinced the jerking is indeed a technical issue on the broadcaster's side. I would leave it at that but for the fact that our previous TV (that did not have motion smoothing) was not sensitive to whatever issue there is so I keep trying to find a way to improve the LG. If I can gather some more evidence I might try talking to the engineering people at the local broadcaster(s) to see if they can shed any light. Too bad this is not good old analog video where I could put a scope on it and SEE what is going on.

    Thanks for participating. This has been an education for sure. I'll keep this thread updated as I find more evidence of what is going on. In the mean time, I am very surprised no one else is reporting jerky video. Either it is a very isolated case here in the Detroit market or most people hate motion smoothing enough to leave it disabled.

    Paul
     
  8. Apr 1, 2021 #8 of 18
    pgoelz

    pgoelz Active Member

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    Another tidbit..... I plugged in our decommissioned Roamio as a test. It was decommissioned last year but it actually had an old episode of The Good Doctor on it, recorded OTA from the same TV station in August 2020. And that old episode played back with the same kind of jerks that came and went after commercial breaks, same as the Bolt. Curious, I played back a section in slow motion and could easily observe the frame refresh rate change in the places where the jerks occurred in normal motion. The 30Hz cadence would run steadily for a while and then suddenly would refresh faster for maybe 3-5 frames in a row and then return to a steady 30Hz. The next step will be to watch an episode live on the TV itself and see if it still jerks.

    Bottom line seems to be that the 720p stream from the TV station is being transmitted at 60fps but only refreshed at 30fps except for momentary increases in fps that trip up the motion smoothing. I assume that examining the video in slow motion (pressing the |> button on the Tivo remote) causes the resulting ~4fps refresh rate to bypass any motion smoothing routine on the TV and what I see is what is actually there. At least I think so....... I can see it with or without motion smoothing enabled on the TV.

    Paul
     
    Last edited: Apr 1, 2021
  9. Apr 1, 2021 #9 of 18
    High Technology

    High Technology Member

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    You probably know this already, but a live episode should not be any different if you are using one of the TiVos as your source -- you're always watching off the disk (the buffer), and what is recorded is simply the same stream. I don't believe the TiVo does anything to the signal when recorded vs. LiveTV, and if you're outputting the native stream in pass-through mode, then no video processing should be applied.

    So you will need to hook your OTA antenna directly to the TV and use the TV's tuner as your source. That will definitely shed some light on whether this is a broadcaster issue or not.
     
  10. pgoelz

    pgoelz Active Member

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    Yes, that is what I meant. I want to watch the same program played back from the Tivo vs. as received directly antenna to TV (bypassing the Tivo). The idea would be to conclusively eliminate the the Tivo as the culprit. First opportunity is the Sunday evening when "The Good Doctor" airs on ABC.

    Paul
     
  11. pgoelz

    pgoelz Active Member

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    Epilog:
    After much experimentation I have come to the conclusion that motion smoothing in our LG OLDE TV is simply not usable for OTA video. The majority of programs are fine but not all. This seems to be confined to programs that are being broadcast in 720p/30fps. Live programming and/or programming in 1080 seems to be OK and commercials are always OK. Rather than turn motion smoothing on and off on a program by program basis, we have decided to simply leave it disabled for the Tivo HDMI input.

    The interesting part is how quickly we got re-accustomed to non-smoothed 30fps. I guess 5 decades of watching non-smoothed video makes that easier than I expected ;)

    Paul
     
  12. dianebrat

    dianebrat wait.. I did what? TCF Club

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    I've never found motion smoothing to be a good thing, it's always off on my 4K sets, including my 2016 LG OLED E6
     
  13. pgoelz

    pgoelz Active Member

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    Just curious.... why have you found motion smoothing to be "not good"? Do you simply not like the look or do you not tolerate the artifacts?

    I do like the look and I tolerate the minor artifacts. But the jerky video "artifact" is not acceptable.

    Paul
     
  14. dianebrat

    dianebrat wait.. I did what? TCF Club

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    I don't like the soap opera effect and I don't like the artifacts, I have never found anything that was improved by having it on, and many things that looked worse, with one of the best displays out there, I don't want to cripple it with a feature that makes things look worse.

    Don't just take my word for it, Tom Cruise agrees Tom Cruise stars in impassioned PSA against motion smoothing
     
  15. pgoelz

    pgoelz Active Member

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    I don't give a hoot for what Tom Cruise thinks. Everyone is entitled to their own opinion and preferences of course. But I prefer that there be no strobing at all. To me that looks the most real. We have been watching film and video for almost a century that has a frame rate sufficiently slow enough to detect, purely because higher frame rates were not economically feasible. Over those decades we have become accustomed to the flicker and trained to ignore it. That is why high frame rate and motion smoothed video looks "unnatural" to many. I am sure that if film and video could have been shot and distributed at 120 fps when the technology was new that we would not be having this discussion. Why would anyone who had never seen anything other than high frame rate ever decide they preferred 24Hz?

    But that is just me and I appreciate that some people prefer the "film look". That is why motion smoothing can be adjusted and/or disabled. Like some people ignore the strobing, I ignore the minor artifacts on my LG OLED. It is very good but it is not perfect.

    Paul
     
    Last edited: Apr 5, 2021
  16. pgoelz

    pgoelz Active Member

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    Sorry, I think that came across as harsh. That was not my intent at all. I truly am curious why there is so much hate for motion smoothing. It is just that I find I like it. When it works.... ;)

    Paul
     
  17. dianebrat

    dianebrat wait.. I did what? TCF Club

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    The hate is because IMNSHO its not natural or pleasing, it's harsh in a way that doesn't reflect the real world and makes things look like they're cheaply filmed video, thank goodness I can turn it off :)
     
  18. pgoelz

    pgoelz Active Member

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    Fascinating! My reaction is exactly the opposite. If I ignore what 24fps film has always looked like, I find motion smoothed / high frame rate video looks FAR more natural. I define "natural" to mean the feeling that there is nothing between my eyes and the objects on the screen, like I was looking through a window. If one defines "natural" to mean the way 24fps film and / or 30fps video has always looked then I can understand motion smoothing appearing very unnatural.

    Paul
     

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