Display problem with HDMI to s-video

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Rikkitic

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#217870 16-Jul-2017 13:32

For anyone bored on a slow Sunday, I have a dinosaur display question.

I am experimenting with some old analogue DVRs and a little downscaling gadget I got from Aliexpress. The downscaler converts HDMI to s-video and composite.

This worked fine when I tried it on a Sony blu-ray player to Panasonic DVR. I put on a blu-ray disk, ran it through the downscaler, plugged that into the s-video input of the DVR, which then upscaled the video back to 1080p for display on the TV. The resulting picture actually wasn’t bad.

Yet I cannot get the downscaler to work with a Windows 8 Pipo mini-pc and a Sony DVR. The connection between the DVR and the TV is fine. If I play a video recording it looks as good as it might be expected to. But the pc through the downscaler is horrendous. At any resolution I get only a square picture with the edges cut off and any text is so blurry it is unreadable. Changing the downscaler output doesn’t help.

The mini-pc works fine when the HDMI is connected to the TV. I think this must be some kind of edid issue with the downscaler and the pc not seeing it as a normal monitor. Can anyone shed more light on this?

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richms

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#1823303 16-Jul-2017 16:03

You need to have the PC to add overscan since it is going thru an analog device which is assuming that the picture has overscan. That will pad the sides of the output with black which was needed when outputting to analog displays since they scanned past the side of the tube to allow for them being crap and the picture size changing all the time.

Its blurry and unreadable text because it is svideo. If you want visable text on anything passing thru obsolete analog formats, then you will have to adjust your display mode down to 640x480 or worse. This is not selectable in the normal windows user interface usually because so much stuff will not work with it.

Richard rich.ms

Rikkitic

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#1823326 16-Jul-2017 17:12

Thanks for the info. I did manage to get the text readable by reducing the resolution. Haven't figured out how to add overscan. I did change the display setting on the TV but it didn't make any difference. I can't seem to find any way to stretch the image horizontally to get an approximately correct aspect ratio. Changing the resolution settings doesn't really help and just makes the text unreadable again.

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richms

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#1823334 16-Jul-2017 17:19

Overscan will be in the software for your display adapter - either nvidia control panel or whatever AMD are pushing now. I dont recall seeing it as an option on intel graphics but must admit I have not been looking that hard for it.

You might find some 848x480 or similar resolutions available which will fix the widescreen problem. Svideo was never really designed for different aspect ratios so there is no signalling on it as to if an image is wide or square, you have to set it on the source yourself and the display, putting a dvr inbetween will only complicate things more.

Richard rich.ms

Rikkitic

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#1823344 16-Jul-2017 17:29

OK, that makes things much clearer. I don't think the Intel graphics on the pc do have the overscan option. I also don't know if there would be another driver that might do it. I may look later but I was just having a play to see what was possible. I don't have a choice about the DVR, since I need that for the s-video input. The TV I am using for this doesn't have one.

Thanks again for the good info.

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