Can upscaling introduce frame jumps in a video

[loninappleton]

I've seen big improvements in historical material such as television classic plays. But the MediaInfo on some of these show framerates of 50fps. I know for a fact that most British video is 25 fps. And I've seen some annoying frame jumping in these upscale so-called 1080p versions. Can this be legitimately considered making the content worse for introduction of those artifacts ? I may not be accurate on the terms I'm just asking for my own information.

[Selur]

'frame jumping' sounds like bob deinterlacing (that would fit to 25fps turns 50fps) while assuming the wrong field order,...
So probably unrelated to upscaling itself, but more related to a user not knowing what he is doing.

[hello_hello]

If the original source was interlaced video I assume it was de-interlaced to 50fps rather than 25fps as it keeps the motion smoother.
Most hardware players would de-interlace interlaced PAL DVDs to 50fps (each field is interpolated into a full frame, doubling the frame rate, rather than merging the fields together in some way for 25fps).

What are you using to play the video? Not all devices support 1080p at 50fps so maybe it's simply an issue with the player not being able to decode it fast enough so it's dropping frames. Or your player is limited to a particular Profile and Level and the video was encoded at a higher one. If it's h264 video, the player needs to support at least Level 4.2 to play 1080p at 50fps. My old TV's media player only supports Level 4.1 (max 30 fps at 1080p).
https://en.wikipedia.org/wiki/Advanced_Video_Coding#Levels

[abolibibelot]

Normally, if done by knowledgeable, consciencious professionals using proper tools and methods, I would say no, but lousy, neglectful job is being performed all the time on this planet... Going from 25 FPS to 50 FPS can be the result of deinterlacing, I don't know much about the intricacies of how it's done, but it involves some kind of interpolation, which could possibly explain weird artifacts, especially on footage with a lot of motion – at least more so than the upscaling part of the processing.
To have better odds of getting in-depth feedback, upload a short sample if you can.
Depending on whether it was originally shot on film, ir might be possible to get a much better quality by doing the new upscaled conversion from the original film rather than the recorded broadcast (much higher potential resolution and no need for deinterlacing), but it's probably much more expensive (and most people wouldn't even notice the difference). If at least they respected the original aspect ratio, they did a better job than the vast majority of television teams handling archive footage nowadays. (I've seen some real horrors, such as this.)

[loninappleton]

As to the clip shown there could be multiple reasons for cutting off the frame-- like masking counters and such depending on the source. But in fact I'm not adept at the technical discussion. My sources for the recodes are not professional jobs, more like info dumps to see how many they can get posted. It's possible the creators don't even notice. Then if you criticize the effort perhaps they'll stop but for sources with a lot of old vids, that's, how to say, worth the difference just to have the content.

Thanks to all who replied.