bild 1:40 White line glitch - upsampling from 720p source

[mani]

Hi - I'm hoping I can get help with a problem I'm experiencing with my latest Loewe TV.

I've owned four Loewe TVs over the years - and the previous three have all malfunctioned in some serious way so that they needed replacing (at my expense). In each case (possibly foolishly) I've replaced the broken TV with another Loewe.

Most recently, I purchased a bild 1:40 two weeks ago, and I'm extremely pleased with the picture quality when playing from a source that matches the TV's native resolution (1080p), but when the source is upscaled (from 720p), I find the picture glitches much more than expected.

The main problem however, (aside from the general glitching), is that an intermittent horizontal single-pixel-height white line will also glitch across the screen, starting from the right hand edge about one-third down from the top, and stretching across approx half the horizontal width of the screen. The glitch usually persists for a fraction of a second, but ocassionally for a little longer, and it returns at random intervals (I've timed it between a couple of seconds to a couple minutes between gliching).

The white-line glitch does not seem to be related to sudden or fast movement in the picture - it can happen when nothing much is changing in the displayed image - but it does not happen if the image is totally still (for instance in an AppleTV menu), or (as said) if the source is 1080p. In other words, I do think it's related to up-sampling.

The white line flashing across the picture is much more distracting than a 'normal' motion image glitch, and seriously distracts from the program being watched.

I've updated the unit to the lastest firmware, and tried all the different settings for DMM - switching off entirely and also setting each of the different grades of movement-smoothing, but nothing has made any difference.

If the artifact I'm describing isn't clear, I can try to upload a movie somewhere (such as YouTube). Otherwise maybe this is a known fault?
I'd really like some help solving the problem. I don't want to regret buying yet another Loewe - something my partner warned me against doing, after our unfortunate history with the brand...

[mani]

After a few weeks of watching different types of input on the bild 1:40 I'm now almost definitely sure that the problem lies in the motion interpolation algorithms used on upscaled content.

The white lines and general jerkiness in the picture - which I now see have been discussed in this thread:
viewtopic.php?f=74&t=7241
occur only on content that's been compressed and/or transmitted as 720p and upscaled.

It would be nice to hope that the Loewe engineers can do something about the problem through firmware upgrades, but it's entirely possible that the hardware simply isn't capable of better or faster processing.

In any case, when the source material is good, the image on the bild 1:40 is fantastic. And after I added external speakers, the sound is also incredible.

[Pretch]

In Deutschland wird ja öffentlich rechtliches Fernsehen in 720p ausgestrahlt. Da kann ich bei keinem Loewe hier ein Problem feststellen.
...oder tritt das explizit nur bei externer Zuspielung auf?

[mani]

The problem is most noticeable when playing streams from the SVTplay (Sweden's national TV) AppleTV application. The streams are 720p, but they're also compressed to a greater or lesser extent depending on the original material.

Incidentally, playing material that is originally 480p shows quite extreme and persistent flickering lines, approx one-third from the top and one-third up from the bottom of the image. So this reinforces my feeling that the problem is the scaling algorithm.

If I play 1080p from the AppleTV (Plex, Vimeo, original movies etc) then the problem never occurs at all, and the picture is magnificent: detailed and rich without any artifacts.

In other words the flickering line is an annoyance, but I can live with it. But ideally a firmware update would eliminate the problem altogether. Because of what I suspect are the hardware limitations of the bild 1, I'm not holding my breath.

[Pretch]

You`re shure it`s not the SVTplay Stream on AppleTV? I never heard of problems like this. On the contrary, great upscaling is a main feature of Loewe TVs.

[mani]

Pretch - first of all, thanks for your engagement in the problem - I really appreciate it.

Naturally with so many interconnected variables in the flow it's difficult to know which element is the actual cause of the flickering white line problem. Here's some more information:

- before the bild 1:40 I owned a Loewe Individual Selection DR+ 40 (the model from middle 2015 or early 2016) - which isn't 1080p, and which didn't show the artifacts at all with the same source material.
- When that TV was at the dealer trying (unsuccessfully) to fix a blown motherboard, I took my older (2008?) Loewe Individual 32 from storage (it has intermittent problems with newer HDMI protocols) and during that time I never saw the white lines.
- They aren't visible if I watch SVTplay on my computer screen (the display is capable of much higher than 1080p resolution) or on any other unit such as an iPad.

I do think the poor quality of the original stream is the underlying trigger for the flickering line, but because this TV is the only place I see it, I can't avoid suspecting that there's some problem with the upscaling that's specific to this model.

[Pretch]

OK. I never see something like this on my bild 7 or Connect 40.

I will bring my AppleTV to work and check this in the store on a FullHD Model. Unfortunately we have no bild 1.40 in Stock, but bild 5.32 is the same Base.

[Pretch]

OK, i've seen the error.
and i think i know the reason. It is a framerate problem. Set the Framerate in AppleTV Menü to 1080 @50Hz. That should solve the isue and it`s also the correct setting for TV content.

[mani]

Wow! Thank you so much! That does indeed solve the problem for these streams!

I see I'll have to manually change back to @60hz for optimum quality of some sources, but as 90% of TV-viewing in our household is the kids watching SVT, then leaving the AppleTV on 50hz for most of the time is the solution I was looking for! Thanks again!

[rudi-ratlos]

In Deutschland wird ja öffentlich rechtliches Fernsehen in 720p ausgestrahlt. Da kann ich bei keinem Loewe hier ein Problem feststellen.
...oder tritt das explizit nur bei externer Zuspielung auf?

...nö, bei mir sind es 1080p und DD+ bei DVB-T2

[Pretch]

Ja, per DVB-T2 HD. Ich spreche von den gebräuchlichsten Ausstrahlungswegen (Sat/Kabel).