Diagnostic videos?

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mathog
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Diagnostic videos?

Post by mathog » Wed Jun 17, 2020 10:58 pm

Is there somewhere a collection of videos, stored the way MythTV currently stores recordings, which could be used to diagnose video output problems? I'm thinking particularly of a few use cases, for 720p 1080i 4K (?) and any other format in common broadcast usage. They need not be very long, maybe 5 minutes each, tops.

1. Display size. The video would have 1 pixel wide color coded and labeled rectangles, with the outermost being the edge pixels and the others stepping in by 5 or 10 pixels.

2. Content known or suspected to trigger display artifacts (tearing, etc..) In the relevant part it might be labeled "look for tearing" and so forth. Also possibly problems during pause or fast forward. (Our current box when set to use some drivers drops every other line of 1080i when paused or fast forwarding, for instance, but those look normal on 1X playback.)

Ideally I think these would be built in, found under Setup -> Video -> Testing. There are two videos available now in the top Setup option, one high and and one low resolution, but they seem to be mostly an all or none sort of test.

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mark_k
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Joined: Tue Jan 28, 2020 3:14 pm
Great Britain

Re: Diagnostic videos?

Post by mark_k » Fri Jun 19, 2020 11:47 am

I've considered generating some test patterns/material etc before - but there are various sources already.

Probably closest to your first request:-

https://www.avsforum.com/forum/26-home- ... icker.html

Otherwise, a trove of mostly ancient formats:-

http://samples.mplayerhq.hu/

Mostly newer stuff:-

https://kodi.wiki/view/Samples

Stress tests for very high bit rates and 10bit:-

http://jell.yfish.us/
http://dl.ganjanetwork.ru/Files/Video%2 ... ate/Birds/

With respect to tearing - genuine tearing can be induced with just about any fast moving scene if the display/driver etc isn't syncing properly.

Regards
Mark

blm-ubunet
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Cambodia

Re: Diagnostic videos?

Post by blm-ubunet » Sat Jun 20, 2020 10:03 pm

Over the years I've tried to collect every ticket or post's video sample to use for testing stuff.

I was going to suggest the (in)famous 'CheeseSlices' for de-interlacing tests until came across this.
https://www.isovideo.com/deinterlacing_ ... ssment.php
They have a good explanation of the limitations of synthetic patterns & have an interesting collection of difficult video.

CheeseSlices has been discussed on doom9 & AnandTech.

This extensive collection looks very interesting/useful/revealing:
http://www.w6rz.net/

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