Pixel ratio (auto saved?)


I’ve been trying to optimize video on my Vero 4k. I already discovered a few new things about my setup, for example:

1.) If I set “display 4:3 video” to “HDMI AVI Signalling”, my TV jumps out of its “no-overscan” (correction = zero) mode. For example, while my GUI is set to 1080p/60 Hz (in no-overscan), when I start playing a 50 Hz movie, the TV frequency changes to 50 Hz. When I stop playback, it changes back to 60 Hz, but it is no longer in no-overscan mode and I would need to apply significant correction in Kodi. I thus reset the option to “normal”.

Is this behaviour a common occurence? (I have an older Grundig TV set.)

2.) When I use the Whitelist to enable direct-output at 576p resolution, the picture doesn’t fill the screen: There are black bars at the top and bottom (not at the sides.) No, these are not letterbox bars, they are much smaller than that. I found that I can adjust “pixel ratio” while playing. A value of 0.94 gives me a full screen picture.

When I repeated the test with the same video just now (after being powered down for a few hours), this value was already set, even though I can’t recall having saved it myself.

Is this value saved automatically? And does the saved value apply to all video, or just the resolution/framerate combo that it was set for in the first place?


The settings when you calibrate are saved are saved for the resolution and frame rate combo you are in when you calibrated. These are stored in your guisettings.xml such as…

        <description>720x480 @ 59.94 - Full Screen</description>

As you can see it stores both the aspect and overscan. Only SD content should be overscanned though so for all other content your TV should be set with overscan off and there should be no calibration done in Kodi. For SD content which should have overscan I think it is covered fairly well in the how-to on whitelisting that @angry.sardine wrote.

Excellent. This is exactly what I need; thanks for the description.

Yes, I was wondering that as well. I’m trying not to use overscan with any of my video, but have to be careful since my TV seems to reset to overscan on some occasions - like the one I described above when changing aspect ratio.

I wholehartedly agree, this is a superb summarization of the topic. I learned a lot from this post.

Thanks again!


Most of the SD 4:3 content was designed to be overscanned as that is how the old CRT TV’s were designed to work. I think the best way for maximum quality is to not do any correction at all in Kodi and when the source is such that you need overscan enabled or the aspect adjusted for anamorphic sources then adjust it as needed on the TV. If your going to let Kodi adjust it you might as well just let it upscale as well. Basically the TV is probably going to do a bit better job but require some manual adjustment depending on source (just like you had to do back in the day with a DVD player), or let Kodi adjust, probably take a bit of a quality loss, but allow you to not have to touch your TV’s settings.

I would add, if you adjust the a/r (pixel ratio) while watching a video, the setting is saved for only that video, not for all videos of that resolution.

Also, small black bars top and bottom is pretty common for movies. They are intended to be 1:1.85 instead of 1:1.78 (16:9) so by adjusting them you are distorting the image. I don’t do that but it’s up to you.

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Ok - that’s not so ideal for my case. I need to look at this some more, but I never noticed this “deformation” when I let Kodi just upscale everything to 1080p. The problem only came up when I started to export direct 576p resolution to my TV for the first time.

No, I don’t believe that’s the issue here. The picture is visually distorted with the bars, and they are much (!) smaller than the usual “framing” bars. They are just over a centimeter or so on my 55" screen.

I was wondering if it could be a problem with anamorphic video, since I noted the issue mainly with playing back DVD ISOs, not with already encoded movie files. The difference could be about right.

But I’m going to watch this over the next few days with different kind of video to see if I can spot a pattern there.


The difference between 1:1.85 and 1:78 gives you 1.3cm bars top and bottom.

On content that was mastered with overscan expected there was no standard for what is in the overscan area, because it was never suppose to be visible. It could be all normal video and so removing overscan gives you more of the picture. It might also be a little or a lot of padding if they didn’t have enough extra source material to run off the screen and they wanted to preserve the full frame as it was seen in theaters. This is not really related to anamorphic as DVD’s encoded this way are also expected to have overscan.

Actually, what I started this thread with were - from what I can make out - two completly seperate issues. The overscan one was the less critical of the two:

Number 1 was the overscan thing, which is caused by my TV not handling its preferences correctly on a change of aspect ratio. I “cured” that one by selecting “show 4:3 as” = “normal”.

Number 2 is the problem with the 16:9 video being shown “wide enough, but not tall enough”. This is visible not only from the bars top and bottom, but also from the picture itself: A circle is not round. Before, when Kodi was doing the scaling, it was. One idea as to the reason of this would have been incorrect handling of anamorphic video. But that was just an idea and may well be completly off.

For number 2 so far I modified the “pixel ratio” value. Of course, this is no solution if I have to set it for every individual video I’ll play at this resolution. If it were remembered for the resolution, it would be.